Sei Woo sets sights on micromolding market

Although a number of LSR molders and an LSR material supplier say in-house mold making is crucial to success in automatically molding flash-free parts, Sei Woo Hi-Tech Polymer GmbH in Holzhausen, Austria, is a notable exception.

Sei Woo decided to work closely with mold maker ACH Solutions GmbH Hefner Moulds in Fischlham, Austria, located around 60 miles west, near the border with the state of Bavaria in Germany.

ACH Solutions Hefner claims to be one of the world's leading engineering companies for tooling and production equipment for processing of silicone rubber and other multicomponent tools. ACH has demonstrated LSR technology at a number of injection molding machinery company open houses and trade fair booths.

"The greatest genius in the silicone sector, not [just] because I work with him, is [Christian] Hefner as founder of ACH Solution. He is well ahead of others, that is certain," said Peter Lehmann, managing director of Sei Woo Hi-Tech Polymer.

Lehmann, a former Starlim employee, explained: "We just produce LSR parts for customers, as we are too small to do our own toolmaking, as we only need five, six or eight new tools per year."

LSR World visited Sei Woo in its new building, several kilometers away from its previous site, so new that a Sei Woo street sign was still showing the wrong direction. This frustrated Lehmann, who has tried for months to get the sign changed. The council told Lehmann he had no authority to change the sign himself.

Sei Woo runs 14 Engel injection molding machines in its machine park, along with three Fanuc Roboshot machines. Lehmann said tests have started on the Fanuc machines, rebuilding by Nexus Automation GmbH in Schörfling/Attersee, Austria, for LSR. Among various turnkey plastics processing solutions, Nexus will show an LSR one on the Fanuc booth at Fakuma 2017.

Lehmann justified including Fanuc machines in the machine park by saying, "Although I have had a lot of positive experience with Engel machines and the Sei Woo group head in Singapore is an Engel fan, one shouldn't go through the world with blinkered eyes. We tried some years ago to convert a Fanuc machine for LSR, but it wasn't the right time or just too soon. But the experience that we gained is that the Fanuc machines work with incredibly high precision and reproducibility."

Sei Woo Hi-Tech Polymer was founded in 2000, when it started molding solely for its parent company, Singapore-headquartered Sei Woo Polymer Technologies Pte Ltd., a rubber parts producer, established in 1962 by the group's head, Low Yoon Keong.

The group has production plants in Austria (Sei Woo in Holzhausen), China, Malaysia and Thailand — the company having moved production away from Singapore when it became too expensive.

Lehmann said Sei Woo Hi-Tech Polymer no longer produces for the parent company, having set up its own molding production in Singapore at the end of 2016, adding to the Holzhausen molding facility. The parent company produces for large renowned international customers such as Apple, Samsung and GoPro.

Lehmann said these electronics OEMs served by the parent company are a "crazy world," with very short product lifetimes and incredibly large number of parts required in this short period. Largest quantities are needed in the summer and fall, the next model starting in January/February. "As it is difficult to hold professional trained staff during these ups and downs, we therefore focus more on the medical area with its longer product lifetimes as it is more stable. Even though it takes a while to start, major LSR materials producers have approved grades," Lehmann said.

LSR has weakness, as it allows air ingress, "like a sponge." Attempts are being made to compound approved additives into standard medically approved LSR grades to overcome air permeation. Lehmann hopes to arrange a mold for Singapore for local production, as the customer seeks fast local delivery there without buffer stocks.

Multinational companies now seek flash-free parts without the post-molding work that is still largely in Asia, as Asian unit wage costs rise, Lehmann said.

"We remain competitive with European production as long as parts come out of the mold automatically and don't need further work," he said.

He continued: "In our Singapore plant, we get all the support we need these days from Engel and material suppliers locally, so if something goes wrong, it is mostly solved within a day."

He also praised interest, commitment and incredibly fast reaction and decision-making of the Singapore government. "We could learn from this in Europe," he said, comparing it with difficulties in getting his Sei Woo direction sign changed by Austrian authorities.

"Having the two locations will certainly help us in future. It would be perfect if we also had a plant in America, on which we are naturally working, but we can start everything at the same time. But we will certainly start there in the longer term," Lehmann predicted.

He said that Sei Woo, as the smallest molder in the Wels area, has the disadvantage of paying a huge amount more for LSR materials than others in the area, while its machines do not run any faster. Lower overhead costs alone do not suffice to make Sei Woo competitive vs. the local competitors in large volume items such as baby teats. So the company adopted a strategy of focusing on smaller volume and physically smaller yet highly precise parts, where high material cost is less important. Lehmann sees advantages in using Fanuc machines for such micromolded parts, even two-component ones.

"Having received quite large orders for such parts, typically 50 million, these are checked by a camera system from Keyence in Singapore, as the machine itself simply can't to it. We have been getting better results with a 15-metric-ton Fanuc machine here, equipped with a 12-millimeter-diameter screw. We will probably move to 30 tonnes to have more space between tiebars," Lehmann said.

Sei Woo still has to see how stable the process is on Fanuc machines. The company continues to work mainly with Engel, which provides "very good sensational co-operation."

By comparison, Fanuc appears to want to have less to do with the Robot machines after they have been rebuilt for LSR, Lehmann said, adding that communication is more difficult than with Engel.

Micromolding with a 15-mm screw "is just possible," but better with 12 mm. "But molding is less difficult than demolding, as even after sucking air out by vacuum before injection into the cavity, there is still residual air left behind," Lehmann said. "But nevertheless, there is much more fun in focusing on micro parts."

The parent company plant in Singapore molds LSR for an Apple iPhone lightning cable part, as well as overmolding an Apple iPhone cover with LSR, presumably coated due to LSR's sticky nature. Lehmann said he has found discussion with Apple on problem areas longer and more difficult than Singapore staff did, which he cannot really explain. In contrast, he found meetings with action camera producer GoPro both very pleasant and cooperative, with decisions easily made within one month after constructive brainstorming sessions, to mutual benefit: Sei Woo now molds four to five seals for waterproof GoPro cameras.

In the area of LSR baby drinking teats, Lehmann is surprised teats are tempered in Europe at four hours at 120-130°C to drive off residual volatile substances. He cannot comprehend this, as it involves a lot of time and energy, while American teat molders do not temper. Although Shin-Etsu was apparently the first LSR material supplier to introduce temper-free material and others are following, molders seem to be insisting on following tradition and playing [unnecessarily] safe. This is a huge cost factor, Lehmann said, since some teat molders make 100 million or more teats per year, a level that clearly excludes Sei Woo Hi-tech Polymer. He does, however, admit that tempering of conventional LSR grades brings some advantages in mechanical properties and better adhesion to thermoplastics in multicomponent molding.