Sterilization Wrapping Material

Field of the Invention

The present invention relates to a wrapping material for wrapping items, typically hospital equipment as well as surgical instruments and appliances, before sterilizing such items.

Background Art

The following discussion of the background art is intended to facilitate an understanding of the present invention only. The discussion is not an acknowledgement or admission that any of the material referred to is or was part of the common general knowledge as at the priority date of the application,

Hospital equipment that is to be sterilized needs to be wrapped for storage and later use. Sterility of the equipment can be maintained for various lengths of time, depending on the type of wrapping material, the conditions of storage, and the integrity of the package. Presently, such equipment is double wrapped in two separate wrapping sheets which require separate handling processes. Such sheets do not provide immediate identification of tampering of damage to the wrap. It is the object of the present invention to substantially overcome the disadvantages of the prior art or at least provide a useful alternative.

Disclosure of the Invention

The present invention provides a wrapping material comprising at least two superimposed sheets joined to each other adjacent their edges, the sheets being of differing colours.

Preferably, a first of said sheets is a four layer polymer laminate construction having a spuπbonded layer, a meltblown layer, a second meltblown layer and a spunbonded layer.

Preferably, a second of said sheets is a four layer polymer laminate construction having a spunbonded layer, a mettblown layer, a second meltblown layer and a spunbonded layer in a different colour to the first sheet,

The wrapping material preferably comprises an intermediate sheet comprising a cellulose based material.

The sheets are preferably joined at their two side edges at a distance of 5-10 mm from the side edges. The joining area preferably has a width of 7 to 10 mm. Each of the sheets preferably has a basic weight ranging from twenty-five grams per square meter to ninety grams per square meter.

Preferably, the material is adapted and suitable for use under steam, ethylene oxide and/or hydrogen peroxide sterilization conditions and for exposure of the wrapped article for a sufficient period of time to this method of sterilization to substantially ensure that the wrapped article is sterile and safe to use in any medical procedure.

The sheets are preferably of substantially similar dimensions. The sheets can be joined to each other by means of stitching, an adhesive medium, heat bonding, pressure bonding or ultrasonic bonding, or any suitable combination thereof.

The first and second sheets preferably each have bacterial filtration efficiency greater than 60 percent. The sheets forming the wrapping material are preferably made from a disposable material. At least one of the sheets preferably has liquid repelling characteristics. The sheets are preferably anti-static. The sheets are also preferably flame retardant. The first sheet is preferably green in colour, the second sheet is preferably blue in colour and the intermediate sheet is preferably clear or white in colour.

The present invention thus provides a multi layer, single handling sterilization wrapping material that is suitable for multiple applications such as wrapping medical surgical devices and instruments for sterilization, storage and

^" transportation as well aβ covering trays, trolleys, furniture and equipment used in

operating theatres and other parts of hospitals and areas outside hospitals where medical procedures, medical handlings and/or treatment is performed.

Traditional wrapping systems and techniques involve double wrapping in two separate wrapping sheets in two handling processes. The present invention provides, aside a more efficient, time and money saving way of wrapping and unwrapping, a unique safety feature as a result of colour coding. The inner layer and the outer layer have different colours. In the event of a damaged outer layer of the pack, a different colour can be seen indicating that the outer layer has been damaged. After the pack has been opened and the sterile contents has been presented on the sterile field of the inner layer, damage to this inner layer can easily be identified as a different colour can be seen in the sterile field. This safety feature distinguishes this wrapping material from any other wrapping system used.

Brief Description of the Drawings

Preferred forms of the present invention will now be described by way of examples only with reference to the accompanying drawings wherein;

Figure 1 shows two superimposed sheets for forming a wrapping material according to a first preferred embodiment of the present invention; Figure 2 shows three superimposed sheets for forming a wrapping material according to a second preferred embodiment of the present invention;

Figure 3 shows the process of joining the sheets of Figure 1 to each other adjacent their side edges;

Figure 4 shows the process of joining the sheets of Figure 2 to each other adjacent their side edges;

Figure 5 shows the finished product of the first preferred embodiment; Figure 6 shows the finished product of the second preferred embodiment;

Figure 7 schematically shows the outer surface of the wrapping material of the first preferred embodiment when compromised by a slit; and

Figure 8 schematically shows the inner surface of the wrapping material of the first preferred embodiment when compromised by a slit.

Best Modes for Carrying Out the Invention

Figure 1 shows superimposed outer sheet 10 and inner sheet 12 for forming a wrapping material 14 according to a first preferred embodiment of the present invention. The outer sheet 10 in the embodiment is blue in colour and the inner sheet 12 is green in colour.

Figure 2 shows superimposed outer sheet 20, inner sheet 22 and intermediate sheet 24 for forming a wrapping material 26 according to a second preferred embodiment of the present invention. The outer sheet 20 in the embodiment is blue in colour, the inner sheet 22 is green in colour and the intermediate sheet 24 is clear or white in colour.

