Plasma overmolding

Evaluation of plasma technology to improve the tightness and mechanical connection of an assembly manufactured by overmolding.

Injection overmoulding is an integrative assembly technique established in the plastics industry. In particular, it is used for the manufacture of products in all fields of industry (connectivity, mechatronics, medical, automotive, etc.). However, a major problem with this technology is the production of tight and durable connections over the long term between the inserts and the overmolded polymer part, because of the weak chemical bonds. Today, operations such as potting or the use of primers are necessary before or after overmoulding to ensure an airtight bond of the final product. These operations are largely done manually, as they are difficult to integrate into an automated process. In addition, the primers used are generally very corrosive, toxic and therefore dangerous for operators and the environment. Plasma technology for the pre-treatment of inserts uses, for the functionalization of surfaces, the same active ingredients as the primers, but without toxic solvents, and this using less material input. This technology is easy to automate, so it is possible to integrate it into a production line as part of serial production.

The main objective of this project is to study and validate the use of plasma technology for the pre-treatment of elements (metal, plastic or others) that will be overmolded. In particular, the Plasma Overmolding project aims to:

  • Improve the bond between the inserts and the plastic overmolded part, by applying a plasma to the inserts before overmolding, in order to achieve, after the overmolding, a direct waterproof connection or a strong mechanical connection.
  • Delete potting operations or applying primers,
  • Establish a compendium of good practices in the use of plasma for overmolded connections, based on different combinations of materials used by the industrial partners of the project

The results of this project will allow industrial partners to validate the application of plasma technology for their respective products, through pilot applications tested as part of the project. This technology will allow them to optimize their manufacturing processes and improve the final quality of their products. Thanks to this pre-competitive project, partner companies will develop their skills in cutting-edge technology, thus gaining competitiveness.