Plastic Molding Manufacturer | China Custom Plastic Parts Services Contact@china-plasticparts.com
Author: MULAN -Plastic Molding Manufacturer
1. Mold overview: Everyone is familiar with the saying that mold is the mother of industry, the importance of mold is more and more recognized by people, and mold design and manufacturing technology have also made great progress. The innovative design of mold processing technology, the wide application of various new mold materials, and the standardization and specialization of mold parts force us to adapt to the development of molds more quickly and accurately in design. The improvement of speed requires that the design stage be delivered to the post-production section in about 3 days; the improvement of precision requires that the processing method of each component be considered during the design process, and the processing method with high precision and low processing cost should be adopted as much as possible.
Accuracy and speed improvements go hand in hand. An increase in speed will inevitably require an increase in precision; an increase in precision will inevitably lead to an increase in speed. 2. Basic composition of plastic mold: Plastic mold consists of seven systems: guide system, support system, molding parts system, pouring system, cooling system, ejection system and exhaust system.
The mold composed of the above system enters the mold cavity through the pouring system and the gate, and is cooled by the cooling system after filling and maintaining pressure. After the finished product is condensed and solidified, it is ejected by the molding part and the ejection system to complete the molding cycle. 3. Clamping guide system: In the plastic mold, the mold guide mechanism is mainly used to ensure the accurate cooperation between the two parts of the mold and the mother mold or other parts in the mold, so as to ensure the shape and dimensional accuracy of the plastic product, and avoid various parts in the mold. Collisions and interference of components. The basic requirements for the design of the mold guide mechanism are accurate positioning, accurate guidance, sufficient strength, rigidity and wear resistance.
The guide mechanism includes a guide post guide mechanism and a cone (straight face) positioning mechanism. 4. Support system: The male and female templates, upper and lower fixing plates, mold feet, support columns (SP), stop pins (STP) and other components in the plastic mold are called support components. The supporting part is assembled with the mold guiding mechanism device to form the injection mold base.
The function of the mold base is to install and fix various functional structures in the injection mold. Therefore, when designing an injection mold, it is necessary to ensure that the various supporting parts have sufficient strength and rigidity. The male and female templates play the role of various functional mechanisms such as installing and fixing molding parts, mold guiding mechanisms, and ejection and demoulding mechanisms in the mold.
The upper and lower fixing plates support the male and female templates and the parts installed on the male and female templates, and the mold can be installed on the molding machine. The mold foot and the support column (SP) lean against between the common formwork and the lower fixing plate, and can form a movement space for the ejection and demoulding mechanism. Stop selling (STP) is to adjust the flatness of the ejector ejection mechanism.
V. Molding parts system: The molding parts system is mainly designed to make the finished product injection molding smoothly and obtain ideal products. At present, the more common situations are: The mechanism for processing the external barbs of the finished product (slider mechanism) The mechanism for processing the internal barbs of the finished product (slant pin mechanism) A channel for flow through the mold in front of the cavity. The basic principle of gating system design: while satisfying the quality of plastic products, it is also conducive to improving the molding speed and shortening the molding cycle.
7. Cooling system: The mold cooling system includes: cooling water channel, mold temperature controller and heating components. The function of setting the cooling water circuit: 1. In order to improve the quality of injection molded parts, the control of mold temperature is mainly reflected in the influence of surface finish, residual stress, crystallinity and thermal bending. 2. Shorten the molding cycle, 80% of the molding cycle is used for cooling.
A well-designed cooling system in the early stage of the mold is a necessary condition for improving production efficiency. 3. Cool large sliding parts to avoid jamming during work. 8. Ejection system: Product ejection is the last link in the injection molding process.
When the product is solidified in the mold, an effective method is needed to eject it from the mold. The quality of the ejection will determine the quality of the product. Therefore, the ejection of the product cannot be ignored.
In addition, the product must not be deformed, whitened, or broken during the ejection process. 9. Exhaust system. The role of the exhaust structure in the process of plastic filling and injection mold cavity, in addition to the original air, there are water vapor evaporated by the plastic at the injection temperature, low molecular volatile gas generated by local overheating and decomposition of the plastic, and volatilization of plastic additives (or Gases produced by chemical reactions) and gases released by hardening of thermosetting plastics.
If these gases cannot be discharged from the mold cavity, it will affect the quality of the product after molding and demoulding. Therefore, when designing the cavity structure and gating system, it is necessary to consider how to set up the exhaust system to ensure that the product will not have quality problems due to poor exhaust. The form of the exhaust groove.
The exhaust groove needs to be processed into a curved shape, and the cross section gradually increases from thin to thick. This can reduce the kinetic energy when the plastic melt overflows from the exhaust groove, reduce the flow velocity when the plastic melt overflows, and prevent work-related accidents. The opening position of the exhaust slot.
Generally, it needs to be confirmed after the mold trial, but for large molds, it is often necessary to open the exhaust groove before the mold trial, and then adjust after the mold trial. For more information about injection molds, please visit the official website of Xingye: http://www.dgxingyesj.com.