WO2006082374A1

WO2006082374A1 - Web-winding core

Info

Publication number: WO2006082374A1
Application number: PCT/GB2006/000287
Authority: WO
Inventors: Steven John Morgan
Original assignee: Deva Composites Ltd
Priority date: 2005-02-01
Filing date: 2006-01-27
Publication date: 2006-08-10
Also published as: GB2439658A; GB2439658B; GB0714588D0; GB0502078D0; GB2422593A

Abstract

A core for forming a wound roll of web material is disclosed. The core comprises a rigid cylinder (1) and an elastomeric covering (2) of self-healing polymer, the covering disposed at least on an external part of the cylinder. A covering (4) may also be applied to an internal surface of the cylinder. The coverings may be formed from urethane having a Shore A hardness in excess of (60).

Description

WEB-WINDING CORE

BACKGROUND TO THE INVENTION

Field of the invention

This invention relates to a web-winding core.

In the conventional manufacture of a product such as paper in the form of a web, the web is mechanically wound onto a rotating core member. Covers are commonly applied to web- winding cores to improve the performance of the winding process. The use of a cover diminishes the occurrence of damage to the web during winding, thereby reducing the necessity to discard deformed webs. Deformable covers can accommodate irregularities in the web. The cover can also promote "pick-up"; that is, the process that starts the web rolling onto the core.

A number of different polymeric covers for core members have been described.

US-A-5,857,643 shows a core for winding a web of knurl-edged base material for photographic film. The core comprises a rigid cylinder having a soft, deformable cover and harder end members for the knurled margins of the material.

EP- A- 1,211,214 describes a core comprising a hollow cylinder covered by a water-resistant rigid sleeve of polypropylene, polystyrene, nylon, acrylonitrile butadiene styrene or a combination thereof. The sleeve has a hard polished outer surface that may be ground down and re-polished for reuse if necessary. Web-winding cores are typically installed as a final component of a machine on which a web-based product such as paper is manufactured. A core that is carrying web material is typically so heavy as to require mechanical handling. For example, a forklift boom may be used. It is easy to cause damage to the core during such operations.

In many cases, the web is not subsequently unwound from the core entirely. Process operators typically stop their machinery while there is still web on the core to avoid potential process problems. The remaining material is commonly removed by cutting it in an axial direction with a knife. This is not a great problem in the case of a core that is to be used just once or only a small number of times. However, in a core that is intended for multiple re- use, its surface can become damaged beyond usability.

Summary of the Invention

With the aim of providing a particularly robust core, the invention provides a web-winding core comprising a rigid cylinder and an elastomeric covering of self-healing polymer, the covering disposed at least on an external part of the cylinder.

The outer surface of a typical known core is hard and smooth. Thus, the act of cutting material from the roll may cut the covering, but the cuts will self heal, leaving the core undamaged. This is in contrast to known cores, in which such cuts mar the surface and create jags that may adversely affect the web on a subsequent winding operation.

The elastomeric covering may extend from a longitudinally central region of the cylinder towards the ends of the cylinder. It may cover the cylinder substantially entirely.

The rigid cylinder may be of a material typically but not exclusively selected from fibre- reinforced plastics (for example, glass or carbon fibre), fabric impregnated with a resin such as a phenolic resin, aluminium, steel and cardboard.

In an embodiment of the invention, the interior of the core also comprises a layer of elastomeric material. The layer of material within the core may be similar to that of the covering on the external part of the cylinder, or may differ. The core may comprise engaging means at least one end of the core for engaging a rotational driving member of a winding apparatus.

Embodiments of the invention may be suitable for winding webs of various materials, but it is particularly, but not exclusively, applicable for winding paper products, including tissue, such as toilet tissue, newsprint and label stock.

The invention additionally provides a web-winding core as defined above, bearing a wound length of a web based product

Brief Description of the Drawing

Particular embodiments of the invention will now be described by way of example only, with reference to the single figure of the drawing, which shows a transverse cross section through a core embodying to the invention.

