Insert Mold

Common Manufacturing Methods of Injection-molded Insert Products

Generally, there are two methods for making injection molded insert parts:

1. Place the insert into the mold before injection molding, and then inject together, due to most of the inserts are manually placed into the mold, this method will reduce the production efficiency of injection molded products, according to the current production technology conditions, it is gradually moving towards automatic production.

2. Putting the insert into the plastic part after finishing the injection by the welding process, common press-in methods include an ultrasonic press-in method and heating press-in method. In order to make the positioning accurate, a tapered hole is often reserved at the embedded part, the advantage of this method is higher production efficiency, but requires more types of equipment, more processes, and may cause flash around the insert.

Design Considerations for Insert Mold

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. During the injection process, the metal insert is easy to deform and mismatch, 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 which will need to make some testing in advance.

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 insert surface and affect the quality of the product, the quality should be confirmed limit range 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 items 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.

6. It should be confirmed whether the metal inserts need 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 when the mold is affected by environmental conditions such as heat, force, and vibration, it should be confirmed whether it is used.

8. The part of the insert placed in the mold should be designed to be cylindrical in order to make and fixing of metal inserts, so that it is convenient to place the insert in the relevant positioning hole on the mold, such as the placement of the insert the angle is required, and a positioning structure is also required to ensure that the insert can be quickly and reliably positioned when placed in the mold.