Techsil has been approached by Speed Plastics to find a transparent flexible adhesive to bond the mouthpiece of a smoke hood and plan a new method of production.
Numerous adhesives had been tried but under stress tests were too brittle for the substrates which were silicone rubber and cotton backed PVC.
A 1-part flowable silicone adhesive was recommended by Steve Green, one of Techsil’s Application Development Engineers, as the contours of the mouthpiece made applying the adhesive by hand tricky.
Green said: “Momentive IS5628E silicone adhesive cures at room temperature, requires no mixing and its flowable consistency makes it easy to apply. It adheres well to silicone rubbers and cures to make a tough durable bond which can withstand very high and low temperatures. Making it an ideal solution for this application.”
For the production process, a semi-automated system was chosen.
A circular, even bead of adhesive was required and a Nordson EFD Ultimus 1 dispenser with a 310 cartridge assembly was deployed, with a fly press to deliver the adhesive.
The hood and mouthpiece is placed on a turntable and is rotated 360 degrees during dispense.
Techsil concluded that this project has increased the speed of the manufacturing process, with the Momentive IS5628E adhesive, producing a sound bond which is uniform and repeatable due to the automated dispensing.