WO2024003054A1

WO2024003054A1 - Dressing material comprising a mesh-like fabric

Info

Publication number: WO2024003054A1
Application number: PCT/EP2023/067486
Authority: WO
Inventors: Thomas Guter
Original assignee: Paul Hartmann Ag
Priority date: 2022-06-27
Filing date: 2023-06-27
Publication date: 2024-01-04
Also published as: DE102022115970A1

Abstract

The invention relates to dressing material comprising a mesh-like fabric (10) with a warp direction and a perpendicular weft direction, and with warp threads (14) extending in the warp direction and weft threads (16) extending in the weft direction, the fabric (10) having cut, open edges (12), characterized in that the warp threads (14) and/or the weft threads (16) contain polyester threads and/or polyester blend threads.

Description

Title: Bandage material comprising a grid-like

tissue

Description

The invention relates to a dressing material comprising a grid-like fabric with a warp direction and a weft direction running perpendicular thereto, as well as with warp threads running in the warp direction and weft threads running in the weft direction, the fabric being designed with cut, open edges.

When it comes to bandage materials made from grid-like fabrics, a basic distinction is made between gauze and tamponade bandages. Tamponade bandages according to the DIN EN 14079 standard are designed in the form of continuous bands of different widths with woven edges.

In contrast, gauze is usually woven in a plain weave, with the gauze then being cut from the fabric to produce open selvages.

Gauze or gauze is then folded together as a compress or gauze in a zigzag fold or on a roll for use. In addition, provision can also be made for the gauze to be used as a swab in a twisted form.

The terms gauze and gauze will be used interchangeably below. The bandage material with open selvedges is therefore gauze or gauze.

The gauze according to the invention can be designed as a 17-thread gauze or as a gauze with 13 threads in accordance with DIN EN 14079. In principle, other thread counts in accordance with DIN EN 14079 are also conceivable according to the invention. The thread count is understood to mean the number of threads per cm ² and this defines the type of gauze.

Such dressing materials have been known in the art for many years. Gauze or gauze is made from cotton in accordance with DIN EN 14079. Cotton is a natural product that is subject to large fluctuations in price and quality.

Alternatively, considerations were given to producing gauze as a fleece or nonwoven instead of as a woven material. However, some users have concerns about switching to non-woven materials and want to continue using woven materials as dressing material.

Based on the known state of the art, namely dressing materials with open edges, i.e. dressing gauze or gauze, made of cotton, the object of the invention is now to provide a dressing material that is less dependent on the naturally occurring cotton resources and the associated fluctuating costs for cotton.

The invention solves this problem by a dressing material with the features of claim 1, namely a dressing material in which the warp threads and / or the weft threads contain polyester threads and / or polyester blend threads.

Warp threads are understood to mean the threads that run in the machine direction, with weft threads being the threads that run transversely to this. This is the usual assignment of terms in web technology. It can preferably be provided that the weft threads are preferably made of polyester threads or polyester blend threads, with polyester threads being particularly preferred. The use of polyester in the weft threads is particularly advantageous compared to the use in the warp threads because the warp beam can be used as usual during weaving (100% cotton) and therefore no change in warp beam production is necessary. Instead, only the weft thread on the weaving machine is replaced. This means there is a slight change in production. Another advantage is that the polyester thread is less rough and can therefore be shot easily

Ultimately, the warp thread in the finished gauze is more taut than the weft thread. Since the weft thread lies "loosely in loops", the fabric is more elastic in the weft direction than in the warp direction.

Alternatively, it can also be provided that cotton or viscose can be alternated with polyester threads. According to the invention, it is preferred if at least 30%, in particular at least 50% and in particular at least 70% of the weft threads are polyester threads or polyester blend threads.

Polyester blended threads can include threads in which cotton and/or viscose and/or other materials are spun together with polyester. Alternatively, bicomponent fibers can also be used be provided as polyester blend threads which, for example, have a sheath-core arrangement in which a cotton sheath has a polyester core. Particular preference is given to using a monofilament produced by polycondensation, in particular from polyethylene terephthalate (PET), as the polyester fibers. The advantage of a monofilament thread is its low cost, for example in comparison to a bicomponent thread.

However, it is preferred that the weft threads consist entirely or partially of polyester. It is particularly preferred that they are made entirely of polyester.

Polybutylene terephthalate, polylactide, polytrimethylene terephthalate, polyethylene naphthalate, polycarbonate, polyester carbonate, polyarylates and unsaturated polyester resin can be used as possible and preferred polyester types. Polyethylene terephthalate is particularly preferred.

By providing polyester, the values for the tensile strength of the dressing material specified in the DIN EN 14079 standard can be increased in a positive way compared to the values for cotton. At the same time, the other values desired and/or required by the standard, such as the optical appearance, in particular the whiteness, the thread count, the fluorescence, and the sinking time of the material, are retained in the same way. This also applies to the information in the DIN EN 14079 standard for acidic and alkaline substances, surfactants, ether- and water-soluble substances, starch and dextrin Loss on drying, sulfate ash and extractable

Dyes that should preferably continue to correspond to the values specified in the standard.

