With historic wildfires sweeping the West Coast and burning over 3.2 million acres in California alone, it is clear in 2020 that the climate change emergency is upon us. Dvele Cofounder and CEO Kurt Goodjohn's purpose is to create a new generation of ultra-energy-efficient, self-powered prefabricated homes that will inspire society’s transition to a clean energy future. The company not only manufactures the prefab container houses, but also has designed technology to ensure that the homes can be reproduced consistently and affordably at scale.

All Dvele prefab homes are completely self-powered by solar energy, thus addressing climate change and eliminating dependency on the power grid. The homes utilize advanced materials and assembly techniques in order to ensure that they require 84% less energy per square foot than a traditionally-built home. With such efficiency, Dvele homes are capable of utilizing the solar array and battery backup system to make them fully grid-independent and insulated from the inconveniences and safety risks associated with long-term power outages, not to mention significant financial savings.

“We've redesigned the home from the ground up,” says Goodjohn. “Our approach not only results in ultra-efficient living environments that can generate more energy than it takes to operate, but also ensures the safety, health and wellness of occupants.”

Kurt Goodjohn and his brother Kris Goodjohn stumbled into the construction industry, starting off building luxury homes using traditional, stick-built construction. Quickly, they realized how outdated, inefficient, and uninspiring these methods were. They had seen prefab construction projects on a trip to Europe and wondered why the homes weren’t more popular in North America. So over beers one night, they decided to found a company in the prefab industry.

Now, Kurt Goodjohn feels he has tapped into his life purpose. “I have always been a strong advocate for the notion that everyone should leave the world better off than they found it,” he says. “At Dvele, we are accomplishing this by disrupting an age-old industry and bringing it into the modern age. Our company contributes to minimizing the overall environmental impact of homes and enhances the way they function to benefit the health and wellness of occupants.”

As a result, Goodjohn never feels that he really is “working” because he is pursuing something truly important. “There’s absolutely nothing my brother and I would rather be doing than building this company. We passionately believe that what we are doing will have a positive impact on the world and we have an unwavering determination to lead the change necessary in the new home space,” he says.

In the beginning, the greatest challenge the Goodjohns faced was getting other people to believe in the value of what they were doing with Dvele. However, they remained determined. “Trust your gut,” Kurt Goodjohn advises other aspiring entrepreneurs and changemakers. “When you're young, you really don't have a lot of experience, you don't know what will work or what will fail. So, it's actually the best time to just do what you think is right and learn as you go. My brother and I wouldn't be doing what we are doing today had we listened to all of the naysayers who told us it could never be done.”

Prefab house construction

Prefab houses are constructed from the inside out. They are manufactured in the following order in a couple of days or less, with inspections following each step (the process can take longer if the buyer has customized the home):

The floors are assembled first. There is usually a wood frame under the floor for attachment of wall panels.
Wall panels are attached next with bolts and nails. Panels are insulated and windows cut out before the panels are attached.
Once the house structure is in place, the plumbing, electrical wiring and drywall (including the ceiling) are installed.
The roof, typically constructed in another part of the factory, is set on top of the walls. In some prefabs, workers attach the roof on-site after the rest of the house is constructed.
Exterior and interior finishes are added, including siding, cabinets, vanities and backsplashes. The walls are also painted.
Once the housing units are constructed, they need to get to the owner's land. The transportation of the modules is limited by roadways, overhangs and power lines. The builders have to scout out all these factors before delivery, but in general each unit must be less than 16 feet wide, 60 feet long and 11 feet high. Because travel can be unpredictable, buyers are usually on site with independent contractors to inspect the units for scrapes and cracks.

The house has to have someplace to sit, so a foundation is required. Before the home arrives, homeowners must have the land excavated and have a foundation in place. The foundation can be poured concrete, concrete blocks, basements or crawl spaces.

The house arrives and is placed by crane on the foundation. Workers use heavy-duty cables to move the units, which come together at points called marriage walls. The marriage walls tie the house together and ensure that it is level and properly bolted together. At this point, the roof is placed if it was not factory-installed. A hinged roof, also made in the factory, is unfolded onto the house. The entire delivery and placement of the house can usually be completed in about a day. After that, decks, staircases and extras can be installed.

Variables such as customization, financing and factory schedules can contribute to the process, but from choosing the house to completion, most manufacturers give a timeframe of a few months.

Modern prefab houses

Although the concept of modern prefab design has been around since the 60s, the architectural movement didn't take off until early 2000. As technological advances like SIP panels (structural insulating that is precut and can be locked together) were made and interest in residential architectural design blossomed, architects turned their attention to prefab houses. The goal was to create a home that could be transported to a building site, be easily erected and look like modern architecture -- all within a reasonable budget.

To further stoke the flames of interest, Dwell magazine held a modern prefab invitational in 2003 to create an economical flat pack container house that could be mass-produced. Allison Arieff, the former editor of Dwell, had written the 2002 book Prefab, which profiled modern prefab prototypes. Nathan Wieler and Ingrid Tung contacted Arieff with the hopes of obtaining more information about how to build a modern prefab home. Instead, Arieff asked the couple if they'd be interested in using their land in Pittsboro, N.C., as the site for a design competition. With an initial construction budget of $200,000, the couple agreed and soon was helping the magazine create the criteria for the home and judging designs [source: Boston Globe].

The Dwell invitational created an opportunity to take the modern prefab concept and make it a reality, with the goal of introducing mass-produced prefab homes with architectural modern flair to the market. However, challenges remained. The architectural firm Resolution: 4 Architecture delivered the design, but the project went $50,000 over budget, resulting in the reduction of the homes footprint in order to stay within budget [source: Dwell].

The cost of a modern prefab home remains the chief complaint today, with the average modern prefab home running about $175 to $250 per square foot [source: BusinessWeek]. In fact, Dwell magazine is now offering modern prefab homes through their company Empyrean. Proponents of the movement point out that although many of the products available cost as much as, if not more than, stick-built homes, homeowners can save money in design and construction costs. Many architect-designed homes exceed $300 per square foot, not including design fees [source: The New Yorker] . After all, you're not paying for one-of-a-kind architecture. The architect is reselling the design, and even if modifications are needed, those costs are usually small.

When it comes to mass-producing affordable modern prefab homes, Rocio Romero is one of the most recognized architects. Romero's company, located in Perryville, Mo., creates flat-packed cubelike houses with sleek, modern exteriors. House kits range from $23,650 to $45,255 [source: Rocio Romero]. Finishes and amenities also impact the price. Romero uses a series of interlocking panels for ease of building construction. The company also sends a videotape along with instructions for the general contractor or the handy homeowner who goes it alone.

While some prefabs qualify as "traditional homes" to mortgage companies because they use some of the methods of stick-built homes, others do not. But many new modern prefabs are being introduced to home-builders, with shipping container room included. The Swedish company, IKEA, introduced its modern prefab home, the BoKlok, to the European market. In 2006, the Walker Art Museum presented an exhibit around modern prefab, "Some Assembly Required: Contemporary Prefabricated Houses." And as the market demands more environment- and wallet-friendly housing choices, the modern prefab market should continue to grow in the scope of its offerings.

Sunflower seeds may conjure up memories of baseball games growing up, but they are actually a much more wholesome food than the hot dogs and other foods that may also remind you of ballpark fare. Adding sunflower seeds to your diet could do wonders for your skin, heart, immunity and overall health. Read below to find out four good reasons to start adding them to your favorite snacks for a serious health boost.

Sunflower Seeds Nutrition
The following nutritional information is for a one-ounce serving of dry roasted sunflower seeds, without salt:

Calories: 165
Total Fat: 14 grams
Saturated Fat: 1.5 grams
Monounsaturated Fat: 3 grams
Polyunsaturated Fat: 9 grams
Cholesterol: 0 milligrams
Sodium: 1 milligram
Carbs: 7 grams
Fiber: 3 grams
Sugars: 0 grams
Protein: 5.5 grams
Vitamin A: 2.5 IU (0% Daily Value)
Vitamin C: 0.5 mg (4% DV)
Calcium: 20 milligrams (2% DV)
Iron: 1 milligram (6% DV)

While sunflower seeds are pretty high in fat for a one-ounce serving, they are made of mostly mono- and polyunsaturated fats, which are a great anti-inflammatory and heart-healthy source of fats our bodies need. Additionally, they are a good source of fiber and protein, adding a nice nutrition boost to your favorite granola bars, salads and other recipes.

