Overmolding for greater durability

Overmolding can be an important single step in cable assembly. But how does this process work and why can it make cable connections last longer?

What does overmolding mean?

Overmolding refers to the encapsulation of electronic components. In particular, components that are at risk of wear and have to withstand external influences are often overmolded. This ensures the longevity of electronic components. CiS uses the overmoulding process at the connection point from the cable to the connector. This protects the connection point from mechanical stress and ensures a watertight seal.

How does overmoulding work?

There are various techniques and processes for overmoulding cables. CiS uses injection molding machines for this purpose. An insert part, e.g. a plug with a soldered cable, is inserted into the lower part of an injection mold. The injection chamber (cavity) is then closed pressure-tight with the upper part of the injection mold. The desired liquid plastic material (e.g. PVC, PUR, PA, etc.) is then injected into the injection chamber via the injection nozzle on the plasticizing unit, at high pressure, and envelops the insert part in the specified shape.

This injection molding technique is also known as hybrid technology in technical jargon, because several metal molds can be encased in plastic in just one step. Plugs and cables encapsulated in plastic are an optimal solution in many areas of electrical engineering to protect cables from external environmental conditions (e.g. lubricants, gasoline, gases, temperatures, mechanical stress, etc.). Depending on the application, there are various possibilities for overmolding. The following list shows some examples of such connections:

  • Overmolding for strain relief
  • Overmolding as a grip cap
  • Increasing the tightness of Y-connections
  • Production of bend protection sleeves
  • Overmolding of plug connections

What is the process of cable overmoulding?

There are various methods for overmolding cable connections. Injection molding is a sub-variant of casting technology and is mainly used for processing plastics. The method chosen for overmolding depends on the type of components to be overmolded (connectors, cables, electronic components, etc.) and the plastic to be injected. For example, the low-pressure or high-pressure molding process can be used.

The low-pressure process is suitable for overmolding sensitive components. The plastic used is liquefied with heat and forced into the cavity at high speed, enveloping the respective inserts. Afterwards, the thermoplastic material or the injection molding solidifies again. After hardening, the component is removed from the machine. Injection molding in particular is ideal for encapsulating inserts made of electromechanical components, cables and metals.

The Macromelt method, as a type of low-pressure process, offers an environmentally friendly alternative to the high-pressure process. The reason for this is the lower pressure during injection and the shorter cycle times compared to conventional variants.

At CiS, you benefit from cost-effective and environmentally friendly techniques, thanks to faster drying times and lower energy consumption.

Individual overmolding methods for several industries

Our competencies and many years of experience in cable assembly are the basis for developing the necessary tools for overmolding cables ourselves. This is done either in-house or in cooperation with our local partners. Here, we place particular emphasis on speed and flexibility.

Depending on the wishes and requirements of our customers, we produce metal-plastic connections.

We determine the right process for your products, because the components/materials to be overmolded have very different properties when overmolded. When upgrading your cables, we use either thermoplastics such as PUR and PVC or Macromelt. Consequently, we can engrave cables individually and even provide them with a logo or use special colors for overmolding.

With our subsidiary Zabel Technik, we are also able to offer injection moulding of housings, buttons and other customised products.