Publisher: Administrator Date: 2023-11-02
Advantage
1. Save raw materials and reduce costs. (Although the cold material head can still be recovered, it is necessary to accumulate some cold material heads in order to adhere to normal operations due to factors such as human resources and the mixed share of recovered materials, which constitutes the retention of funds.)
2. Shorten the molding cycle and increase machine power. Due to the lack of cooling time constraints in the runner system, the workpiece can be ejected in a timely manner after solidification. Many thin-walled parts produced using hot runner molds can have a molding cycle of less than 5 seconds
3. Advance the quality of the product (During the hot runner mold forming process, the temperature of the plastic melt is accurately controlled in the runner system. Plastic can flow more uniformly into each mold cavity, resulting in parts with common quality.)
4. Advance automation level. (After plastic is formed by a hot runner mold, it becomes a product without the need for trimming the gate or retrieving the cold runner for processing. Many foreign product manufacturers combine the hot runner with automation to greatly increase production power.)
However, each technology has its own shortcomings, and hot runner technology is no exception:
1. The mold structure is messy, with high cost and high protection costs.
2. The process will only be stable after a period of time when the machine is turned on, resulting in a large amount of initial waste.
3. When there are defects such as melt leakage and heating elements, it has a significant impact on the production quality and progress.
The third disadvantage mentioned above can be reduced by buying high-quality heating elements, hot runner plates, and nozzles and carefully protecting them during use.
Planning Procedure
1、 According to the structure and application requirements of the plastic parts, recognize the orientation of the feeding port. As long as the structure of the plastic part allows, the nozzle and nozzle head inside the fixed mold insert do not interfere with the forming structure, and the feeding port of the hot runner system can be placed in any direction of the plastic part. The feeding port orientation for conventional injection molding of plastic parts is generally selected based on experience, analyzing the cooling effect of various parts of the mold, and recognizing the more ambitious feeding port orientation.
2、 Recognize the nozzle head method for hot runner systems. The application characteristics of plastic parts and products are crucial factors in selecting nozzle head methods. The production batch of plastic parts and the cost of mold construction are also important factors in selecting nozzle head methods.
3、 Based on the production batch of plastic parts and the tonnage of injection equipment, the number of cavities per mold is recognized.
4、 Based on the recognition of the mold structure standards based on the plastic part structure, the nozzle specification length series standards are selected based on the thickness standards of the fixed mold insert and the fixed template, and the thickness standards and other related standards of the fixed template are finally adjustedhot runner systemRelevant standards.
5、 According to the shape of the hot runner plate, recognize the shape of the hot runner fixed plate, arrange power line lead slots on the plate, and plan a satisfactory cooling water loop near the hot runner plate, nozzle, and nozzle head.
6、 Complete the planning drawing of the plastic mold for the hot runner system.