Everything you need to know about Insert mold  

What is injection molding process

INSERT MOLDING is a type of injection molding. It is the process of molding thermoplastic material around an metal part to create a finished part that incorporates multiple materials.

The inserts for INSERT Moulds are typically metal stamping or thread parts.   The inserts are most commonly made of metal, typically brass, aluminum or stainless steel.  Threaded inserts are readily available in a number of standard sizes.  Bushings, sleeves and other simple metal forms are also used. Before injection molding, the inserts are placed on a fixed position in the mold and thermoplastics is injected into the mold to form the part. Most moldable thermoplastic resins are compatible with the insert molding process. This kind of products are usually used as structural parts in product development, and the strength requirements of the products are higher, so plastic material containing glass fiber (GF) is often chosen, and the content of GF in PC GF,PA GF, is generally 10% ≤ 50%.

What are the major design guidelines to follow when designing an insert molded part?

Due to the complexity of INSERT MOLDING product structure and the particularity of materials, special design guidelines need to be applied to insert molded parts. As far as product is concerned, the minimum consistent wall thickness  is vital to make sure that the combination of inserts and plastic parts is firm.

Adding draft to help the part release from the mold is a very important consideration when designing a part for insert molding. The draft of insert molded part is larger than that of ordinary plastic parts, because the product surface is rough and the friction between part and steel is great when demolding.

In addition, designing in undercut features can help enhance the retention strength of the inserts within the molded part. Because the inserts must be placed into the mold, it is also important to make sure the insert is located in an accessible area of the mold. Making sure the inserts are not too deep within the part and have a way to be held in place in the mold during the molding process will also help ensure successful results.

HS Mold is the a professional manufacturer of custom prototype and plastic injection molds for 20 year. For any more information on the molds, please contact us at market@hsmolds.com

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