Many manufacturers use surface pre-treatment with atmospheric pressure plasma to increase adhesion of plastics. Plasmatreat GmbH and the research institute Neue Materialien Bayreuth (NMB) have introduced a new application for electric vehicle (EV) production
The duo are using Openair plasma technology to modify the surfaces of injection-molded components before applying polyurethane (PUR) coating systems.
The method supports consistent coating performance for exterior EV parts, reduces process steps, and lowers environmental impact by avoiding heat-intensive or chemical-based treatments.
PUR coating systems are common in the automotive sector for exterior components, such as hoods and bumpers. These coatings protect plastic parts from environmental exposure and distribute forces during operation.
As manufacturers increase the use of lower cost mono-materials, such as polypropylene (PP), to support lightweighting and recycling goals in EV platforms, adhesion challenges become more significant. PP is a non-polar material that does not bond well with paint or coatings without pre-treatment.
Conventional pre-treatment methods like flame treatment or chemical adhesion promoters can increase adhesion strength but also introduce high heat, added safety requirements, or long handling and drying times. Plasma technology offers an alternative that avoids these limitations through controlled surface activation.
PUR in-mold coating as an inline process
The approach developed by Plasmatreat and NMB uses a wide plasma nozzle to treat components immediately after injection molding. A robot-guided nozzle performs large-area pre-treatment at high speed, after which the PUR coating is applied in the same system.
Plasmatreat’s Plasma Control Unit monitors all parameters of the plasma process through integrated quality assurance modules to support consistent functionality and reproducibility.
The process combines injection molding, plasma pre-treatment, and PUR coating in a fully automated inline workflow that reduces handling steps.
Plasma pre-treatment for PP components in EV applications
Plasma pre-treatment increases the surface energy of non-polar plastics such as PP, enabling durable adhesion of PUR coatings used for exterior EV components.
The process supports consistent results with complex geometries and reduces the risk of heat-related damage compared with flame treatment. Because plasma activation allows reliable adhesion on thinner materials, it can support lightweighting targets in EV design.
The method can be applied to large areas or specific zones and can accommodate high processing speeds. Plasma treatment also eliminates the need for chemical solvents and avoids VOC emissions. With no drying or additional cleaning steps required, PUR in-mold coating can achieve shorter cycle times and higher production volumes for EV manufacturing.
Filed Under: Adhesives, Technology News