Abstract:
A method for manufacturing a creped fiber web is provided and includes providing a rotating cylindrical dryer surface, providing a creping adhesive composition or coating package having a pH boosted at least 0.5 pH units relative to its original base formulation pH in the range of from about 4.5 to about 9, for chemically setting a crosslinkable polymer component at least in part before applying the creping adhesive composition to the rotating cylindrical dryer surface to provide an adhesive dryer surface on which a fiber web can be transferred, dried, and creped.
Abstract:
A method and an assembly is disclosed for coating a web (1) of paper or board by a dry treatment agent, the method comprising the step of applying the treatment agent to at least one side of the moving web (1). In the method is used a treatment agent contains a binder capable of undergoing a change of state at least under the effect of elevated temperature. The web (1) after being treated with the treatment agent is subjected to at least an elevated temperature at which the binder becomes deformable, and the web is subjected to a lower temperature serving to set the binder so that the same bonds the treatment agent to the web surface. The solids content of the treatment agent is not less than 75%, preferably not less than 90%, whereby a drying step after the treatment is not required.
Abstract:
Device for the application of a coating composition on a traveling web (17) comprising a transfer roll (5), a support roll (3) cooperating with the transfer roll (5), the traveling web being fed in a nip between said rolls, further comprising a gravure roll (7) intended for the transfer of an adapted quantity of the coating composition onto the transfer roll (5), and a device for passing of the web through said nip, characterized by a blade device (11, 13) for the removal of excess of coating composition from the gravure roll (7), said blade device being arranged in trailing position in relation to the moving surface of the gravure roll (7).
Abstract:
In a device for the coating of a running web of paper or cardboard, provisions are that in a press gap formed between two rolls a coating substance applied in a very small quantity on the surface of the one roll is first pressed on the web leaving a very thin coat on the web which, however, covers all spots including the "mounds" of microroughness. Next, the second coat can be applied and dosed on the still moist first coat with the usual means. In the process, the first coat is preferably dosed on the shell of the first roll, by means of the peripheral grooves of a rotary doctor. The same may be performed also as regards the second coating on the web.
Abstract:
Apparatus for maintaining a relatively placid pool of liquid coating material in the trough between two nipped rolls comprises a pair of deckles, one disposed near either end of the nipped rolls, each of the deckles having an edge generally conforming to a segment of the adjacent roll to effectively form an end of the trough formed by the rolls. At least one of the deckles has one or more openings which permit the liquid coating material to flow laterally out of the trough and through the deckle at a rate proportional to the depth of the coating material in the trough. Controlling the lateral outward flow of material from the trough stabilizes both the turbulence of the liquid coating material in the trough and the surface condition of the coating material.
Abstract:
A coating process for coating traveling webs comprises applying a first coating layer of a pigment substance on a portion of the shell surface of a rotatable roll not covered by the material web, and pressing the pigment substance onto the web in a press gap, thereby impregnating the web. This makes it possible to apply with maximum uniformity and without web breaks and wrinkles a second coating layer of a pigment substance immediately successive to the application of the first layer, while the first layer is still moist.
Abstract:
The invention concerns a device and method for limiting of the width of coating in coating of paper or board. The coating agent is spread onto a moving base to be coated by means of a coating device provided with a grooved coating bar. The coating agent is spread substantially only over the width of the web and any coating agent extending substantially beyond the web width is scraped off the base to be coated with the aid of smooth end areas fitted at both ends of the coating bar. The invention is also related to a device for carrying out the method.
Abstract:
The coating device features a first applicator which, to begin with, forces coating substance applied on the shell of a web roll (1), in a press gap formed between said roll and a press roll (2), into the web (W), thereby impregnating it. This makes it possible to apply with maximum uniformity and without web breaks and wrinkles, immediately successively, a second coating layer during the still wet condition of the first layer where, naturally, again a web guide roll (3) is provided.
Abstract:
A coating press apparatus is disclosed for coating a first and second side of a pressed web formed in a forming section of a papermaking machine. The apparatus includes a first press roll which defines a smooth imperforate first surface. The first surface cooperates with the first side of the web. A first backing roll cooperates with the first press roll for defining therebetween a first nip for the passage therethrough of the web. A first felt supports the web during passage through the first nip and a first short-dwell coater applies a coating directly to the surface of the first press roll upstream relative to the first nip such that a smooth and even first layer of the coating substance is applied to the first side of the web during passage of the web through the first nip. A second short-well coater is disposed downstream relative to the first nip for applying a smooth and even second layer of coating substance to the second side of the web such that the first and second sides of the resultant pressed web exhibit a higher coating content than the coating content betwen the first and the second sides thereby enhancing the surface properties and resulting printability of the web.