Influence of temperature on the vertical injection mold injection molding machine

Date：2014/11/21 11:45:42

A hot mold surface so that the plastic surface of the long-lasting liquid, a pressure in the cavity is sufficient. If the vertical injection molding machine to fill the cavity and skin appear before the freeze sclerosis, cavity pressure can be flexible plastic pressure on the metal, then copy the cavity surface is high. Another point of view, if the cavity under low pressure into the plastic suspended, regardless of how short time, then it's a slight contact with the metal can cause stains, sometimes referred to as the gate stains.

         For each type of plastic with plastic parts, there is a mold surface temperature limits, vertical injection molding machine exceeds this limit may occur one or more adverse effects (eg: flash component can overflow). The mold temperature higher flow resistance means less. On many of the injection molding machine, which naturally means faster flowing water, the gate with the cavity, due to the injection flow control valve is not used to correct the change, filling vertical injection molding machine with a faster runner type in cavity results in a higher effective pressure. May cause flash flash. Because MCP-HT450 hotter model does not freeze plastic before the high-pressure side of the formation into the overflow area, melt in the top of the bar around burr burr and overflowed into the dividing line clearance. This suggests the need for good injection rate control, and some modern flow control programmer indeed able to do this.

         Typically, vertical injection molding machine mold temperature rises will reduce the plastic in the cavity morning condensation layer, so that vertical injection molding machine of the molten material in the cavity flow more easily, leading to greater weight parts with better surface quality . At the same time, enhance the vertical injection molding machine mold temperature will make the parts tensile strength increased. Many vertical injection molding machine mold, especially in engineering thermoplastics, and at relatively high temperatures, if the mold is no insulation, the heat lost to the air with the injection molding machine can be easily lost with exactly the same cylinder plunger much. So you want to die with board insulation, if possible, the mold surface insulation. If considering using hot runner mold, try to reduce the thermal path between the cooling section with the heat of the injection molded parts exchange. This method can reduce the energy loss with the preheat time.

         The need for temperature control

         (1) Temperature control of the formability of the target and as

         Appearance of molded products, materials, physical properties, forming loops, etc., affect the temperature of the mold core subject, which is quite remarkable. General molding conditions, mold core temperature continues to lower the number of ideal injection can improve, but with the shape of the molded product (mold core structure) and finished type of material relating to the molding cycle is also necessary to enhance the register depends on the filling of the mold core temperature.

         (2) to prevent the temperature control should Masterpiece

         This is a molded product material issues, this requirement only ※ cooling rate. Into cold indeed a short time, even if there is still a part of hardening a soft part of the occasion, can still avoid the stress caused by uneven shrinkage. That is the proper cooling of the temperature control can improve stress properties.

         (3) the degree of crystallinity of the molding material adjustments to make the Temperature Control

         Polysulfide ammonia (nylon), polyvinyl acetate, a few fat, polypropylene and other crystalline material adjustment to the degree of crystallinity, and improved mechanical properties, generally require a higher mold core temperature.

【Return】