Method and device for reduction and equalization of transverse shrinkage of paper in single-wire draw in a drying section
AssigneeValmet Paper Machinery Inc.
InventorsPetri Nyberg, Heikki Ilvespaa, Kari Holopainen
Life of this patent
Estimating the term…
Abstract
The present invention relates to a method and device in the draw of a paper web for reduction and equalization of transverse shrinkage of the paper web in the drying section of a paper machine. The lateral areas of the wire running in conjunction with the paper web are provided with a coating adhesion means, whereby, by means of the coating adhesion means, at the drying stage an adhesion force is produced between the lateral areas of the wire and of the paper to prevent transverse shrinkage of the paper web.
Claims9
A method for the reduction and equalization of transverse shrinkage of a paper web, consisting essentially of the steps of:
- providing a single wire draw in a drying section of a papermaking machine on which a paper web is carried in contact with a face of said wire, and
- applying an adhesion means consisting of a coating to lateral areas of said face of said wire such that said lateral areas of said face of said wire are provided with greater adhesiveness to the web than an area of said face of said wire between said lateral areas, said adhesion means causing the paper web to be kept in contact with said wire throughout the single wire draw in the drying section and substantially preventing transverse shrinkage of the paper web.
A papermaking drying section consisting essentially of:
- a single wire draw in a drying section on which a paper web is carried in contact with a face of said wire, and adhesion means consisting of a coating in lateral areas of said face of said wire, said coating increasing the holding force such that the paper web is kept in contact with said face of said wire throughout the single wire draw in the drying section and substantially preventing transverse shrinkage of the paper web.
A wire draw in a drying section of a paper machine consisting essentially of:
- a driving roll defining a nip in conjunction with a second roll,
- a wire running over said driving roll, a face of said wire contacting a paper web running over said second roll at said nip, said wire and the paper web having corresponding lateral areas and defining a single wire draw in the drying section, and
- adhesion means consisting of a coating arranged on the lateral areas of said face of said wire which contacts the paper web, the lateral areas of said face of said wire adhering to the corresponding lateral areas of the paper web after said nip throughout the single wire draw in the drying section, such that a higher holding force is applied to the lateral areas of the paper web than to the other areas along with the width of the paper web, said adhesion means substantially preventing transverse shrinkage of the paper web in the drying section.
Dependencies are inferred from the claim text.