Lenzing Aktiengesellschaft

Chemiefaser Lenzing Aktiengesellschaft

Adalbert G Wimmer

Ernst Rauch

Christian H Schlossnikl

Haio Harms

Ingo G Marini

Josef Baumgartinger

Josef Bachmair

Franz Sasshofer

Friedrich Gotschy

Johannes Krassig

Reinhard Reinmuller

Josef Bachmaier

The invention relates to a process for the production of a low-fibrillation moulded body containing polytetrafluorethylene. The process is characterised in that a pre-moulded body of polytetrafluorethylene is twisted and then pressed flat. The pre-moulded body can be twisted around itself or around another material e.g. a mono- or multifilament or a spun yarn. The invention relates furthermore to a low fibrillation moulded body containing polytetrafluorethylene which can be obtained by means of the process in accordance with the invention and the use of the moulded body in accordance with the invention as dental floss.

Low-fibrillation moulded bodies

Monoaxially stretched molded article made of polytetrafluoroethylene

Moulded article made of polytetrafluoroethylene

To produce a monoaxially stretched shaped article of polytetrafluoroethylene (PTFE), a pasty mass containing PTFE powder is continuously shaped to a shaped body, which is fed over a plurality of rollers or rolls, heated and stretched. The shaped body is heated to a temperature of between 327.degree. and 450.degree. C. prior to stretching strain, it is sintered simultaneously and is then stretched. This process allows for the production of a monoaxially stretched shaped article of PTFE which has strength values in the stretching direction of at least 500 N/mm.sup.2 and a delivery of between 1.80 and 2.30 g/cm.sup.3.

Monoaxially stretched shaped article of polytetrafluoroethylene and

There is disclosed a heated roll for the thermal treatment of formed products. It includes a driven hollow shaft and a hollow roll body of a circular-ring-shaped cross section and closed on all sides to accommodate a heat transfer medium. Power supply lines for heating elements as well as electric wires of temperature probes are led through the hollow shaft. In order to provide a heated roll to be used without problems both in the low-temperature range and in the high-temperature range up to about 600.degree. C. and to reach a uniform temperature profile over the total operation surface of the roll outer shell and a long service life of the heat transfer medium, without excessive temperature prevailing at the bearings of the driving shaft, and to provide for an easy repair, the hollow shaft is connected with the roll body by a hub. One or several saline compound(s) or (a) low-melting metal(s) or metal alloy(s) are contained in the interior of the hollow roll body. The heating elements are provided in the cylindrical inner part of the roll body. The temperature probes are arranged both in the cylindrical inner part and in the cylindrical outer shell, of the roll body.

Heated rotatable roll arrangement

A method of making threads or fibres of polytetrafluorethylene with improved heat conductibility uses thread of fibre cores enclosed by envelopes which contain fine-particle polytetrafluorethylene, a heat conducting pigment and a binder. Such threads or fibres can be used to form a sealing packing.

Threads or fibers of polytetrafluorethylene

A method of producing threads and fibers of synthetic materials uses a cylindrically-shaped body of the synthetic material which is allowed to rotate against a scratching tool and a peeling knife arranged to follow the scratching tool in the direction of rotation. The peeled-off curtain of parallel threads is stretched, possibly while being simultaneously heated, and possibly the threads are cut to form a staple fiber or are ground to a short-staple floccule. A device for carrying out the afore-mentioned method, has a turning mechanism, a foil-peeling knife secured to a carriage of the turning mechanism, and a scratching tool arranged to precede the peeling knife.

Apparatus for producing synthetic fibers

Growing community of inventors

Vocklabruck, Austria

Adalbert G Wimmer