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Engineered thermoplastics have become increasingly useful in mechanical applications where traditional materials such as metal may not provide the ideal combination of weight, durability, chemical resistance, and design flexibility. Engineered thermoplastics are designed to provide enhanced mechanical and thermal properties. This makes them suitable for demanding components that must perform reliably under stress. They also used to manufacture components such as specialty seals, which need materials that can withstand challenging operating conditions while maintaining reliable performance.
These materials are used in a wide range of mechanical applications, from automotive systems to industrial machinery. Here is a list of common uses for engineered thermoplastic mechanical components.
Common Applications for Engineered Thermoplastic Mechanical Components
Automotive Components
This is one of the largest users of engineered thermoplastics. Manufacturers use them to produce components that need to be lightweight while withstanding heat, vibration, chemicals, and repeated mechanical stress.
They can be used for gears, bushings, bearings, clips, housings, brackets, and various under-the-hood components. Replacing certain metal parts with engineered thermoplastics can reduce vehicle weight, improving fuel efficiency or electric vehicle range.
Industrial Machinery
In industrial settings, machines operate under demanding conditions and depend on components that deliver reliable performance during extended operations and challenging environments. Engineered thermoplastics can be used for gears, rollers, wear strips, guide components, bearing cages, pulleys, and machine housings.
They perform well even in environments exposed to moisture, chemicals, or frequent movement because they resist abrasion and corrosion. Depending on the specific material, thermoplastic components can also operate with relatively low friction, helping reduce wear between moving parts.
Electrical and Electronic Equipment
Engineered thermoplastics are widely used in electrical and electronic applications because they can safely insulate electrical parts, maintain their shape, and remain strong and stable even when exposed to heat or regular use.
Mechanical components may include connectors, terminal housings, switches, brackets, cable management components, and protective enclosures. Materials can be selected based on requirements such as temperature resistance, impact strength, flame resistance, and electrical performance.
Thermoplastics can also be molded into detailed shapes and compact components, which is particularly beneficial today as electronic equipment has become smaller and more complex.
Pumps, Valves, and Fluid-Handling Equipment
Components of pumps, valves, and other fluid-handling equipment are often exposed to water, oils, solvents, chemicals, and other fluids. Certain engineered thermoplastics offer excellent chemical resistance, making them ideal for components that would otherwise be vulnerable to corrosion.
Impellers, valve components, seals, bushings, and pump parts may be manufactured from specialized thermoplastic materials. However, selecting the right grade is essential because chemical compatibility varies by material and operating environment.
Food Processing Equipment
Some engineered thermoplastics suit components in food processing and packaging machinery. These components may include wear guides, bearings, rollers, bushings, and conveyor components.
Manufacturers of food processing equipment may prioritize low friction, resistance to cleaning chemicals, dimensional stability, and ease of maintenance. Choosing appropriate materials is crucial to ensure components meet food-contact or food-processing environment requirements.
Aerospace and Transportation
Strong, reliable, and lightweight mechanical parts are needed in the aerospace and transportation industry. They must also withstand temperature changes, vibrations, impacts, and heavy loads.
Specialized engineered thermoplastics can be used for brackets, clips, bushings, cable-management components, interior hardware, and other structural or mechanical parts. Their strength and relatively low weight make them useful for designers looking for alternatives to heavier materials.
Consumer and Commercial Equipment
Everyday products and commercial equipment also use engineered thermoplastics. Thermoplastic materials can be molded into gears, handles, housings, rollers, adjustment mechanisms, and other mechanical parts.
Choosing the Right Material
Material selection should be based on the specific demands of the application. Temperature, load, friction, wear, chemical exposure, dimensional requirements, and manufacturing method are all factors that need to be considered.
The right materials and design give a practical combination of performance, durability, and manufacturing efficiency.
