Wednesday, June 16, 2010

Structural Adhesive for Automotive Uses Improved

ITW Plexus
Methacrylate technology

Plexus adhesives are methacrylate adhesives that have been developed to perform under a wide range of conditions. This is achieved by improving curing, bonding, adhesion and toughening mechanisms.

The free radical cure mechanism of Plexus methacrylates is catalytic in nature. When the adhesive and activators are mixed, amines in the adhesive cause the peroxide to decompose into free radicals, which initiate the process of chain polymerisation of the MMA to PMMA. These reactions are exothermic and take place at room temperature removing the need for applying heat to initiate the cure.

The improved adhesion mechanism of methacrylate adhesives consists of the low viscosity monomer solvating the surface of most thermoplastics prior to the curing mechanism beginning. The monomer can solvate most surface contaminants which removes the need for any surface preparation prior to applying the adhesive.

Plexus methacrylate adhesives have a unique combination of polymers and impact modifiers which enable them to be strong yet flexible. The resulting high tensile strength along with impressive elongation (over 100% at @ 30°C) gives them the processing advantages and convenience of epoxies and polyurethanes, without increased cost.

The total combination of all these factors along with good rheology, thixotropic properties, ease of use and lack of VOCs and solvents, results in a range of structural methacrylate adhesives that can be successfully used in the marine, construction and automotive markets on a wide range of substrates.

Applications

Plexus adhesives are used by major domestic and foreign automotive and truck manufacturers. The ability of Plexus adhesives to bond most thermoplastic and composite materials allows manufacturers to simplify assembly and generally reduce the weight of the final bonded assembly.
Transport & automotive

Plexus adhesives are being successfully used in the automotive and truck industry for bonding, for example, bumpers, instrument panels, spoilers, cosmetic surface repairs, airbag housings, glove boxes, door panels, plastics headlights, tail light assemblies, strengthening and structural body parts, grille components, inner door extensions, roof assemblies, side and roof panels and sleeper cabins.

It is not only thermoplastic applications that can benefit from the use of methacrylate adhesives. Composite materials are used in many industries for a variety of different applications. Composite is a general term which means the assembly of dissimilar materials used together to enable them to do a job that the individual materials can not do by themselves. Plexus adhesives have provided an alternative to traditional methods of bonding composites and also allow the bonding of dissimilar materials, e.g. SMC to E-coated steel, fibreglass to aluminium.

http://www.reinforcedplastics.com/view/9705/the-use-of-structural-methacrylate-adhesives-in-the-bonding-of-thermoplastics-and-composite-materials/

http://www.itwplexus.co.uk/