During the injection molding process of the modified engineering plastics, the nozzle temperature is too low and there is residual cold material, the pressure loss is large, and the surface of the product is prone to cold material marks or stress marks. It is too high to overflow the rubber, and there is drawing, modified plastic injection molding. The common solutions for forming wire drawing are:
(1) drop mouth temperature; (2) increase the withdrawal position; (3) reduce the back pressure; (4) use automatic seating; (5) between the nozzle and the Tsui Tsui add a piece of paper or metal sheet;- --- In fact, is to reduce the actual diameter of the nozzle; (6) Tsui Tsui Riga steel;
Analysis 1: There are two methods for withdrawal: before and after withdrawal; there are also two methods for controlling them - time and location (some machines are controlled by the front and rear sensors on the injection platform, and most of them are input on the control panel). Control; most of the front pumping is used in the case of particularly high pressure holding pressure. Depending on the characteristics of the acting force and the reaction force, the melt at the front end of the screw exerts a large reaction force on the screw after the external pressure (large holding pressure) is eliminated. Let the screw retreat, lead to the 'offside' of the screw, measurement is not accurate; most of the back pumping is to respond to high speed back feed, but also afraid of 'offside' and protect the back material seal (high-speed operation to sudden stop, is very much against mechanical conventions).
Analysis 2: To understand that the screw is out of position, it is necessary to first know the progress of the backward movement of the screw melt. The screw retreat is done under uniform feeding, compression, conveying, and metering. If the material is not eaten or eaten, it cannot reach the actual amount. However, the actual amount of measurement and demand will be different. In short, the so-called screw offside is that in the measurement process, the screw does not have a rotating measurement, but a smooth return to a certain distance. Inaccurate measurement.