Grooved rolls stiffen cross-laminated film.

Inventor Ole-Bendt Rasmussen of O-BR Enterprise in Walchwil, Switzerland, who created the Valeron process for cross-laminating helically cut blown film, is patenting a new wrinkle on that technology. A drawback of cross-laminated films is that when downgauged they become soft and floppy, so they often won't work in conventional bag-making and filling machines.

Rasmussen solves this with a cross-laminating process that starts by MD-orienting each ply and then passing the ply over a pair of finely grooved rollers. He has developed eight different grooved rollers that impart different characteristics. The pitch of the waves or grooves is 1 mm. This results in fluted plies, which are laminated to a transversely oriented film. Both films are coextruded with a structural main layer and a lower-melting lamination layer. The result is a uniquely stiff cross-laminated film, suitable for bags and stand-up pouches. Rasmussen's R&D was done with HDPE, but the same process could be applied to PP or PS, he says. Tel: [phone] * www.xf-plasticfilms.com

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