Based in Marchtrenk, Austria, on the northeastern outskirts of Wels, today’s Starlim Sterner Group started life with establishment of the Franz Sterner GmbH Werkzeugbau mold making company in 1974, which built its first LSR injection tool in 1978.
Starlim’s mold making now takes place fully automatically, 24/7, as the only feasible cost-efficient solution in a high-wage economy like Austria’s. Making its own molds keeps know-how in-house and 5µm precision, as needed to ensure precise molding and effective sealing. That is important to prevent the loss of LSR, in an extremely low-viscosity.
Molding activities started within the company with formation of a rubber and plastics processing subsidiary in 1984 that took on the Starlim Spritzguss GmbH name in 2004, an operation that presently molds 14 billion silicone rubber parts annually, mostly in LSR. That’s almost two parts each year for everyone in the world.
Starlim is highly vertically integrated as it produces all its own molds solely for its own molding production, but not for external processors.
The company is proud of the precision with which it produces silicone moldings, with earlier defect rates of 0.7 parts per million achieved in 2015 having been reduced to 0.5 ppm, “with 0.4 ppm planned to be the next big step,” explained Karl Großalber, vice president of marketing and sales. CEO Thomas Bründl has pointed out, “Zero defects do not exist, also not only purely statistically.”
Starlim Sterner annual sales have been growing continuously for many years, having risen from around 64 million euros ($76.5 million) in 2009 to reach 167 million euros ($200 million) in 2016 and 180 million euros ($215 million) in the 2016-2017 financial year. An identically shaped curve shows how the number of employees has grown from just under 500 in 2009 to 1,110 in 2009 to 1,190 in 2016-2017.
Großalber said the number of staff will rise again by around 8 percent, or 100 to a total of 1,300 employees, in the next year. He summarizes the situation: “The reason for strong growth is that although we are often not the cheapest, we can offer a full package including development.”
This also applies via Starlim’s subsidiary Silcos GmbH in Reutlingen, Germany, which specializes in various forms of surface decoration of plastics and silicone rubber parts such as by painting, laser marking and plasma vapor deposition (PVD). It also provides particularly silky surface effects with new Silmade-brand low-friction coatings, as the company has illustrated with a Weinmann medical technology silky surfaced nasal mask and a soft-feel Stabilo Smartball 2.0 pen, which combines an LSR housing with a conductive LSR cap and Silmade coating over the entire pen. Großalber says of such possibilities: “If a customer wants to have a silicone part with a purple-blue tint coated with stars, we have Silcos as a partner that can do it.”
Großalber said Starlim expects to double sales by 2025 just by organic growth, even more in the event of acquisitions of some smaller companies and/or those with competence in particular market niches. He added that Starlim differs from other companies in the elastomer processing sector, such as Freudenberg and Trelleborg, “who buy up small- and medium-sized companies, as they can’t themselves finance all the investment needed to meet customers’ demand.” This is how Trelleborg entered LSR molding, Großalber observed.
He continued by pointing to the advantage of Starlim being a company privately owned through the FSS Vermögensverwaltung GmbH family investment trust, meaning there is no pressure to depart from long-term growth plans over 10 to 20 years, due to a need to report positive results for each quarter to external investors.
While Starlim uses finite element modeling in part design, Großalber proudly pointed out how the company has additionally introduced 3 million voxel computer tomography (CT) with Zeiss Metrotom 800 equipment with measuring volume capacity of 125 mm diameter by 150 mm length to check on final molded LSR parts quality — for example, whether seals fully sit precisely as they should to fulfill their functions by looking at them from inside.
The technology is similar to the CT used by automotive connector producer Delphi in its Wuppertal, Germany, plant, used to check LSR silicone connector mats. Starlim is also a Delphi supplier, Großalber pointed out, “and that means that Delphi is a yardstick for us, against which we can measure our performance.”
With automotive applications accounting for a 47 percent share of Starlim sales, followed by life sciences (medical and pharmaceutical) at 30 percent and industrial at 23 percent, it is understandable that automotive connector producer Tyco Electronics is Starlim’s largest customer for connector moldings in both LSR and HTV silicones.
All Engel machines
Every one of the more than 100 injection molding machines in Marchtrenk are from Engel, all painted in Starlim’s blue and white corporate colors, except for several white machines in Class 7 and 8 clean rooms. The latter mostly stand still, as they represent a backup security reserve to support molding for a customer served by Starlim North America in London, Ontario, in case production is interrupted there.
Großalber said: “It is less expensive for the customer to have a single source [Starlim] supplying from two locations than to split requirements between two suppliers.”
He explained the machine and materials policy as to “keep it simple,” easing maintenance tasks and running just one control system, as well as keeping up to date with developments together with Starlim’s suppliers, who have been growing with Starlim as silicone technology progresses and many of whom have been placing orders at Starlim for 25 to 30 years. The same single source approach applies to raw materials, too, Großalber added.
One particular feature of the machine park is the way all of the LSR material drums and “Sterner” mixing and dosing equipment, developed by Starlim itself, are located in the cellar below the molding machines. This keeps the floor area clear with a small footprint for each machine.
The company’s control room displays details of all machines running worldwide in real time on large computer screens. This enables staff to identify nonoptimal processing conditions and to inform the local production staff immediately, or at least when they come into work later in the day.
Solid silicone in form of HTV (high-temperature vulcanizing) material used at Starlim addresses the need for higher chemical resistance to automotive fuel needed for spark plug covers and certain automotive connector mats, as the material tends to swell less than LSR. Großalber says 40 percent of the connector mats are molded in LSR, the rest in HTV silicone runner. Showing the solid nature of the material, Großalber said it becomes just as easy flowing as LSR when it is inside the molding equipment.
While touring the parts display room, Großalber pointed to use of LSR for the dog lead of a Playmobil toy figure of a person with a dog, stressing importance of using LSR to avoid safety concerns, in event of the line becoming detached and getting swallowed by children. Just as important are the large seals produced for dialysis equipment, as “if it doesn’t work, the patient dies.” This has been emphasized to Starlim staff by taking them to visit a hospital dialysis station.
The market for LSR computer keyboard mats has been declining, but the decline has been more than compensated by growth in Asia, where there is also strong growth in showerhead mats, produced in Austria and delivered to Asia.
Asked about micromolding LSR, Großalber replied “we are still in the infancy stage here, but we do have some micromolding lines as a means of developing solutions for customers.”
Multicomponent molding at Starlim has been growing at a rate just under 20 percent annually, Großalber said.