SKZ Conference review

Ursula Nollenberger, product director LSR components at Trelleborg Sealing Solutions, focused on wine bottle stoppers at the KZ Süddeutsches Kunststoffzentrum Silicone Elastomers conference, held March 22-23 in Würzburg, Germany.​

Options included a thermoplastic grip with a lower section overmolded with LSR, and two all-LSR corks, one in a more flexible material.

The simulation showed unacceptably high insertion forces for the LSR/thermoplastic and the rigid all-LSR stopper, while the softer all-LSR stopper had an acceptably low 32 N insertion force.

LSR/thermoplastic and rigid all-LSR stoppers withstood higher pressures, even though the 1.1 bar level for the rigid all-LSR stopper would be good for a sparkling wine, Nollenberger said. The ability of the softer all-LSR stopper to withstand 0.64 N was rated acceptable for conventional wines.

Oliver Franssen at Leverkusen, Germany-based LSR producer Momentive Performance Materials talked about using self-lubricating LSR to seal automotive connectors.

Franssen said there is a trend toward replacing separate round seals around each wire with one larger surface area rectangular mat-shaped seal sealing a number of wires.

One development goal, Franssen said, is to obtain LSR with 10 percent compression-set after 24 hours at 175° C, without tempering the material. Low compression-set is particularly beneficial in enabling mat-shaped connector seals to be re-used a number of times, Franssen said.

Udo Wachtler, technical manager at Wacker Chemie AG in Burghausen, Germany, talked about new LSR products with electromagnetic shielding properties, as well as a new high flexible modulus Elastosil LR 3003/90 grade.

He also referred to hard/soft two-component combinations.

Dow Corning Corp.'s R&D manager Patrick Beyer discussed a similar development, an "ultra hard" Shore A90 grade, Silastic LC 8800-90.

He said the material possesses "a unique combination of elasticity and strength."

A wine bottle stopper made from LSR materials.

LSR World photo by David Vink