Get the Right Solution for Your Application
If you need durable, lightweight solutions for your next project, engineered thermoplastic mechanical components can deliver the strength, reliability, and performance demanding applications require. Talk to our experts today to discuss your needs and discover the right engineered thermoplastic solution for your application.
Why You Should Choose a Silicone Gasket
Gaskets are an integral part of any application, especially in automotive engines where they play a crucial role in keeping the engine temperatures in check. This is why choosing a gasket material deserves special attention. Choose the wrong one, and you could see a significant drop in production.
Depending on what your application requires, silicone could be just the material you need.
Silicone Versatility
If you are considering silicone for your application, you will have a wide variety of choices in properties that will make it a perfect fit:
- Silicone sheets and rolls come in a variety of thicknesses, from 0.10” thick to .500” thick.
- Silicone can have a hardness anywhere from 10 Shore A to 80 Shore A.
- Molding compounds can be pigmented to match the color chips or Pantone color designations.
- Closed cell silicone sponge and foam come in sheets and rolls, from .032” thick to .500” thick. Its densities range from ultra soft to extra firm.
- Silicone rubber has the broadest range of firmness and densities.
- Fluorosilicone is resistant to fuel, oil, and chemicals.
Compression Set Resistance
Compression set, which occurs when a rubber cannot return to its original thickness after experiencing prolonged compressive stress, is an important factor to consider when choosing a gasket material. If compression set is one of your main concerns, silicone will be one of your best choices: two of the top-ranked compression-resistant materials are silicone and silicone sponge.
Flame Retardant
If silicone is compounded, its ability to resist flames is impressive. It can achieve UL94V0, UL94V1, and UL94HF1 flammability standards. For this reason, silicone is relied on for analytical instrumentation, telecommunications equipment, and controls found in Mass Transit systems. Even if silicone burns (which is only possible under extreme temperatures), its byproducts are non-toxic, and its residual ash can even provide electrical insulation.
FDA Regulations
Silicone can be compounded with FDA-approved ingredients to gain properties like high tear strength and flexing by using platinum-based catalysts. This makes silicone great for healthcare, instrumentation, food processing, and medical diagnostic equipment.
Electrical Conductivity
By blending silicone with nickel-graphite or silver-plated aluminum particles, silicone can be used as an electrically conductive gasket providing EMI shielding for use in electronic communication equipment. This form of silicone comes in a sheet or a custom-molded gasket.
Electrostatic Discharge (ESD)
In applications where ESD is a problem, silicone can be blended with a semi-conductive carbon to gain ESD properties.
Extreme Temperature Resistance
Unlike other organic elastomers like EPDM and neoprene, silicone rubber can retain its thickness even after exposure to a wide range of temperatures. This range goes as low as -60°C to as high as +250°C. In fact:
- It can be used at 150°C continuously without experiencing any change in its properties.
- Certain compounds can even withstand up to 200°C for 10,000 hours or more.
- Certain forms of silicone can withstand 350°C for short periods.
- Most forms of organic rubber become embrittled at -20° to -30°C.
- Some kinds of silicone products can retain elasticity at -100°C and lower.
Silicone Sponge and Silicone Foam
Silicone sponge (also called closed cell silicone sponge) is made from a thin sheet of uncured silicone gum. Closed cell means that the cells are not interconnecting, preventing water from wicking through the sponge. It also has strong mechanical properties.
Silicone foam is an open cell, lightweight material. Higher density open cell variants are suitable for water sealing, while lower densities will allow moisture to pass through.
Other Properties
- Due to its closed cell structure, silicone is great at water sealing with relatively low compressive forces. UL 50 and UL 50E are available.
- Silicone is excellent at resisting UV and ozone because it has an inorganic backbone. This extends the performance of the gasket in the long-term.
- Silicone sponge is much tougher than silicone foam.
- All of silicone’s properties make it a great choice for outdoor environments with extreme conditions, such as the Arctic tundra and the desert.
No matter what gasket material you choose, make sure that you understand the major causes of gasket failure, and how to prevent them.
