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Characteristics of insert injection molding technology


Insert molding (molding) refers to a molding method in which a pre-prepared insert of dissimilar materials is put into a mold and then resin is injected, and the molten material is joined and solidified with the insert to make an integrated product. Out-sert molding refers to a method of embedding injection molded parts on a part of a metal plate surface.

The above two forming methods are essentially the same.

Its characteristics are as follows:

1. The combination of easy formability and flexibility of resin and rigidity, strength and heat resistance of metal can be combined to make complex and exquisite metal-plastic integrated products.

2. In particular, using the combination of resin insulation and metal electrical properties, the molded products can meet the basic functions of electrical products.

3. The pre-molding combination of multiple inserts makes the post-engineering of product unit combination more rational.

4. Insert products are not limited to metals, but also cloth, paper, wires, plastics, glass, wood, coils, electrical parts, etc.

5. For rigid molded products and curved elastic molded products on rubber gaskets, after injection molding on the substrate to make an integrated product, the complicated operation of arranging the sealing ring can be omitted, making the automatic combination of subsequent processes easier.

6. Because it is the joining of the molten material and the metal insert, compared with the press-in molding method, the gap of the metal insert can be designed to be narrower, and the molding reliability of the composite product is higher.

7. Choose appropriate resin and molding conditions, that is, for products that are easily deformed and damaged (such as glass, coils, electrical parts, etc.), they can also be sealed and fixed by resin.

Characteristics of insert injection molding technology

8. Choose the appropriate mold structure, the insert product can also be completely enclosed in the resin.

9. After the insert is formed, it can also be made into products with hollow grooves after core hole processing.

10. With the combination of vertical injection molding machine, manipulator, and insert product aligning device, most of the insert molding process can realize automated production.

Precautions for design selection of automatic insert molding system

1. The molding of metal inserts is prone to uneven molding shrinkage, so the limit test of the shape and dimensional accuracy of important parts should be done in advance.

2. The metal insert is easy to deform and shift during the injection process, so full consideration should be given to the mold composition and the design of the mold shape that is easy to maintain the metal insert. For products whose insert shape cannot be changed, prior testing is indispensable.

3. When the arrangement of the metal inserts is separated and the conveyor is used, the contact between the metal inserts and the inserts and the vibrating ball will cause slight damage to the surface of the inserts, which will affect the quality of the product. The allowable limit range of its quality should be confirmed in advance.

4. The jaggedness, warpage, material thickness difference, diameter difference, and thickness difference caused by gold-plating processing of metal inserts should be measured in advance. On this basis, the matching selection design of the automation device and the design of the mold structure are carried out.

5. Predictable issues that restrict the mold structure such as the position of the mold gate, the molding cycle, etc., should be resolved in advance or corresponding improvement measures as much as possible.

6. It should be confirmed whether the metal insert needs to be preheated or dried. The purpose is to ensure product quality and stability of molding.

7. The various detection devices installed in the mold are used to ensure the stability of the molding action under the influence of environmental conditions such as heat, force, and vibration of the mold, and should be confirmed whether to use.

8. In order to avoid the accumulation of small pieces of metal inserts and molded products in the mold cavity, an air blowing device can be assembled if necessary.

9. Due to the high investment price of system equipment, it is necessary to fully consider whether it can ensure the production volume after equipment operation before adopting it. When using a dedicated machine, it is necessary to ensure that the product can be continuously produced without a formal update for several years.

10. When a general-purpose machine is used, it is necessary to confirm how many types of inserts are produced in combinations of more varieties and less batches. If mass production cannot be guaranteed as a whole, it is difficult to recover the fixed assets of each product. In this case, it is necessary to replace a part of the device to adapt to the variety update requirements within a certain range.

11. The precision of the metal insert product, the shape of the insert, whether the mold is beneficial to the insert molding and the shape of the molded product, etc., determine the molding rate, productivity and molding cost conditions of the insert.

12. The effective combination of injection machines, molds, and automation devices and how to function in a short time are the keys to determining the automatic insert molding system. It is recommended to consult with manufacturers with considerable performance and experience to discuss options.

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