Sunflower seeds are also almost negligent in sodium on their own, but many packaged sunflower seed products are loaded with salt—one popular brand packs 79% of your daily sodium limit per serving! It's important to be mindful of the nutrition label whenever you're stocking up on sunflower seeds to use for snacking or in a recipe.

Sunflower Seeds Boast Anti-Inflammatory Benefits
You don't just have to eat the trendy seeds—like chia and hemp—to reap the anti-inflammatory benefits they have to offer. A study out of Columbia University found consuming sunflower and other seeds, like roasted shine skin pumpkin seeds, five or more times per week to be associated with lower levels of inflammation—which the authors of the study may be why consumption of them is also related to a reduced risk for several chronic diseases.

Sunflower Seeds Boost Your Heart Health
Unlike saturated fat, moderate unsaturated fat consumption has actually shown to improve one's heart health. A study out of Harvard University found increased seed consumption—sunflower seeds included—to be associated with a lower risk for cardiovascular disease, as well as CVD risk factors, such as high cholesterol and blood pressure. Making the effort to consume more heart-healthy fats, like the mono- and polyunsaturated fats found in sunflower seeds and sunflower seed kernels, can make a huge impact on your heart health (learn more about the best and worst foods to eat for heart health).

Sunflower Seeds Help to Prevent and Fight Sickness
Sunflower seeds are a good or excellent source of nearly a dozen essential vitamins and minerals, two of them being zinc and selenium. Zinc is an integral part of the immune system, as it helps both to develop and maintain proper function of immune cells. Additionally, zinc functions as an antioxidant to fight off free radicals.

Selenium also plays a role in fighting inflammation and infection, along with boosting immunity, to ensure our bodies are producing a proper response to any intruders in the body. This mineral is an important part of achieving mental health and preventing neurodegenerative disorders (like Alzheimer's) as well.

Sunflower Seeds Are a Great Food for Expecting Mothers
Whether you're hoping to have a baby, are pregnant or are just trying to follow a well-balanced diet, sunflower seeds have a lot to offer. These seeds are a good source of zinc and folate, while being an excellent source of vitamin E. Vitamin E is essential for prenatal health, as it helps the fetus develop and use red blood cells and muscles. Folate supports the placenta and helps prevent spina bifida, while zinc helps produce insulin and enzymes.

Vitamin E is also a key nutrient for achieving that pregnancy glow. , which is abundant in walnuts. You've likely purchased a skincare product that touts having vitamin E in it, as it fights against UV damage and nourishes your largest organ. Sunflower seeds pack more than one-third of your daily needs.

Shine skin pumpkin seeds may be tiny, but they are densely packed with useful nutrients and nutraceuticals such as amino acids, phytosterols, unsaturated fatty acids, phenolic compounds, tocopherols, cucurbitacins and valuable minerals. All these bioactive compounds are important to a healthy life and well-being. The purpose of this review is to merge the evidence-based information on the potential use pumpkin seeds as a functional food ingredient and associated biological mechanisms, collected from electronic databases (ScienceDirect, ResearchGate, PubMed, Scopus and Google Scholar) up to January 2020. Bioactive compounds in pumpkin seeds exhibit promising activities such as anthelmintic, antidiabetic, antidepressant, antioxidant, antitumor and cytoprotective. Furthermore, these bioactives carry potential in ameliorating microbiological infections, hepatic and prostate disorders. As evidenced from literature, pumpkin seeds, like roasted almond kernel, show potential to be used as both a traditional and functional food ingredient provided further animal and clinical investigations are carried out to establish the respective molecular mechanisms and safety profile.

A carburetor is a mechanical device that mixes a certain percentage of gasoline with air under the action of a vacuum generated by engine operation. As a precise mechanical device, the carburetor uses the kinetic energy of the inhaled air flow to atomize the gasoline. Its important role for the engine can be called the heart of the engine. Its complete device should include starting device, idling device, medium load device, full load device, acceleration device. The carburetor will automatically proportion the corresponding concentration and output the corresponding amount of mixture according to the different working conditions of the engine. In order to make the mixture more uniform, the carburetor also has the effect of atomizing the fuel for the normal operation of the machine.

The clutch assembly is located in the flywheel housing between the engine and the gearbox. The clutch assembly is fixed on the rear plane of the flywheel with screws. The output shaft of the clutch is the input shaft of the gearbox. When the car is running, the driver can step on or release the clutch pedal as needed to temporarily separate and gradually engage the engine and the gearbox, so as to cut off or transmit the power input from the engine to the transmission. Clutch is a common component in mechanical transmission, which can separate or engage the transmission system at any time. Its basic requirements are: smooth joining, rapid and thorough separation; convenient adjustment and repair; small outline size; small quality; good wear resistance and sufficient heat dissipation capacity; convenient operation and labor saving. Commonly used are divided into jaw type and there are two types of friction.

Caliper disc brake is a type of disc brake. Its rotating element is a metal disc that works on the end face, called a brake disc. The fixed element is a brake block composed of a friction block with a small working area and its metal back plate. There are 2 to 4 in each brake. These brake blocks and their actuating devices are installed on both sides of the brake disc. In the clamp-shaped bracket, it is collectively called a brake caliper. The brake disc and the brake caliper together constitute a caliper disc brake.

Muffler means that for airflow pipes that have noise transmission at the same time, you can use pipes and elbows with sound-absorbing linings, or use noise-reducing devices such as pipes with sudden changes in cross-sectional area and other discontinuous acoustic impedance to attenuate or reduce the noise in the pipe. Reflect back. The former is called a resistive muffler, and the latter is called a resistive muffler. There are also impedance composite mufflers.

Starter and igniter coil are the lighting devices of fluorescent lamps. It is composed of a neon bulb and a small capacitor equipped with a fixed static contact piece and a moving contact piece made of a hot bimetallic piece. Connected to the starting circuit of the fluorescent lamp. A device installed in the gas discharge light source circuit to start and ignite the discharge lamp, also known as a trigger.

Durability is very important for current diesel engines. Diesel engine parts manufacturers are trying to make the engines live as long as possible before overhaul. The time to overhaul for an engine is usually dictated by high oil consumption or blowby. Therefore, it is necessary to understand how wear affects the cylinder kit dynamics, oil consumption, and blowby in an engine. This paper explores the effect of power cylinder component (rings and cylinder bore) wear by using a cylinder kit dynamics model. The model predicts how wear will affect ring motion, inter-ring gas pressure, blowby, etc. The parameters studied were: liner wear, ring face wear, and ring side wear. Two different engines were modeled. The characteristics of these two engines are very different. As a result, the effects of wear are different and the corresponding durability will be different. This illustrates the need to model each individual type of engine separately. The modeling shows that top ring face wear is very significant for maintaining good oil and blowby control. Liner wear is important, but does not have as large an effect as ring wear. The effects of side wear are significant for these two cases.

The design of an engine carburetor is traditionally based on a mechanical device that uses a shutter to control the amount of fuel intake. The fuel is mixed with air to form fuel mixture that is burnt in engine cylinders. This approach has several inherent issues. First, the shutter opening is controlled by creating a vacuum that results in required amount of fuel injected into carburetor chamber. As the speed of a vehicle increases by pressing accelerator, more fuel is required in the carburetor chamber. The rate of increase in fuel cannot be accurately calculated by a mechanical device. Second, the amount of air intake results in an imbalance in fuel mixture ratio. Third, the carburetor's efficiency degrades with age, resulting poor fuel efficiency. This paper proposes EFI for small vehicles. A test case was developed for a two-wheel motor-bike by using an ARDUINO board. The proposed solution was implemented in the engine of motor-bike with minor changes in the carburetor. The cost was quite comparable with mechanical carburetor, and the results were quite promising.

