Gullfiber Ab

Other

Gulfeber, A.b.

Heikki Korpela

Jan-Olof Johansson

Karel Spacek

Ralf Warna

Alf G Assarsson

Lars Norrhede

Leif Ampler

Raw material to be expanded is supplied to an expansion chamber (12). The volumetric weight (M) and the moisture content (F) of the expanded material is measured, and signals representing the measured values obtained, are supplied to a microcomputer (27). This is programmed for comparing the volumetric weight as measured with a nominal value of the volumetric weight at the prevailing moisture content of the expanded material and is adapted to supply in dependence of the comparison made a signal for controlling the screw conveyor and drive unit (11, 13) for the supply of raw material to the expansion chamber to control the expansion of the material in dependence of the comparison by increasing or decreasing the amount of raw material supplied per unit of time.

Method and apparatus for measuring and controlling the volumetric weight

Method and device to be used in the continuous manufacture of foamed plastic in which pre-expanded granules of thermoplastic material are introduced into a channel (38) defined on at least two sides by the inside surfaces (18) of endless, perforated moving belts. Passing through a first zone (26) of the channel and in direct contact with steam injected through the belts, the granules are caused to expand further and to sinter or agglomerate to form a coherent, continuous thermoplastic strip or web (21). This is then treated by a vacuum process in a second zone (28) of the channel. In order to bring about an increase in the machine's (10) capacity for producing foamed plastic, or, alternatively, to reduce its length, the thermoplastic web (21) is cooled by a 'forced cooling process' taking place in the third zone (30) of the channel in which the inner surfaces (18) of the belts are acted upon by a coolant of higher thermal capacity than air. A suitable coolant would be a liquid; a special apparatus (34, 36, 44, 46, 48, 50) is therefore provided to direct the liquid against and/or along the said surfaces (18) of the belts for at least a section (32) of the third zone (30) of the channel.

Method for continuous manufacture of foamed plastic

An apparatus for cutting a cellular plastic web emerging from a web forming machine into a plurality of predetermined lengths is described. A cutting device including a plurality of mutually spaced filaments is provided on a movable carriage slidably supported on a support stand. The filaments extend transversely of the carriage and the direction of the web emerging from the forming machine. The carriage is mounted on the stand for reciprocating sliding movement. In one direction of traverse, the carriage moves in synchronism and in the same direction as the web and simultaneously divides the web into separate lengths by means of transverse cutting devices. The filaments move alternately toward and away from the carriage to cut the web during successive synchronized movements of the carriage and web. Further, the filaments may be horizontally moved to cut profiles other than straight, vertical sections in the separate lengths of the web.

Transverse cutter

An apparatus for cutting a cellular plastic web emerging from a web forming machine into a plurality of predetermined lengths is described. A cutting device including a plurality of spaced filaments is provided on a movable carriage slidably supported on a support stand. The filaments extend transversely of the carriage and the direction of the web emerging from the forming machine. The carriage is mounted on the stand for reciprocating sliding movement and in one direction of traverse moves in synchronism and in the same direction as the web. The filaments move alternately toward and away from the carriage to cut the web during successive synchronized movements of the carriage and web.

The invention relates to an apparatus for continuous production of a strand of porous thermoplastic material from preferably pre-expanded granules of said material containing an expanding agent. The apparatus comprises an elongated rectangular channel, two opposite sides of which are formed by the horizontal parts facing one another of two superimposed endless belts moving in a closed path between turning rollers. The granules are introduced through the open intake end of said channel and are expanded to final size and sintered together to a porous coherent strand by means of steam fed between the horizontal belt parts facing one another. The steam and the granules are fed into the channel through individual ducts which are separated from one another and connected to the intake end portion of the channel. Usually, a plurality of granule feeding ducts and a plurality of steam supplying ducts are attached to the intake end portion formed as a box of particular shape. Some specific grouping of the ducts connected to said box has proved to render excellent results in uniform distribution of the granules and even heating to sintering temperature.

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Helsingborg, Sweden

Heikki Korpela