HK1236796A1 - Surgical swab composed of non-woven fabric and textile polymer net - Google Patents

Description

Surgical swab consisting of a non-woven fabric and a woven polymer mesh

Technical Field

The present application describes a surgical swab and a method of making the same.

Background

Pre-washed surgical swabs made of hydrophilic gauze are very common items on the market. In many countries, the use of pre-washed surgical swabs instead of normal surgical swabs is considered to be preferred due to the higher absorbent capacity and spongy and soft feel. The introduction of such surgical swabs is very similar to the advent of reusable surgical swabs which are washed and sterilized after use and which have begun to be abandoned due to the risk of cross-contamination.

With the advent of nonwoven fabrics, surgical gauze swabs were largely replaced by surgical nonwoven fabric swabs. In the present application, a nonwoven fabric is considered to correspond to a layer of fibers, continuous filaments or chopped strands of any nature or origin, which are organized into a web by any means and attached to one another by any method or technique other than weaving or knitting.

Nonwoven fabric swabs have higher absorbent capacity and rate, suitable resistance, flexibility and conformability than conventional gauze swabs. Since nonwoven fabric swabs are less worn and damaged, they ultimately form a product that is very comfortable for the patient. This feature allows the product to be used for all surgical procedures, including the most critical surgical procedure.

Two other critical points in nonwoven fabric swabs are the complete lack of loose threads and stitching. Loose wires from gauze swabs can lead to infection and even complications in the operating room. The absence of threads in the nonwoven would completely eliminate this problem, while the stitching threads used are often contaminated with optical brighteners. In contrast to the production of gauze swabs, which involves a very large number of folding and sewing operations, the production and folding of these swabs is carried out entirely by the machine in a controlled environment, without the product being treated, which ensures a reduction in the microbial load. On the other hand, the use of nonwoven fabric swabs is advantageous both from an environmental point of view and for the protection of natural resources. Gauze swabs are produced from cotton thread. It is estimated that over 95% of the cotton produced in the world is obtained using environmentally harmful technologies because of the large amount of pesticides and fertilizers used. Its production also requires large amounts of water. This lack of limited resources is a serious environmental threat. In addition to all technical advantages, nonwoven fabrics are also cheaper to produce and consume raw materials than the gauze alternative.

Therefore, surgical non-woven fabric swabs are a very advantageous alternative to gauze swabs, which can be obtained by pre-washing the gauze swabs, in addition to regarding sponginess, smoothness and appearance. Surgical nonwoven swabs are generally present in a planar form because the pre-wash effect does not produce the same result in the material.

The present application discloses a technique with the aim of creating a surgical non-woven fabric swab that presents similar structures and features as in surgical pre-wash gauze swabs. This possibility has been studied previously, as described in us patent 3683921. The main purpose is to introduce a second element inside the non-woven fabric, which, by its technical features, gives the final article a corrugated appearance. This second element, the production of the nonwoven and the method of joining between the different layers are the main differences between the product described in us patent 3683921 and the present invention.

The production of nonwoven fabrics begins with the arrangement of fibers into a veil or web. One mechanical method for obtaining these webs is carding. In this method, the fibers are arranged in a carding machine and carded by means of a cylinder or a series of drums covered by clothing or rotating teeth. For many years, all nonwoven fabrics have required the addition of chemical binders to provide structural integrity and enhance the effect thereof in order to compact the face yarns formed by carding. Such nonwoven fabric production is described in U.S. patent 3683921 for forming surgical swabs. The fibrous veil formed in carding is interlaced with the thermoplastic web by means of water jets, forming a laminated structure to which a chemical binder is subsequently added. Other bonding technologies were rapidly developed in the early 1980 s, and an efficient process enabled factories to produce stronger and soft nonwoven fabrics without the use of chemical adhesives. The main advantage of these new bonding techniques is that the nonwoven fabric does not contain formaldehyde or chemical additives.

