Determining Hydrolytic Degradation Thresholds in Virgin Resin Feedstocks
Hydrolytic degradation thresholds require drying virgin polyesters below 0.02 percent and polyamides below 0.10 percent water before melt processing.
Thermal Processing
Meaning
Manufacturing operations that utilize controlled heat and pressure to melt, shape, and solidify thermoplastic materials define the core conversion methods of the plastics industry. The efficiency of thermal processing dictates the output rate, part quality, and energy consumption of extrusion and injection moulding facilities. This activity must balance the heat required for melting against the risk of thermal degradation.
Melt Control
Precise temperature zones along the extruder barrel are required to systematically melt the polymer while preventing localized overheating. During thermal processing, the shear heat generated by the rotation of the screw provides a significant portion of the thermal energy needed to achieve a uniform melt. This heating must be monitored closely to prevent polymer chain scission and the associated loss of mechanical properties in the final product.
Cooling Phase
Heat removal from the shaped melt represents the primary constraint on the overall cycle time of the moulding process. Inefficient or uneven cooling leads to internal stresses, warpage, and dimensional instability in the finished component. Mold temperature controllers are used to regulate this cooling rate and optimize the crystalline structure of the polymer.
Operational Efficiency
Optimizing the heating and cooling cycles within these manufacturing operations reduces both the energy footprint and the production cost of the parts. Advanced simulation software helps moulders design cooling channels that maximize heat transfer and minimize the time needed for the material to solidify.