Detailed Description of Particular Embodiments

The core shown in the drawing comprises a rigid hollow cylinder 1 of fibre-reinforced (in this case, glass-fibre-reinforced) plastic material having a thickness of about 6mm.

A layer 2 of urethane is applied to the external surface of the cylinder 1. In this embodiment, the layer is 2-3 mm thick. Suitable methods of applying the urethane layer include pouring, calendaring and application of the layer as a self-adhesive strip.

The urethane layer 2 is self-healing. It is selected to have a Shore A hardness of at least approximately 60 and thus to resist abrasion due to rough handling. The Shore A hardness may, for example, be between 60 and 100, and more particularly between 70 and 90.

As shown in the drawing, the outer surface of the urethane layer 2 has a knurled configuration. For example, there may be grooves 3 in the surface which intersect, e.g. at right angles, when the length of the core is viewed. This configuration may assist in picking up the end of a web of paper-based product. For thermoplastic urethane the pattern is embossed by means of a hot tool, whereas for thermosetting urethane, the pattern can be formed by cold grinding. However the knurled configuration is optional and it may be that a smooth outer surface is effective for certain paper-based webs.

An inner urethane layer 4 is formed on the inner surface of the cylinder 1. Methods of application of the inner layer 4 include spraying, screeding, application via an adhesive carrier film that is adhered to the interior of the cylinder, casting in-situ, mechanical fastening and combinations of these methods. The inner layer avoids damage to the core when the core is handled, for example by a forklift boom.

A core embodying the invention is optionally provided with engaging means at its ends for engaging driving machinery, which rotates the core about its axis.

Alternative materials for the cylinder 1 include strong fabric such as Kevlar reinforced with a phenolic resin, polyvinyl chlorides, aluminium, steel and cardboard. It will be appreciated that the thickness of the cylinder will vary if a material other than fibre-reinforced plastic is used.

Elastomers other than urethane can be used for the outer layer and the optional inner layer.

Cores according to the invention can be reused thousands of times even when used in operations that involve it being rotated at high speed. As compared with known cores, embodiments of the invention may have enhanced acoustic and vibrational properties. This is particularly important if the bare core comes into contact with the rotating drum of a tissue-making machine.

All forms of the verb "to comprise" in this specification and the appended claims should be understood as forms of the verbs "to consist of and/or "to include".

Kevlar is a registered trade mark of E.I. du Pont de Nemours and Company.

Claims

1. A web-winding core comprising a rigid cylinder and an elastomeric covering of self- healing polymer, the covering disposed at least on an external part of the cylinder.

2. A core according to claim 1 in which the covering is of a self-healing elastomer.

3. A core according to claim 2 in which the covering is of urethane.

4. A core according to any preceding claim in which the covering has a Shore A hardness of at least approximately 60

5. A core according to claim 4 in which the covering has a Shore A hardness of between 60 and 100

6. A core according to claim 4 in which the covering has a Shore A hardness of between 70 and 90.

7. A core according to any preceding claim in which the elastomeric covering extends from a longitudinally central region of the cylinder towards the ends of the cylinder.

8. A core according to any preceding claim in which the elastomeric covering covers the cylinder substantially entirely.

9. A core according to any preceding claim in which the rigid cylinder is of fibre- reinforced plastics.

10. A core according to claim 7 in which the cylinder is of fibre-reinforced plastics.

11. A core according to any preceding claim in which the rigid cylinder is of a material selected from: fabric impregnated with a phenolic resin, thermoplastic, aluminium, steel and cardboard.

12. A core according to any preceding claim in which the covering is textured.

13. A core according to any preceding claim in which the interior of the cylinder also bears a layer of elastomenic material.

14. A core according to claim 13 in which the layer of elastomeric material in the interior of the cylinder is a self-healing elastomer.

15. A core according to claim 14 in which the layer of elastomeric material in the interior of the cylinder is urethane.

16. A core according to any preceding claim further comprising engaging means at at least one end thereof, for engaging a rotational driving member of a winding apparatus.

17. A core according to any preceding claim bearing a wound length of a web material.