Insert Molding Vs. Overmolding

What is Insert Molding?

Insert molding is an injection molding process that utilizes encapsulation of a component in the plastic part. The process consists of two necessary steps. Firstly, a finished component is inserted into the mold before the molding process actually takes place.

What is Overmolding?

The overmold meaning is the manufacturing process that involves a seamless combination of numerous materials into a solitary part or item. There are two necessary steps in carrying out the overmolding process.
The first step involves molding and curing a substrate that is usually plastic.Differences Between Overmolding vs Insert Molding
Although there are many similarities between insert molding and overmolding based on their applications, certain differences exist. The overmolding vs. insert molding difference spans over the following:

Application

Inserts are objects which are used for fastening and assembling plastic parts with their counterparts. Sometimes even two inserts are used in a single part for smooth function. Below is the list of the most widely used inserts.
Male threads
Female threads
Electrical contacts
Spring-loaded clips
Dowel Pins

Over-molded rubber is usually a substrate joined on the top of a plastic part. The substrate used TPE or TPU typically.

Process

Overmolding involves a two-step manufacturing process. The molding and curing of substrate entail one step, while the second step is molding another layer on the former. Insert injection molding does not involve a two-step manufacturing process. Still, it eventually leads to molding another layer on top of a product.

Speed

Insert molding takes time in molding another layer on the product because both pieces are developed separately. This makes it relatively time-taking than overmolding. It entails a total product encapsulation in the molded component, unlike overmolding, which entails a partial encapsulation.

The overmolding process reduces the manufacturing time. This is possible because it does not require producing the two pieces separately and requires direct molding of the second piece to the product. However, the process of overmolding is difficult; therefore, operators need to adhere to stated instructions.

Material Selection

Adhesives are unnecessary for overmolding. Therefore, the products tend to be very durable and flexible. There is no need for any types of mechanical fasteners during the insert molding process since the essential parts of the metal are present in the mold. Due to the materials used, products that go through overmolding tend to be stronger than those that go through insert molding.

Cost

Insert injection molding greatly reduces the cost of assemblage and generates more than a thousand parts in a day is possible. Insert injection molding costs reduce greatly when the production is in large quantities. However, overmolding involves two steps, and it is more expensive than insert molding.