In a recent project that showcases the merits of the latest adhesives, an expert in this sector provided its customer with a flexible silicone adhesive and a fast, reliable, consistent dispensing solution for the manufacture of a smoke hood.
Speed Plastics specialises in high-frequency welding of flexible plastics and also offers customers bespoke engineering solutions in sectors such as healthcare, aviation, defence and marine. Adhesive and dispensing specialist Techsil was approached to find a transparent flexible adhesive to bond the mouthpiece of a smoke hood and plan a new method of production.
A number of adhesives had been tried but under stress tests proved too brittle for the substrates, which were silicone rubber and cotton-backed PVC. Furthermore the contours of the mouthpiece made applying the adhesive by hand very tricky. A one-part flowable silicone adhesive was recommended by Steve Green, one of Techsil’s application development engineers.
Green says: “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 that can withstand very high and low temperatures. Therefore it’s 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 and a fly press to deliver the adhesive. The hood and mouthpiece is placed on a turntable and is rotated 360° during dispense.
This project has increased the speed of the manufacturing process. The Momentive IS5628E adhesive produces a sound bond that is uniform and repeatable due to the automated dispensing. In addition, adhesive wastage has been eliminated, which was an inevitability of hand application.