Claims (10)
1. Apparat til tørformning af et fibervæv og omfattende en sugekasse og et overfor anbragt formerhoved med en derimellem anbragt formerwire, hvorpå vævet dannes, idet sugekassen har et sugeareal, som .suger fibrene ned mod formerwiren, kendetegnet ved, at der i sugekassen er monteret et trykfaldsregulerende organ i et delområde af sugearealet.An apparatus for dry forming a fibrous web and comprising a suction box and an opposite forming head with an intermediate forming wire on which the tissue is formed, the suction box having a suction area which sucks the fibers down to the forming wire, characterized in that the suction box is mounted a pressure drop regulating means in a sub-region of the suction area.
2. Apparat ifølge krav 1, kendetegnet ved, at organet er monteret justerbart, fortrinsvis med rumlig justeringsmulighed i tre dimensioner.Apparatus according to claim 1, characterized in that the means is mounted adjustably, preferably with three-dimensional spatial adjustability.
3. Apparat ifølge krav 1 eller 2, kendetegnet ved, at organet har en tilnærmelsesvis glat overflade for at være selvrensende.Apparatus according to claim 1 or 2, characterized in that the means has an approximately smooth surface for being self-cleaning.
4. Apparat ifølge ethvert af de foregående krav, kendetegnet ved, at organet er fremstillet med en afgrænsning, der er tætsluttende til en del af sugearealets afgrænsning, idet nævnte delområde er tilvejebragt tilstødende en kant af sugearealet.Apparatus according to any one of the preceding claims, characterized in that the means is made with a boundary which is tightly closed to a part of the boundary of the suction area, said sub-area being provided adjacent an edge of the suction area.
5. Apparat ifølge ethvert af de foregående krav, kendetegnet ved, at organet er dannet af en plade, som er monteret til sugekassen.Apparatus according to any one of the preceding claims, characterized in that the means is formed by a plate mounted to the suction box.
6. Apparat ifølge ethvert af de foregående krav, kendetegnet ved, at formerhovedet er af typen med mindst en perforeret roterende tromle, hvor fibre opblandet i luft indføres i en første ende af tromlen, der indeholder midler for fluidisering af de indførte fibre, og at organet er placeret i sugearealet ud for nævnte første ende af tromlen.Apparatus according to any one of the preceding claims, characterized in that the forming head is of the type having at least one perforated rotating drum, wherein fibers mixed in air are introduced at a first end of the drum containing means for fluidising the introduced fibers and the member is located in the suction area adjacent to said first end of the drum.
7. Apparat ifølge krav 6, kendetegnet ved, at formerhovedet indeholder to eller flere tromler, og at organet er placeret ud for nævnte første ende af den tromle, som befinder sig forrest, således som set i formerwirens fremføringsretning.Apparatus according to claim 6, characterized in that the forming head contains two or more drums and that the means is located at said first end of the drum which is at the front, as seen in the direction of the feeding wire of the former.
8. Fremgangsmåde til tørformning af et fibervæv og omfattende en sugekasse og et overfor anbragt formerhoved med en derimellem anbragt formerwire, hvorpå vævet dannes, idet sugekassen har et sugeareal, som suger fibrene ned mod formerwiren, kendetegnet ved, at der i sugekassen etableres en trykfaldsregulering i et delområde af sugearealet.A method of dry forming a fibrous web and comprising a suction box and an opposite forming head with an intermediate forming wire on which the web is formed, the suction box having a suction area which sucks the fibers down towards the forming wire, characterized in that a pressure drop regulation is established in the suction box. in a sub-area of the suction area.
9. Fremgangsmåde ifølge krav 8, kendetegnet ved, at trykfaldsreguleringen varierer over nævnte delområde. - -------Method according to claim 8, characterized in that the pressure drop control varies over said sub-region. - -------
10. Fremgangsmåde ifølge krav 8 eller 9, kendetegnet ved, at trykfaldsreguleringen anvendes til ændring af et ellers stort set jævnt trykfald over sugearealet.Process according to claim 8 or 9, characterized in that the pressure drop control is used to change an otherwise substantially uniform pressure drop across the suction area.