DOTMAR EPP has released the Ertalon and Nylatron ranges of rod, sheet, and tube cast nylon products. Standard and modified cast nylons are available.
Typical parts developed in these materials including rollers and guides, bushings and bearings, gears and sprockets, sheaves and idlers, wear pads, load pads. They can also be used for slap blocks such as those used to prevent damage to metal surfaces from cables moving past them.
Cast nylon can be used in nearly all industries, including agriculture, cranes, food processing, manufacturing, timber processing, pulp and paper, materials handling, mining equipment, railways, shipping, transportation, and waste water treatment.
Nylon casting differs from injection moulding or extrusion in that it produces a product by polymerisation right in the mould. The extrusion and moulding processes, by comparison, simply reshape a pre-polymerised resin.
Polymerising in the mould produces a material with higher molecular weight and crystallinity. This leads to better dimensional stability, easier machining, and higher compressive and tensile strengths than those achieved by extruding or moulding.
The process of polymerisation produces a chemical chain reaction to form nylon 6. Additives such as plasticisers, lubricants, and heat stabilisers can be used to modify or improve the material's performance. Plasticisers improve the material's impact resistance while reducing tensile and compressive strengths.
Internal lubricants used in materials such as Ertalon LFX reduce the material's coefficient of friction. They allow materials to perform at pressure/velocity levels five times higher than unlubricated nylons, without the use of additional oils or greases in application.
The casting process can also be used to produce large near-net-shape parts or custom cylinders that are close to finished part dimensions. These require minimal post-machining to achieve a finished part, with lower stress and better dimensional stability than parts machined from solid blocks.
Cast nylons allow free machining on conventional machine shop equipment without the use of coolants. Drilling operations still need to use coolant and all tools must be properly ground with low rake and high clearance angles. Tools must be kept sharp to prevent grabbing, which produces chatter or rubbing, causing overheating, dimensional instability and possible part failure problems. Machining tolerances in general are higher than those used for metal parts.
Cast nylons find greatest use as a cost-efficient replacement for bronze and in applications involving medium speed and medium temperatures in environments involving high abrasion and high impact.