Take 5: A look at silicones

Silicone is one of the hot spots for innovation at K2016 and one in which smaller players often hold their own with the big materials suppliers in the development stakes:

Silicone Engineering Ltd. of Blackburn, England, is showcasing kSil V-0, a sheet sponge materials developed to improve safety and comfort for rail passengers. According to Steve Hadlington, technical and innovations director at Silicone Engineering, the material is "the complete silicone material" for sealing and vibration dampening within rail carriages. The material, he pointed out, has been approved and specified to rail industry standards, including EN 45545-2, BS 6853 Cat 1 and NF F-16-101 F0, and has generated considerable interest at the Duesseldorf show.

In Hall 6 Momentive is featuring two-component LSR on LSR molding with Silopren LSR 2670 liquid silicone rubber in cooperation with Elmet and Arburg. System supplier, Elmet, created a 4+4 cavity mold manufacturing egg-holders and built a fully automated turn-key cell by integrating an Arburg injection molding machine with its own peripheral devices and dosing system. The installed close-loop controlled color injection at the dosing system is a new feature that is being presented for the first time at K.

Sigma Engineering GmbH is displaying an “entirely new perspective” on its virtual molding technology—featuring the complete development chain, from part design, over-mold manufacturing up to serial production. Sigma furthermore offers a first outlook on future software developments, which include Design of Experiments and an optimization tool. These capabilities are being illustrated with displays including a bottle carrier mesh by CVA Silicone, presented in collaboration with Momentive, CVA Silicone and Engel.

Machine maker Arburg is demonstrating a new watch manufacturing concept involving multi-component injection molding, automation and the processing of liquid silicone with an efficient turnkey system. An electric two-component Allrounder 570 A with a clamping force of 2,000 kN and size 400 and 70 injection units produces two two-colored wrist straps LSR Silopren 2670 and 2620 in a cycle time of 75 seconds. The 2+2-cavity mold is from Rico, while the dosing system is supplied by Reinhardt-Technik and the peripherals by Regloplas. Assembly into a ready-to-use wristwatch takes place within the injection molding cycle with a linear Multilift V 15 robotic system.

Wacker A.G. is presenting a “world first” with its ACEO Imagine Series K industrial 3D printer. The printer head deposits tiny silicone droplets on a substrate. In this way, the work piece is built up layer by layer. The silicone is formulated so that the droplets flow together before the curing process begins, which is activated by UV light. The end product is a homogeneous work piece, which does not differ much from injection-molded parts. Until now, there has been no “mature” 3D printing technology available for silicones, said Wacker, adding that the device prints faster and is more compact than any existing design. “It can be used to make parts and assemblies with complex geometries,” says Bernd Pachaly, head of Wacker's silicones research and responsible for the ACEO team. Target markets include the automotive, aerospace and medical industries.