Slitter-winder for winding of pulp webs

Abstract

A slitter-winder for winding of pulp webs or corresponding webs with a thickness of at least 0.5 mm, in which the winder is a two-drum winder having two winding drums on support of which at least two pulp web rolls are wound. At least one of the winding drums is a nip acceptance winding drum (NAWD), that is a winding drum with a cover having a hardness of 40-80 Shore A and a thickness of 3-50 mm. The winding drums and a steel core or a shaft of the at least two pulp web rolls have parallel rotation axes and are in a rolling contact where the at least one winding drum is driven.

Claims

1. A winder for winding of pulp webs after a slitter comprising: a plurality of pulp rolls each pulp roll having a density of 400-600 kg/m.sup.3 and is formed of a web of 1.5-2.5 mm thickness; a two-drum winder comprising two winding drums positioned to support at least two pulp web rolls, the two-drum winder having a first drum with a first drum surface, wherein each pulp roll is wrapped by the pulp web which first wraps a portion of the first drum surface and is guided through a first nip at the first drum of the two-drum winder which is a nip acceptance winding drum (NAWD) having a cover with a hardness of 40-80 Shore A, a thickness of 3-50 mm, wherein the at least two winding drums are rotatable about parallel rotation axes; and wherein the pulp web rolls are wound about cores or shafts which are parallel to the winding drum rotation axes, the pulp web rolls being supported in driven rolling contact to be driven by at least the winding drum which is driven.

2. The winder of claim 1 wherein the NAWD is a plain roll without grooves or bores.

3. The winder of claim 1 wherein the material of the cover of the NAWD is elastomeric polymeric material.

4. The winder of claim 1, wherein the winder further comprises a rider roll disposed to press the pulp web rolls to be wound and transmitting torque.

5. The winder of claim 1, wherein the cover with the hardness of 40-80 Shore A has a thickness of 10-50 mm.

6. A method of forming and winding a multiplicity of pulp webs comprising the steps of: slitting in the machine direction a pulp web having a density of 400-600 kg/m.sup.3 and thickness of 1.5-2.5 mm to form a plurality of web pulp webs; passing each of the plurality of pulps webs in a machine direction along a surface of a first drum of a two-drum winder, wherein the first drum surface is a drum cover with a hardness of 40-80 Shore A and a thickness of 10-50 mm, and wherein the first drum defines a radial direction perpendicular to the drum cover; forming from each of the plurality of web pulp webs a pulp roll about a core or shaft supported between the first drum and a second drum of the two drum winder so that each of the plurality of pulp webs passes though a nip formed between said core or shaft and the drum cover; wherein at least one of the first drum and the second drum of the two drum winder is driven to cause the winding of the pulp webs.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a schematic illustration of a two-drum winder according to an advantageous embodiment of the invention.

(2) FIG. 2 is a schematic illustration of a winding drum according to one advantageous feature of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

(3) In FIGS. 1 and 2 the same reference signs are used for the same or respective components, part assemblies etc. unless otherwise stated. Some reference signs have been omitted from some of the figures for the sake of clarity.

(4) The winder 10 shown in FIG. 1 is a two-drum winder which comprises two winding drums 11, 12 and a rider roll 13. In the winder at least two longitudinally successive pulp web rolls 15 to be wound are supported by the winding drums 11, 12 from below and by a rider roll 13 from above the pulp web rolls 15. In two-drum winders one of the winding drums can be a set of belt rolls in which an endless loop/loops of belt/belts is/are arranged around two guide rolls depending on the type of two-drum winder. In a slitting section (not shown) preceding the winder the pulp web is slit longitudinally into parallel partial webs W which are wound in the winder to a set of successive partial pulp web rolls 15. By the arrows r in the figure are shown the direction of rotation of the corresponding drum and the running direction of the web W is indicated by arrows s. The winding nips are formed between the pulp web rolls 15 to be wound and the winding drums 12.

(5) One or both of the winding drums 11, 12 are NAWD drums. The NAWD drum is the front 12 or back 11 winding drum or both front 12 and back 11 winding drums are NAWD drums.

(6) In FIG. 2 is shown a winding drum 11; 12 that is NAWD, which is soft covered provided by a soft cover 14. The hardness of the cover 14 of the soft covered NAWD 11; 12 is advantageously 40-85 Shore A. The NAWD 11; 12 is advantageously plain i.e. without grooves or bores. The material of the cover of the NAWD is elastomeric polymeric material for example polyurethane, natural rubber, synthetic rubbers such as neoprene, styrene-butadiene (SBR), nitrite rubber, chlorosulfonated polyethylene, or EDPM. The thickness t of the cover 14 of the NAWD 11;12 is 3-50 mm.