Dow Chemical Co. and Sentinel Polyolefins LLC separately introduced on June 1 high-performance foams based on Dow's new Index ethylene/styrene copolymers.
Dow's exceptionally soft and tough Synergy soft-touch foams are substitutes for cross-linked foams in applications such as automotive materials handling, padding and protection for military electronics and munitions.
Sentinel's SenFlex foams have the softness and flexibility of high-density foams at a fraction of the weight. They also exhibit very low compression set, usually a property of high-density foams. The Hyannis, Mass., firm is aiming them at gaskets and seals, marine flotation products, athletic padding, electronic packaging, auto applications and building materials.
Although both companies announced the new foams on the same day, officials said the announcements were unrelated except that Index copolymers are involved. Sentinel Chief Executive Officer Scott Smith said his firm has no restrictions on the use of SenFlex, which is based on Sentinel's own technology. He said he views Dow's new foams as competitive products.
Dow of Midland, Mich., makes Index copolymer using its Insite single-site, constrained-geometry catalyst technology. Officials said in a June 2 telephone news conference that the Dow Performance Foams business unit will introduce later in the month Quash sound-management foams for acoustic uses and Envision custom foam laminates, also based on Index copolymers.
Dow Performance Foams was created late last year to reflect the firm's expanding product line and supply to a greater variety of markets.
Smith said converters can save costs with SenFlex because its density is half or less than high-performance PVC/nitrile and foams made from ethylene diene propylene monomer. SenFlex also can be thermoformed and compression molded into complex shapes, eliminating scrap generated in conventional foam-cutting operations, Smith said by phone.
SenFlex-h, made by blowing with isobutane, is supplied in continuous rolls or planks. It has a density of 1 pound per cubic foot and gives high shock attenuation and two-thirds less compression set than typical physically blown PE foams, the firm claims.
SenFlex-b is a chemically blown, cross-linked foam in bun form up to 4 inches thick. With density of 2 pounds per cubic foot, it can replace PVC- nitrile foams with densities of 4-12 pcf, Sentinel said. It exhibits low compression deflection, low compression set and high shock attenuation.
Dow's Synergy foam now is available in development quantities, but supply will grow as markets open up. Dow touts its back integration in Index resin as an advantage in market development. It estimates the annual market for soft-touch foams at about 250 million board-feet. Dow will rely heavily on its authorized fabricators to develop and supply the market. It now is working with more than 15 such firms around the world, estimated Mark Henning, global business director for Dow Performance Foams.
Dow did not disclose typical styrene content for Index resins used in Synergy foams, but said it varies according to application. Synergy is made from a blend of Index resin and low density PE. The foam was developed to meet customer needs rather than replace specific materials now used in the market, said Anthony Johnson, sales manager for Dow Performance Foams North America. One advantage it has over cross-linked polyolefin foams is that it is recyclable.
Synergy 5000, the softest grade, has density of 1.5 pcf. Synergy 3000 and 1000 densities are 1.6 pcf and 1.5 pcf, respectively. The materials are supplied as planks.
Dow has been in polyolefin foams since 1959, when it introduced Ethafoam PE foam. Synergy foams are made using its RapidRelease technology, in which the hydrocarbon blowing agent is purged from the foam in an accelerated curing stage.