Apparatus and method for applying a fluid to a paper web

Abstract

 An apparatus and a method for applying a fluid to a paper web, including a means for feeding a continuous paper web to at least one fluid application station, which includes at least one roller that is in contact with the web and is adapted to convey fluid to be applied to the paper web. The rotation rate of the roller is variable with respect to the advancement speed of the web in order to vary the amount of fluid applied by the roller to the web.

Description

[0001] The present invention relates to an apparatus and a method for applying a fluid to a paper web.

[0002] More particularly, the present invention relates to an apparatus for applying a fluid, such as a lotion or a softener, to a paper web or ribbon for producing tissue-type products, such as handkerchiefs, toilet paper, et cetera.

[0003] Currently, fluids, such as lotions, softeners and others, are applied to tissue-type products while they are still in the form of a continuous web, by virtue of sprayers or applicator rollers.

[0004] There is the problem of correctly dosing the amount of fluid to be applied to the product and/or of varying the dosage according to specific requirements.

[0005] The aim of the present invention is to provide an apparatus for applying a fluid to a paper web that allows to vary rapidly and easily the amount of fluid that is applied.

[0006] Another object of the invention is to provide an apparatus for applying a fluid to a paper web that can be used easily in existing lines for the production of tissue-type products.

[0007] Another object is to provide an apparatus for applying a fluid to a paper web that is constructively simple and reliable.

[0008] This aim, these objects and others that will become better apparent hereinafter are achieved by an apparatus for applying a fluid to a paper web, comprising a means for feeding a continuous paper web to at least one fluid application station, comprising at least one roller that is in contact with said web and is adapted to convey fluid to be applied to the paper web, characterized in that the rotation rate of the roller is variable with respect to the advancement speed of the web in order to vary the amount of fluid applied by the roller to the web.

[0009] Further characteristics and advantages of the present invention will become better apparent from the description of preferred but not exclusive embodiments thereof, illustrated only by way of non-limitative example in the accompanying drawings, wherein the only figure is a schematic side elevation view of the apparatus for applying a fluid to a paper web, according to the invention.

[0010] With reference to the above cited figure, the apparatus for applying a fluid to a paper web, according to the invention, generally designated by the reference numeral 1, comprises a supporting frame 3 having a means for feeding at least one continuous paper web 5 to at least one station 7 for applying a fluid.

[0011] In the illustrated embodiment, the apparatus according to the invention is provided with two application stations, designated by the reference numerals 7 and 107 respectively and each adapted to apply fluid to one side of the web 5.

[0012] More particularly, the paper web 5 is, for example, constituted by coupling two plies, designated by the reference numerals 9 and 11 respectively, and is fed to the application stations 7 and 107 by a feeder means comprising rollers 13.

[0013] The system for coupling the plies 9 and 11 in order to form the paper web 5 and the system for feeding the web can be of a per se known type and are not described here for the sake of brevity.

[0014] According to the invention, the first feeder station 7 comprises an engraved roller 15, which cooperates with a doctor 17 for spreading the fluid to be applied to the web 5.

[0015] The engraved roller 15 is motorized by a variable-speed motor means in order to vary the rotation rate of the engraved roller with respect to the feed rate of the web 5 at the application station 7.

[0016] Likewise, the second application station 107 comprises an engraved roller 115, which cooperates with a doctor 117 for spreading the fluid to be applied to the web 5.

[0017] The engraved roller 115 is motorized by a variable-speed motor means in order to vary the rotation rate of the engraved roller with respect to the feed rate of the web 5 at the application station 107.

[0018] The engraved roller of each application station rotates in contact with the doctor and conveys liquid, contained in appropriately provided tanks, in order to deposit it on the paper web. By varying the rotation rate of the engraved roller with respect to the feed rate of the paper web, at least in the region of contact with the roller, a mutual sliding is produced between the roller and the web, and by adjusting this sliding it is possible to vary the dosage of fluid applied to the web.

[0019] According to a preferred aspect of the invention, the engraved roller is turned with a peripheral speed that is lower than the advancement speed of the paper web, raising the fibers of the paper web and thus giving greater thickness and softness, the so-called "hand feel" of the product.

[0020] The embodiment of the illustrated example comprises two application stations, designated by the reference numerals 7 and 107 respectively, for applying fluid to both sides of the web 5.

[0021] In practice it has been observed that the invention achieves the intended aim and objects, an apparatus for applying a fluid to a paper web having been provided which allows to vary rapidly and easily the amount of fluid applied.

[0022] The apparatus according to the invention is susceptible of numerous modifications and variations, within the scope of the appended claims and all the details may be replaced with technically equivalent elements.

[0023] The materials used, as well as the dimensions, may be any according to requirements and to the state of the art.

Claims

1. An apparatus for applying a fluid to a paper web, comprising a means for feeding a continuous paper web to at least one fluid application station, comprising at least one roller that is in contact with said web and is adapted to convey fluid to be applied to said paper web, characterized in that the rotation rate of the roller is variable with respect to the advancement speed of said web in order to vary the amount of fluid applied by said roller to said web.

2. The apparatus according to claim 1, characterized in that said application station comprises a doctor, which cooperates with said roller.

3. The apparatus according to claim 1, characterized in that said roller is an engraved roller.

4. The apparatus according to one or more of the preceding claims, characterized in that it comprises at least two application stations, one for each side of said web.

5. The apparatus according to one or more of the preceding claims, characterized in that the engraved roller is turned at a peripheral speed that is lower than the speed of the paper web and is adapted to raise the fibers of the paper web so as to thicken said web and increase its softness.

6. A method for applying a fluid to a paper web, comprising sliding a paper web at a roller that is adapted to convey fluid to be applied to the web, characterized in that the rotation rate of the roller is varied with respect to the feed rate of said web.

Drawing