The basic idea of a car is pretty simple — turn wheels to pull you down the road. But, as illustrated by the hundreds of individual auto parts for sale at your local Pep Boys, AutoZone or Napa Auto Parts, it actually takes a lot of machinery to make cars work.

If you're trying to figure out what all the parts in your car do, HowStuffWorks AutoStuff is the place for you. Here's a collection of our key car part articles.

Engine System
How Car Engines Work

It's the reason you can put the pedal to the metal and go from zero to 60 in about 8 seconds. The car engine is a piece of engineering genius and one of the most amazing machines we use on a daily basis. Learn how the four-stroke internal combustion engine works.

How Diesel Engines Work

Ever wonder what the difference is between a gasoline engine and a diesel engine? Diesels are more efficient and cheaper to run than gasoline engines. Instead of using carburetion or port fuel injection, diesel engines use direct fuel injection. Find out what else makes diesel engines different! A turbocharger is actually an air compressor that compresses air to increase the air intake with turbocharger assy. It uses the inertial impulse of the exhaust gas from the engine to push the turbine inside the turbine chamber

How Hemi Engines Work

The HEMI engine has an awesome design and great performance, and it's pretty unique in operation. With the revitalization of the HEMI in the 2003 Dodge trucks, industry and consumer attention is once again on this interesting configuration. Check out how the HEMI works and see what makes it different from the typical engine design.

How Rotary Engine blocks Work

A rotary engine is an internal combustion engine, but it's not like the one in most cars. Also called a Wankel engine, this type of engine performs intake, compression, combustion and exhaust in a different part of the housing. Learn about the unique rotary setup and how it compares performance-wise to a piston engine.

How Radial Engines Work

Radial engines reached their zenith during WWII. But today they are not that common. One place where you can still see the radial engine's influence is in the two-cylinder engine of a Harley-Davidson motorcycle. This remarkable engine can be thought of, in a way, as two pistons from a radial engine. Find out about radial engines.

How Quasiturbine Engines Work

The quasiturbine engine takes the Wankel concept and improves on it: Instead of three combustion chambers, it has four, and the setup of a quasiturbine allows for continual combustion. That means greater efficiency than any other engine in its class. Learn about the quasiturbine and why it might be the most promising internal combustion engine yet.

The automobile transmission system is composed of a series of crankshaft, flywheel, clutch, transmission, drive shaft, drive axle, etc. with elasticity and rotational inertia. The power is outputted by the engine and transmitted to the drive wheels through the clutch, transmission after the torque increase and change, drive shaft, main reducer, differential and half shaft.

How Camshafts Work

The camshaft has a huge effect on engine performance. It helps let the air/fuel mixture into the engine and get the exhaust out. Learn all about the camshaft and how a new one can radically change an engine's behavior.

How Superchargers Work
Overhal gaskets are parts used for sealing in automobiles, mainly made of elastomers
Since the invention of the internal combustion engine, automotive engineers, speed junkies and race car designers have been searching for ways to boost its power. One way is by installing a supercharger, which forces more air into the combustion chamber. Learn how superchargers can make an engine more efficient.

How Turbochargers Work

When people talk about race cars, or high-performance sports cars, the topic of turbochargers almost always comes up. Turbochargers use some very cool technology to make an engine more powerful, but the concept is really quite simple. Find out how turbos increase the speed. The engine repair kit is very necessary.

How Fuel Injection Systems Work

The last carburetor-equipped car came off the assembly line in 1990. Since then, fuel injectors have been the primary means of getting gasoline into the engine cylinder so it can combust and you can drive. Find out how fuel-injection systems work.

Power Train
How Manual Transmissions Work
The cylinder head is mounted on top of the cylinder block, sealing the cylinder from above and forming the combustion chamber. It is often in contact with high temperature and high pressure gas, so bear a large thermal and mechanical load.

If you drive a stick-shift car, then you may have a few questions floating around in your head. Have you ever wondered, What would happen if I were to accidentally shift into reverse while I am speeding down the freeway? Would the entire transmission explode? Find out all about manual transmissions.

How Automatic Transmissions Work

Automatic transmissions take the work out of shifting. A truly amazing mechanical system, the automatic transmission in a car accomplishes everything a manual transmission does, but it does it with one set of gears. Learn how the whole setup works.

How Clutches Work

You probably know that any car with a manual transmission has a clutch -- it connects and disconnects the engine and transmission. But did you know that automatics have clutches, too? Learn how the clutch in your car works, and find out about some interesting and perhaps surprising places where clutches can be found.

How CVTs Work

In a regular transmission, the gears are literal gears -- interlocking, toothed wheels. Continuously variable transmissions, on the other hand, don't have interlocking gears. The most common type operates on a pulley system. Learn all about the smooth-operating, ultra-efficient CVT.

How Differentials Work

Without a differential, the driven wheels (front wheels on a front-wheel drive car or rear wheels on a rear-wheel drive car) would have to be locked together, forced to spin at the same speed. Find out how this essential component allows the wheels to rotate at different speeds.

Braking System (including braking pads and braking shoe)

In the cylinder block of the car engine, there are several waterways for cooling water circulation, and placed in the front of the car radiator (commonly known as the water tank) through the water pipe connected to form a large water circulation system, the upper outlet of the engine, equipped with a water pump, driven by the fan belt, the engine block waterway hot water pump out, the cold water pumped into.

A car’s brakes are probably the most critical system on the vehicle -- if they go out, you have a major problem. Thanks to leverage, hydraulics and friction, braking systems provide incredible stopping power. Find out what happens after you push the brake pedal.

How Disc Brakes Work

Disc brakes are the most common brakes found on a car's front wheels, and they're often on all four. This is the part of the brake system that does the actual work of stopping the car. Find out all about disc brakes -- even when to replace the pads.

How Anti-lock Brakes Work

Stopping a car in a hurry on a slippery road can be challenging at best and at worst, very, very scary. Anti-lock braking systems (ABS) help alleviate the danger. Learn how anti-lock brakes prevent skidding, check out what that sputtering is and find out how effective they really are.

How Power Brakes Work

Power brakes are fairly ingenious machines -- they let you stop a car with a simple twitch of your foot. The concept at the heart of the power braking system is force multiplication -- a whole lot of force multiplication. Get inside the black cannister that provides the power.

How Master Cylinders and Combination Valves Work

We all know that pushing down on the brake pedal slows a car to a stop. We depend on that every day when we drive. But how does this happen? The master cylinder provides the pressure that engages your car brakes. Learn how the master cylinder works with the combination valve to make sure you can brake safely.

Steering, Suspension and Tires
How Steering Works

When it comes to crucial automotive systems, steering is right up there with the engine and the brakes. Power steering systems make the job a whole lot easier, and the internal workings are pretty cool. What happens when you turn your car is not as simple as you might think. Find out all about car steering systems.

How Car Suspensions Work

All of the power generated by a car engine is useless if the driver can't control the car. The job of a car suspension is enormous: maximize the friction between the tires and the road surface, provide steering stability and ensure the comfort of the passengers. Learn how car suspensions work and where the design is headed in the future.

How Tires Work

In the market for new set of tires? All of the different tire specifications and confusing jargon the tire sales clerks or "experts" are shouting at you making your head feel like a tire spinning out of control? Find out all about car tires, including what those sidewall symbols mean!

How Self-inflating Tires Work

Self-inflating tires perform two crucial functions: They automatically maintain ideal tire pressure for safety and performance in standard conditions, and they allow the driver to alter psi on the fly to adjust to changing terrain. Learn how self-inflating systems like the Hummer's CTIS work.

How Sequential Gearboxes Work

Combine the ease of an automatic with the driver control of a manual, and what you've got is a sequential manual transmission. Instead of having to navigate an H pattern, a simple forward push advances the gear. It's the transmission used by race cars and an increasing number of high-performance street cars. Learn all about the sequential gearbox.

