Meaning
Progressive material degradation resulting from mechanical sliding contact governs component lifespan in unlubricated plastic moving assemblies. In polymer gear trains and sliding tool components, tribological wear defines the cumulative loss of material caused by surface adhesion and abrasion at contacting surface asperities. Datasheet tensile or flexural properties cannot predict friction-induced surface failure because localized frictional heating lowers resin surface hardness during continuous motion.
The boundary of this surface degradation regime transitions into thermal melting when sliding speeds and contact pressures exceed the material pressure-velocity limit.
Abrasive Filler Mechanism
Reinforcing fillers such as glass fibers or mineral powders drastically accelerate mechanical abrasion on mating metal or plastic components. When molding abrasive compounds, tribological wear erodes barrel liners and mold gate insert surfaces, altering part dimensions over extended production runs. Molders use hardened tool steels or specialized physical vapor deposition coatings to withstand abrasive resin flow.
Contact Surface Friction
Frictional heat generated at sliding interfaces softens semi-crystalline polymers, promoting adhesive material transfer between mating parts. Elevated tribological wear generates fine polymer debris that clogs sliding mechanisms and contaminates cleanroom moulding operations. Internal lubricants like polytetrafluoroethylene or silicone additives reduce surface friction coefficients, extending part operational life in unlubricated environments.
Regrind material containing degraded polymer chains exhibits lower surface strength, accelerating wear rates compared to virgin resin formulations.
Velocity Pressure Boundary
Operating conditions exceeding specified pressure-velocity limits cause rapid thermal softening and catastrophic surface scoring. System designers select self-lubricating engineering thermoplastics to maintain structural stability without liquid lubricants.
