2013 | Technology review A cool approach to moulding LSR
Austrian LSR processing specialist Elmet demonstrated the latest development of its cold-curing moulding technology, which allows LSR to be overmoulded onto low melting point thermoplastics such as PE, PP or PMMA. While LSR can be over- moulded onto thermoplastics, the high curing temperatures of 150-180˚C mean that material selection has been restricted in the past to polymer such as PA and PBT, with associated higher cost, according to Elmet sales manager Wolfgang Leitner. Elmet has previously
demonstrated a cold-cure system using UV lamps to cure the LSR via a transparent window integrated in the mould, but such solutions are prone to wear and windows can require replacement at intervals of 5,000-10,000 cycles. In this new demonstra- tion, producing a PP soap dish with a moulded in LSR base, the transparent PP part acts
curing material is not available in self-bonding grades so we have to use mechanical bonding features and this needs to be accommodated at the design phase. But for many applications the seal only has to hold in place until assem- bly,” Leitner said. Aside from the opportunity
as the illumination window. The turnkey system was running on a standard 50 tonne Engel e-Mac moulding machine using a special UV curing grade of LSR from Momentive and a two cavity mould from Elmet. In the first production step the main body of the translucent tray was moulded in PP in the lower mould cavity. That part was then demoulded by a robot and moved into the upper second cavity. The LSR component was injected in the second cavity,
where the translucent PP substrate moulding acted as the window over the UV lamp. “We are using the PP part as part of the cavity,” said Leitner. The entire cycle time for the part was 45s, but the system has run effectively at 35s in Elmet’s own development centre. Leitner said that for thin LSR sections, UV curing is slower than thermal curing. However, thicker sections can be faster as the process is not delayed by thermal conduction. “At the moment, the UV
to use LSR in combination with less costly polymers, the UV curing process also requires less complex equipment. A standard thermoplastic moulding machine can be used with the LSR delivered from a simple standalone compressed air-powered mixing and dosing pump.
“Because we are cold
curing, the injection of the LSR is not critical – we just fill the mould and once it is full we switch on the light. No pre- heating is required,” Leitner said. “This is not a solution for all combinations but it opens up a new market and it runs on any thermoplastic machine.” ❙
www.elmet.com
Moretto introduces OW6
Italian ancillary equipment maker Moretto showed its new One Wire 6 (OW6) self adaptive material conveying control system, which is designed to make adding new equipment to a network a more simple task. According to the company, connecting a
processing machine to the material store becomes as simple as just connecting the pipe using the OW6 system – it is not necessary to modify system data or parameters as the control system will recognise and self-adapt to the new condi- tions to maintain maximum efficiency.
52 INJECTION WORLD | January/February 2014
The OW6 server is able to manage up to 80 client devices, including receivers, suction units and automatic manifolds. It features a main control with a 10-inch touch screen panel and is preconfigured for use with the company’s Kruise Control material feed control. The company also introduced a revised
range of receivers at the show. The updated Kasko models are said to be more compact and efficient and less noisy in operation. A new maintenance-free cyclone filter system was also announced. ❙
www.moretto.com
www.injectionworld.com
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