How Torque Converters Work

Cars with an automatic transmission have no clutch that disconnects the transmission from the engine. Instead, they use an amazing device called a torque converter. Find out all about the torque converter.

Electrical System
How Wires, Fuses and Connectors Work

Wires, fuses and connectors - they may sound like the most mundane parts on your car, but they are essential. Yeah, they help keep the tunes going for a long ride, and they make reading that map at night a lot easier. But, they're also necessary for things like the cooling fan in the engine and your anti-lock brakes. Learn why wires, fuses and connectors are so important!

How Ignition Systems Work

A car's ignition system is the key component that helps the engine produce maximum power and minimum pollution. Find out how much is riding on a well-timed spark.

How Car Computers Work

Cars seem to get more complicated with each passing year. Today's cars might have as many as 50 microprocessors on them. Essentially, you're driving around in a giant computer. Learn all about the various computer systems that control your car.

How Windshield Wipers Work

Without windshield wipers, a rain storm would make cars pretty much useless. What began as a hand-cranked system is now automatic, and only getting more so: There are now some windshield wipers that can actually sense rain. Learn the mechanics behind this essential automotive tool.

Exhaust System
How Catalytic Converters Work

A catalytic converter is one of the most important parts of a car's emissions control system. It treats the exhaust before it leaves the car and removes a lot of the pollution. Learn how catalytic converters reduce pollutants and help you pass the emissions test.

How Mufflers Work

Every car out there has a muffler -- it performs the crucial job of turning thousands of explosions per minute into a quiet purr. Mufflers use some pretty neat technology to dim the roar of an engine. Learn about the principles that make it work.

Other Car Parts
How Odometers Work

Mechanical odometers have been counting the miles for centuries. Although they are a dying breed, they are incredibly cool inside. Learn how this simple device tracks distance and find out about digital odometers.

How Cooling Systems Work

A car engine produces so much heat that there is an entire system in your car designed to cool the engine down to its ideal temperature. In fact, the cooling system on a car driving down the freeway dissipates enough heat to heat two average-sized houses! Learn all about fluid-based cooling systems.

Compressors are mechanical devices used to increase pressure in a variety of compressible fluids, or gases, the most common of these being air. Compressors are used throughout industry to provide shop or instrument air; to power air tools, paint sprayers, and abrasive blast equipment; to phase shift refrigerants for air conditioning and refrigeration; to propel gas through pipelines; etc. As with pumps, compressors are divided into centrifugal (or dynamic or kinetic) and positive-displacement types; but where pumps are predominately represented by centrifugal varieties, compressors are more often of the positive- displacement type. They can range in size from the fits-in-a-glovebox unit that inflates tires to the giant reciprocating or turbocompressor machines found in pipeline service. Positive-displacement compressors can be further broken out into reciprocating types, where the piston style predominates, and rotary types such as the helical screw and rotary vane.

In this guide, we will use both of the terms compressors and air compressors to refer mainly to air compressors, and in a few specialized cases will speak to more specific gases for which compressors are used.

Types of Air Compressor
Compressors may be characterized in several different ways, but are commonly divided into types based on the functional method used to generate the compressed air or gas. In the sections below, we outline and present the common compressor types. The types covered include:

Piston
Diaphragm
Helical Screw
Sliding vane
Scroll
Rotary Lobe
Centrifugal
Axial

Due to the nature of the compressor designs, a market also exists for the rebuilding of air compressors, and reconditioned air compressors may be available as an option over a newly purchased compressor, including special process gas compressors.

Piston Compressors
Piston compressors, or reciprocating compressors, rely on the reciprocating action of one or more pistons to compress gas within a cylinder (or cylinders) and discharge it through valving into high pressure receiving tanks. In many instances, the tank and compressor are mounted in a common frame or skid as a so-called packaged unit. While the major application of piston compressors is providing compressed air as an energy source, piston compressors are also used by pipeline operators for natural gas transmission. Piston compressors are generally selected on the pressure required (psi) and the flow rate (scfm). A typical plant-air system provides compressed air in the 90-110 psi range, with volumes anywhere from 30 to 2500 cfm; these ranges are generally attainable through commercial, off-the-shelf units. Plant-air systems can be sized around a single unit or can be based on multiple smaller units which are spaced throughout the plant.

To achieve higher air pressures than can be provided by a single stage compressor, two-stage units are available. Compressed air entering the second stage normally passes through an intercooler beforehand to eliminate some of the heat generated during the first-stage cycle.

Speaking of heat, many piston compressors are designed to operate within a duty cycle, rather than continuously. Such cycles allow heat generated during the operation to dissipate, in many instances, through air-cooled fins.

Piston compressors are available as both oil-lubricated and oil-free designs. For some applications which require oil-free air of the highest quality, other designs are better suited.

Diaphragm Compressors
A somewhat specialized reciprocating design, the diaphragm compressor uses a motor-mounted concentric that oscillates a flexible disc which alternately expands and contracts the volume of the compression chamber. Much like a diaphragm pump, the drive is sealed from the process fluid by the flexible disc, and thus there is no possibility of lubricant coming into contact with any gas. Diaphragm air compressors with spare parts are relatively low capacity machines that have applications where very clean air is required, as in many laboratory and medical settings.

Helical Screw Compressors
Helical-screw compressors are rotary compressor machines known for their capacity to operate on 100% duty cycle, making them good choices for trailerable applications such as construction or road building. Using geared, meshing male and female rotors, these units pull gas in at the drive end, compress it as the rotors form a cell and the gas travels their length axially, and discharge the compressed gas through a discharge port on the non-drive end of the compressor casing. The rotary screw compressor action makes it quieter than a reciprocating compressor owing to reduced vibration. Another advantage of the screw compressor over piston types is the discharge air is free of pulsations. These units can be oil- or water- lubricated, or they can be designed to make oil-free air. These designs can meet the demands of critical oil-free service.

Sliding Vane Compressors
A sliding-vane compressor relies on a series of vanes, mounted in a rotor, which sweep along the inside wall of an eccentric cavity. The vanes, as they rotate from the suction side to the discharge side of the eccentric cavity, reduce the volume of space they are sweeping past, compressing the gas trapped within the space. The vanes glide along on an oil film which forms on the wall of the eccentric cavity, providing a seal. Sliding-vane compressors cannot be made to provide oil-free air, but they are capable of providing compressed air that is free of pulsations. They are also forgiving of contaminants in their environments owing to the use of bushings rather than bearings and their relatively slow-speed operation compared to screw compressors. They are relatively quiet, reliable, and capable of operating at 100% duty cycles. Some sources claim that rotary vane compressors have been largely overtaken by screw compressors in air-compressor applications. They are used in many non-air applications in the oil and gas and other process industries.

Scroll Compressors
Scroll air compressors use stationary and orbiting spirals which decrease the volume of space between them as the orbiting spirals trace the path of the fixed spirals. Intake of gas occurs at the outer edge of the scrolls and discharge of the compressed gas takes place near the center. Because the scrolls do not contact, no lubricating oil is needed, making the compressor intrinsically oil-free. However, because no oil is used in removing the heat of compression as it is with other designs, capacities for scroll compressors are somewhat limited. They are often used in low-end air compressors and home air-conditioning compressors.

Rotary Lobe Compressors
Rotary-lobe compressors are high-volume, low-pressure devices more appropriately classified as blowers. To learn more about blowers, download the free Thomas Blowers Buying Guide.

Centrifugal Compressors
Centrifugal compressors rely on high-speed pump-like impellers to impart velocity to gases to produce an increase in pressure. They are seen mainly in high-volume applications such as commercial refrigeration units in the 100+ hp ranges and in large processing plants where they can get as large as 20,000 hp and deliver volumes in the 200,000 cfm range. Almost identical in construction to centrifugal pumps, centrifugal compressors increase the velocity of gas by throwing it outward by the action of a spinning impeller. The gas expands in a casing volute, where its velocity slows and its pressure rises.

