Adhesive for Polyolefins
For an adhesive to bond to the surface of a component, the surface energy of the component material must be higher than that of the adhesive. Otherwise, the adhesive does not wet the material’s surface sufficiently. Usually, adhesives have a surface energy of 35 to 40 mN/m. In the case of polyolefins such as PP and PE, the surface energy is considerably lower. As a result, they could be glued in the past only after undergoing a time-consuming surface treatment.
With Loctite 3038, Henkel has developed a polyolefin adhesive that, thanks to its special formulation, achieves high bonding forces on such low-energy plastic surfaces. As a result, polyolefins such as PP, PE, LDPE and HDPE can now be glued without time-consuming pretreatment. The adhesive is suitable for use with materials that have different coefficients of thermal expansion as well as for bonding polyolefins to metal components.
The solvent-free, nonflammable adhesive contains no methyl methacrylate and as a consequence creates only a mild odor when processing. It can be applied either manually or fully automatically. The adhesive is thixotropic and can be applied on vertical surfaces without dripping. It contains appropriate fillers to permit formation of a layer of adhesive with minimal thickness. The strength of the adhesive itself is similar to the intrinsic strength of the substrates. The adhesive layer withstands impact and vibration and is resistant to chemicals and environmental factors.
Its property profile predestines the adhesive for many applications in the automotive sector, e.g. gluing of plastic covers, housings and air ducts. With regard to exterior applications, hybrid front end modules, for example, could be glued together. Additional applications can be envisioned in door and roof systems.
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