Consult the Industry Leader
If you are ready to make a purchase for your seal, consult the industry experts at Real Seal today. Real Seal has been an industry leader since the 1970s, and continues to innovate with its own chemist and technical staff. No matter what type of seal or mechanical component you are looking for, Real Seal will have the answer you need.
Unless you’re dealing with water, the solutions that are being sealed within systems are either acidic or basic. Either one can wreak havoc on a seal made of the wrong material type. For acidic solutions, a weak seal can cause a dangerous situation that can damage property and harm employees, this is where acid-resistant o-rings come into play.
Knowing what types of seals are best for these operations is imperative to protecting your assets and your employees. Not only are acids dangerous when touched, the fumes can often be just as harmful to both people and materials. Avoid making the mistake of choosing a material that is weak to acid. Here is a list of materials that can be used in operations involving acidic solutions:
Fluorocarbon Rubber
Fluorocarbon Rubber, or FKM, is best for applications requiring both chemical and heat resistance up to 400 degrees Fahrenheit, in addition to the acid resistant quality. There are even FDA grades available for food and beverage applications. A lot of food products are acidic, such as sodas, juices, and other fruit products.
Specialty fluorocarbons allow for a large range of resistances to various forces and chemical properties. If your application includes extremely acidic solutions, then these may be your best option. Customization is often a key concern for applications in the current industry trends as each operation has such unique and specific needs for their operation to run at the highest possible efficiency. Specialty materials allow for the most flexibility and can be designed by experts to fit your application.
EPDM
Ethylene Propylene Diene Monomer, or EPDM, is resistant to weathering, ozone, water, and steam, as well as the acid resistance needed for these operations. Compounds cured with peroxide have excellent compression set resistance. So, if you are looking for a material that can retain its shape under high levels of pressure and is resistant to most acids, EPDM may be the way to go. Often it’s a combination of harsh factors that destroy a seal, so knowing if it is acid-resistant is merely the first step. High-pressure operations aren’t uncommon, and when you need a compound that resists acid and deformation, EPDM should be considered.
Materials to Avoid
A lot of materials are able to handle lower acidity fairly well. However, there are certain materials that are very bad at handling acids and will degrade quickly under this kind of stress. Knowing these materials is just as important as knowing ones that are good for acid-resistance.
Silicone is an extremely common material for o-rings and is not good at resisting acids. While you may want to use silicone because of its low cost and good set resistance, it is a poor choice if the solutions you are sealing are acidic. Urethane is another material that should be avoided in operations using acids. Certain rubbers have a mild resistance to acids in static applications, but high acidity is very corrosive to most rubbers.
Selecting the Right Seal for Your Operation
Acidity is merely one factor that should be considered when choosing the right seal for your operation. Other factors in combination with acid can make the process of finding the right seal complicated and potentially dangerous and expensive.
When you are choosing the o-rings for your systems, consulting with an expert in the industry, and buying seals from a reliable manufacturer are essential to your success. Real Seal has been in the industry for decades, creating and finding solutions for a massive range of applications. Contact Real Seal today to ensure your company’s success!
The Benefits of a Backup Ring
No matter what type of application you have or who you work for, having a system that will run well for as long as possible should be one of your top concerns.
A backup ring is just one of the many little things you can do to help keep your system running smoothly for as long as possible, along with these other methods. But you might be wondering, just how does it work? There are a few ways a backup ring could improve your system performance and longevity.
Extrusion
O-Rings experience a lot of stress, causing them to wear down in various ways. One of the biggest causes of an O-Ring failure is extrusion, particularly in hydraulic rod and piston seals. Extrusion occurs when the internal pressure of an application becomes too great, causing the O-Ring to extrude – or stick out – into the clearance gap. This extruded or extended portion of the O-Ring will wear down quickly, reducing the amount of material in the O-Ring. After a short period, extrusion results in seal failure.