In US3683921 the intermediate layer comprises a web of thermoplastic film, in particular polypropylene, which gives the pledget a corrugated character after heat treatment. The formation of such a net film is described in detail in document US3881381 and is based on heating a film of high density polyethylene or polypropylene at elevated temperature, forming a net structure and subsequent cooling. The inclusion of such a web film in two layers of fibers enables its structure to contract 3 to 25% (due to the "elastic memory" of the film). In contrast, the technology proposed here allows the pledget to shrink/collapse by inserting a textile web, which can be obtained by a knitting or weaving process, made of materials such as elastane (elastane) or polyamide and polyester or even polyamide and cotton, between the layers of non-woven fabric. In this document US3683921 the bonding between the outer layer of fibres and the web of thermoplastic film is carried out by passing the three layers through a first passage of a system of high-pressure water jets so as to cause the fibres to be interwoven in the thermoplastic web, then applying the adhesive, and then curing and drying the adhesive. The different layers of this reinforcing laminate are then overlapped, welded by heating, and cut to size. Welding and cutting all four sides of a web-formed swab of these plastic film layers and interwoven fibres will inevitably produce a hard and rough surface in the cut area. This step is not required in the present invention because the outer layer is formed of a finished nonwoven fabric without applying any adhesive. The bonding between the layers is performed by ultrasound, thus enabling the end of the swab (including the cutting area) to be soft and flexible.

Disclosure of Invention

The present application describes a surgical swab consisting of two or more outer layers of non-woven fabric, one inner layer of woven polymer mesh, with or without x-ray detectable threads, consisting of a material with high elasticity, such as spandex, or a material with high ability to shrink after heat treatment, such as polyamide or polyamide and polyester or even polyamide and cotton, which feature causes a shrinking effect in the final product.

Also described herein is a method of producing such a surgical swab, the method comprising ultrasonically welding two or more layers of a nonwoven fabric and an inner layer of a woven polymer web after joining and overlapping the layers.

General description of the invention

The present application describes a surgical nonwoven fabric swab having similar visual characteristics as a surgical pre-washed gauze swab, but with a softer and spongy tactile feel.

Such swabs have significantly improved performance characteristics, including high strength, high capacity and absorption, and reduced fiber or particle release, compared to the main items available on the market.

These aspects are very important depending on the intended end use of the article. The use of a nonwoven fabric in the outer layer is advantageous from the point of view of the properties of the article, as well as in terms of economy and environmental impact. Nonwoven fabrics as textile webs are all made of biocompatible materials which are conventionally used in other articles in the medical field and therefore do not pose any risk of use.

The surgical swabs described in this application are constructed of two or more outer layers of non-woven fabric and an inner layer of woven polymer mesh, with or without x-ray detectable threads, with high elasticity or high shrinkage capability through the application of heat, thereby enabling a crimp or sponge-like effect to be obtained in the final article.

After joining and juxtaposing, the layers are joined or welded by ultrasound, thereby forming a laminate. Followed by cutting and subsequent shrinking/shrinking.

If the textile web comprises spandex, the joining, overlapping and welding is performed under tension so that the tension is retained. The cutting allows a relaxation of the stress, which causes a contraction of the material, which causes a very crumpled structure on the surface of the non-woven fabric, giving the article an extremely soft and spongy feel.

In the case of woven polymer webs comprising polyamide or polyamide and polyester or even polyamide and cotton, a heat treatment is performed after cutting, which results in shrinkage of the polyamide and thus of the surgical swab.

The use of a textile web comprising polyamide does not require application under tension.

In the product described here, the welding of the layers is carried out ultrasonically and therefore does not require the addition of any adhesive, and therefore does not require a drying process and does not require the curing of the adhesive.

After stretch relaxation or heat treatment, depending on the type of textile web used, a shrinking and softening effect will be produced which is particularly appreciated by the user. Moreover, these treatments are easy to apply and have reduced costs at the industrial level. The heat used in the process also creates the same soft shrink surface when the product is packaged and steam sterilized.

The components and method of manufacture of the surgical swab enable the article to be processed into a "flat" appearance until a final stage, at which time it is collapsed by heating or relaxing.

This method uses inexpensive materials and constitutes an automated production process with few steps. The final article is therefore produced in a significantly more economical manner than current methods of producing surgical gauze swabs. Also, automation and complete absence of human intervention in the production process will necessarily reduce the microbial load (load) found in the item when compared to surgical gauze swabs, in which there are a large number of folding and sewing operations.

Drawings

For a more complete understanding of the technology, reference is made to the accompanying drawings, which illustrate preferred embodiments, but which are not intended to limit the subject matter of the present application.

