Characteristics of LUBMER™ in injection applications
Abrasion resistance, sliding properties, quietness, greaseless
CASECASE
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CASE04
Injection moldable U-PE
Engineering plastic boasting high abrasion resistance, quietness and sliding properties
Examples of use and evaluation
Automotive, home appliance, OA, mechanical components, joint parts, etc.
Issues with resin sliding components
Plastics have various properties, from elasticity to transparent materials and materials used as fibers. Among them, those with superior mechanical properties are referred to as engineering resins. As these resins are lighter than metals, they are extensively used as metal alternatives. However, from the perspective of sliding properties and abrasion resistance, engineering plastics often have room for improvement. Particularly from the perspectives of the shift to electric vehicles and the comfort of home appliance use, quietness is being required in more and more cases, but there are also cases where creaking sounds are generated due to insufficient sliding properties. Additionally, to achieve a sustainable society as described in recent trends, nylon and POM exhibit inadequate durability, resulting in the need for a material with higher abrasion resistance.
Solution
LUBMER™ from Mitsui Chemicals is an injection- and extrusion-moldable pellet type ultra-high molecular weight polyethylene. LUBMER™ has excellent sliding properties and abrasion resistance, and is seeing great success in fields that require performance levels that other resins cannot handle. It is used across a wide range of applications from reducing the noise of OA equipment to sliding components in cars as well as electrical and electronic devices, and has been recognized for those properties and its high quality. LUBMER™ is also used for construction materials and various mechanical components.
Excellent sliding properties and abrasion resistance
The following diagram shows sliding properties and relative abrasion quantity under the conditions of a ring abrasion test. LUBMER™ exhibits superior sliding properties and abrasion resistance to nylon-based PBT and POM. Its abrasion resistance also far outweighs that of HDPE.
| Suzuki Method Ring Abrasion Test | |
|---|---|
| Testing Temperature: 23ºC, Opposite Material: S45C, Load: 0.75MPa, Speed: 30m/min., Distance: 3km | |
Excellent quietness
Additionally, these sliding properties also help reduce the squeaking noises produced when resins come into contact with one another. The squeaking sounds when resins come into contact with one another is also referred to as "stick slip." This is a phenomenon that occurs on the engaging surfaces of resins and occur due to a high friction coefficient between engaging surfaces and the large resistance force during sticking and sliding. Using LUBMER™ for these cases can prevent this slick slip from occurring. The below table shows measurements of the amount of friction in a ring abrasion test performed between different resins. While a squeaking noise is produced when PA6 and POM come into contact with one another, when LUBMER™ is used, no such noise is generated.
| Suzuki Method Ring Abrasion Test | |
|---|---|
| Testing Temperature: 23ºC, Opposite Material: Change the ring's material., Load: 0.2MPa, Speed: 30m/min. | |
Applications for actual use
LUBMER™ is used as a sliding component for a wide range of applications. Using LUBMER™ for gears and parts in OA equipment does not produce the kinds of issues that occur when POM is used, such as paper slippage due to the high friction coefficient. When LUBMER™ is used, these issues are resolved thanks to the improved sliding properties of the equipment. Similarly, for automotive components, switches and the parts of internal mechanisms, exchanging POM and grease for LUBMER™ maintains sliding properties at around the same level while eliminating the grease coating process and resolving stick slip issues during operation. Also, while HDPE is usually used as a plate spring cushioning material in trucks, there are cases where LUBMER™ is used because cracking does not occur even under harsh abrasive environments that HDPE cannot withstand. LUBMER™ is also employed in areas that require high sliding properties and abrasion resistance, including medical materials and components, shutter rails and cosmetics parts.
Summary
As an injection- and extrusion-moldable ultra-high molecular weight PE, LUBMER™ is a product that combines extremely high sliding properties with abrasion resistance. Due to those sliding properties and high abrasion resistance, LUBMER™ can achieve reduced noise, greaseless operation and improve durability, making it possible to provide high-performance components that cannot be achieved using other engineering resins.