Customized Pet Preform Injection Mold Self Lock Needle Valve Preform Mold

Product Parameters

Technical Analysis of the Preform Mold

The preform mold plays a crucial role in the plastic packaging industry and is a key part of manufacturing various plastic bottles. A high-quality preform mold requires comprehensive consideration from material selection to the configuration of the hot runner system. The following is an in-depth analysis of a high-precision preform mold that uses a P20 mold plate, S136 or 632 inserts, and is equipped with a needle valve hot runner system.

I. Material Selection

1. P20 Mold Plate

P20 is a pre-hardened plastic mold steel with an out-of-factory hardness ranging from HRC25 to 30. This characteristic greatly simplifies the mold processing procedure. Without the need for complex heat treatment, it can be directly machined, significantly shortening the mold manufacturing cycle. Through vacuum degassing and refining treatment, the purity of P20 steel is remarkably improved. Not only does it have stable mechanical properties, but it also shows good adaptability in subsequent polishing and texturing processes. In the preform mold, the P20 mold plate, with its excellent strength and rigidity, ensures that the mold maintains stable dimensional accuracy during the frequent opening and closing operations in production, providing strong support for long-term and large-scale preform production.

2. S136 or 632 Inserts

- S136: This is a high-quality plastic mold steel with a uniform structure and an extremely low impurity content. After quenching and tempering treatment, its hardness can reach 45 - 48HRC. It not only has excellent wear resistance but also exhibits outstanding dimensional stability during the quenching process, laying a solid foundation for the machining of high-precision preform inserts. The remarkable corrosion resistance of S136 makes it an ideal choice for preform mold inserts that come into contact with various chemical substances. It can effectively resist the erosion of additives in plastic raw materials, mold release agents, and corrosive substances that may be generated during the molding process, greatly extending the service life of the inserts and ensuring the long-term stable operation of the mold.

- 632: This is also a mold steel with excellent performance, featuring good machining performance. It can ensure machining accuracy while significantly improving machining efficiency and reducing machining costs. 632 achieves a good balance between hardness and toughness, which can not only meet the wear resistance requirements of preform molds but also effectively avoid the cracking problem of inserts caused by excessive brittleness. In addition, its heat treatment process is relatively simple and easy to control, providing greater convenience for mold manufacturing.

II. Needle Valve Hot Runner System

1. Working Principle

The needle valve hot runner system precisely controls the timing and flow rate of the plastic melt entering the cavity by accurately controlling the opening and closing of the needle valve. During the injection molding stage, the needle valve opens, and the plastic melt smoothly flows into the cavity under the pushing force of the injection pressure. In the holding pressure and cooling stages, the needle valve closes, effectively preventing the backflow of the plastic melt and ensuring the quality of preform molding. This precise control method greatly reduces the gate marks, improves the appearance quality of the preform, and also reduces the scrap rate and increases production efficiency.

2. System Advantages

Compared with the traditional open hot runner system, the needle valve hot runner system significantly improves the molding precision of the preform. Through the precise control of the needle valve, the plastic melt can be uniformly filled into each cavity, avoiding dimensional deviations and quality defects caused by uneven filling. In a multi-cavity preform mold, the needle valve hot runner system can ensure that the pressure and temperature of the plastic melt in each cavity are consistent, effectively improving the consistency and yield rate of the preforms. In addition, the needle valve hot runner system reduces the generation of waste, not only reducing the consumption of raw materials but also effectively lowering the production cost, which is in line with the concept of green production.

3. Realization of High Precision Requirements

To achieve the high-precision control of the needle valve hot runner system, it requires the support of an advanced temperature control system and a pressure control system. The temperature control system can precisely control the temperature of the hot runner plate and the nozzles, ensuring that the plastic melt is always in the optimal flowing state. The pressure control system can monitor and adjust the injection pressure in real time to ensure the stable and reliable filling process of the plastic melt. In addition, the manufacturing precision and installation precision of the needle valve are also crucial. It is necessary to strictly control the dimensional tolerance and surface roughness of the needle valve to ensure that the needle valve can open and close flexibly and accurately.

III. Assurance of High Precision

1. Machining Process

From the mold plate to the inserts and then to each component of the hot runner system, high-precision machining equipment and advanced machining processes are required. The application of equipment such as CNC machining centers, EDM machines, and slow wire electrical discharge machines can ensure the dimensional accuracy and surface quality of the mold parts. During the machining process, strictly follow the machining process specifications, and through multiple measurements and corrections, ensure that the machining accuracy of each part can meet the design requirements.

2. Assembly and Debugging

The assembly and debugging of the mold are key links to ensure its precision. During the assembly process, strictly control the fitting accuracy of each part, and use high-precision positioning pins and keys to ensure the accurate relative position between the parts. After the assembly is completed, conduct a comprehensive debugging. Make detailed adjustments and optimizations to the opening and closing movement of the mold, the temperature and pressure of the hot runner system, and the action of the needle valve to ensure that all performance indicators of the mold can meet the design requirements.

This preform mold, which uses a P20 mold plate, S136 or 632 inserts, and is equipped with a needle valve hot runner system, can produce high-precision and high-quality preforms with its reasonable material selection, advanced hot runner system, and strict precision control, meeting the growing needs of the plastic packaging industry.

Product Description

	ADVANTAGE   1) Saving 10%-30% cost than others.   2)  Direct factory price   3) Life:3, 000, 000 time   4) 2D and 3D provided   5) Quick T1  time: 25-40 days   6) More than 15 years experience
	MOULD  MANUFACTURE  PROCESS   Cap Mould : grinding→fly-cutter →CNC   Milling→drilling→lathe→boring lathe→electric pulse →fine   fly-cutter→polish→electroplate→install

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