Plastic and Pet injectiopn molding: Recent Episodes
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These silver streaks are also known as spots or cracks.
This is because the stress in the vertical direction of the tensile stress is generated, and the weight of the polymer molecule is expressed by the heavy flow orientation and the difference in the folding rate of the unoriented portion. Follow the Plastic injection mould manufacturers to see what solutions: 1, improve the flow and cavity exhaust conditions. 2. Clean up possible blockages in the nozzles, runners, and gates. 3. Increase the injection pressure and reduce the injection speed. 4. Increase or decrease the pre-plastic back pressure and reduce the screw speed. 5. Eliminate the interference of gas and other impurities, and fully dry the plastic. 6. Reduce the material temperature, adjust the temperature of the barrel in stages, and increase the mold temperature appropriately. 7. Shorten the molding cycle. After demolding, the annealing method can be used to eliminate the silver streaks: the polystyrene is kept at 78 ° C for 15 minutes, or at 50 ° C for 1 hour, and the polycarbonate is heated to above 160 ° C for several minutes.
Plastic injection moulds are basically divided into static molds and dynamic molds. When some molds must be demoulded, the static mold release mechanism must be added. The static mold generally consists of a sprue bushing, a backing plate and a template. If the general product does not have a core support, the shrinkage should be larger. In practical applications, the wall thickness and structure of the product and the size and orientation of the temperature and pressure during injection molding are determined. The use of the sprue bushing is conducive to the installation of the mold, easy to replace, without polishing. The Bottle mould manufacutrer is only a rough introduction in this article. The simple mold (especially the mold without the core in the static mold) can also be used without the backing plate. The structure of the movable mold is generally a movable formwork, a movable formwork plate, a demolding mechanism, and a die and an installed fixed plate. In the injection molding machine, the sprue bushing on the side of the injection head is a static mold. The sprue bushings are generally standard and are not recommended for special reasons unless cancelled. Product shrinkage is also related to the shape of the product, gate, thermal expansion and contraction, temperature, holding time and internal stress.
Some special mold sprue sleeves can be drilled or cut with a taper line. Nowadays, various complex injection molded structural parts, functional parts and special-purpose precision parts have been widely used in all fields of national economy such as transportation, transportation, packaging, storage and transportation, communication, construction, home appliances, automobiles, electronics and aerospace..
Since it is a chain structure, the direction of shrinkage of the plastic during processing is also related to the orientation and cooling shrinkage of the molecular chain of the polymer under stress, and the shrinkage in the flow direction is more than the shrinkage in the vertical direction. Generally, the range of shrinkage provided in the book is wide. An important product that is indispensable. Just use a thicker template.?Introduction to the main points of the design principle of injection mold
Injection molding is an important method in plastic moulding processing, and injection molding of thermoplastics dominates the injection molding process