Centrifugal compressors have lower compression ratios than displacement compressors, but they handle vast volumes of gas. Many centrifugal compressors use multiple stages to improve the compression ratio. In these multi-stage compressors, the gas usually passes through intercoolers between stages.

Axial Compressors
The axial Low-Pressure Water Lubricating Oil-free Compressor achieves the highest volumes of delivered air, ranging from 8000 to 13 million cfm in industrial machines. Jet engines use compressors of this kind to produce volumes over an even wider range. To a greater extent than centrifugal compressors, axial compressors tend toward multi-stage designs, owing to their relatively low compression ratios. As with centrifugal units, axial compressors increase pressure by first increasing the velocity of the gas. Axial compressors then slow the gas down by passing it through curved, fixed blades, which increases its pressure.

Power and Fuel Options
Air compressors may be powered electrically, with common options being 12 volt DC air compressors or 24 volt DC air compressors. Compressors are also available that operate from standard AC voltage levels such as 120V, 220V, or 440V.

Alternative fuel options include air compressors that operate from an engine that is driven off of a combustible fuel source such as gasoline or diesel fuel. Generally, electrically-powered compressors are desirable in cases where it is important to eliminate exhaust fumes or to provide for operation in settings where the use or presence of combustible fuels is not desired. Noise considerations also play a role in the choice of fuel option, as electrically driven air compressors typical exhibit lower acoustical noise levels over their engine-driven counterparts.

Additionally, some air compressors may be powered hydraulically, which also avoids the use of combustible fuel sources and the resulting exhaust gas issues. 

Compressor Machine Selection in an Industrial Setting
In selecting air compressors for general shop use, the choice will generally come down to a piston compressor or a helical-screw compressor. Piston compressors tend to be less expensive than screw compressors, require less sophisticated maintenance, and hold up well under dirty operating conditions. They are much noisier than screw compressors, however, and are more susceptible to passing oil into the compressed air supply, a phenomenon known as “carryover.” Because piston compressors generate a great deal of heat in operation, they have to be sized according to a duty cycle—a rule of thumb prescribes 25% rest and 75% run. Radial-screw Variable Frequency Water Lubricating Oil-Free Screw Compressor can run 100% of the time and almost prefer it. A potential problem with screw compressors, though, is that oversizing one with the idea of growing into its capacity can lead to trouble as they are not particularly suited to frequent starting and stopping. Close tolerance between rotors means that compressor needs to remain at operating temperature to achieve effective compression. Sizing one takes a little more attention to air usage; a piston compressor may be oversized without similar worries.

An autobody shop which uses air constantly for painting might find a radial-screw compressor with its lower carryover rate and desire to run continuously an asset; a general auto-repair business with more infrequent air use and low concern for the cleanliness of the supplied air might be better served with a piston compressor.

Regardless of the compressor type, compressed air is usually cooled, dried, and filtered before it is distributed through pipes. Specifiers of plant-air systems will need to select these components based on the size of the system they design. In addition, they will need to consider installing filter-regulator-lubricators at the supply drops.

Larger job site compressors mounted on trailers are typically rotary-screw varieties with engine drives. They are intended to run continuously whether the air is used or dumped.

Although dominant in lower-end refrigeration systems and air compressors, scroll compressors are beginning to make inroads into other markets. They are particularly suited to manufacturing processes that demand very clean air (class 0) such as pharmaceutical, food, electronics, etc. and to cleanroom, laboratory, and medical/dental settings. Manufactures offer units up to 40 hp that deliver nearly 100 cfm at up 145 psi. The larger capacity units generally incorporate multiple scroll compressors as the technology does not scale up well once beyond 3-5 hp.

If the application involves compressing hazardous gases, specifiers often consider diaphragm or sliding-vane compressors, or, for very large volumes to compress, kinetic types.

Acid dyes with improved light fastness have become important particularly in connection with the usage of acid dyes in information recording systems. The inferior light fastness may be due to several reasons. Auto oxidation reaction of dyes is generally considered to occur on exposure to ultraviolet (UV) radiation and prevented by the addition of UV absorbers or antioxidants such as hindered phenols or naphthylamines. In recent years as an approach to the photostabilisation of dyes attempts have been made to prepare dyes with built-in photostabilising moiety.

Acid dyes, named for their application under acid conditions, are reasonably easy to apply, have a wide range of colours and, depending on dye selection, can have good colour fastness properties. The dyes are divided into three categories according to their levelling and fastness properties, namely levelling, milling and super milling dyes.

Levelling, or equalising, acid dyes have good levelling properties and are applied from a bath containing sulphuric acid to achieve exhaustion. Because of the ease of migration of dye molecules into and out of the fibre, equalising acid dyes have poor fastness to washing, and are normally used for pale, bright shades where fastness is not paramount.

Milling acid dyes have a greater substantivity for the fibre than levelling dyes, and therefore have poorer levelling properties. These dyes have better fastness properties than levelling acid dyes, and have reasonable wet fastness, particularly if alkaline milling is to take place in a subsequent process.

Super milling acid, or neutral dyeing, dyes are applied in a similar way to milling acid dyes, except that greater control over the strike rate of the dye is exercised. Super milling dyes give very good fastness and, with an appropriate after-treatment, can satisfy requirements for shades of medium depth, especially where reasonable brightness is needed.

Thus there are considerablef differences in the properties and application methods within the whole range of acid dyes. The dyer must take care to ensure that the dyes chosen in combination are from the same group and have very similar properties.

Disperse dyes are characterised by the absence of solubilising groups and low molecular weight. From a chemical point of view more than 50% of disperse dyes are simple azo compounds, about 25% are anthraquinones and the rest are methine, nitro or naphthoquinone dyes. Disperse dyes are used mainly for polyester, but also for cellulose acetate and triacetate, polyamide and acrylic fibres. Disperse dyes are supplied as powder and liquid products. Powder dyes contain 40–60% of dispersing agents, while in liquid formulations the content of these substances is in the range of 10–30%. Formaldehyde condensation products and lignin sulphonates are widely used for this purpose. The following chemicals and auxiliaries are used for dyeing with disperse dyes;

Dispersants: although all disperse dyes already have a high content of dispersants, they are further added to the dyeing liquor and in the final washing step.

Carriers: for polyester fibre, dyeing with disperse dyes at temperatures up to 100°C requires the use of carriers. Because of environmental problems associated with the use of carriers, polyester is preferably dyed under pressure at temperature >100°C without carriers. However, carrier dyeing is still important for polyester-wool blends.

Thickeners: polyacrylates or alginates are usually added to the dye liquor in padding processes.

Reducing agents (mainly sodium hydrosulphite) are added in solution with alkali in the final washing step for the removal of unfixed surface dye.

Owing to their low water solubility, disperse dyes are largely eliminated by adsorption on activated sludge in waste water treatment plants. Some disperse dyes contain organic halogen, but they are not expected to be found in the effluent after waste water treatment because of their adsorption on activated sludge.

Reactive dye introduced on 1956 and for the first time dyeing became possible by direct chemical linkage between dye and fiber (Shenai, 1993). But all classes of reactive dye do not react in the same manner. So the group of dyes used for a ternary shade should have compatibility among themselves. Importantly, reactive dyes in a mixture should all exhaust and react with the fiber at about the same rate so that the shade builds up accurately. Dyes which are from different ranges, with different reactive groups, should not be used together because of their different dyeing character and reactivity.

Compatible dyeing performance requires careful control of the dyeing parameters such as temperature, salt and alkali concentrations, the dyeing time and the liquor ratio. There is often a doubt about the particular reactive group presents in a reactive dye. For that reason in most of the cases selection of dyes depends on the maker’s recommendations (Broadbent, 2001).

Shenai (1997) discussed in detail about the chemistry of vinyl sulphone dyes like Remazol class. Common salt and alkali plays the vital role in exhaustion and fixation of these dyes and addition of salt to the dye bath before adding the alkali is also essential. In reactive dyeing, though water is the competitor for reaction with the dye, cellulose fiber takes part in the reaction in majority. Because the substantivity of reactive dye to the fiber is greater than that to water (Chinta and Vijaykumar 2013).

