Sterilisation Wrap

Technical Field

This invention is concerned with a sterilisation wrap suitable for use in hospitals and similar environments.

Background of the Invention

Sterilisation wraps are used in hospitals and other environments to wrap instruments which have been sterilised for use and reuse.

From the mid-twentieth century the practice arose of setting up central sterilisation units for sterilising reusable surgical instruments, etc., and wrapping them for delivery to a hospital ward or theatre. By the 1960s, disposal packaging for sterilised articles was adapted, mostly in the form of kraft paper, which had a good bacteria barrier, was permeable to steam during sterilisation and which could be disposed of easily.

However, studies around the same time showed that although the kraft paper and similar substitutes available at that time were superior in acting as a bacteria barrier, compared to surgical cloth which had been used previously, it was found that the paper could degrade over time and the bacteria barrier quality could decrease.

Further developments in the 1960s and 1970s saw the establishment of breathable barrier materials suitable for sterilisation wraps and bags.

In relation to wraps, in order to reduce the likelihood of a sterility breach, whether by degradation of the wrap material or because of a tear or similar, it became a recommended practice to double wrap articles. In this practice, sheets of sterilisation wrap were provided. An article to be sterilised would be wrapped first in one sheet and then in a second sheet, or else wrapped in one operation, using

two sheets together. Typically, the sheets have consisted of laminates of separate layers. For example, a sheet may be made of a laminate of three separate layers, the two outer layers being known as spun bond, being material made from extruded polyolefin fibres. In this example, the inner layer is known as a melt blown layer, also made from extruded polyolefin fibres. The middle, melt blown layer acts as a bacteria barrier, while the outer spun bond layers provide strength. This type of laminate is known as an SMS material.

Other laminates may have a different number of layers, with different combinations of spun bond and melt blown layers.

Kimberly-Clark products sold under the trade mark KIMGUARD have provided an alternative to the two-step or single step double wrapping of articles to be sterilised, using separate single sheets, as described above. The KIMGUARD products provide separate laminated sheets bonded together at a limited number of sites, the product being distinguishable as two sheets, despite the bonding.

It is an object of the present invention to provide a sterilisation wrap which can have advantages over the prior art, or which at least will provide a useful alternative.

Disclosure of the Invention

Accordingly, this invention provides a sterilisation .wrap formed from a single sheet of sterilisation material, the sheet adapted to be folded before use.

The invention also provides a method of sterilising an article, the method including the steps of:

(a) using a folded single sheet of sterilisation material to wrap the article; and

(b) exposing the wrapped article to sterilisation for a sufficient period to substantially sterilise the article.

In the sterilisation wrap and method of the invention, the single sheet is preferably a laminate of a polyolefϊn, preferably polypropylene. More preferably, the laminate has five layers, the first two and the fifth layer being spun bond and the third and fourth layers being melt down. The laminate may be referred to as SSMMS. The single sheet is not limited to this example.

In choosing the sterilisation material for use in the wrap and method of the invention, attention should be given to the qualities required for a sterilisation wrap, such as the need for the sterilisation procedure to penetrate the sterilisation material so as to sterilise the article, while at the same time providing a bacteria barrier to prevent contamination of the article and to provide strength to the material so that it is not easily compromised by the article or during handling after the sterilisation procedure. As will be appreciated by one skilled in the art, the SSMMS laminate referred to above is regarded as sterilisation material.

The single sheet may take various forms. In one embodiment, the sheet resembles the letter "T". In this embodiment, the vertical part of the letter "T" is intended to be folded over the horizontal part. The vertical part may be sized so that, when folded, it extends completely across the horizontal part. In a variation, the vertical part is dimensioned so that it extends part way across the horizontal part.

It is especially preferred that the single sheet is made so that the two outermost layers of the laminate are a different colour or tone from one another. When the single sheet is "T" shaped as described above, after folding, the different colour or tone of the part of the sheet which is folded over will contrast against the colour of the remainder of the sheet when viewed in plan. This visually distinguishes the folded sterilisation wrap from an unfolded sheet and signifies to personnel that the sterilisation wrap of the invention effectively provides a double wrap for articles to be sterilised.