According to Daemar, some of the common causes of extrusion include:
- Excessive clearances.
- Pressure exceeding system design.
- An O-Ring with an insufficient durometer for the application.
- Degradation of the O-ring due to system fluid.
- Irregular clearance gaps caused by eccentricity.
- Increased clearance gaps due to excessive system pressure.
- Improper machining of O-ring gland.
- Wrong O-ring size installed, resulting in an excessively filled groove.
You should inspect your O-rings for signs of extrusion. Examine the edges of your O-rings on the low pressure or downstream side to see if it appears chewed or chipped. If extrusion has caused your O-ring to fail, you should see small pieces missing from the low pressure or downstream side. In some cases, 50% of the O-ring may have been lost already before the leakage has been found.
Preventing Extrusion
There are three ways to combat extrusion. The first is to reduce the clearances in order to lower the extrusion gap. Unfortunately, this is not practical due to the high expenses involved.
It would be much cheaper to instead raise the durometer of the O-ring. An O-ring with a higher durometer would have a much higher resistance to extrusion, but would also bring two other problems with it: namely, the limited availability of higher durometer materials, and that these materials are not as effective in low pressure applications.
Backup Ring
This brings us to the third option: backup rings. Rather than acting as a replacement for your installed O-rings (as its name suggests), a backup ring is actually meant to work in tandem with the O-Rings you have already installed. Backup rings are typically made of materials with high durometers and resistance to extrusion, including nitrile, Viton (FFKM), or PTFE.
The backup ring is installed between the O-ring and the extrusion gap. The addition of a backup ring will improve the pressure resistance of the O-ring, and prevent it from being forced into the clearance gap, reducing the chances of extrusion and premature seal failure. Depending on the direction of the pressure, you may even be able to install two backup rings. This will provide added protection against extrusion and O-ring failure.
Choosing a Backup Ring
You will have a number of options to choose from to cater an O-ring for your application. They come in two styles: a flat, washer-like style, or a contoured face which provides greater grip and support on the O-ring.
They may also have a solid or spiraled construction. A spiraled construction is made of overlapping rings, providing several different contact levels against the shaft. They provide greater support over solid construction backup rings.
Buy Your Backup Rings From an Industry Leader
From humble beginnings as an O-ring distributor in 1970, Real Seal has grown to become a full-service O-ring supplier and industry leader. Real Seal is not only one of the most technologically advanced O-ring suppliers today; we are also one of the few organizations with a fully-equipped laboratory as well as a full-time chemist and technical staff. This allows Real Seal to meet design challenges special material formulations in a way that no other company can. Don’t wait: give us a call and we’ll provide you with backup rings made to your exact specifications as soon as possible.
For most people, the acronym APQP does not resonate as anything important, but in the world of engineering, it has become a familiar point of reference. Beginning with major industries like automotive and heavy equipment, APQP has trickled its way down to specific components, and many customers are getting sophisticated enough to ask for specific APQP data as a condition of doing business with them. A general outline of what APQP means to the rubber and plastics industry would include a number of considerations.
APQP starts with a control document and raw material specification. The control document must specify measurable product dimensions and tolerances, and accurately reflect constraints such as parting line restrictions, gate locations, allowable flash extension, and allowable radii. It is practically impossible to include every conceivable constraint or to specify any conceivable outcome for the finished product, but generally accepted norms are published by RMA and SPE, and can be referred to by default. The raw material specification should be objectively identified with ASTM (American Standard Test Methods) or better yet, with a specific material, as this will limit variables of different materials that still meet a specification.
The next step for APQP is to coordinate the results of the control document and specifications with a capable vendor, and develop an assessment of capability and competitiveness. A wise engineer will request a “self-audit” of a prospective vendor, and ask them to score their strengths against a checklist of resources that will determine product quality. At this stage, basic variables such as machine tonnage, tool size and complexity, and number of cavities should be reasonably determined. These variables will begin to paint the picture related to product cost, and begin to standardize the competitiveness of the vendors being considered for full production. Paying specific attention to control resources such as raw material test/validation and measurement test/validation should provide advantage, as the better a vendor can validate defined process steps, the less the likelihood that non-conforming product will be realized. A capable vendor should be able to qualify the major variables, and provide a preliminary cost model.
