ENGEL has developed a new machine concept for clearmelt systems based on the duo combi M two-platen injection molding machine in order to make the clearmelt process even more efficient, easier to implement, and flexible.

The new system concept for clearmelt, shown here on an ENGEL duo 5500 combi M injection molding machine, requires around 25% less floor space and operates with considerably shorter PUR feed lines.

Redefining the long-established clearmelt technology

The clearmelt technology itself has been established in series production for many years: plastic components are flooded in the mold with a transparent or colored polyurethane layer and thereby receive high-quality, scratch-resistant surfaces directly in the injection molding process, including the integration of functional films.

Downstream painting or coating processes can be replaced in many applications.

With clearmelt technology, decoration, protective function and component geometry can be combined in a highly integrated process. The process continues to gain importance in the automotive industry. New vehicle concepts call for larger, high-quality designed and at the same time robust interior and exterior components.

What’s new?

In the new machine concept, the thermoplastic component is injected via the injection unit on the moving side of the machine. The technical basis is formed by the combi M design of the ENGEL duo two-platen injection molding machines.

In the new design, the standard injection unit on the side of the fixed platen is omitted. In its place, the polyurethane equipment is positioned. The thermoplastic component is injected from the moving side of the machine, while the PUR mixing head is arranged on the fixed platen.

As a result, the PUR technology sits closer to the mold, the PUR feed lines become shorter, and the system periphery becomes more compact, easier to handle, faster to convert and more cost-effective to operate. For users, these translate to lower investment and installation efforts.

The new system concept is available in a mirrored version. This positions the injection unit so that the material supply remains on the customary side and fits seamlessly into the processor's existing in-plant logistics. Additional modifications in the production environment are not required.

Color change in less than 10 minutes

The new system concept also enables more flexible use of the color units. In the previous configuration, these were permanently assigned to one machine. Previously, unused color lines had to circulate permanently to prevent color particles and additives from settling.

Now, this is no longer necessary. Flushing processes for the lines in order to disconnect the color units from the production cell are completely eliminated.

This enables color change in less than 10 minutes. Operators can therefore distribute the units across several systems more in line with demand, reduce downtimes and utilize existing resources more efficiently.

Existing clearmelt molds can continue to be used and merely need to be turned around, without having to keep adapted mold variants for different system layouts on hand.

Not just for clearmelt!

The systems remain not limited to clearmelt applications despite the design optimized for clearmelt.

Thanks to the duo combi M design, it can also be used for standard injection molding applications. This brings greater flexibility in production planning and reduces investment risk. Subsequent retrofitting with an injection unit on the fixed side can also be carried out easily.

In addition to the technical advantages and lower investment costs, the new system layout also saves production space with a 25% smaller footprint.

The first systems based on the new concept will go into operation in 2026’s autumn. From November, such a clearmelt production solution for large exterior parts will additionally be available for customer trials at the ENGEL technical center in Shanghai.