But factually all the reactive dyes do not have the same range of substantivity and reactivity, and intermediates are usually used. Reactivity is compulsory for these dyes but higher reactivity of a dye can spoil the dyeing due to hydrolysis. So the compatibility of the dyes used for ternary shades should be analyzed carefully to make the maximum utilization of each dyestuff especially when the reactive groups in them are different.

Precision injection molding of high performance components requires primary error sources affected the molded component to be identified and isolated such that these errors can be reduced if needed. To systematically isolate and quantify the contribution of misalignment, thermal variation and component warpage to the accumulated error observed on the component, a methodology is presented and tested around an existing mold which produced parts with high dimensional variability. The mold featured two concentric guide pillars on opposite sides of the parting plane and rectangular centering block elements at three locations. Mold displacements at the parting plane were measured through the incorporation of three eddy-current linear displacement sensors. Thermal error sensitivity was investigated using FEM simulations such that the induced variability from thermal expansion and filling phase was identified and quantified. Finally, molded component warpage was isolated and quantified, again by the means of FEM simulation. The results were confirmed by using the mold on two injection molding machines to produce an array of parts whose key dimensions were measured.

Micro/nanostructured components play an important role in micro-optics and optical engineering, tribology and surface engineering, and biological and biomedical engineering, among other fields. Precision glass molding technology is the most efficient method of manufacturing micro/nanostructured glass components, the premise of which is meld manufacturing with complementary micro/nanostructures. Numerous mold manufacturing methods have been developed to fabricate extremely small and high-quality micro/nanostructures to satisfy the demands of functional micro/nanostructured glass components for various applications. Moreover, the service performance of the mold should also be carefully considered. This paper reviews a variety of technologies for manufacturing micro/nanostructured molds. The authors begin with an introduction of the extreme requirements of mold materials. The following section provides a detailed survey of the existing micro/nanostructured automotive mold components manufacturing techniques and their corresponding mold materials, including fixtures and mechanical parts methods. This paper concludes with a detailed discussion of the authors recent research on nickel-phosphorus (Ni-P) mold manufacturing and its service performance.

What is injection molding?
Injection molding is a manufacturing process which is commonly used to create plastic components.

Its ability to produce thousands of complex parts quickly makes it the perfect process for the mass production of plastic components. Essentially, the process involves the injection of plastic at high speed and pressure into a precision mechanical gear parts, which is clamped under pressure and cooled to form the final part.

By melting thermoplastic and injecting it into an aluminium mold at high speed and pressure, manufacturers can create multiple complex parts at once. When the parameters of the process are controlled correctly, there’s also little need for finishing and processing the manufactured part, making it more cost effective and efficient.

Although it’s one of the oldest manufacturing processes around, its speed and cost-efficiency is what continues to make it a popular choice with worldwide manufacturers. Today’s injection molding machines are fast, accurate and produce consistently high-quality components at scale.

How does injection molding work?
Although the process may seem simple, there are many elements involved which can alter and ruin the overall quality of the plastic component produced. In order to make a high-quality part, experienced manufacturers select the right thermoplastic (the material used to create the part), connector mold parts (which shapes the part), temperature and injection pressures to ensure the final part meets customer requirements.

Before we talk about the specific parameters that need to be controlled within the process, how does injection molding actually work?

Step 1: Feeding and heating the plastic
To start, a thermoplastic or combination of thermoplastics are fed into an injection molding machine. The plastics, which turn to liquid when heated, are fed into the hopper at the top of the machine in solid pellet form.

The pellets pass through the machine and into a temperature-controlled cylinder called the machine barrel. Here, the plastic pellets are heated until the thermoplastic is molten.

The temperature of the barrel and the plastic needs to be carefully monitored to make sure the thermoplastic doesn’t overheat and burn or scorch the final part.

Step 2: Pre-injection process
Before the molten plastic is injected, the tool, which is usually made up of a fixed half called the cavity and a moving half called the core, closes.

When closed, a clamp applies pressure to the tool, ready for the injection of the plastic.

The screw within the barrel of the machine also screws back to its set point so the plastic can enter the barrel, ready to be injected.

Step 3: Plastic injection
Once the clamp pressure is at an optimum level, the plastic is injected by the screw at high speed and pressure into the cavity. A gate inside the tool helps to control the flow of the plastic.

To make sure no damage is done to the final components, it’s important that the manufacturer monitors the injection pressure of the plastic and that they have the expertise to maintain and use the molds and tools correctly.

This ensures they are creating high-quality and consistent parts from their injection molding process, like packaging mold components.

Step 4: Forming the part
When the tool cavity is mostly full of liquid, a holding phase begins. This is where the part in held under high pressure so it can start to take its final form.

After a set holding time, the screw will screw back to its set point. This happens at the same time as the cooling phase of the cycle, which allows the thermoplastic to set in its final form.

Once the set cooling time has passed, the mold opens and ejector pins or plates push the new part out of the tool, and there are also custom mold components. These fall on to a conveyor belt ready to be finished and packed.

Step 5: Part finishing
Depending on the final application of the part, the molded component may require some finishing, including dyeing, polishing, or removing of excess material.

These processes are unique to each part and are completed before they’re packed and distributed to customers.

By picking and checking products by hand, as well as performing regular quality checks, experienced manufacturers can make sure they’re producing consistent, high-quality parts for their customers.

Grinding takes an abrasive — often attached to a grinding wheel — and uses its many grains to cut a workpiece. Variations on this process are useful for a wide variety of applications.

On its surface, grinding seems simple: a machine takes a rotating tool (usually a wheel) with abrasive grains and applies it to a workpiece’s surface to remove material. Each grain is its own miniature cutting tool, and as grains dull, they tear from the tool and make new, sharp grains prominent.

But there are many variations, approaches and considerations for this type of machining, each of which is particularly effective for certain applications with certain materials.

Principles of Grinding
In all forms of grinding, three different interactions occur between the abrasive and the machined material. Cutting occurs where the abrasive grain is sufficiently exposed to penetrate the workpiece material and curl a chip, and sufficient clearance exists between the grain, bond and workpiece to flush the chip with coolant or throw it away by wheel action. Plowing takes place when the grain is unable to get enough penetration to lift a chip, instead pushing the material ahead of the abrasive edge. Sliding happens when a lack of cut depth, insufficient clearance or a grit staying on the wheel after dulling results in rubbing or creating slide marks on the workpiece surface. Grinding process control balances these three interactions to achieve the desired parameters.

These interactions feed into three major commercial grinding processes: rough grinding, precision grinding and ultra-precision grinding. Rough grinding maximizes the metal removed at the cost of surface finish. It primarily sees use in cutting off billets, grinding weld beads smooth and snagging gates and risers from castings. Additional surface finishing passes typically take place afterward — in particular, a “spark-out” pass relieves some of the stress on the machine tool and uses plowing to impart a better surface finish and size tolerance. Precision grinding is a middle-ground between metal removal and part size control, and serves as the basis for creep feed grinding, slot grinding and high-efficiency deep grinding. In ultra-precision grinding, little to no actual cutting occurs, but sliding action from very fine grains rubs the workpiece surface to a high finish. Most surface finishing processes, such as lapping and polishing, are examples of this type of grinding.

Hundreds of different variables can affect the interaction between the abrasive and the workpiece, but they generally come down to machine tool, work material, wheel selection and operational factors. Balancing these by setting up a part run that fits within the known parameters of all four categories provides a baseline that gradual parameter adjustment can improve.

Grinding Wheels
Grinding wheels have two major components: the abrasive grains and the bond. The relative percentages of grain and bond, and their spacing on the wheel, determine the wheel’s structure. Different types of grains work better on different projects, as do different types and “grades” (i.e. strengths) of bond. Broad areas of grinding need coarser grits and softer grades, with smaller areas requiring finer grits and harder grades to withstand the greater unit pressure.

