POLYMER". Isn't that just another word for plastic? Perhaps, but the term polymer actually describes the material and not the end product. Poly, meaning "many", and "mer", parts, refer to the long chain molecules that make up the miracle of modern plastics. Unfortunately, many people still associate the term "plastic" with that Christmas toy that broke five minutes after being opened, or a plastic lawnmower gear that stripped the month after the warranty expired. These same people think of "polymer components" as a contradiction in terms.
Polyethylene is the largest volume thermoplastic polymer used today. A thermoplastic polymer is capable of being repeatedly softened by heat and hardened by cooling. Polyethylene is available in a wide variety of grades and formulations that have an equally wide range of properties. Certain polyethylenes are flexible, others are rigid; some have poor impact strength, others are virtually unbreakable. Service temperatures can range from –40 to 200°F. In general, polyethylenes are characterized by toughness, excellent chemical resistance, low coefficient of friction, near zero moisture absorption, light weight (approx. one-eighth that of steel) and ease of processing. Polyethylenes are classified into three categories, according to density:
A fourth type, UHMW-PE, is in the high-density range. In some cases, properties of this high-performance plastic are similar to other polyethylenes, but in other cases, can be dramatically different.
HDPE (High Density Polyethylene) Rigidity and tensile strength of the HDPE resins are considerably higher than those in the low and medium density materials. Impact strength is slightly lower, as is to be expected in a stiffer material. Applications of HDPE range from film products to large blow molded industrial containers. The largest market area is in blow-molded containers for packaging fluids. Other major uses include injection molded housewares, industrial pales, food containers and tote boxes. Also, mechanically ground HDPE resins are used to mold large, complex shaped products such as fuel tanks, trash containers, pallets, highway barriers and all 1997/2001 Tekvest models.
UHMW-PE (Ultra High Molecular Weight Polyethylene). This is a polymer with a molecular weight of 3 and 6 million. UHMW-PE has outstanding abrasion resistance, low coefficient of friction, self-lubricating, chemical and stress cracking resistance. Another key characteristic is impact strength, which is 8 times greater than HDPE. UHMW-PE does not break in impact tests using standard notched specimens compared to HDPE, which will break. UHMW-PE must be double notched to break in a Izod impact test. In a ballistics test conducted at -65°F, a 1” slab of UHMW-PE stopped a .45 caliber bullet at a distance of only 25 ft!
UHMW-PE Applications: Conveyor wear strips, Guide rails, Bearings, Paper machine suction boxes, Chute linings, Trailer linings, Snowmobile skis, sliders, idler wheels, drive sprockets & suspension bushings. All 2002 Standard & Arctic Cat Adult Pro Lite Tekvest models.