Adhesion of PS on metal and glass surfaces
Polystyrene (PS) is a thermoplastic, aromatic polymer. It is one of the most widely used types of plastics, especially for consumer products. General purpose PS is hard and clear and is e.g. often used in food packaging. PS foam contains up to 98% air and is used as an insulating and a cushioning material (e.g. Styrofoam™). Additionally, appliances, electronics, automobile parts, toys etc. are often made from PS combined with colorants, additives, or other polymers.
Adhesion of PS to glass
Glass surfaces are coated with RadiSurf’s invisible PS adhesion layer, which makes the surface hydrophobic and compatible with PS. This is easily visualized by a significantly decreased wetting of the glass slide, compared to the bare glass substrate.
A blank glass slide displays a low water contact angle and high wetting, whereas a RadiSurf PS adhesion layer makes the surface hydrophobic to resemble PS.
PS can be applied directly on the RadiSurf coated glass element, e.g. through solvent welding or over-molding. Scratching and peel-tests both reveal ultra-strong adhesion between PS and the RadiSurf coated glass element.
The top image is a RadiSurf coated glass slide after peel- and scratch-test, where PS still binds strongly to the surface. In comparison, PS on a silane-based adhesive delaminates immediately in a peel-test (bottom image).
The video shows how RadiSurf coated glass slide performs in comparison to the silane-coated one.
Adhesion of PS on metal surfaces
The RadiSurf PS adhesion coating can be applied on most types of metals to provide excellent adhesion between the metal element and PS. The adhesion works even on smooth surfaces, and in most cases surface roughening such as sandblasting can be avoided.
Adhesion of PS to PS blends
As mentioned above, many uses of PS are based on PS blends. In RadiSurf we have so far tested adhesion to general purpose PS, but strong adhesion is expected to most types of blends, and we are rapidly expanding material combinations of our adhesion portfolio.
High stability of PS adhesion layer
The RadiSurf PS adhesion coating is very stable and can be stored at least 2-3 months before applying the PS ina welding or molding process. This means that the glass/ metal coating process is completely decoupled from the adhesion/ assembly step, which can be an immense advantage in many industrial workflows and logistics.