Fig. 1 shows a schematic view of a surgical non-woven fabric swab, the surgical non-woven fabric swab (1) having a pre-washed look in its final appearance.

Fig. 2 shows a method for producing a pledget (1) in the case of a textile web comprising a material with high elasticity, such as spandex, by joining the outer layer (2) of a two-layer nonwoven and the inner layer of an elastic textile web and arranging them under tension (3) so as to remain stretched. The three layers are overlapped by a press roll (11) and welded together by ultrasound (12) to form a laminate (4) still under tension. The laminate (4) is then cut to the required dimensions by means of a blade system (13). The cutting of the laminate (4) causes the web of woven fabric to relax, thereby causing it to return to its original shape, thus creating a crimping effect on the surface of the nonwoven fabric to which it is welded when stretched. Thus, a collapsed open swab (5) is obtained, which swab (5) is moved to the fixed strip application platen and folded (4) into the final article.

Fig. 3 shows a schematic representation of the production of a swab (1) with a textile web comprising polyamide or polyamide and polyester or even polyamide and cotton. A polyamide or a polyamide and polyester or cotton textile web (6) is used without any stretching being applied. The overlapping of the nonwoven layer (2) and the polyamide, polyamide and polyester or polyamide and cotton woven web (6) is carried out by means of a press roll (11). Then, the laminated material (7) is welded by ultrasonic waves (12). Cutting the laminate to the appropriate size will be performed in a blade system (13) to obtain an open swab without crimps (8). The swab is then subjected to a heat treatment (15) resulting in a contracted open swab (9). The final steps of applying the securing straps and folding are the same as described above and are performed on the platen (14).

In both cases, shown in fig. 2 and 3, it is also possible to apply lines or strips detectable by X-rays (10) by welding or by another method.

Fig. 4 shows the application of ultrasonic welding (12) by a single roller at both the ends (15 and 16) and the interior (17) of the pledget.

Figure 5 shows the application of ultrasonic welding (12) by two different rollers.

Detailed Description

Some embodiments will be described in more detail below with reference to the accompanying drawings, which, however, do not limit the scope of the present application.

In one embodiment, in the case of a textile web comprising elastane, the production process of the pledget (1) includes joining the outer layer (2) of the two-layer nonwoven and the inner layer of the elastic textile web, arranged under tension (3), so as to remain stretched. The three layers are overlapped by a press roll (11) and welded together by ultrasound (12) to form a laminate (4) still under tension. The laminate (4) is then cut to size by a blade system (13). The cutting of the laminate (4) causes the web of woven fabric to relax, thereby returning it to its original shape, thus creating a crimping effect on the surface of the nonwoven fabric to which it is welded when stretched. Thus, a collapsed open swab (5) is obtained, which swab (5) is moved to the fixed strip application platen and folded (14) into the final article.

In one embodiment, in the case of a textile web comprising polyamide or polyamide and polyester or even polyamide and cotton, the method of producing the pledget comprises joining and overlapping two outer layers (2) of non-woven fabric and one inner layer of a textile web of polyamide or polyamide and polyester or even polyamide and cotton by means of a pressure roller (11). Then, the laminated material (7) is welded by ultrasonic waves (12). Cutting the laminate to the appropriate size will be performed in a blade system (13) to obtain an open swab without crimps (8). The swab is further subjected to a heat treatment (15) to produce a contracted open swab (9). The final steps of applying the securing straps and folding are the same as described above and are performed on the platen (14).

In a preferred embodiment, the heat treatment is carried out at a temperature between 40 and 80 ℃. In this temperature range, the sterilization by ethylene oxide will cause a suitable shrinking effect, so that no heating station in the production machine is required.

In a preferred embodiment, the overlapping of the layers is performed by means of a press roll, irrespective of the type of textile web used.

In a preferred embodiment, the cutting is performed by a blade system, regardless of the type of textile web used.

In one embodiment, the operation of applying the fixing strip is performed so that it is fixed at one end. The securing strap remains outside the surgical incision and the swab is inside to ensure that the swab is not left behind in the patient after the surgical procedure.

In one embodiment, a line or strip detectable by X-rays (10) can also be applied. In one embodiment, this application is performed by welding.

As shown in fig. 4 and 5, there are two alternative methods for applying ultrasonic welding (12) on a thin layer of non-woven fabric and a woven web of spandex (4) or on a thin layer with non-woven fabric and a woven web of polyamide or polyamide and polyester or even polyamide and cotton (7).

