Insert Molding

What Is Insert Molding?

The Insert Molding is a special processing method of plastic injection molding that allows one or more pre-manufactured inserts or plug-ins to be embedded in the injection mold during the plastic injection process, so that these inserts become part of the finished product. Inserts can be made of various materials, such as metal, plastic, ceramics, or other materials. These inserts can have different shapes, sizes, and functions, such as screws, electronic components, metal connectors, plastic sockets, etc. These inserts can be used to provide mechanical strength, electrical connections, guidance, or other functions.



What Are the Differences Between Insert Molding and Metal Insert Molding?

Insert molding and metal insert molding are both advanced technologies in injection molding. They mainly differ in the positioning and application of the inserts. Inserts are mainly used to embed external components into plastic parts, while metal insert molding is mainly used to surround plastic around metal parts to achieve specific purposes. Here are the main differences between these two methods:


Types Insert Molding  Metal Insert Molding
Definition Insert Molding is an injection process in which one or more pre-manufactured metal or non-metal inserts (plugs) are embedded in the injection mold during the injection process to make the inserts part of the finished product.  Metal insert molding is to surround plastic around one or more pre-manufactured metal inserts (usually one or more metal parts) to enhance structure or provide other functions. 
Insert Positioning Inserts are usually accurately positioned in the injection mold to ensure their correct position during the injection process.  Inserts are usually placed in the mold but can be moved when necessary to achieve specific design requirements.
Application Inserts are usually used for applications that require external components to be embedded in plastic parts to provide mechanical strength, electrical connections, or other functions.  Metal insert molding is usually used for applications that require surrounding metal parts with plastic to provide protection, increase structural strength, or improve appearance, such as handles, tool handles, protective shells for electronic equipment, etc. 
Types of Inserts Inserts can include metal and non-metal inserts depending on the required function. Metal insert molding mainly involves metal inserts and is usually used to provide additional strength and protection. 



The Process of Insert Molding

Insert molding allows one or more pre-manufactured inserts or plug-ins to be embedded in the injection mold during the plastic injection process, so that these inserts become part of the finished product. Below is a general process of insert molding:


  1. Insert Preparation: Firstly, pre-manufactured inserts need to be prepared. These inserts can be made of various materials, such as metal, plastic, ceramics, etc. They usually have specific shapes and functions to meet the requirements of the final product.
  2. Mold Design: The injection mold needs to be designed to accommodate the position of the inserts. The mold usually includes special slots or holes for locating and accommodating the inserts.
  3. Injection Machine Setting: The injection machine is set to heat and inject the required plastic material. Temperature, pressure, and other parameters are adjusted according to the materials used and product specifications.
  4. Insert Positioning: The inserts are precisely positioned or placed in the corresponding position of the injection mold. The inserts are usually placed in a special position of the mold to ensure that they do not move or deviate from the required position during the injection process.
  5. Injection: The plastic material is heated and injected into the injection mold. During the injection process, the plastic flows and fills the mold, while surrounding and adhering to the inserts.
  6. Cooling and Solidification: Once the plastic has filled the mold and surrounded the inserts, the injection machine stops injection and waits for a period of time to ensure that the plastic cools and solidifies. The cooling time depends on the materials used and the size of the product.
  7. Mold Release: Once the plastic has completely cooled and solidified, the mold is opened, allowing the finished parts to be removed from the mold.
  8. Part Inspection and Post-processing: The finished parts need to be inspected to ensure quality and undergo possible post-processing procedures, such as removing any possible redundant materials or trimming.
  9. Repetition: The entire process can be repeated to manufacture multiple insert molded parts.


Insert molding is a multi-material injection molding process that allows different materials of inserts to be integrated into plastic parts to achieve specific functional or performance requirements. This process has a wide range of applications in many different fields, such as automotive manufacturing, electronic devices, medical equipment, etc.



The Materials of Insert Molding

  • Plastic Parts: PPS, PPA, PBT, PET, PC, POM, TPU, Nylon, Delrin, Acrylic, etc.
  • Special Material: Peek

Layana's Capabilities of Insert Molding

Layana introduces dual-alloy material pipes to facilitate smooth mass production of insert molding, providing customers with the highest quality service from precision injection molds, continuous stamping molds, mold processing, injection molding, stamped part processing to product assembly. Plastic Inserted parts are suitable for sensors, connectors, medical equipment, and automotive precision components, etc.

injection machines equipment 90tonv p01.   f0006 min


Item/TypeVertical Injection MachinesHorizontal Injection Machines
Tonnage Ranging From 35T to 250T From 60T to 200T


Product Size

INCH: 8.5 x 11 x 6

MILLMETER: 216 x 279 x 150


Product Weight


Mold: ± 0.005mm

Product: ± 0.03~0.05mm




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