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US 3,941,902 AGranted
Method of making surface-treated paper
AssigneeSvenska Cellulosa Aktiebolaget
InventorsBengt Axel Wennerblom, Gustav Robert Svensson
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AssigneeSvenska Cellulosa Aktiebolaget
InventorsBengt Axel Wennerblom, Gustav Robert Svensson
Estimating the term…
Surface-treated paper in the form of a continuous web is made by first roughening a base paper which serves as a starting material on the sides to be treated. The roughened web is then passed over and in direct contact with a discharge slot from a container that extends across the web and through which the desired treatment liquid is flowed onto the surface of the web, and the surface-treated paper is then dried and finally reeled.
Method of surface sizing paper in the form of a continuous web, which consists essentially of passing the web over and in direct contact with a slot-shaped aperture in a container, which aperture is co-extensive with the width of the web, while continuously introducing into the container and exiting the same via the slot thereof a sizing material consisting essentially in an aqueous suspension of a sizing agent, continuously transferring the so-exiting sizing material without pulsations and without any excess, to the web passing said web over the surfaces adjacent the aperture at an angle of from 0.degree. to 45.degree. while under a controlled tension of at least 50 newton, said sizing material being introduced into said container at such a rate that the sizing material is applied to the paper web in an amount of at least (1.4 + 0.0107.B)cm.sup.3 per m.sup.2 of the paper web, where B = the surface roughness of the web measured according to Bendsten, and drying and reeling the so-sized paper web dried and finally reeled.
Dependencies are inferred from the claim text.
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No related US applications are recorded in the indexed filing history.
Addition to the formed paper: pouring or allowing the fluid to flow in a continuous stream on to the surface, the entire stream being carried away…
Processes or apparatus specially adapted for applying liquids or other fluent materials to finished paper or board, e.g. impregnating, coating: by…
Pulp compositions
Term ended 2 Mar 1993 (estimated)
USPTO file history isn’t available for this patent, so only indexed dates are shown.
This invention relates to a method of continuously making surface-treated paper, in which method the web is provided with agents suitable for surface sizing purposes and solved or dispersed in water.
The purpose of surface sizing is to increase the bonding between the fibers, and for this purpose there are used water-soluble or water-dispersible binding agents such for instance as starch.
__________________________________________________________________________ Purpose Agent Specific term of the surface treatment __________________________________________________________________________ Increase of bonding Water-soluble bind- Surface sizing between the fibers ing agent, e.g. starch Increase of brightness White pigment, e.g. Coating and improvement of kaolin and binding printability agent, e.g. starch and synthetic po- lymers Increase of brightness Bleaching agent, Surface bleaching e.g. hydrogen per- oxide Colouring Colouring substance Surface colouring Increase of barrier Synthetic polymers, (Plastic) dis- properties and effect- e.g. polyvinyli- persion coat ing heat sealing capa- dene chloride, in bility the form of aqueous dispersion __________________________________________________________________________
The invention is described in greater detail in the following by way of examples, with reference to the drawing, in which
FIG. 1 shows a basic outline of the invention,
FIG. 2 shows the smallest uniformly applicable amount of coating liquid as a function of the surface roughness,
In FIG. 1 is shown a basic outline of the surface treatment proper by means of a coating unit, which comprises a container 1 with a slit-shaped aperture 2, over which the paper web 3 is passed and to which treatment liquid 4 is fed by means of a pump 5. As according to the invention the entire liquid flow is to be applied to the paper web, the basic relation apparently is as follows: ##EQU1## where P = amount of applied coating liquid, cm.sup.3 /m.sup.2
q = supplied flow of coating liquid, cm.sup.3 /min
v = speed of paper web, m/min