When Fakuma, the German trade fair for plastics processing, opens its doors from 16 to 20 October in Friedrichshafen this year, Plasmatreat and system partner CeraCon will demonstrate live to visitors how two incompatible plastics can be bonded together without the use of primers.
Openair® plasma treatment of polypropylene surface prior to applying the 1-component PUR sealing foam.
When it comes to adhesion, polypropylene (PP) and polyurethane (PUR) foam just don't get along. That is, unless the non-polar PP is pretreated in a way that modifies its surface, increasing the surface energy to such an extent that it becomes receptive to the polyurethane bond. At their joint exhibition stand Plasmatreat GmbH and its system partner, the foam technology specialist CeraCon GmbH, will demonstrate live just how simple, effective and environmentally friendly this process can be by producing small picture frames on the stand to give away to visitors. And the clever thing is that the frames can be used in wet rooms or even in the shower – once they have been made waterproof.
The waterproof seal is achieved by pretreating the polypropylene back of the frame with Openair® atmospheric-pressure plasma jet technology and then applying a 1-component PUR foam to the pretreated surface. Unlike other pretreatments, plasma has a dual effect: It cleans and activates the material surface in a single step. Pretreatment with plasma energy significantly increases the adhesion capacity and wetability of the non-polar plastic surface in a precisely adjustable manner.
The foam sealant is applied immediately after the pretreatment. The result: Polyurethane and polypropylene, two otherwise unjoinable plastics, are now firmly adhered to one another. The foam bead does not come unstuck even when the sheet of glass and front section of frame is applied. With a 100% waterproof seal, there is nothing to stop you creating a picture gallery in your shower!
An ingenious idea to demonstrate an innovative adhesion process which will benefit the industrial production of leak-proof polypropylene components intended for external use. The automotive and electronics industries will be the main focus of interest. In these fields, the polyurethane seals used in the plastic safety covers of batteries and control units, headlights, circuit boards or lights must adhere well enough to completely exclude the possibility of moisture or dust ingress. This requirement can be achieved by using the highly effective pretreatment with Openair® plasma.