Dynamic Viscosity Curve Generation and Transfer Point Calibration in Technical Molding
Calibrating transfer points via press-side viscosity curves optimizes fill pressure, cuts part mass variation, and locks in DIN 16742 tolerance bands.
Barrel Temperature Profile
Meaning
Injection moulding machine parameters dictate the distribution of thermal energy along the heating zones of an extruder cylinder. The establishment of a barrel temperature profile ensures that thermoplastic resin transitions from solid pellets to a homogeneous melt under controlled conditions.
Thermal Distribution
Viscosity consistency depends heavily on the gradual transition of the polymer as it travels through feed, compression, and metering zones. When the barrel temperature profile is too flat, un-melted pellets can bypass the compression zone and cause severe mechanical wear on both the screw and the barrel wall. A progressive increase in temperature from rear to front ensures uniform screw torque, which prevents pressure fluctuations and stabilises the melt front.
Melt Uniformity
Frictional heating within the polymer melt contributes more to the final melt temperature than the external heater bands. Adjusting the barrel temperature profile downward in the metering zone compensates for high shear heating. This prevents localized thermal degradation.
Cycle Efficiency
Cooling times in the mould are directly affected by the temperature of the entering melt. A barrel temperature profile that is unnecessarily high extends the required cooling time and increases the production cost of each part. Lowering the profile to the minimum processing threshold increases throughput without sacrificing part quality.