Bellignat, France-based injection molding machine producer Billion SAS included use of liquid silicone rubber in one of several multi-component for multi-innovation machine demonstrations running on the company's booth at the K 2016 fair in Düsseldorf, Germany.
This involved an example of one-shot Multitube technology to produce a three-component injection molded hard/soft air intake part. The soft gray elastomeric component used to overmold a gasket onto the black plastic base of the air intake consisted of the Elastosil LR 3023/60A/B grade of opaque LSR from Wacker Chemie AG in Burghausen, Germany.
As this paste-like, easily pigmentable two-component compound with 60A Shore hardness has low compression set, Wacker says it does not need post-curing. Wacker refers to the material's “extremely short curing times and excellent coolant resistance.” Other properties include 300 percent elongation at break, 5.5 N/mm 2 tensile strength and 15 N/mm tear strength.
The two hard thermoplastic components were both molded in the 30 percent glass-fiber-reinforced Grilon 30BG-30S grade of nylon 6, 6/6 blend from the EMS-Grivory division of EMS-Chemie AG in Donat/Ems, Switzerland, as black (229 shot weight) and red (100g shot weight) parts.
Molding took place on a Billion Select 200T all-electric drive injection molding machine fitted with a 1+1-cavity mold from mold maker Georges Pernoud SAS of Groissiat, France. Injection screw diameters were 50mm, 35mm and 16mm for respectively the black Grilon, red Grilon and grey Elastosil materials, which were injected by respectively H780 and H260 injection units and a Milacron Mold-Masters E-Multi EM1-30LS-16 injection unit.
Although the part had been already shown and demonstrated at the Amerimold 2015 and NPE 2015 fairs, Billion and Pernoud chose to call the K 2016 demonstration a “world premiere.” The earlier examples had involved a nylon rather than nylon 6/66 blend, plus they had involved TPE as the soft gasket material component in 2015, as opposed to LSR at K 2016.
“The need for this new innovation was identified during NPE 2015 as a real request from the automotive market,” Pernoud said.
Billion and Pernoud put together a fully automated production process at K 2016 for the air intake. It was based on a Select 200 molding machine (as at NPE 2015), supported by a Billion B5X-35 linear handling robot made for Billion by Sepro in La Roche-sur-Yon, France. Billion's molding production cell cooperation with Sepro had been formally concluded in July 2015.
The B5X-35 was fitted with a head from Process Industrie and it also placed four brass threaded screw inserts from SECAM Fixing Solutions into the mold area for overmolding into the black nylon 6/nylon 66 base. The inserts were fed into the pick-up position by a vibratory bowl feeder from Roland Bailly in Besançon, France and molding materials were dosed by equipment from Moretto in Massanzago, Italy. Crizaf srl of Saronno, Italy provided the conveying system for finished parts.
A Billion Dixit 3 control system controlled the K 2016 process, while the E-Multi injection unit had its own control system. Overall cycle time was 50 seconds and specific energy consumption was 0.14 kWh/kg.
The A and B components of the LSR material were mixed and dosed by servo-electric piston pump driven Silcomix PE 200 equipment from the Dopag business division of Hilger & Kern GmbH in Mannheim, Germany. The mixed LSR material was injected into the mold via a cold sprue at 20° C (68° F); mold cores were heated to 130° C (266° F) for injection and to 180° C (356° F) to cure (vulcanize) the LSR. S.I.S.E. of Oyonnax, France, provided its M Series V2 temperature controller for the process. The mold system designed by Pernoud used a vacuum pump to optimize LSR molding.
Pernoud's R&D department developed Multitube technology as an in-mold process to mold and assembly a number of parts together by overmolding in linked zones within a mold, with the parts being moved within the mold by robot or (preferably) rotating plates. Pernoud maintains rotating plates result in better shrinkage control, as the part remains on the core during rotation from one cavity to another.
The Multitube process results in highly productive cost-effective fully automatic molding of tightly sealed multi-component tubular parts without requiring downstream processes such as welding or intervention by the molding machine operator.
It represents a part of what Pernoud general manager Fred Barcons described at the ReInEU2016 reindustrialization of the European Union conference in Bratislava, Slovakia: “Pernoud is evolving from being just a moldmaker, through robotics and automation, to become a plastics systems integrator.” Barcons illustrated this by showing the K 2016 air intake demonstration part during his ReInEU2016 presentation.
Pernoud's R&D department has been involved since May 2016 in integration of information technology and communication with production on Industry 4.0 principles within the European BEinCPPS Business Experiment In Cyber Physical Process Systems project. It aims here to develop the “mold of tomorrow” as a 100 percent electric, intelligent and connected tool.