What is the injection molding process of polyethylene PE?
What is the injection molding process of polyethylene PE?Polyethylene (PE) is a common plastic material, because of its excellent performance, low cost and other characteristics, widely used in various fields. In the injection molding industry, polyethylene PE is also one of the common raw materials.
What is the injection molding process of polyethylene PE? Polyethylene (PE) is a common plastic material, because of its excellent performance, low cost and other characteristics, widely used in various fields. In the injection molding industry, polyethylene PE is also one of the common raw materials. The following is a detailed introduction to the polyethylene PE injection molding process and relevant points, I hope you have a better understanding of the polyethylene injection molding process.
1, raw material processing
First, the polyethylene particles need to be pre-treated, such as drying or mixing other additives (such as color masterbatches), in order to achieve better molding results. At the same time, it is necessary to choose the appropriate injection molding machine and mold, and determine the parameter setting of the molding machine according to the size, shape, quantity and other factors of the parts.
2, polyethylene injection molding process
(1) Mold design: First, we need to design a suitable mold according to the requirements of the product. Molds can be designed and optimized using computer aided design (CAD) software.
(2) Loading: Put the pre-treated polyethylene particles into the hopper in the injection molding machine.
(3) Heating and melting: Through the mold locking system of the injection molding machine, the mold is aligned with the injection system and closed. Then enter the heating melting stage, it is necessary to control the melting temperature, pressure and time parameters, so that the polyethylene particles melt into a liquid state in the injection cavity.
(4) Injection molding and pressure maintenance: After the completion of melting, the injection molding machine begins to inject liquid polyethylene into the mold. After the injection is completed, a certain amount of pressure should be maintained to ensure that the filling material fully fits the mold.
(5) Cooling curing: After the completion of pressure maintenance, the injection molding machine will no longer apply any pressure. The polyethylene will be cooled quickly in the mold, thus curing quickly.
(6) Mold opening and unloading: under the control of the injection molding machine, the mold is separated and the molded parts are pushed out of the mold. At the same time, the mold needs to be reset for the next fill.
(7) Post-treatment: post-treatment operations such as cleaning, dressing and quality inspection are carried out on the finished products to ensure that the products meet the quality standards.
3, polyethylene molding parts design points
When performing polyethylene PE injection molding, the following aspects need to be considered:
(1) Product size and shape: large and complex shapes require the use of large injection molding machines and molds.
(2) Product wall thickness: related to the melting fluidity of polyethylene, too large or too small wall thickness has an impact on molding.
(3) Raw edge treatment: Because polyethylene is soft and easy to produce raw edge, attention must be paid to treatment.
(4) Shrinkage rate: Because there is a certain shrinkage rate in the curing process of polyethylene, it is necessary to reserve enough to make the product size meet the design requirements.
In summary, the polyethylene PE injection molding process mainly includes raw material treatment, heating and melting, injection molding and pressure maintenance, cooling and curing, mold opening and unloading steps. At the same time, factors such as wall thickness, raw edge treatment and shrinkage rate need to be considered in product design to ensure product quality and production efficiency.