GB2255110A

GB2255110A - Embossing sterilisable wrapping paper

Info

Publication number: GB2255110A
Application number: GB9208901A
Authority: GB
Inventors: David William Bewsher
Original assignee: BIBBY PAPER Ltd J
Current assignee: BIBBY PAPER Ltd J
Priority date: 1991-04-24
Filing date: 1992-04-24
Publication date: 1992-10-28
Also published as: GB9108763D0; GB9208901D0

Abstract

To improve the drapability of creped sterilisable wrapping paper the creped paper is passed through a pair of embossing rollers (1, 3) which are spaced a set distance apart so as to avoid completely flattening the creped effect. The embossed pattern may comprise squares inclined to the feed direction. The embossing rollers are located downstream of the drying cylinder. <IMAGE>

Description

Title: Manufacture of sterilisable wrapping paper material DESCRIPTION The present invention relates to the manufacture of a sterilisable wrapping paper material using as the base material creped paper.

Creped paper has an application as a sterilisable wrapping paper. For the best results this requires a soft drapable paper and one which will lie flat when unwrapped. This calls for drapability in both the machine direction and in the cross machine direction.

The folding properties of creped paper make it particularly suitable as a wrapping material but even when subject to bengalining it does not provide the required degree of drapability. The creping process imparts machine directional properties whilst the bengaline process influences the cross-direction. It is an aim of the present invention to modify the properties of creped paper to make it more suitable for this application.

It is known to embossed paper by passing it through a pair of contacting crimping rollers for the purpose of introducing a decorative effect. It has now been realised that the form of the embossing can affect the drapability of the paper and it is therefore proposed to emboss creped paper by the application of diagonally intersecting lines to improve the drapability. However using an embossing technique employing contacting rollers on creped paper destroys the crepe properties by squashing out the peaks and troughs which arises as part of the creping process.

Accordingly embossing using such contacting crimping rollers is unsatisfactory. It is an aim of the present invention to overcome this problem.

Accordingly, the present invention provides a method of manufacturing a sterilisable wrapping paper comprising passing dried creped bengalined paper through a pair of mating embossing rollers which are spaced a set distance apart with the distance being chosen to avoid completely flattening out the creped effect.

The distance apart is adjustable to the desired set distance, but the structure is conveniently referred to as a "fixed gap" structure to distinguish over embossing rollers whose distance apart is not controlled to a definite setting which if used in this application would have the disadvantage of completely flattening out the crepe structure. The form of the embossing rollers is such as to consolidate the structure which has previously been fashioned to promote both machine and cross machine directional drape properties. The preferred form of the rollers gives rise to a plurality of diagonally intersecting lines angled with respect to the machine and cross machine directions. The localised consolidation caused by the fixed gap embossing rollers has the advantage that it does not destroy the properties of the creped paper in other areas.By passing the creped paper through fixed gap embossing rollers there is a flattening of the peaks which are a characteristic of the earlier process and this usefully increases the surface area to enhance the adhesion properties of such as sterilisation indicator tapes or general securing tapes. The process also has the affect of softening the product which is a most desirable feature in its intended use. Limiting the compression also avoids compromising bacterial barrier performance.

The present invention will now be described further by way of example only with reference to the accompanying drawings, in which: Figure 1 is a schematic side view of apparatus for treating creped paper according to the invention, Figure 2 is a fragmentary perspective view in the region of the embossing rollers, and Figure 3 is a fragmentary cross-section through the embossing rollers.

The method of the present invention is carried out on dry crepe paper, preferably creped and bengalined paper, which paper is made using any conventional technique. For the purpose of illustrating the invention a pair of embossing rollers 1, 3 are shown downstream of a drying cylinder 5 for paper 7 which has previously been creped at an earlier stage not shown in the drawing. The paper web is shown entrained around numerous guide rollers 8 and is eventually wound onto a reel at 10.

The pair of embossing rollers, as opposed to being urged into contact with the paper, are disposed at a fixed distance apart and driven to rotate at a speed in synchronism with the speed of the paper web and geared to rotate together so that the mating formations carried by the respective rollers act to impart the desired embossing pattern to the creped paper as it passes between the rollers but without completely crushing the creping in other areas. In the preferred embodiment the formations on the rollers are such as to impart intersecting diagonal lines to the creped paper with the diagonal lines angled with respect to the machine and machine cross direction as indicated by lines X and Y. Machine direction is indicated by arrow A.

The preferred configuration of intersecting diagonal lines is formed by squares, each having sides of approximately 3mm, evenly fashioned across two mated rolls, one of which is a perfect mirror image of the other so that the peaks of one are aligned with the troughs of the other.

In the illustrated embodiment the upper roller has a fixed axis of rotation and the lower roller is adjustable by way of a hand wheel 11 to set the desired fixed gap "g" as read off from the gauge 13. Location is by way of an hydraulic ram 15.

Claims

1. A method of manufacturing a sterilisable wrapping paper comprising passing dried creped bengalined paper through a pair of mating embossing rollers which are spaced a set distance apart with the distance being chosen to avoid completely flattening out the creped effect.

2. A method as claimed in claim 1 in which the distance apart is adjustable to the desired set distance.

3. A method as claimed in claim 1 or 2 in which the embossing rollers impart to the paper a plurality of diagonally intersecting lines angled with respect to the machine and cross machine directions.

4. A method as claimed in any preceding claim in which passing the paper through the embossing rollers flattens the residual peaks of the earlier processing.

5. A method as claimed in any preceding claim in which the pair of embossing rollers are disposed downstream of a drying cylinder.

6. A method as claimed in any preceding claim in which the pair of embossing rollers are rotatably driven at a speed in synchronism with the speed of the paper web and geared to rotate together.

7. Apparatus for performing the method of claims 1 to 6 comprising a pair of mating embossing rollers spaced a set distance apart through which the paper is passed.

8. Apparatus as claimed in claim 7 in which the rollers have formations which are a mirror image of one another whereby the peaks of one are aligned with the troughs of the other.

9. Apparatus as claimed in claim 8 in which the formations are square with their sides angled with respect to the machine and cross-machine direction.

10. A method of manufacturing a sterilisable wrapping paper substantially as hereinbefore described with reference to the accompanying drawings.

11. Apparatus for manufacturing a sterilisable wrapping paper constructed and arranged substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

12. A sterilisable wrapping paper made by the method of any one of claims 1 to 6.