In another embodiment, the single sheet is square or rectangular in the unfolded state. In this version, the single sheet may be folded in half, or it may be folded in a different manner, so that the part folded is of a smaller dimension than the remaining part of the sheet. Where the outermost layers of the sheet are of contrasting colours or tones, as described above, the unequal folding described can result in a contrast in colour or tone between the folded part and the remaining part of the sheet, when viewed in plan.

The invention is not limited to the folding examples above.

The single sheet for the sterilisation wrap of the invention may be cut from a larger sheet. Where the single sheet is a "T" shaped sheet as described above, it may be desirable to minimise wastage if cutting the single sheet from a larger, rectangular or square sheet. For this purpose, the "T" shape may be dimensioned so that the horizontal part of one "T" shape is cut from vertical parts of two neighbouring "T" shapes, as illustrated in connection with the drawings, below. It will be appreciated by one skilled in the art that this can result in minimum wastage of sterilisation material.

If desired, the folded single sheet may include bonding. The purpose of this may be to more securely hold the folded sheet together, or to provide a pocket for the article to be sterilised. It is within the scope of the invention that bonding is applied to a substantial part of the folded sheet, between a flap formed by the fold and the remainder of the sheet in contact with the flap. Alternately, one or more margins of the flap may be bonded. This is particularly suitable when forming a pocket, in which case one margin of the flap should be left open for insertion of an article to be sterilised.

Bonding may be effected by any suitable means, such as by ultrasonic bonding, bonding using heat, by stitching or by use of adhesives. The. adhesive used in this option may be any suitable adhesive known in the art.

Preferably, the bonding is achieved by continuous sealing. Alternately, the bonding is achieved by spot sealing.

In the method of the invention, the sterilisation to which the wrapped article is to be exposed may be any suitable sterilisation. One example is the use of steam. Others are ethylene oxide (EtO) and plasma-based sterilisation.

It is to be noted that in the embodiments of the invention where the single sheet is folded in an 'uneven' way, such as illustrated in the drawings below, it is easier to wrap articles in the sterilisation wrap of the invention.

Brief Description of the Drawings

The invention may be better understood from the following non-limiting description of preferred embodiments, in which:

Figure 1 is a plan view of a first embodiment of the invention, showing a single sheet of sterilisation material, unfolded;

Figure 2 shows the embodiment in Figure 1, after folding;

Figure 3 shows a second embodiment in unfolded form, being a variation of the Figure I/Figure 2 embodiment;

Figure 4 shows the Figure 3 embodiment after folding;

Figure 5 shows a step in the manufacture of the Figure I/Figure 2 embodiment, showing how a plurality of single sheets of Figure 1 may be - cut from a larger, rectangular sheet, with little wastage;

Figure 6 shows in plan view a single sheet being a third embodiment of the invention;

Figure 7 shows a first folded version of the third embodiment in Figure 6; and

Figure 8 shows a second folded version of the embodiment in Figure 6.

Detailed Description of the Drawings

Possible and preferred features of the present invention will now be described with s particular reference to the accompanying drawings. However, it is to be understood that the features illustrated in and described with reference to the drawings are not to be construed as limiting on the scope of the invention.

Referring first to Figures 1 and 2, sterilisation wrap 10 is a single sheet 12, made of an SSMMS laminate, cut in a "T" shape. Single sheet 12 has, in the orientation ino Figure 1, a horizontal part 14 and a vertical part 16. Sheet 12 is adapted to be folded along fold line 18, which forms a junction between horizontal part 14 and vertical part 16.

In Figure 1, the first spun bond layer in the SSMMS laminate is coloured a pale green. The fifth layer in the laminate in sheet 12, also a spun bond layer, is5 coloured a darker green. Consequently, when the vertical part 16 of sheet 12 is folded over the horizontal part 14, as shown in Figure 2, the darker green of the fifth layer of the laminate contrasts against the paler green colour of the first layer of the laminate. This contrast is indicated by the cross hatching of vertical part 16 in Figure 2. o To sterilise an article, the article is placed preferably centred in vertical part 16, sheet 12 being folded as shown in Figure 2. Sheet 12 is then wrapped around the article, in a single step. In the resulting wrapped article, a double layer of sheet 12, formed by the flap comprising vertical part 16 overlying horizontal part 14, will enclose the article. The wrapped article is then exposed to sterilisation by steaming5 in an autoclave for a sufficient period to provide substantial sterilisation of the

article. The wrapped article may then be stored or transported to a site for use, as required.

