Overmoulding – adding an extra layer of plastic to an existing product

Overmoulding is an umbrella term for the two injection moulding techniques known as insert moulding and outsert moulding. The overmoulding process involves adding an extra layer of plastic to an existing product or component. In contrast to 2K injection moulding, overmoulding always involves the use of a non-plastic material. This can be accomplished in a number of different ways. 

With insert moulding, a component of a different material type – the insert part – is encapsulated in plastic. With outsert moulding, the plastic is also combined with a different type of material, but the difference with this technique is that the plastic is only moulded against part of the non-plastic material. 2K injection moulding is an injection moulding technique where two types of plastic are combined to form a single end product. 

Want to know which injection moulding technique is most suitable for the production of your product? Plastic injection moulder GL Plastics would be happy to work with you to identify what is most suitable – we have the experience and resources to turn the best advice into practical solutions. At GL Plastics, we can successfully implement different overmoulding injection techniques under one roof.     

Overmoulding – the insert moulding technique – what is it?

Insert moulding is a form of plastic injection moulding whereby a component of a different type of material is moulded with plastic to encapsulate it. Metals are commonly used as insert parts. This type of material can help to strengthen the product in certain places and provide electrical or thermal conductivity, if these are features critical for the end product. In the latter two examples, the plastic must then act as an insulating material. 

Overmoulding – the outsert moulding technique – what is it? 

Outsert moulding has many interfaces with insert moulding, but with this injection moulding technique, the insert part has a larger surface than the plastic. The plastic is only moulded onto a certain part of the insert and does not encapsulate it. 

Overmoulding – the 2K injection moulding technique – what is it? 

2K injection moulding is a variation of plastic injection moulding whereby two differing plastic materials are processed to form a single end product. This requires two injection stages in a single injection moulding process.

The benefits of insert and outsert moulding 

The two overmoulding techniques – insert and outsert moulding – are not significantly divergent, and it goes without saying that they bring comparable benefits for the end product. These include:

  • Time and cost savings thanks to fewer operations in the assembly process.
  • Properties can be added to the plastic materials to make them stronger and more durable. 
  • Properties can be added to the product that would not be possible with plastic alone. This helps to improve overall functionality. 
  • If you opt for insert or outsert moulding as a replacement for metal, the injection moulding technique will lead to a decrease in the weight of the end product. 
  • Injection moulding can be used for thermal or electrical insulation. 
  • A wide selection of materials, colours, shapes, and combinations is possible with 2K injection moulding. 

Benefits of 2K injection moulding 

The following are some of the benefits of 2K injection moulding:

  • With 2K injection moulding, all assembly stages are merged into a single injection moulding process, which in many cases helps to reduce costs. 
  • 2K injection moulding means almost endless combination, including the ability to combine plastics with different properties, colours, and hardness levels into a single product. 
  • 2K injection moulding can make a product more user friendly – combining hard plastics with a soft plastic, for example, can make a product nicer to the touch and/or easier to operate. 
  • The components fit together seamlessly, allowing a product to be designed in two colours. 
  • There is also less risk of damage, as no manual assembly is required. 

Would you like to know more about the possibilities offered by overmoulding? 

At GL Plastics, we have many years of experience with different overmoulding techniques. Please get in touch if you would like to discuss the options that are available. 

Request a quote