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Two Important Factors Affecting The Molding Of Plastic Lunch Boxes
- Oct 09, 2017 -

The temperature is an important condition for the successful molding of the extruded plastic lunch box. From the powdered or granular solid material, the high temperature product is extruded from the head and continues to undergo a relatively complex temperature change process. Strictly speaking, the extruded plastic lunch box molding temperature should refer to the plastic melt temperature, but this temperature is largely dependent on the barrel and screw temperature, a small part of the mixture from the barrel generated when Of the friction heat, so often with the cylinder temperature approximation that the molding temperature. 

The temperature adjustment of the barrel is achieved by the extruder heating and cooling system and the temperature control system. The head temperature must be controlled under the thermal decomposition temperature of the plastic, the temperature of the plastic lunch box mold is lower than the head temperature, but to ensure that the plastic melt has a very good flow performance. Plastic meal box molding process of temperature fluctuations and temperature difference, the plastic parts will produce residual stress, the intensity of each point is not uniform, the surface dark and dull and other defects.

In the process of extruding the plastic lunch box, due to the material flow resistance, the screw groove depth change and the filter, the filter plate and the die mold obstruct, so along the cylinder axis direction, inside the plastic will produce some pressure, this kind of The pressure is an important condition for the plastic to become a homogeneous melt and to obtain a compact plastic. As with temperature, the pressure fluctuates over time, and this fluctuation also has an adverse effect on the quality of the plastic lunch box. The change in screw speed, the instability of the heating and cooling systems is the main cause of pressure fluctuations. In order to minimize the pressure fluctuations, reasonable control of the screw speed, to ensure the heating and cooling device temperature control accuracy.