Just the beginning for LSR at Rico

Rico Group has its headquarters in Thalheim, Austria, where it operates as Rico Elastomere Projecting GmbH in mold making, automation and molding of both liquid silicone rubber and high-temperature vulcanized (HTV) silicone rubber parts.

Although founded as a mold maker with its own patented cold runner system, Rico has been also molding parts since 2012. The Thalheim molding shop has Arburg machines, while the technical department has both Arburg and Engel presses.

The machines are supplied with LSR by mixing and dosing units from Reinhardt-Technik and 2KM.

Presses in the technical department try out molds in pilot series. This enables the molding shop machines to focus on serial production, where Rico also encourages companies "to extend their workbenches" by outsourcing some or all of their production to Rico.

Markus Landl, head of international business development at Rico Group, said the development of applications and markets has been an exciting history in LSR's relatively short 40 years lifetime. Multishot molding has been developed just within the past 25 years, and "it is certainly exciting to see, when looking back, how this concept has developed, both in terms of materials and tooling, especially in the way it combines a cross-linking material with thermoplastics."

Multicomponent molding needs a larger molding machine than single-shot molding. While secondary LSR components can be fed via injection units mounted vertically or at an angled piggyback way, Rico's preferred configuration is with side injection in the so-called "L" orientation, relating to the position of the secondary injection unit to the main one.

This facilitates cleaning, which is difficult with sticky LSR materials, aside from challenges when feeding the extremely low-viscosity LSR from above, Landl said.

"The bottom line that always has to be taken into account is that it always has to pay off. I may be a company liking multishot molding because it is cutting edge technology in LSR that is nice to have. But I should look at it more closely already in product development and ask myself whether I can integrate more functions in the part and also whether multishot may be the only possible solution. Does it make sense?

"This may be indeed the case, especially if it enables elimination of laborious assembly operations. But decisions need to be made on a case-by-case basis," Landl said.

"Although designers have the best ideas, can their designs be produced?" Landl asked. Since Rico molds parts 24/7 with lights-out, unmanned operation at night, processes, materials, machines, tools and product design all have to agree with each other, Landl stressed, both for single and multishot molding.

In November, Landl will present a case study from Simtec Silicone Parts — one of three companies that comprise Rico Group. The paper, "Multishot molding — from fiction to reality," will be given at the Smithers Rapra Silicon Elastomers World Summit in Munich.

Landl said Rico would also soon be revealing details of a multicomponent automotive application involving polycarbonate and polybutylene terephthalate overmolded by transparent LSR.

Landl said it is interesting that many do not realize where LSR is used. Examples include in shower heads, as a complete mat with integrated nozzle functions largely hidden from view behind a large diameter metal plate. Compared with thermoplastic elastomers, Landl said, LSR performs well under extremely high temperature conditions.

He added that Rico Group's combination of mold making and molding competence is a win-win situation for the market.

"We position ourselves definitely in the premium segment, which means the applications we have are demanding in both part development and production-oriented design, where we use tools such as finite element modeling [FEM] calculations and thermal analysis through to start of project after using prototype tools and running pre-series production."

Rico uses Sigmasoft mold filling simulation to avoid knitlines and to ensure full venting of air at the end of flow paths. The material data bank it built up over 20 years forms the basis for FEM calculations to predict demolding forces.

Landl says Rico often provides complete turnkey solutions, with all tools tried out before delivery and subsequently performing maintenance of customers' tools. Landl stressed importance of cold runner thermal separation to ensure mixed LSR components do not prematurely cure prior to injection, although there is always some curing starting already at around 25°C.

In Landl's opinion, "LSR is a relatively young material, and I believe designers and product developers and managers worldwide are only now beginning to notice which value this material has. It is becoming attractive for many areas."

For Rico, it has meant a wide range of applications, in automotive, sanitary, electronics, medicine, household appliances (coffee machine seals), packaging (closure seals and dosing membranes) and life sciences. While baby drinking teats, soothers and pacifiers used to be entirely in latex rubber, they are now made mostly in LSR, as a biocompatible material that easily conforms to U.S. Food and Drug Administration requirements, Landl said.

Rico expanded the mold production space in Thalheim in 2016 from 10,000 to 21,500 square feet. It will increase the size of the Thalheim chemical laboratory and development department in 2018 and make more space available for more machines, mainly for injection molding. This expansion will be accompanied by a new modern logistics center, Landl said.

Looking ahead, Landl said that with part production continuing to grow, the company's tooling activities will remain stable and constant and that the company will continue investment to support LSR technology in the market.

The term Industry 4.0 has taken on a tendency of being too much overused, Landl said, and then asked, "What does it really bring? Everyone has to decide on what it brings for them."

For its part, Rico has anyway established the efficiency and reliability of its production systems, having received IATF 16949 certification from the International Automotive Task Force, as one of the first companies to become IATF-certified in Austria.

Partner companies Silcoplast AG of Wolfhalden, Switzerland, and Simtec Silicone Parts LLC of Miramar, Fla., have obtained ISO 13485 medical quality management systems certification, Simetec also has ISO TS 16949 certification.

As Landl puts it: "We don't want to just monitor quality but to really produce quality."

Rico was established in 1994 as a toolmaker by its present managing partners Alfred Griesbaum, Johannes Grabner and Gerhard Kornfelder and has meanwhile grown to employ 200 staff in Thalheim, where it has annual sales of around 28 million euros.