Fine Powdered UHMW-PE – Markets, applications, and benefits
Conventional UHMW-PE has an average particle size in the range 100µm to 200µm, but it can be further processed to be produced with a particle size in the range 10µm to 30µm making it one of the finest UHMW-PE.
Figure 1 compares particle size of fine- UHMW-PE to the particle size of conventional polyethylene.
Fine – UHMW-PE
Conventional Polyethylene
Figure 1: Particle size of 10-30µm compared to conventional polyethylene which has a particle size of 150 - 200µm.
The high molecular weight, coupled with the small particle size, makes up an ideal additive for use in coatings, greases & lubricants, plastics, rubbers, and other materials. This category of UHMW-PE also improves durability of products and enhances heat and water resistance of materials when used as an additive.
Rubber Additive
The finer version of UHMW-PE is used as an additive in rubber compounding for improvement of sliding properties and durability of rubber components. Its addition makes the rubber wear-resistant and increases the working life of the product.
Grease
These finer particles, when added to greases and lubricants, act as micro-bearings inside the lubricating material, decreasing the coefficient of friction. The UHMW-PE spheres improve lubrication by enhancing the sliding properties of the grease. Therefore, they become an ideal choice to produce long-lasting, high-performance greases and lubricants, having high durability which reduce the wear on moving parts and eliminate squeaking noise. Long-lasting greases also reduce the need for frequent re-lubrication cutting down maintenance costs.
Coatings
Use of these particles as an additive in paints, printing inks and other industrial coatings improves their abrasion and chemical resistance, increases smoothness, and enhances their self-lubrication properties. When mixed with fillers and pigments, their excellent dispersion properties improve the overall properties of the coating.
These fine particles can be further used for producing low friction coatings. Low friction coatings produce durable, slippery surfaces and reduce surface wear. These coatings show better resistance to corrosion and are easy to clean. The coefficient of friction of surface coatings is reduced by its addition.
Polytetrafluoroethylene (PTFE) is commonly used to reduce friction coefficient of paints. PTFE, however, has poor dispersibility and tends to settle out. PTFE powder begins to settle out of the polyurethane-based paint within 24 hours due to the difference in specific gravity. Use of different UHMW-PE grades produces excellent dispersibility and stays uniformly dispersed in the coating even after 72 hours