Recherche dans les collections de brevets nationales et internationales
Une partie du contenu de cette demande n'est pas disponible pour le moment.
Si cette situation persiste, contactez-nous auObservations et contact
1. (WO1980002575) METHODE ET DISPOSITIF POUR UNE MACHINE DE FABRICATION DE PAPIER
Note: Texte fondé sur des processus automatiques de reconnaissance optique de caractères. Seule la version PDF a une valeur juridique

Claims :

1. A method of forming a paper web in a fourdrinier paper making machine where the stock is ejected through a slice (!) onto the wire (3), characterized in that the paper web is formed in a space (8) between a flexible upper lip (5) projecting from the slice and a portion of the wire (3), which portion is unsupported at least at the end of the formation while at the same time dewatering of said stock takes place through said portion of the wire by means of a vacuum, and that the vacuum is maintained unchanged after the forming while the paper web is on the unsupported portion of the wire.

2. A method as defined in claim 1, characterized in that the paper web is formed in the space (8) between the flexible upper lip (5) and and an unsupported portion of the wire (3),

3. A method as defined in claim 1 or 2, characterized in that the stock is dewatered in the forming space (8) in such a manner, that no free liquid surface remains on the web after the forming space (8).

4. A method as defined in any one of claims 1 - 3, characterized in that microturbulence is imparted to the stock at the beginning of the formation.

5. A method as defined in any one of the claims 1 - 4, characterized in that a paper web comprising several layers is formed by ejecting in a manner known per se the stock through subsequent slices (la, b, c), and that the layers are formed one after and one above the other each between its flexible upper lip (5a, b, c) and the portion of the wire (3), which portion is unsupported at least at the end of the formation.

6. A device for forming a paper web in a fourdrinier paper making machine according to the method defined in claim 1, comprising a head box with a slice (1) for ejecting the stock (2) onto the wire (3), characterized in that the space (8) for forming the paper web is defined by a flexible upper lip (5) projecting from the upper portion of the slice (1) and a portion of the wire (3), which por tion is unsupported at least at the end of the forming space (8), that the unsupported portion of the wire is located above an upwardly open suction box (9) for dewatering the stock, and that the unsupported portion of the wire (3) extends through a distance past the flexible upper lip (5) in the direction of movement of the wire (3).

7. A device as defined in claim 6, characterized in that the space (8) for forming the paper web is defined by the flexible upper lip (5) and an unsupported portion of the wire (3).

8. A device as defined in claim 6 or 7, characterized in that the unsupported portion of the wire (3) extends through a distance past the upper lip (5), the length of this excess distance being at least 10JS of the length of the forming space (8).

9. A device as defined in any one of the claims 6 - 8, characterized in that the flexible upper lip (5) has a smooth lower surface.

10. A device as defined in any one of the claims 6 - 8, characterized in that the lower surface of the flexible upper lip (5) at the beginning of the forming space (8) is provided with unevennesses (10).

11. A device as defined in claim 6, characterized in that dewatering strips (14) are arranged under the wire at the beginning of the forming space (8).

12. A device as defined in any one of the claims 6 - 11, charocterized in that several slices (la, b, c) are arranged one after the other for making multi-layer paper in a manner known per se,and that each slice (la, b, c) is provided with a flexible upper lip (5a, b, c) in such a manner, that the upper lip for a layer higher up extends past the upper lip for the layer next below and form forming spaces together with the portion of the wire (3), which portion is unsupported at least at the end of the forming space (8),