Colorants used in masterbatches must fully account for the compatibility of the colorant, the plastic carrier resin and other formulation additives. Key selection criteria: the colorant must not react with the resin or other additives, and must have excellent solvent resistance, low migration and good thermal stability.
PBT (polybutylene terephthalate) is widely used in electronics and electrical equipment: circuit breakers, electromagnetic switches, flyback transformers, appliance handles, connectors and housings. It is also used in the automotive industry and consumer goods manufacturing.
Melt temperature is a critical parameter in injection molding. It can be measured at the injection machine nozzle or estimated using the air-shot method. Barrel temperature settings must account for the melt temperature, screw speed, back pressure and injection volume.
Leakage is a common fault in injection molding machines, caused by pressure differences and clearances between parts as fluid moves through hydraulic components and piping. Harsh operating conditions also negatively affect machine sealing. We look at the causes and remedies.