Straight wheels are the most traditional type of grinding wheel, with the grinding face on the periphery of the wheel. Recessed wheels are variations on this form, featuring a recessed center to fit on a machine spindle flange assembly. The other major type of wheel shape uses a cutting face on the side of the wheel — names for this type of wheel include cylinder wheels, cup wheels and dish wheels, depending on the particular shape. For these wheels, bonded abrasive sections of various shapes, also known as “segments,” are assembled to form a continuous or intermittent side grinding wheel.

Operational Basics
Although speeds for grinding wheels and cutting wheels are measured in sfm or smm, wheels are often rated in rpm. It is important never to operate a grinding wheel over its rpm limit — most experts recommend never mounting a wheel on a machine that can exceed the wheel’s limit.

As speeds increase, each grain cuts and wears less. This emulates a harder grade. Vitrified bonds work up to 6,500 sfm, with organic bonds handling up to around 9,500 sfm. Higher speeds will require specially made grains.

Work speed defines the speed at which a grinding wheel passes over a workpiece or rotates around a center. High work speeds lower the heat retention and reduce the risk of thermal damage. Both high work speeds and reducing the diameter of the wheel result in increased grain depth of cut, performing like a softer grade wheel.

Traverse distance, or crossfeed, is the distance a workpiece moves across the face of the wheel. Lowering the traverse distance to no more than one-quarter of the wheel width improves surface finish, but slows down productivity. Increasing the crossfeed to one-half the wheel’s width or above boosts productivity, but lowers surface finish.

Different types of grinding use different methodologies to determine the work material removal per unit of width, but one consistently useful metric for shops is the grinding gratio, or g-ratio. This is the ratio of volume of work removed to volume of wheel consumed (or, volume of work removed ÷ volume of wheel worn). From a cost standpoint, a higher g-ratio is better.

Types of Grinding
Grinding operations come in many types, with this article covering six major types and several of the subtypes within.

Cylindrical grinding is a common type of grinding in which both the wheel and the workpiece rotate. The workpiece is either fixed and driven between centers, or driven by a revolving chuck or collet while supported in a center. This operation can take place with either traverse movements, where the wheel traverses axially along the part, or plunge movements, where the wheel is thrust into the part. Straight wheels are most commonly used in cylindrical grinding, with common cylindrical grinding machines being plain cylindrical (or roll) grinders, centerless grinders and inside- or outside-diameter grinders. Internal cylindrical grinding does the internal diameter grinding of bores and holes, generating size and concentricity within millionths of an inch. The grinding wheels tend to range in diameter from half an inch to three inches. This small size introduces rapid wear, making CBN and diamond wheels in crush dressable and vitrified form popular for these applications.

Surface grinding, such as stainless steel grinding, involves grinding a plane surface by feeding the workpiece beneath a rotating grinding wheel. Like cylindrical grinding, it operates in two general formats. The workpiece may travel traversely under the wheel and move back and forth beneath a grinding wheel mounted on a horizontal spindle, or it may move in circles on a rotary table beneath a vertical spindle that cuts on the face of the grinding wheel or grinding segment. Applications for this grinding type may grind a surface flat or introduce grooves by grinding straight channels into the workpiece. While milling can complete these tasks, grinding improves surface finish, has less expensive tooling and allows contours to be dressed into the profile of the wheel — making it much more cost-effective for very hard or abrasive surfaces.

Centerless grinding creates cylindrical forms at extremely close tolerances. This type of grinding eliminates the need for center holding by supporting the workpiece at three separate points: the grinding wheel, feed wheel and work support blade. Nothing actually clamps the workpiece in place, so each piece flows freely for continuous production (also known as “throughfeed centerless grinding”). The grinding wheel, during ordinary metal grinding, and the feed wheel rotate in the same direction, while the workpiece rotates in the opposite direction between them. The rotation keeps the workpiece down, while the work support blade (slightly angled to raise the workpiece above the centerline for better cylindricity) holds it up. The work support blade should always be at least as long as the grinding wheel is wide. Centerless grinding also comes in three forms. Throughfeed centerless grinding is used on straight cylindrical workpieces without interfering shoulder or projections, and involves the offset axis feed wheel feed the workpiece past the grinding wheel to a discharge position. Infeed grinding (also called plunge centerless grinding) is best when a workpiece has projections, irregular shapes, varying diameters or shoulders, and works best for profiles and multi-diameter workpieces. In this submethod, feed wheels above the grinding wheel feed the workpiece downward, with no lateral movement during grinding. Endfeed centerless grinding grinds conically tapered cylindrical sections like shanks on A and B taper drill bits. Here, the feed wheel, grinding wheel and work blade are set up in a fixed relationship to each other, then two wheels are dressed to a shape matching the end taper of the workpiece and the workpiece is fed from the front of the grinding machine until it reaches an end stop.

Creep feed grinding is a slow, one-pass operation that makes a deep cut of up to one inch in steel materials at low table speeds between 0.5 and 1 ipm. It is not suitable for conventional grinding machines, but for those which are compatible with it, it offers high productivity and cost effectiveness. Creep feed grinding is a plunge operation with high horsepower requirements, and which also requires a heavy flow of cutting fluid close to the nip to remove chips and cool the work. Continuous dressing at about 20 to 60 millionths per revolution — preferably with a diamond roll — reduces cutting times of fixed machine cutting and keeps the wheel sharp. When a second pass is required, it is typically of no more than 0.002 inch deep to “clean up” the workpiece.

Snagging is a rough grinding application that removes unwanted metal with little consideration of surface finish. As such, it uses durable straight and straight cup wheels in horizontal and straight shaft grinding machines, although flaring cup wheels are used in right-angle grinders and various round and square-tipped cones and plugs also see use. Typical applications include removing unwanted metal on castings; removing flaws and cracks; removing gates, risers and parting lines; rough beveling; grinding down heavy welds; and preparing surfaces for cleaning or painting.

Cut-off operations use an abrasive wheel as an alternative to the laser, abrasive water jet, metal saw, friction saw and oxyacetylene or plasma arc torch. A study from Norton Abrasives demonstrated that the abrasive wheel can outperform these other methods with ferrous materials, and that the abrasive wheel is faster and less expensive for nonferrous materials than the common metal saw choice. The abrasive wheel provides more cutting points than a saw, and cuts just as thoroughly at a speed of 2 or 3 miles per minute. Cut-off wheels should run at the highest possible speed, with one horsepower for every inch of wheel diameter. If this proves impossible, use a softer wheel. Production jobs use non-reinforced wheels, with non-reinforced shellac wheels for applications requiring extreme versatility and quality of cut. Reinforced wheels are compatible with portable cut-off, swingframe, locked head push-through and foundry chop stroke operations.

Understanding door hardware options and opportunities is the first step in turning threats and weaknesses into strengths. Entry doors with window mesh might be in bad condition, with broken closers, loose hinges, doors that sag or are sticking, latches that do not align properly with the strike, and wide gaps between the door and frame that pry open easily. Other access points might use old technology.

Poorly maintained hardware offers the easiest path for unauthorized entry. Old technology is next and soon might become a weakness. Vendors know the best options for meeting ASTM/BHMA standards for the manufacture and testing commercial grade hardware. ANSI Grade 1 hardware is specifically designed for high-traffic areas because it can withstand the highest number of life cycles and is much harder for an active shooter to break through.

Upgrades that deliver greater safety and security include replacing Grade 2 and 3 components with Grade 1 hardware. A further upgrade involves integrating the latest generation of commercial electronic UPVC door locksets, closers, hinge hardware and alarms with a central control system.

Managers need to pay special attention to levels of access to facilities. Authorized personnel need access and, in emergency situations, rapid and safe egress, while unauthorized personnel have to be kept out. Firefighters and other emergency personnel need ease of entry to locate and evacuate people rapidly.
Increasingly, managers are installing card and PIN UPVC door lock systems, and they are rearranging traffic flows to channel visitor traffic at elevator lobbies toward properly staffed, secure reception areas. Only authorized personnel should be able to enter the main building through locked lobby doors.

