LIQUID SILICONE RUBBER | INNOVATION
control and iQ flow control also leads to fewer rejects, he said.
LSR foam moulding is a technology development with good potential, according to Vahid Salamat, Area Manager at Negri Bossi. The injection moulding technology group has developed a patented process called Foam Microcellular Moulding (FMC) for use with thermoplastics and LSR, he said at the LSR Innovations conference. In the FMC process, gas is released from the screw into the barrel, unlike other established processes where gas is injected from outside the barrel. Salamat said this approach provides more thor- ough gas dispersion and more even cell distribu- tion. Previous LSR foam moulding work by other developers was hampered by uneven distribution. Negri Bossi supplies a kit to injection moulders for converting machines to the FMC foam moulding process. The kit includes a gas accumulator, a specially designed screw (which the company says can easily replace the machine’s installed screw), pneumatic/hydraulic nozzle and connectors, and a proportional control gas valve. Salamat said Negri Bossi is still developing applications with customers, but it foresees market potential for FMC in areas including automotive (for non-cosmetic or painted parts), industrial packaging and household goods. At Fakuma 2017, KraussMaffei showed an injection moulding machine from its new PX series in an LSR demonstration. The PX 50-180 SilcoSet moulded a high-precision Fresnel lens in LSR. Jochen Mitzler, Head of Strategic Product Manage- ment at KraussMaffei, said: “In the case of this application, the modular concept of the new PX series from KraussMaffei particularly distinguishes itself. At Fakuma, the PX 50-180 SilcoSet [com- bined] hydraulic nozzle contact force with an electric injection unit in an unparalleled way. The
result is extremely high precision. The machine-to- mould connection is tight, the production is leakage-free.” Arburg gave a LSR demonstration at Fakuma in a
turnkey system centred on an electric two-compo- nent Allrounder 570 A. Two two-tone wrist straps made from Momentive’s LSR materials Silopren 2670 and 2620 were produced fully automatically in a cycle time of 75 s. Partners in the Arburg demonstration were Rico Elastomere Projecting, supplying a 2+2-cavity mould, Reinhardt-Technik supplying the dosing system and Regloplas the temperature control system. A Multilift V 15 linear robotic system was used for handling the flexible parts. The assembly of the watch mechanisms to complete the wrist- watch took place automatically within the injection moulding cycle.
Austrian mould maker Rico Elastomere Project-
ing specialises in the production of components using LSR and two-component moulds, and also in-mould techniques. As well as the collaboration with Arburg, Rico partnered with Momentive in another demonstration at Fakuma, showing production of form-locking tubing for peristaltic pumps. In a presentation at AMI’s LSR Innovations conference, Markus Landl, Rico’s Head of Interna- tional Business Development described high precision mould making in LSR being at “the heart of production”. He stressed the technological value proposition in LSR moulding which takes into account the vital role of the mould and mould maker from part design, through to production and planned maintenance. Reinhardt-Technik makes LSR dosing and metering systems that are designed to optimise materials usage, said Thomas Gerke, Senior Manager Systems & Applications – Adhesives & Sealants. At the LSR Innovations conference, he described features of the company’s technology that contribute to material savings during dosing of the A and B liquid components. The systems have servo-driven scoop piston pumps for simultaneous drum emptying, which reduce the loss of material
www.injectionworld.com
Above: KraussMaffei’s PX 50-180 SilcoSet
machine and Elmet dosing system for LSR moulding
Left: LSR moulding examples from Rico Elastomere Projecting
April 2018 | INJECTION WORLD 31
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60
