Insert molding refers to a molding method in which pre-prepared inserts of different materials are placed in the mold, the resin is injected, and the molten material is bonded to the insert to solidify to form an integrated product.
Injection molding on the substrate refers to the method of embedding injection molded parts on a part of the metal plate surface.
1. The above two molding methods are essentially the same. Its characteristics are as follows:
1.1 The combination of the formability and bendability of resin and the rigidity, strength, and heat resistance of metal can be combined and supplemented to make complex and exquisite metal-plastic integrated products.
1.2 Especially by using the combination of the insulation of resin and the electrical properties of metal, the molded products can meet the basic functions of electrical products.
1.3 The pre-forming combination of multiple inserts makes the post-engineering of the product unit combination more rational.
1.4 Insert products are not limited to metal, but also include cloth, paper, wire, plastic, glass, wood, coils, electrical parts, etc.
1.5 For rigid molded products and curved elastic molded products on rubber sealing pads, after injection molding on the substrate to make an integrated product, the complicated work of arranging the sealing ring can be omitted, making the automatic combination of the subsequent process easier.
1.6 Because it is the joint between the molten material and the metal insert, compared with the press-in molding method, the gap between the metal insert can be designed to be narrower, and the reliability of composite product molding is higher.
1.7 Select the appropriate resin and molding conditions, that is, for products that are prone to deformation and damage (such as glass, coils, electrical parts, etc.), the resin can also be sealed and fixed.
1.8 Select the appropriate mold structure, the insert can also be completely sealed in the resin.
1.9 After the insert is formed, it can also be made into a product with a hollow groove after the core hole is removed.
1.10 Combination of the vertical injection molding machine, manipulator, insert product alignment device, etc., most insert molding projects can realize automatic production.
2. Considerations for the Design and Selection of Automatic Insert Molding System
2.1 Metal insert molding is prone to uneven molding shrinkage, and the limit test of the shape and dimensional accuracy of important parts should be done in advance.
2.2 The metal insert is easy to deform and shift during the injection process, the mold composition and the design of the mold shape that is easy to maintain the metal insert should be fully considered. For products in which the shape of the insert cannot be changed, prior testing is indispensable.
2.3 When the arrangement of the metal inserts is separated and the conveyor is used, the contact between the metal inserts and the contact between inserts and the vibrating ball will cause slight damage to the surface of the inserts and affect the product quality. The allowable limit range of its quality should be confirmed in advance.
2.4 The jaggedness, warpage, material thickness difference, diameter difference, and thickness difference caused by gold plating processing of metal inserts caused by stamping processing 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.
2.5 For predictable matters that restrict the structure of the mold, such as the position of the mold gate, the molding cycle, etc., it should be resolved in advance as much as possible or have corresponding improvement measures.
2.6 It should be confirmed whether the metal insert needs to be preheated or dried. The purpose is to ensure product quality and molding stability.
2.7 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 on the mold. It should be confirmed whether they are used.
2.8 In order to avoid metal inserts and fine pieces of molded products from accumulating in the mold cavity, an air-blowing device can be assembled if necessary.
2.9 Due to the high investment price of the system equipment, it is necessary to fully consider whether the production capacity of the equipment can be guaranteed before adopting it. When using a special machine, it is necessary to ensure that the product can be continuously produced without form updates for several years.
2.10 When using a general-purpose machine, it is necessary to confirm how many combinations of inserts with multiple varieties and small batches are produced. 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 of update requirements within a certain range.
2.11 There are many factors and technical decisions such as the accuracy of metal inserts, the shape of inserts, whether the mold is conducive to insert molding, and the shape of molded products, etc., which determine the insert molding rate, productivity, and molding cost conditions.
2.12 The effective combination of injection machine, mold, and automation device and how to function in a short time are the key to determining the automatic insert molding system. It is recommended to consult and discuss with manufacturers who have considerable performance and experience.