One particularly versatile family of high-performance engineering plastics comprises Ultra High Molecular Weight Polyethylenes (UHMW-PE), represented in Australia by Dotmar EPP’s Polystone range.
Different formulations of these engineering plastics cannot only provide the perfect performance for particular jobs, but also often cut costs compared with specialist metals – as well as providing low coefficients of friction.
Uses of UHMW-PE cover a diverse spectrum of applications, including mining and mineral processing equipment, civil engineering and earthmoving equipment, and transport-related applications, including truck trays, bins and hoppers.
Polystone UHMW-PE materials are odourless, non-toxic and tasteless. Made of unusually long molecular chains, these chains serve to transfer load more effectively to the polymer’s backbone by strengthening intermolecular interactions. This results in one of the most durable thermoplastic polyethylenes on the market.
Simply put, Polystone UHMW-PE has a rare ‘DNA’. While every thermoplastic stands out with one or two key benefits, Polystone UHMW-PE possesses several. When compared with traditional polymers, it has the highest resistance to abrasion and chemical erosion, while at the same time maintaining product integrity under higher impact/stress situation.
Additionally, their self-lubricating character yields a non-stick surface comparable with PTFE. Put all these benefits together with its low moisture absorption character and its low coefficient of friction and you have the most durable plastic available anywhere ? and ready to go into service just about anywhere.
However, it is important for the engineer and designer to appreciate that no single product in the Polystone UHMW-PE family exhibits all of the desirable characteristics that a customer looks for in a polymer. In selecting the perfect Polystone for particular applications, it pays to know the difference between the major categories.
Polystone 7000
Polystone 7000 is the general purpose UHMW-PE. It is suited to engineered applications where its unique properties of excellent impact strength, wear and abrasion resistance are required. Its key features and benefits include:
? Impact strength – it is virtually unbreakable
? Light weight – easy to handle without special equipment
? Physiologically inert
? Electrical insulation – it is a good insulator
? Weatherproof – it doesn’t absorb water
? Chemical resistant – resists corrosive chemicals
? Abrasion resistant – rated better than carbon steel for sliding abrasion applications
? Low coefficient of friction – it does not require lubrication
Polystone Ultra
Polystone Ultra is specifically formulated for improved sliding characteristics, enhancing its resistance to wear, abrasion and environmental stress cracking.
This material is ideally suited to flow promotion and mechanical transmission support products. Sharing the key advantages of general purpose UHMW-PE, this material is engineered to deliver top performance in applications such as:
? Bulk storage flow promotion
? Bulk storage wear liners
? Mechanical chain guides
? Mechanical wear strips
Polystone Ultra not only reduces friction, wear, clogging and noise compared with metal, but also never needs lubrication.
Polystone 7000SR
Polystone 7000SR is specifically formulated to suit applications where reduced static is required in handling of bulk materials and other high-speed sliding applications. It is particularly suited to:
? Bulk storage flow promotion
? Bulk storage wear liners
? Coal handling
Polystone M Flametec
This is the first flame-retardant and anti-static UHMW-PE that is:
? Halogen free
? Antimony free
? No strong smoke emission
? Non-toxic smokes/gases
? Fire Rating – achieved UL94 class V0
Applications for which it is designed include underground mining, scraper blades, hopper liners, liner beds, wear profiles, impact slider blades and chain guides.
Polystone Matrox
Polystone Matrox is a specially formulated premium grade UHMW-PE. Its unique combination of properties includes outstanding abrasion resistance, excellent non-stick properties and excellent corrosion resistance.
Polystone Matrox is ideally suited for the lining of hoppers, bins and earth moving equipment to promote flow, reduce hang-up and carry-back.
This new premium-grade polymer alloy liner is specifically designed for lining hoppers, chutes, bins, dump truck bodies, dozer blades and many other applications requiring solutions to sliding, abrasion and release of sticky, hard-to-move materials. Matrox delivers best-case production flow rates at optimum wall angle.
Its formulation achieves an extremely low coefficient of friction. Strict measurement of results during its development ensures an extremely high-quality product for use in many demanding bulk solids handling industries, including mining, minerals handling and quarrying.
Aldo Mostacci is Engineering Manager for plastics specialists Dotmar EPP.