Specific expertise for specific claims: in coordination with the material specialists at Evonik, KraussMaffei developed a surface technology that allows a thin functional layer to be applied to PMMA parts directly in the injection molding process. This system solution for applying an anti-scratch coating to heavily loaded components is called CoverForm. It can be managed without subsequent processing steps. This means: no temporary storage, no separate painting, no quality-reducing interference. Thus, your manufacturing costs are significantly reduced.
PMMA is the thermoplastic material with the highest surface hardness. Nevertheless, articles made from this plastic must have a protective coating for special requirements. For CoverForm, a protective layer just a few micrometers thin is applied to plastic parts using reaction process machinery in the injection molding process. This protects the parts from scratches and a wide variety of aggressive chemicals. Evonik developed an innovative material combination for this. It consists of a special Plexiglas molding compound and a precisely matched solvent-free multicomponent reactive system with an acrylate base. This features excellent adhesion to PMMA and gives the surface of your component the desired resistance.
KraussMaffei specifically developed its small-volume metering unit to dispense the liquid multi-component reactive system into the cavity of the mold mounted on a KraussMaffei CX injection molding machine. The following compression molding step spreads the coating evenly over the surface of the part. Here, cover layers can be made that are thinner than 50 micrometers. CX machine equipment adapted for use in a cleanroom environment provides a dust-free product area in the process. This completely eliminates contamination of your components. The coating cures enough while still in the mold for the parts to be demolded without damage. After demolding, the curing process for the anti-scratch coating is completed using UV radiation.
The system solution can be used for any surfaces that are not supposed to show scratches or abrasion, even after years of being subjected to stress. Examples of this include panel covers in motor vehicles, covers for household appliances or displays on electronic devices. Thanks to CoverForm, you not only benefit from highly resistant components with the highest surface quality, but also from advantages in efficiency during manufacturing. You save on the logistical effort required for component finishing, while the CoverForm system also takes up much less space than a conventional finishing system.