In the first roll of fig. 5, external welding parallel to the roll (16) and internal welding (17) are performed, while external welding perpendicular to the roll (15) is performed on the second roll.

Results of the swab test

The results obtained in tests carried out on representative samples of surgical swabs of non-woven fabric, when used internally with spandex, polyamide and polyester or polyamide and cotton textile webs, have a pre-washing effect compared with other options currently available:

absorption capacity

The absorbent capacity of nonwoven fabric swabs with a web of spandex, polyamide and polyester or polyamide and cotton is much higher than the absorbent capacity of different types of swabs available.

Table 1-values of the absorption capacity of surgical nonwoven fabric swabs with a web of spandex, polyamide and polyester or polyamide and cotton compared to other products currently on the market.

Absorption rate:

surgical nonwoven fabric swabs with webs of spandex, polyamide and polyester or polyamide and cotton had higher percent water retention than surgical pre-washed gauze swabs after 5 and 10 seconds from the start of the test.

Tables 2 and 3-absorption rate values obtained at the end of 10 and 5 seconds for pre-washed surgical gauze swabs and for surgical non-woven fabric swabs with a web of spandex, polyamide and polyester or polyamide and cotton, respectively.

TABLE 2 test time-10 seconds

TABLE 3 test time-5 seconds

Fiber and particle delivery

Surgical non-woven fabric swabs having a web of spandex, polyamide and polyester or polyamide and cotton have lower amounts of release particles than surgical pre-washed gauze swabs.

Table 4-release values of fibers and particles obtained for surgical pre-wash gauze swabs and for surgical non-woven fabric swabs with a web of spandex, polyamide and polyester or polyamide and cotton.

Chemical characteristics:

the values obtained in the chemical property test for surgical nonwoven fabric swabs with webs of spandex, polyamide and polyester or polyamide and cotton are within parameters determined by available standards.

Table 5-values obtained in different chemical property tests for surgical pre-washed gauze swabs and for surgical non-woven fabric swabs with a web of spandex, polyamide and polyester or polyamide and cotton.

The embodiments of the invention are of course in no way limited to the embodiments described herein, but a person skilled in the art will be able to make many variations thereof without departing from the general idea as defined in the claims.

All of the above embodiments can obviously be combined with each other. The following claims define further preferred embodiments.

Claims (14)

1. A surgical swab comprising, in its construction:

a) two or more outer layers of nonwoven fabric;

b) an inner layer of a woven polymeric mesh comprising a polymer selected from the group consisting of:

elastic fibers;

a polyamide;

polyamides and polyesters; and

polyamide and cotton.

2. The surgical swab of claim 1, wherein: the woven polymer web comprises spandex.

3. The surgical swab of claim 1, wherein: the woven polymer web comprises polyamide or polyamide and polyester or even polyamide and cotton.

4. A method of producing a surgical swab according to any one of the claims 1 to 3, comprising the following steps:

-joining and overlapping two layers of nonwoven fabric and a woven polymer web comprising a polymer selected from:

elastic fibers;

a polyamide;

polyamides and polyesters; and

polyamide and cotton;

-ultrasonic welding of the layers forming the laminate; and

-cutting the laminated material.

5. The production method according to claim 4, wherein; the woven polymer web comprises spandex.

6. The production method according to claim 4, wherein: the woven polymer web comprises polyamide or polyamide and polyester or even polyamide and cotton.

7. The production method according to any one of claims 4 to 6, wherein: the woven polymer mesh is obtained by weaving or knitting.

8. The production method according to claim 5, wherein: the joining, overlapping and welding are performed under tension.

9. The production method according to claim 6, further comprising: a heat treatment after cutting that produces a shrink wrap of the surgical swab, preferably at 40 and 80 degrees.

10. The production method according to any one of claims 4 to 9, wherein: the overlapping of the layers is performed by means of a press roll.

11. The production method according to any one of claims 4 to 10, wherein: the cutting is performed by a blade system.

12. The production method according to any one of claims 4 to 11, further comprising: a securing strip is applied.

13. The production method according to any one of claims 4 to 12, further comprising: a step of folding the surgical swab.

14. The production method according to any one of claims 4 to 13, further comprising: a line or strip detectable by X-rays is applied.