SOUND ENGINEERING FROM - Loctite.ph

Assembling Speakers with Loctite ® AdhesivesNormal manufacturing process calls for the polepiece and magnet to be assembled in one operation,while the frame and top plate are assembled in aseparate operation. Punched steel frames alwaysinclude a ring of holes which mate with a ring of raisedpins on the top plate, and the parts are swaged togetherin a press. Cast aluminum frames are generally fixed tosteel parts by bolts threaded into the top plate. Thinpaper gaskets are sometimes fitted between the frameand the top plate to prevent buzzing, and to seal the gap,thus avoiding whistling noises. A better solution is a thinTop Plate To Framebead of Loctite ® structural adhesive, eliminating gasketinventory, while both sealing and reinforcing the joint.In making frames more attractive, particularly for theautomotive aftermarket, manufacturers have embracedpowder coat finishes on their frames, which introducesome unwelcome bonding challenges. Most of thepowders used in these processes contain epoxiescombined with wax compounds, to create smoother andmore attractive surfaces. However, this wax interfereswith the bond and must be stripped off any bondingsurfaces. Washing these surfaces with solvents such astoluene, xylene or methyl ethyl ketone can significantlyimprove bond strength, although these solvents havefallen out of use in the last few years. Isopropyl alcoholmay be the best alternative.Recommended products for the Top Plate to Frame Assembly:Loctite ® Cyanoacrylate Adhesives 380 or 410.See detailed Product Information on Cyanoacrylates on pages 22 and 23.10