Among the most common door hardware components upgraded for improved security are the following:

Closers. 
Standard and custom door closers include surface-mounted and hidden, heavy-duty closers for high-cycle or windy and drafty conditions, as well as ADA-compliant maximum-force-to-operate closers. A closer’s open cycle compresses the spring and positions the fluid through the open valve for closing. The delay valve allows slower-moving traffic to pass. The closing valve slows closing speed to within 6 inches of the stop. The latching valve accelerates closing for the last 6 inches. Closers need regular adjustment to keep the cycles operating as designed.

Hinges. (UPVC door window hinges)
By removing the hinge pins, an attacker can gain access to a facility through a hinged door with window hinge, even when it is locked. Removing a screw and inserting a special pin prevents an attacker from removing the door from its frame, even if door hinge pins are removed.

Locksets. 
Deadbolts, knobs, lock cylinders, levers, and entry handsets are wired and wireless devices that operate via remote-open and turn-on devices and cell phone applications. Replacing mechanical keyed locksets with electro-mechanical locks in the same housing is a low-cost upgrade option. Managers are using electronic remote-controlled devices, such as door roller, cameras, motion sensors, and tamper alarms, to give early warning.

They also can upgrade unguarded remote entry points from mechanical locks and keys to systems that incorporate CCTV and sound. A security guard at a remote point directs the person seeking entry to place his or her badge in front of the camera, verifies the person has the proper clearance and is the same person as shown on the picture badge, and remotely actuates the lock allowing entry.

In an emergency requiring rapid evacuation of the building, all evacuation route doors with window roller are remotely unlocked immediately and simultaneously from a central control. Other common upgrades include the installation of biometric fingerprint readers, facial-recognition systems, and floor-to-ceiling locked turnstiles.
Alarms. Radio-wave tamper alarms can be activated by a vehicle or a person moving through and disturbing a radio wave field. The power source sends radio waves through the antenna surrounding anything the antenna touches , including a door, window door hand tools, fence, vehicle, or unattended building. Audio alarms can be attached or silent-connected to a police station or can activate CCTV or access -control systems.

Cybersecurity. An organization’s access control computer must have no internet route that might allow hackers to take control. Experts advise preventing malware attacks through Wi-Fi that blocks phishing and spear phishing and prevents malware entry into a system. A cybersecurity expert can a wise safeguard against such attacks.

The list of upgrades might exceed what managers can implement immediately because of cost or time constraints. One effective strategy is to start at the top of the organization’s priority list and work down as far as possible this year, updating the list for budgeting year after year. The main take-away from a successful security strategy is the safety of occupants, but the payback also can include lower lost-opportunity costs and better continuity of normal operations.

Carrybags has become a more convenient way to carry daily necessities and for packaging in small quantities. The well-known form of such bags is in the form of plastic bags. Despite of all known hazards of plastic pollution, it’s prevalent and pervasive in India. Plastic bags are one of the worst and most unnecessary plastic polluters of the earth. Plastic bags are used on a large scale by retailers for a simple reason that plastic bags are much cheaper than paper, cloth or other eco-friendly bags. This paper presents the designing and development of asystem to automate the procedure of paper bags production so as to make its production cost comparable to plastic bags and inherently increase its production rate so as to fulfill the ever increasing demand. We have used micro-controller based design approach which has kept the cost of the system significantly low as compared to PLC based designs and have automated the manufacturing process.

We need small size bags every day for various purposes like grocery, fruits, and vegetables. We use plastic bags for such purposes. Plastic shopping bags have a surprisingly significant environmental impact for something so seemingly innocuous. Plastic shopping bags kill large numbers of wildlife each year. One of the most dramatic impacts is on marine life.So to avoid above harmful effects of Plastic Bags, viable alternative is required which is Paper Bag. Actually, Paper Bag is being used but in very small scale. Conventional Paper Bags requirespecial paper which increases the overall cost of the Paper Bag. This is the main cause due to which use of Paper Bag is less. Also initial investment cost is very much in conventional paper bag making machine. So it cannot be used for small scale production.All these problems are eliminated in the presented machine. Amachine whose initial cost is less, which does not require any special paper, which can be used for small scale production, is developed. Thismachine willhelp a poor family to earn money through small scale production of paper bags.

Paper bags have been gaining popularity since then plastic bags have been banned in various countries and cities. The product is made in two ways; traditionally, i.e. manual which is a manual or technical means i.e. with the help of automated equipment. The second method is much larger. In other words, it requires less workers and more money to buy land and equipment. Based on the core business of nonwoven bag making machine Manufacturers, the machine has 2 different output capabilities with good finish and seamless quality.

Amazing Benefits of Using a Paper Bag Production Machine: -

Excellent Quality: The great advantage of producing a paper bag from an automated machine is the excellent quality one can achieve throughout the production process. When we make paper bags in traditional ways, the quality of the product does not always match the whole production process. It is difficult to maintain the same level of quality per unit. Machine paper bags offer the same quality and precision each time.

Save on Work Expenditure: The introduction of an automated production process machine including slitting machine has reduced the need for workers in the paper industry. One only needs to change the paper roll and collect the finished product after the production process is completed. This saves unnecessary costs on jobs and you can invest in machinery and land instead of workers. Too much machinery and land can lead to a double standard of business production at the same time.

Distributed Production Level: Quality and fast production are two of the most important factors in any production process and automated production for the purpose of the product satisfies both of these factors while improving the quality of production. Save real time financially and increase your productivity compared to handmade methods. You can actually upgrade your product over time.

Energy Saving: An automated machine saves human energy and helps increase productivity. Both man and machine have different working powers. The machine can work more efficiently than man and requires fewer working breaks than man. You can have a good level of mechanical production. The machine can double your production rate at the same time. However, one can only increase the product because everyone has a different working capacity.

Paper bags are gaining importance as these bags are 100% reusable, recyclable and biodegradable and at the same time environment friendly and pose less threat to wildlife. it requires less energy for paper bags to be recycled than plastic bags. Paper bags have come a long way since their beginnings in the mid-eighteenth century when some paper bag manufacturers started developing paper bags that are more hardy and long lasting. The paper bags are generally box-shaped in design that allows them to stand upright and hold more goods. Corporates are using paper bags for promotions, seminars, product packaging and branding purposes.

By selecting high quality paper bag manufacturer can deliver recycled brown color paper bags in big and small quantities, regular and premium paper bags which add a professional touch that consumers love and appreciate. Besides, you can add your own custom brand to any paper bag to promote your business. Read on to discover the importance of paper bags.
1. Plastic bags cause environmental damage such as increase the level of air pollution. Plastic bags not only have adverse effects on our natural habitats, death of many animals. Plastic bags are not renewable and you need UV rays to destroy it, which is harmful for environment.Paper bags on the other hand are environment friendly and can be recycled.
2. Paper bags are usually made from wood. So, these bags can be produced into a new paper like newspapers, magazines or books. Waste papers are also biodegradable so they can be easily degenerate and do not pile up on dump sites.
3. You can also buy them at a very cheap price particularly if they are bought wholesale.
4. Possessing a paper bag is practical and you can use them to bring your groceries and the premium quality paper bags can be used as paper gift bags.
5. Most people nowadays prefer using paper bags because they are easy to carry, neat and can hold lot of items. It adds to your status symbol as they can be embossed and grained to enhance the look.
6. Paper bags are usually used extensively in malls and exhibitions for delivering over the counter products as research shows that paper bags contain at least 35% recycled material.
7. Corporates are nowadays using paper bags for promotions, seminars, product packaging, and branding purposes as they are competitively priced.
8. Paper bag manufacturers can help you to decide the right size and type of paper bags as per your project, budget and quantity.
9. You can choose paper bags with special properties that will seal the freshness and give an aesthetic look to your brand as offset and screen printing is possible.
10. When your product is properly packaged with premium quality paper bags, you can attract more customers which will help in promoting your brand to the targetaudience.
So, if you are ecofriendly and at the same time want to be ahead of your competitors, start using paper bags.