Once the cost estimate is deemed acceptable as a part of the overall project cost model, the unit should be put through a more rigorous design and engineering review, including design for tooling, design for manufacturability, design for assembly, and aesthetics. This is a prime opportunity to catch “downstream” issues before they become obstacles to production. The opportunity is prime because vendor input is normally very valuable in determining these variables, and in developing alternatives and options to improve cost and control. This will also lay the groundwork for the process flow, Control Plan, PFMEA, and Cpk if/when a PPAP is developed.
This design/engineering review should yield a control document and specification that balances required engineering and controls with cost control, and should empower purchasing with the most objective and well-articulated basis with which to negotiate terms with prospective vendors. It should also determine the measurement features and controls for Quality Assurance, so that any validation that occurs at the point of manufacture can be reasonable replicated when the product is received, and apples are indeed compared to apples.
Real Seal has extensive experience in dealing with the sometimes complex task of product development, and can offer considerable value to customers with product development. Rubber and plastics bring unique variables to the game, so the experience, systems, and guidance Real Seal can provide can equate to considerable long term savings.
When planning for the processing of rubber or plastic seal products and mechanical components, there are several factors that must be considered to satisfy customer requirements. Although the conventional wisdom is to bring larger volume projects to China for the low prices, American manufacturing innovation and good old fashioned productivity have created many opportunities to produce products domestically – and do it competitively.
The first consideration is the material requirement or specification for the part being considered. The physical requirements for the application will largely determine the material selection, which, in turn, will create the pathways for processing options. As a general rule, thermoset rubber materials have superior physical characteristics over thermoplastics. Theroset rubber materials have traditionally been processed with compression and transfer molding methods, which are quite labor intensive. In the last several years, however, great advances in injection molding technology of thermoset rubber materials have been made domestically. The materials are modified chemically to improve their flow properties, which then allow them to be molded in much the same way that plastics are. They still require secondary finishing to remove flash, but the productive processing rate could make a strong competitive base to work from. If the material is to be thermoplastic, domestic manufacturing is generally more competitive than comparable
The next consideration is the geometry of the part, and the type of tooling necessary to meet geometric, size, and tolerance requirements. There is a limit to the layout of cavities for all processes of molding, so considering spacing and symmetry, the broad rule of thumb is the smaller the geometry, the higher number of cavities. The total volume of the cavities, however, cannot exceed 4 X the projected area of the hydraulic ram tonnage of the press, or the press will not be capable of closing the mold. Generally speaking, thermosetting rubber materials will have a longer cycle time to vulcanization than plastics will to set up, so the productive rate multiplied by the # of cavities will begin to set the stage for the most economical approach to production.
When these parameters begin to be fleshed out, one of the important considerations is what kind of repeatability can be achieved in meeting customer requirements. The more capital intensive the process (generally speaking), the more repeatable the process. Processes that require human interaction will by their very nature vary with the nature of the human element. Advances in controls that include large quantities of sensors create conditions that are optimized by machines, so that any variables are minimized, and so that the process can be stopped at any time if the variables begin to drift away from optimized limits. The result of this approach normally includes a higher yield, better dimensional consistency, and more consistent results overall.
American innovation is on the forefront of advances in capital equipment, primarily in electronic sensors and controls that create higher and higher degrees of control. There is much to be gained by utilizing a more capital intensive approach to production, but the cost of capital can be considerable. While there is still a strong argument for the old fashioned approach in many cases, engineers and designers are wise to keep up with advances in production, and design their rubber and plastic seal products and mechanical components accordingly.
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