Application of the adhesive accelerator
Acrylic adhesives when cured with an adhesive accelerator can create a fast curing system that will quickly bond to a wide range of prepared or unprepared metals or plastics. When combined properly, the acrylic adhesive and the accelerator can replace the processes of welding, brazing, riveting and other mechanical fastening methods. There are no-mix adhesive accelerators that can be applied to a substrate before the acrylic adhesive so that curing can be quickly achieved at room temperature. However, in all applications of acrylic adhesives and adhesive accelerator, surface preparation is very important.
Surface preparation and how it is handled
Surface preparation is the process wherein the surfaces that will be adhered are cleaned or chemically treated to promote better bonding. The way that the surface has been cleaned will determine how well and how long the bond will last. In fact, the chosen adhesive can withstand different conditions that it may be subjected to but its life expectancy is directly proportional to the degree with which the surface has been cleaned and prepared. Even the finest kind of instant adhesive combined with an adhesive accelerator will produce a poor bond if the surface has not been prepared properly. The manner with which the surface will be cleaned is determined by the amount of contaminants that include dust, oil, grease and oxide resulting from air corrosion. Grease and oil do not only interfere with bonding; they can create problems for cleaning methods such as chemical surface alteration. The kind of surface preparation required depends on the kind of materials that will be bonded. Plastics only require simple cleaning; however, some materials may require abrading for optimum performance of the adhesive and the adhesive accelerator mix.
The mix-in adhesive accelerator
No-mix accelerators are applied to one or both the substrate surfaces and allowed to dry before the adhesive is dispensed. In the mix-in adhesive accelerator, it must be mixed with the proper amount of adhesive. Handheld cartridges will automatically dispense the correct volumetric ratios of each component. Even color distribution will visually indicate a thorough mix. Take note that when mixed, the adhesive cures quickly. Handling strength is achieved within 2 to 4 minutes which means that the mating surfaces must be fixture as soon as possible. Complete cure is usually achieved within 24 hours at room temperature.
Shell life storage of the adhesive accelerator is approximately 6 months when stored at temperatures under 80oF (27oC) in an original and unopened container. However, it is important for accelerators that have been cooled in low temperature to return to room temperature before application.