Turning now to the Figure 3 and Figure 4 embodiment, it can be seen that sterilisation wrap 1OA presents as a single sheet 12 A, once again made of an SSMMS laminate, cut into a "T" shape, which is a slightly modified form to the embodiment in Figures 1 and 2.

In the Figures 3 and 4 embodiment, horizontal part 14A is deeper than in the previous embodiment, compared to vertical part 16A. Vertical part 16A is also wider, compared to vertical part 16 in the previous embodiment

When vertical part 16A is folded about fold line 18A, sterilisation wrap 1OA presents as shown in Figure 4. Once again, the first spun bond layer of the SSMMS laminate of sheet 12 A is coloured in a paler tone than the fifth layer, so that when in the folded state shown in Figure 2 there is a contrast, indicated by the cross hatching in Figure 4. As illustrated, the flap formed by folded vertical part 16A exposes a paler margin formed by the uncovered portion of horizontal part 14A.

Folded sterilisation wrap 1OA is used in the method of the invention in the same way as described above in relation to sterilisation wrap 10.

Figure 5 shows one way in which eight sterilisation wraps 10 is cut from a single, rectangular sheet 20 of SSMMS laminate. It can be seen from Figure 5 that each "T" shaped sheet 12 is reversed between neighbouring "T" shaped sheets 12, with a horizontal part 14 abutting a neighbouring vertical part 16 from the top to the bottom of sheet 20 in Figure 5. From side to side of sheet 20 in Figure 5, a horizontal part 14 of one sheet 12 abuts a horizontal part 14 of a neighbouring sheet 12 and a vertical part 16 of another sheet 12 abuts a vertical part 16 of a neighbouring sheet 12.

In this illustration, the only wastage from sheet 20 is represented by cut offs 22.24 and 26.

The embodiment in Figure 6 shows wrap 30 in a square format sheet. It will be appreciated by one skilled in the art that a similar embodiment may be derived 5 from a rectangular sheet.

Wrap 30 is shown as having two fold lines 32 and 34. Wrap 30 is made from an SSMMS laminate as before, with the first spun bond layer being of a different colour from the fifth spun bond layer.

When wrap 30 is folded about upper fold line 32, the sterilisation wrap shown in o Figure 7 results. If wrap 30 is folded about lower fold line 34, the sterilisation wrap illustrated in Figure 8 results, where the flap formed by folded part 36 is a darker colour which contrasts against the exposed part of wrap 30, as indicated by the cross hatching.

Any of the embodiments illustrated may be subject to bonding, using heat,5 ultrasound, stitching or adhesion.

In the case of the Figure 1 /Figure 2 embodiment, bonding may take place along margins 38 and 40 of the flap formed by folded vertical part 16. The bonding is achieved by continuous sealing. This would leave margin 42 open, forming a pocket for receipt of an article to be sterilised. Sterilisation wrap 10 may be0 provided in this bonded form, so that a user has the option of placing an article to be wrapped on the folded vertical part 16 or of inserting it through open margin 42 before wrapping.

Alternately, the flap formed by folded part 16 may be bonded to horizontal part 14 over several sites, for example indicated by circles 44.

In a similar manner, in the case of wrap 1OA in Figure 4, the flap formed by folded vertical part 16A may be bonded to horizontal part 14A along margins 38A and

4OA, leaving margin 42A open. Wrap 1OA may be used as described above in relation to wrap 10, with an article being placed on folded wrap 1OA or in the pocket accessed through unbonded margin 42A.

Instead, wrap 1OA may have folded vertical part 16A bonded to horizontal part 14A in the areas indicated by circles 44, for example.

With reference to wrap 30 in Figures 7 and 8, bonding may take place along margins 38 and 40, leaving margin 42 free to form a pocket. Alternately, bonding may take place along margins 38 and 42, leaving margin 40 open to form a pocket.

Instead, bonding may take place at other sites, in a simitar way to the previous embodiments or in any other desired way.

It will be appreciated by one skilled in the art that the embodiments described are not limiting on the scope of the invention and that modifications and variations may be made within the spirit of the invention.

Industrial Applicability

The sterilisation wrap of the present invention has many advantages. For example, it can effectively provide a double wrap for articles to be sterilised, while facilitating wrapping because of single sheet areas provided in the wrap. Especially, if contrasting colours or tones are used, the location of the double wrap area can be indicated.