Paste and seal technology | Low pressure injection molding for hot melt adhesives to protect electronic components

The low pressure injection molding process (low pressure moulding, LPM) based on polyamide hot melt adhesives offers many economic, structural and environmental advantages over traditional methods.

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The injection molding process, developed by Henkel more than 30 years ago, is increasingly used to protect electronic components in the fields of medical technology, power generation and industrial automation, HVAC technology, as well as lighting technology. This allows sensitive components to be quickly over-moulded using polyamide-based hot melt adhesives combined with appropriate processing equipment and cost-effective injection molding tools.

Because Henkel’s Technomelt adhesives used here are not abrasive and are injected with much lower pressure compared to conventional injection molding, the risk of damaging sensitive components during the LPM process is greatly reduced, according to the company. This technology is particularly suitable for protecting sensitive components, such as B. PCBs or jumper cable connections.

Sustainability and efficient use of materials

As Henkel emphasizes, Technomelt’s hot melt adhesives meet European RoHS (Restriction of Hazardous Substances) directives and REACH regulations. Michael Otto, Director of Key Accounts explains: “Another important environmental aspect of this polyamide, which is becoming increasingly important, is the fact that it is largely bio-based, meaning that up to 80% of its ingredients come from plant sources. renewed”. In the engineering adhesives department for low pressure injection molding processes at Henkel.

An additional advantage of the LPM process is the improved economic efficiency in terms of material consumption. With traditional potting operations, the ingredient to be protected is usually placed in a container and filled until all ingredients are covered. In the Technomelt LPM process, on the other hand, the component is put into a precisely defined tool and then filled with Technomelt. According to Henkel, this allows the components to be protected with the least amount of material possible. This means that one follows the topology of the circuit board, for example. It is also possible to use multi-cavity tools in order to increase the pressure of several components at the same time.