Figures 3 and 4 respectively show the process of joining the sheets of wrapping materials 14 and 26 to each other adjacent their side edges. The sheets 14 and 26 are moved in the direction as indicated by arrows 30 relative to stationary joining machines 32 which are disposed adjacent the sides of the wrapping materials 14 and 26. The machines 32 produce joins 34 to join the sheets of the wrapping materials 14 and 26. The joins 34 can be produced by stitching, adhesive, heat bonding, pressure bonding, ultrasonic bonding, or any other suitable means. The particular joining method will be selected as desired and will also depend on sheet material used. Figures 5 and 6 respectively show the finished wrapping materials 14 and 26 having sheets joined along the full length of their sides by joins 34. The distance 36 from the sheet edge to the join 34 is 5 to 10 mm while the width 38 of the joins 34 is 7 to 10 mm.

Typical use of the invention will now be described with reference to Figures 7 and β which show the wrapping material 14. The wrapping material 14 is typically

used to wrap sterilised items, with adhesive being uβed to retain the material 14 to such items. Some of these items have sharp edges or points which can damage the material 14. For example, as shown in Figure 7, a slit 40 has been formed in the blue outer sheet 10, The slit 40 in the blue outer sheet 10 can be easily identified and located as the green inner sheet 12 is easily and quickly seen from the slit 40, providing a quick indication that the wrapping material 14 has been compromised. Inverting the material 14 as shown in Figure S, a slit 42 in the green inner sheet 12 can be also quickly identified and located as the blue outer sheet 10 can be seen from the slit 42. If the blue outer sheet 12 cannot be seen in the inverted position of Figure 8, this provides an indication that a slit has not been formed in the green inner sheet 12, and vice versa. As the sheets 10 and 12 are joined only at their edges, the sheets 10 and 12 can substantially be moved relative to each other which can assist in quickly locating slits, cuts or holes. Protocols can then be decided as to whether sterilised items wrapped with compromised material 14 are to be resterilised only if both sheets 10 and 12 are compromised, or if they are to be resterilised even if only one of the sheets 10 and 12 is compromised.

Identification of possible slits or holes in the wrapping material 26 (the second embodiment) are performed as above. If the blue outer sheet 20 or green inner sheet 22 is compromised, the clear or white intermediate sheet 24 can be easily seen and thus provides easy identification and location of the slit or hole.

In the wrapping materials 14 and 26, the sheets are preferably of substantially the same dimensions with the edges thereof aligned when joined together. The sheets can be of the same type and having the same physical properties. Alternatively, the sheets can be of different types having different physical properties. For each application, the choice of sheets can be specifically engineered to satisfy client and application requirements.

The outer and inner sheets are preferably of a four layer polymer laminate construction having a spunbonded layer, a rneltblown layer, a second meltblown layer and a spunbonded layer. The intermediate sheet is preferably a cellulose based material.

The sheets are preferably joined at their two side edges at a distance of 5-10 mm from the side edges. The joining area preferably has a width of 7 to 10 mm. Each of the sheets preferably has a basic weight ranging from twenty-five grams per square meter to ninety grams per square meter. Preferably, the material is adapted and suitable for use under steam, ethylene oxide and/or hydrogen peroxide sterilization conditions and for exposure of the wrapped article for a sufficient period of time to this method of sterilization to substantially ensure that the wrapped article is sterile and safe to use in any medical procedure. The sheets are preferably of substantially similar dimensions. The sheets can be joined to each other by means of stitching, an adhesive medium, heat bonding, pressure bonding or ultrasonic bonding, or any suitable combination thereof.

The first and second sheets preferably each have bacterial filtration efficiency greater than 80 percent The sheets forming the wrapping material are preferably made from a disposable material. At least one of the sheets preferably has liquid repelling characteristics. The sheets are preferably anti-static. The sheets are also preferably flame retardant.

The safety feature of providing colour coding (different colour inner and outer layers) makes ft easy for theatre staff and any other medical staff or user of the wrapping material to recognize whether the instruments and/or devices are presented on a sterile field and/or whether the wrapping material has been damaged after sterilization. If a wrapping material has been damaged a different colour can be seen through the damaged outer wrap (Figure 7). The same damage indicator is there when the wrapping material has been opened whereby the inner layer has formed a sterile field and a different colour can be seen in this sterile field (Figure 8). In both occasions the wrap has been damaged and the sterility of the instruments and/or devices cannot be guaranteed. Instruments and/or devices presented in a damaged wrapping material or on a damaged sterile field cannot be used and have to be cleaned, re-packed and re-sterilized. Since the different colour coded wrap layers are permanently joined to each other, the chance of human error in colour coding has been eliminated

Medical devices and/or instruments can be wrapped with the wrapping material in a single action and unwrapped in a similar single action providing a more efficient wrapping system which provides time and money savings,

The present invention can be manufactured with sheets available under the following trade marks in a series of different strength and basic weights as listed in Table 1 below:

Table 1

The basic weights indicated in Table 1 are for each individual sheet used to compose the entire wrapping material product. These individual sheets can be manufactured and traded under the name MediSheet as listed in Table 2:

Table 2

The physical properties of the wrapping material are listed below in Table 3:

The physical properties indicated in Table 3 are for each individual sheet used to compose the entire wrapping material product.

Throughout the specification, unless the context requires otherwise, the word "comprise" or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.