Insert molding
Insert molding refers to the molding process in which resin is injected after the pre prepared inserts of different materials are filled into the mold, and the fused materials are joined and solidified with the inserts to make an integrated product. Injection molding on the substrate refers to the process of inserting injection molded parts into the local surface of metal plate.
Its characteristics are as follows:1. The combination of the formability and bending of resin with the rigidity, strength and heat resistance of metal can make the complex and exquisite metal plastic integrated products.
2. In particular, the combination of the insulation of resin and the conductivity of metal is used to make the molded products meet the basic functions of electrical products.
3. The pre forming combination of multiple inserts makes the post engineering of product unit combination more reasonable.
4. Inserts are not limited to metals, but also cloth, paper, wire, plastic, glass, wood, coil, electrical parts and so on.
5. For the rigid products and the bending elastic products on the rubber sealing pad, after the integrated products are made by injection molding on the substrate, the complex operation of arranging the sealing rings can be omitted, which makes the automatic combination of the subsequent processes easier.
6. Because it is the joint of molten material and metal insert, the gap of metal insert can be designed narrower than that of press in molding method, and the forming reliability of composite products is higher.
7. Select the appropriate resin and molding conditions, that is, for the products easy to be damaged (such as glass, coil, electrical parts, etc.), the resin can also be sealed and fixed.
8. The insert can also be completely enclosed in the resin with proper die construction.
9. With the combination of vertical injection molding machine, manipulator and embedded product whole line device, the embedded molding engineering can realize automatic production.
10. The products with hollow grooves can also be made after the insert is molded and the core hole is removed.
Precautions for design and selection of automatic insert molding system:
1. It is easy to produce uneven shrinkage in metal insert molding. The limit test of shape and dimension accuracy of important parts should be done in advance.
2. During the injection process, the metal insert is easy to deform and shift, so the mold structure and the mold shape of the metal insert should be fully considered. For the products whose insert shape cannot be changed, it is necessary to test in advance.
3. The fine contact between the insert and the insert surface will affect the quality of the insert. The allowable limits of quality should be confirmed in advance.
4. The serration, warpage, material thickness difference, diameter difference, and thickness difference caused by gold deposit should be measured in advance. On this basis, the matching selection design of automation device and the design of die structure are carried out.
5. The predictable problems that restrict the structure of mould, such as gate location and molding cycle, should be solved in advance or corresponding improvement measures should be taken as far as possible.
6. It should be confirmed whether the metal insert needs preheating or drying treatment. The purpose is to ensure the product quality and molding stability.
7. Various detection devices set in the mold are used to ensure the stability of molding action under the influence of mold heating, force, vibration and other environmental conditions.
