Materials

ABS is an amorphous material, like RPVC. It is naturally ivory in color. It is made of three components, with varying degrees of each, depending on the properties desired. The Acrylonitrile gives the material chemical resistance and heat stability, the Butadiene gives it mechanical toughness and impact strength, and the styrene provides rigidity. ABS is used in many different areas because of its versatility. It is used in appliances, for example refrigerator door liners and crisper drawers. Because of its impact performance you will find ABS used in various housings, consoles, and toys. The automotive sector is a large consumer. You will find ABS used for instrument panels and trim. It can be used on the interior as well as the exterior of the vehicle. ABS is known for it good processability and it is easy to fabricate. It is desired for its high gloss and it can be colored to fit your needs.

Acetal is a highly crystalline material and is therefore is an opaque white color in its natural state. Acetal is available as a homopolymer or copolymer, although both classes provide excellent mechanical, chemical, and electrical properties. They are able to do so over a wide temperature range and over long periods of time. Unlike nylon, acetal is not hygroscopic and will not change dimensionally in a humid environment. They also provide superior creep and fatigue resistance. Acetal is well known for its friction and wear properties and is one of the strongest and stiffest plastics out there. Additives can be used to increase these and other properties even more so. Acetal requires protection from UV by using additives, such as carbon black, in order to keep it from degrading with prolonged exposure. You will find acetal in many plumbing applications, such as impellers, pumps, showerheads, nozzles etc., typically where water exposure is high. They are also common in industrial and electrical applications for things such as gears, cams, switches, buttons, and handles. Spiratex has experience extruding profiles, filled and unfilled, for various industries.

Nylon was originally developed to be used as a fiber. Its natural color is white or ivory. Today there are many uses for nylon. Nylon is the material of choice for applications involving high service temperatures, low coefficient of friction, chemical resistance, good abrasion or wear, and toughness. Nylon comes in numerous variations depending on the properties required. There is nylon 6, 6/6, 11, 12, filled (glass or moly), alloys and more. Some of the largest applications include gears, cams, bearings, guides, and housings. Nylon does tend to absorb water over time from the environment, some grades more than others. This can affect dimensional stability. Spiratex has a lot of experience with nylon tubing, spiral wrap, and profiles, with many of the profiles being used in the conveyor industry. Some grades can be used in food contact applications when used in accordance with FDA standards.

Polycarbonate is known for being one of the toughest thermoplastic materials available. It has excellent clarity and can be colored to fit your needs. It is ideal in high continuous use temperatures, up to 250 degrees F, but is limited when exposed to high heat and high humidity for long periods of time. P/C has excellent outdoor weathering properties. P/C is easily extrudable and has good dimensional stability. You will find it in applications where you want to replace glass with an indestructible material such as windows, shields, and even eye glasses. P/C lends itself to many secondary processes like welding, solvent bonding, hot stamping, printing, and more. It can be machined as well as reshaped using heat. Spiratex has a lot of experience extruding tubing and unique profiles from Polycarbonate.

Polyethylene is a member of the olefin family. Polyethylene can be produced with both branched and linear molecular chains. High density polyethylene is made up of linear molecular chains, as is linear low-density, high molecular weight-high density, and ultrahigh-molecular weight. Low-density polyethylene has branched molecular chains and unlike the other polyethylenes, is produced under very high pressure. This method produces molecular chains with various side chains lengths or branches. The difference between the two is in the degree of crystallinity. Branched polethylenes are limited.

The density of the polyethylene determines many of the properties of the polyethylene. The higher the density, the more stiff the material. It has a higher softening point, higher tensile and creep resistance. With higher density, some other properties are lost. Increased density means lower impact strength, elongation and flexibility. Properties can also be changed by means of changing the molecular weight. By changing the density or molecular weight when making polyethylene, a wide variety of properties can be had.

HDPE is used for small tubing up to large pipe used for natural gas, sewer pipe, or drainage lines. It can be made into profiles and can be used to coat wire and cable. A large amount of HDPE is used in blow molding to produce things like fuel tanks and containers. LLDPE is used for films or bags. They are puncture and tear resistant. LDPE is also used for films and because of the low crystallinity, they typically have good optic qualities. They are also good for coatings to help with heat sealability or moisture barriers. UHMWPE is quite different from the most of the other polyethylenes and therefore has a dedicated material description.

