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Chris Passanante
By Chris Passanante
Wednesday, July 23, 2014 - 11:25

Plastic and elastomer components often go through at least one decorating stage before they are considered complete.  Elite Plastics offers a variety of value-added processes which allow for additional functionality and decoration.  Overmolding is a molding process in which rubberized plastic is formed over existing plastic. This process takes multiple materials with different properties and combines them into one molded component.  In order to overmold the plastic or metal substrate with thermoplastic elastomers, we use either multi-shot or insert molding.

The multi-shot molding process uses an injection molding press, which injects multiple materials in one operation. This allows the second and third shot to be molded in sequence immediately after the first shot has been molded.  Insert molding is a different method that allows for a product to be completely overmolded and requires two separate steps. The substrate is molded then transferred to another tool that shoots the thermoplastic elastomer directly over the substrate. The choice between insert molding and multi-shot molding depends on design and volume.

Overmolding is most often used for durability for the “ruggedization” of products.  It also can be a decorating method with multiple benefits, including increased aesthetics and functionality. This process can give the product a soft rubberized feel, making it much more comfortable to handle than hard plastic. It also enables hard edges to be smoothed over and rounded.  The main functionality benefit of overmolding is the ruggedized and non-slip surface, keeping products safe in extreme environments.  In many industries, such as the medical industry, it’s important to make sure the product won’t break when dropped.  The thermoplastic elastomer covering can help to reduce that likelihood.  Other benefits from overmolding include reducing unwanted vibrations or noise and an opportunity for additional brand identity.  

Overmolding is just one of many molding and decorating methods we offer at Elite Plastics.

By Chris Passanante
Thursday, April 26, 2012 - 16:36

April's edition of Medical Design has an interesting article on overmolding, 2 shot and mult-ishot.

Here is a link to the online version of the article.