Source: GW Plastics.
GW Silicones, a division of international custom precision injection moulder and contract manufacturer GW Plastics, Inc., is in the final stages of a three million dollar expansion of its Royalton, VT Liquid Silicone Rubber (LSR) moulding operation, adding both cleanroom manufacturing space and new Engel injection moulding equipment.
Established in 2008 to support the needs of existing GW Plastics customers, GW Silicones has quickly outgrown their original class 8 cleanroom moulding and assembly facility, and is undergoing a 15,000 square foot expansion that will provide space for up to 18 new injection moulding machines. The entire facility (scalable up to 25,000 sq ft) is devoted to cleanroom LSR moulding and assembly.
“Having reached our current manufacturing capacity, we needed to add additional injection moulding systems to meet new business demands. This meant expanding our facility to match the growth of our LSR business,” states Mark Hammond, General Manager of GW Silicones.
In keeping with their parent company philosophy, GW Silicones also plans their machinery purchases to maintain open capacity in order to take on new business with no delay to the customer.
GW Silicones dedicated to Engel machines
GW Plastics believes that standardization of equipment across all locations is the best way to meet customer and market requirements. Molds can be moved from machine to machine, facility to facility, and within hours they can be producing precision parts.
At GW Silicones, the machine of choice is Engel. GW Silicones’ current cleanroom is equipped with Engel machines ranging from 50-200 tons – the sweet-spot for LSR moulding -- with additional machines and robots scheduled for delivery by the end of March. The new cleanroom will be equipped with all-electric, hybrid and hydraulic machines, giving GW Silicones the ability to match the best machine to each prototype and production moulding application. Multiple screw/barrel assemblies for each press will allow for the moulding of parts from fractions of a gram to larger pound shots, providing an extremely wide range of moulding capabilities, encompassing the size range of most LSR product requirements.
“The Engel machines provide accuracy with the all-electric equipment, production flexibility with the tiebarless clamp design, ease of set up with integrated robotics, and the proven Engel technology and reliability,” says Hammond.
GW Silicones frequently incorporates automation into their injection moulding cells. For example, a current cell at GW Silicones includes a 6-axis robot, that operates within the machine envelope, enabling both insert-loading and moulded-part extraction. Two of the new Engel systems being added to the expanded cleanroom will include Engel viper servo robots.
LSR materials challenge moulders
The field of LSR moulding is a challenging one. From the perspective of GW Silicones, there are very few LSR moulders capable of manufacturing precision, flash-free componenets and assemblies. Most are equipped to manufacture only the most basic LSR products, not the high precision, close-tolerance, complex LSR applications that require a specialist like GW Silicones. GW Silicones customers know that it takes a unique combination of capabilities, expertise and resources to get the job done quickly, effectively and successfully the first time.
When planning their expansion into LSR moulding, GW Plastics sought to extend their industry-leading design and manufacturing capabilities to seamlessly integrate GW Silicones into their robust portfolio of full-service customer offerings. To accomplish this goal, they hired highly-experienced technical and commercial specialists to launch and grow GW Silicones and to ensure that the new division would meet the high standard of expertise and service its customers expect. This includes in-house LSR mould design and construction as well as niche process capability.
The ability to mould multimaterial (thermoplastics and LSR) components such as 2-shot, insert- or overmoulded parts is a specific skill of GW Silicones, and one that gives them a particular niche in the moulding marketplace. LSR can be used to create complex moulded parts with finer detail and tighter tolerances than are often possible with other materials. When moulded onto thermoplastic substrates, the resulting multi-material performance options are numerous. Their familiarity with the demands of LSR processing and their knowledge of material properties, allows the staff at GW Silicones to assist their customers in ways most LSR moulders cannot.
The future of LSR moulding
Hammond sees exciting growth opportunities for LSR in healthcare, automotive and industrial/consumer markets. Among the most tested biomaterials, silicones are increasingly desired based on their unique combination of biocompatibility and performance properties:
• Chemically inert, odourless, tasteless and stainless
• Bacterial resistant and easy to clean and sterilize
• Biocompatible and short/long-term implantable
• Lubricious for less invasive biological applications
• Temperature flexible – 180ºF to 600ºF
• Fatigue and compression set resistant
• Chemically resistant
• Elongatable – 100 to 900%
• Dielectric with superior insulating characteristics
Because of these unique properties, LSR is particularly applicable to high-growth healthcare and medical device market segments like cardio- and peripheral vascular, aesthetic surgery, minimally invasive and micro-surgery, in-vitro diagnostics, drug delivery, wireless monitoring, neurostimulation and neuromodulation.