Polypropylene is a crystalline material from the same family of polymers as polyethylene, the polyolefins. Polyethylene and polypropylene have some very similar properties such as resistance to water, good chemical resistance and good dielectric properties, but there are some important differences that set it aside. Polypropylene's relative density runs in the 0.90 range versus polyethylene which is in the 0.940 to 0.965 range. Polypropylene has a higher service temperature. It is more rigid and is more resistant to environmental stress cracking. Typically, you will hear of two different types of polypropylene. There is the homopolymer P/P and the random copolymer P/P. One of the homopolymer's biggest uses is in fibers and filaments. It is also used in packaging as a film, due to its water barrier characteristics. When you need a tougher more impact resistant part, you need to look at the copolymer. Here, a flexible ethylene component is added to the molecular structure, giving the material better impact, flexibility, and clarity properties. The copolymers are also used in films because of their toughness, but when you want interior or exterior trim pieces or parts for furniture, the copolymer is the material of choice. Polypropylene can be difficult to bond, normally flammable, and has poor weatherability, but Polypropylene's properties can be enhanced by adding fillers such as glass, talc or a flame retardant.

Spiratex is a custom extruder of all thermoplastics, but our capabilities with thermoplastic polyurethane deserve some special attention. Spiratex has always been at the forefront of TPU extrusion, in particular since the early 1970's, when many flexible PVC hoses and tubes began being replaced with polyurethane. We have worked with all the big name TPU suppliers over the years such as BASF, Goodrich (now Lubrizol), Dow, and Bayer. TPU is known for its overall toughness and flexibility at low temperatures, and therefore outshined PVC in many demanding applications. People also saw the opportunity to replace rubber and PVC profiles with TPU in applications such as seals and industrial belting. Spiratex has many years of experience extruding both tubing and profiles using TPU.

There is quite a variety of TPU's out there to choose from. The grade you use really depends on what your application is. Our engineering department will work with you to help choose the polyurethane that best meets your needs. The first thing to consider is the environment that your product will be subjected to. All TPUs can be divided into two categories, esters and ethers. Ester based TPUs are usually the tougher of the two, but when exposed to water over long periods of time, they tend to break down, or degrade. Esters are ideal for industrial applications such as belting or roller covers, since they are tougher and are more resistant to chemicals and oils. Ether based TPUs do not degrade in water, but they are not considered to be quite as tough.

Another nice feature of all TPUs is the degrees of hardnesses available. This is controlled by how much of the hard segment chemical is added to the mix by the supplier. The hardness is measured as the durometer of the material and most common TPUs fall into the A-Scale, which ranges from 55A to 98A, but there are some harder versions out there. 98A TPU is roughly equivalent to a 55 on the D-Scale. Polyurethane can go as high as 75 durometer on the D-Scale. Once into the D-scale, the TPU is very stiff. Typically is seems most uses of TPU require a material in the 80A to 90A range.

Some of the other excellent properties you can expect to get when you choose TPU are high tensile strength, cut resistance, high wear and abrasion resistance and sound dampening. Additives can be added to TPU also, to enhance the above properties as well as add others, such as UV protection. Spiratex has a reputation as a company that will test run new TPU formulations. We have extruded such things as aramid fiber reinforced and tungsten filled TPU. Check out our products and you will see the multitude of parts that can be made from thermoplastic polyurethane.

Spiratex has vast experience with the extrusion of Rigid PVC. RPVC is an amorphous plastic that is used extensively in the construction industry. You will find the majority of RPVC is used for window profiles, home siding, and piping. It is rigid, dimensionally stable, and has good resistance to weathering and corrosion. RPVC can be used in situations where flame and electrical resistance is needed. RPVC is a fairly low cost material, although it is important to remember PVC has a higher density than many other similar plastics. It does have a relatively low thermal decomposition temperature, but this, and other properties, may be improved by alloying it with other thermoplastics. Spiratex has had success with co-extruding RPVC profiles with either FPVC or TPU. RPVC usually comes to us clear, bluish translucent, white, or black in color, but it can be colored to fit your needs.

