Apparatus for applying abrasive substances to continuous paper webs
AssigneeVits Maschinenbau GmbH
InventorsGisbert Krossa, Walter Müller, Ernst Klas
Life of this patent
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Abstract
An apparatus applies a coating composition consisting of a resin and fine abrasive particles like corundum particles, to a paper web by feeding the composition to the paper web as it loops around a guide roller to a metering roller juxtaposed with the guide roller. The coating composition, which may develop stripes, is then equalized with a structured roller engaging the paper-web pass leaving the guide roller and formed with at least one thread-like structuring element which may be followed by or preceded by a doctor blade arrangement or a smooth-surfaced roller.
Claims10
An apparatus for applying a coating composition containing a liquid resin and fine-grain abrasive material to a continuous paper web, said apparatus comprising:
- a guide roller around which said web is looped so that said web has a coating-receiving surface extending arcuately around said guide roller;
- a metering roller parallel to said guide roller and having a surface juxtaposed with said surface of said web across a narrow gap;
- a slit nozzle juxtaposed with one of said surfaces for delivering said composition over a width of the web, said composition passing through said gap and forming a coating on said coating-receiving surface of said web;
- and
- an equalizing device for rendering said coating uniform, said equalizing device including at least one structured roller juxtaposed with said coating-receiving surface downstream of said gap and having a helical rib structure.
An apparatus for applying a coating composition containing a liquid resin and fine-grain abrasive material to a continuous paper web, said apparatus comprising:
- a guide roller around which said web is looped so that said web has a coating-receiving surface extending arcuately around said guide roller;
- a metering roller parallel to said guide roller and having a surface juxtaposed with said surface of said web across a narrow gap;
- a slit nozzle juxtaposed with one of said surfaces for delivering said composition over a width of the web, said composition passing through said gap and forming a coating on said coating-receiving surface of said web;
- and
- an equalizing device for rendering said coating uniform, said equalizing device including at least one structured roller juxtaposed with said coating-receiving surface downstream of said gap and having a helical rib structure, said equalizing device including at least two parallel structured rollers juxtaposed with said coating-receiving surface downstream of said gap and each having a helical rib structure.
An apparatus for applying a coating composition containing a liquid resin and fine-grain abrasive material to a continuous paper web, said apparatus comprising:
- a guide roller around which said web is looped so that said web has a coating-receiving surface extending arcuately around said guide roller;
- a metering roller parallel to said guide roller and having a surface juxtaposed with said surface of said web across a narrow gap;
- a slit nozzle juxtaposed with one of said surfaces for delivering said composition over a width of the web, said composition passing through said gap and forming a coating on said coating-receiving surface of said web;
- and
- an equalizing device for rendering said coating uniform, said equalizing device including at least one structured roller juxtaposed with said coating-receiving surface downstream of said gap and having a helical rib structure, said equalizing device further comprising a doctor blade engaging said coating and located upstream or downstream of said structured roller and in a form of a substantially rectangular flap of a flexible elastomeric material having a rearward edge parallel to said structured roller and fastened to a support and lying slackly upon an upper pass of said web coming off said guide roller.
Dependencies are inferred from the claim text.