By adding a plasticizer to PVC it becomes more flexible. The amount of plasticizer controls the hardness of the PVC. The hardness, or durometer, is measured using the Shore A-Scale. PVC with a hardness of 50A to 90A is considered flexible. FPVC is usually clear or bluish translucent, although it can be made any color desired. Its uses, as related to extrusion, are in medical tubing, tubing in general, and seals. It has good sound and vibration dampening properties. It also is known for its chemical resistance properties. FPVC is comparatively cheap versus a similar TPU part. One drawback with FPVC is that over time some of the plasticizer has been known to leach out onto mating parts.

Santoprene is a thermoplastic vulcanizate (TPV) resin that is an in-situ mixture cross linking of EPDM rubber and Polypropylene. It is an elastomer that combines the attributes of vulcanized rubber - such as flexibility and low compression set - with the processing characteristics of thermoplastics. Environmental aging resistance, electrical properties, and liquid resistance are about the same as EPDM and it can replace EPDM in certain applications. Santoprene TPV is recyclable in the polyolefin recycle stream.

Santoprene TPV Advantages

• Harsh-environment performance
  • Parts made from Santoprene TPV's offer a constant service temperature range from -60°C to 135°C (-81°F to 275°F) with no cracking or tackiness. Excellent heat aging combines with good resistance to many acids, bases and aqueous solutions.
• Soft-touch aesthetics
  • The dry silky feel of grips, handles, etc. made with Santoprene TPV's add appeal and cost-effective market value to products.
• Broad range of flexibility
  • Santoprene TPVs range from supple 35 Shore A to tough 50 Shore D. General purpose grades are suitable for most applications. FDA-compliant, NSF-listed and medical grades are also available. Flame-retardant grades meet UL requirements.
• Easier design for Parts
  • Design tolerances can be two to three times more precise than with EPDM or polychloroprene rubber. This enables product designers to create parts with thick or thin walls and to simplify multipart designs. Several grades that bond with ETPs, nylons, metals and various polyolefins are available creating co extrusion options saving costs through parts consolidation and design flexibility.

TPEs are high strength materials. They combine the properties of high performance elastomers and flexible polymers. They are very tough. They are known for their ability to take repeated flex cycles. They have high impact strength, even at low temperatures and have high heat resistance up to 300 degrees F. They are also resistant to many chemicals and oils. Just like thermoplastic polyurethanes, there is a large range of durometers or hardnesses to choose from. TPE's hardness ranges tend to be in the "D" scale, unlike TPUs, which tend to stay in the "A" durometer scale. There are many uses for TPEs, such as belting, tubing, fascias, bushings and gears. They can be found in many industries such as automotive, sporting goods, power tools, conveyor, cable, and fluid power.

There a few different types of thermoplastic rubbers out there. Thermoplastic rubber can replace many rubber components. It is easy to extrude and eliminates the vulcanization process. There are different types of thermoplastic rubbers. Different companies have taken different approaches to producing the product. Some are actually made up of a highly vulcanized rubber and plastic mixture. The plastic is usually a polypropylene and the vulcanized rubber component is evenly mixed throughout the melt. There are also melt-processable rubbers. These materials can be extruded and they have the same characteristics of actual rubber. They are also alloys, but are more like a single homogenous material. TPRs come in different durometers, from around 55A to 50D. They have excellent resistance to fatigue and high tear strength. They also have good fuel and oil resistance. If you're looking to replace seals, tubing, hoses, spacers, bumpers or other rubber parts, a TPR is worth looking at.

Polymers are large molecules built from monomers.

U.H.M.W.P.E. denotes Ultra High Molecular Weight Polyethylene. UHMWPE's monomer is ethylene. It is a linear polyolefin. UHMWPE's average molecular weight is greater than 3,100,000 as defined by ASTM D4020 standard specification for UHMWPE. This resin with a molecular weight 3,100,000 + is well above the molecular weight of most typical polymers which are between 10,000 and 1,000,000 thus earning the name Ultra-High Molecular Weight Polyethylene. The molecular weight of UHMWPE must be approximated using the solution viscosity procedure found in ASTM D4020. Commercially available resins are available from 3-6 million molecular weight. Resin in the 3.1 -4.5 range have the best combination of impact strength and abrasion resistance.

UHMWPE is also commonly referred to as UHMW PE, UHMW-PE, UHMW P/E, UHMW, Ultra-high, and sometimes just UH. There are several trade names for UHMWPE such as the Spiratex company's "ULTREX". It our trade name for extruded UHMWPE.

For Polyethylene molecular weight classification the following guidelines can be used:

Some Properties are:

• Excellent abrasion resistance
• Excellent impact strength (the highest of any plastic)
• Superior chemical resistance even to the most aggressive chemicals. Greater chemical resistance than HDPE, polyurethane, steel, polyacetal and nylon.
• Water repellent highly resistance to hydrolysis
• Biologically inert
• Excellent dielectric & insulting properties
• Stress crack resistant

UHMWPE is commonly used in the material handling industry including food contact surfaces as it is acceptable under FDA and USDA guidelines. It is used in lead-acid battery separators, medical implants, filters and a wide variety of other applications.

In addition to standard UHMWPE the Spiratex Company has years of experience with the modification of the base resin through the addition of additives to alter performance properties to suit custom applications. A few are:

16020 ULTREX Enhanced Conductivity UHMWPE is achieved by adding a superconductive carbon black which colors the material black and lowers the surface resistivity range to 10⁵ - 10⁹. The dispersed superconductive additive allows electron movement across the part itself. The product color is black and the material is not FDA complaint. This is the most effective option for dealing with conductivity and static charges.

16026 Ultrex Ultraviolet (UV) Stabilized UHMWPE

UHMWPE can be attacked by ultraviolet (UV) radiation. The attack is known as UV degradation, and can be a problem in products highly exposed to sunlight or in some cases artificial sources. Continuous exposure for a long period of time is a more serious problem than intermittent exposure, since the attack is dependent on the extent and degree of exposure.

Examples of UV degradation on natural UHMWPE include chalking, a yellow discoloration and cracking. In severe cases, complete product disintegration can occur. The attack can be detected before serious cracks are seen in a product using infrared spectroscopy.

UV attack by sunlight can be slowed or prevented by dispersing UV stabilizers in the polymer prior to extruding. The most effective methods for protecting plastic polymers for UV attack is the addition of specific carbon blacks which when added in sufficient quantities absorb the UV radiation and give it off as heat; protecting the polymer chain. Properly loaded carbon black can give 10+ years of protection from normal exposure. Simply coloring the part black doesn't mean the product willbe optimally protected from UV attack.

Our UHMWPE UV Stabilized product known as 16026 ULTREX is black in color and has optimal protection against UV attack. This material is not FDA compliant.

16050 ULTREX UHMWPE with antistatic additives has the ability to reduce the buildup of static electricity generally caused by the triboelectric effect. The additive leaches to the surface or the material and absorbs moisture from the air. The molecules of an antistatic additive have both hydrophilic and hydrophobic areas, similar to those of a surfactant; the hydrophobic side interacts with the surface of the material, while the hydrophilic side interacts with the air moisture and binds the water molecules. The effectiveness of this option is dependent on the humidity of the environment as well as the leaching of the additive. This material when used in accordance with 21 CFR 177.1520, the applicable FDA polyolefin regulation, meets the requirements of 2.1 and 2.2 of that regulation for food contact applications.

16303 Lubricated ULTREX UHMWPE was developed to have supplementary lubricity in the form of a continuously regenerating surface film. This effect is achieved by incorporating proprietary additives into the base UHMWPE polymer which are extruded under high pressure. This homogeneous blend of an ultra-high molecular weight polyethylene polymer and normally solid lubricants with a grease yield products that are self-lubricating, slowly releasing lubricant at temperatures developed in ordinary use.The extruded product exhibits excellent dimensional stability, good wear resistance, and a surface which is not oily to the touch. The character of the additives that produce the lubricating film are such that dimensional changes, as the surface film is displaced, are inconsequential and other desirable properties are not unfavorably affected.The standard color for this material is gray when used in accordance with 21 CFR 177.1520, the applicable FDA polyolefin regulation, meets the requirements of 2.1 and 2.2 of that regulation for food contact applications.