The weight per unit area specified by the standard DIN EN 14079 can be designed in accordance with the standard or reduced, provided that the tear strength in the warp and weft directions that the standard specifies is achieved.

The tear resistance is particularly important in the case of gauze or gauze, since here the tear resistance is not provided and maintained by the selvedges as with tamponade bandages, but must be provided in particular by the weft threads. The tear resistance is of particular importance so that no residue of the gauze remains in or on a wound.

In particular, in order to maintain the ability to absorb liquid, in particular wound fluid, but also saline solution or water, it can be provided according to a preferred exemplary embodiment that the warp threads are made of cotton and/or cotton blend threads. According to an alternative embodiment, it can also be provided that the warp threads include both cotton threads and viscose threads.

Cotton blend threads are either Biko fibers, which have a cotton cover, or fibers in which cotton filaments are spun with other filaments to form a thread. Cotton threads are particularly preferably used as warp threads. These are what they offer Properties known to previous dressing materials made from cotton, such as good water absorption, but also, for example, the basis weight required according to the DIN EN 14079 standard and the required tear resistance.

Particularly preferably it can be provided that the fabric is woven in the usual way using plain weave.

In principle, however, a twill weave or another type of weave, such as a leno weave or a panama weave, is also conceivable. Using a plain weave ensures that the fabric and thus also the dressing material has the usual look that users perceive as familiar and desired. In particular, all weaves provide users with a familiar and familiar look and feel compared to nonwoven materials.

It is particularly preferred if the polyester threads and/or polyester blend threads used as warp and/or weft threads do not cross each other but always run essentially parallel to one another. Essentially parallel should preferably be understood to mean that the polyester threads and/or polyester blend threads are only used either as a weft or as a warp thread, but not in two thread systems that run transversely to one another.

It can be provided that the fabric, in the case of a gauze with a thread count of 17 threads, has a tear strength in the warp direction (machine direction - MD) of > 50 N/50 mm when dry, in particular of > 55 N/50 mm, in particular > 60 N/50 mm. The procedure for determining the tear strength is specified in DIN EN 14079. The values for a gauze with a thread count of 13 threads are > 35 N/50 mm. This means that the tear resistance always exceeds what is required by the DIN EN 14079 standard.

In particular in the weft direction (transverse direction) (also referred to as Cross Direction - CD in relation to Machine Direction - MD), the fabric has a tear strength in the weft direction of > 30 N/50 mm, in particular of > 70 N/50 mm, in particular of > 100 N/50 mm is many times what is required by the standard and therefore offers significant advantages. These values apply to a gauze with a thread count of 17 threads. For a gauze with a thread count of 13 threads, the value is > 20 N/50mm. The warp direction corresponds to the machine direction and the weft direction corresponds to the cross direction.

In addition, the fabric also has very good tear resistance when wet. The tear strength when wet, which is not covered and represented by the DIN EN 14079 standard, is of particular importance as it allows a statement to be made about the behavior of the dressing material in the application. To create a "wet state", the test samples are placed in 0.05% Tergitol solution until completely wetted, then removed from the solution and the excess liquid wiped off. The test for tear strength is then carried out in accordance with the DIN EN 14079 standard. Here the tear strength in the machine direction, i.e. warp direction, is preferably >50 N/50 mm, in particular >55 N/50 mm and in particular >60 N/50 mm. In the transverse direction to this, i.e. the weft direction, the tear strength is in particular >30 N/50 mm, in particular >70 N/50 mm and in particular >100 N/50 mm. The values apply to gauze with a thread count of 17 threads.

For gauze with a thread count of 13 threads, the values measured when dry apply analogously. In principle, other thread counts are also conceivable, for example a thread count of 20. The thread count corresponds to the number of warp threads and weft threads per 100mm. This results in the following values:

In particular, the tear strength of the fabric according to the invention does not vary significantly, regardless of whether the fabric is in a dry or wet state. The difference is in particular less than 30%, in particular less than 20% and is in particular 5-15%.

Furthermore, it is preferably provided that the fabric has a basis weight of at least 23 g/m ² for a gauze with a thread count of 17 threads. With a 13-thread gauze, the weight per unit area is at least 14 g/ ^m2 . This essentially achieves a basis weight that is also provided with conventional products that are used as gauze.

This means that the handling feeling for the user is kept constant compared to what is known.

In particular, it is preferred if the water absorption of at least 5 g/g, in particular of at least 5.2 g/g and in particular of at least 5.4 g/g is achieved. The water absorption test is carried out as follows:

testing devices/

Aids: - Punching knife: 100 x 100 ± 0.25 mm

(Check the punching knife for damage or similar before use)

- Wire basket 110 x 110 mm, made from wire sieve base 1.4401, mesh size 0.8 mm, wire thickness 0.5 mm

- Stainless steel plate 100 x 100 x 2 mm, 250 ± 2.5 g (see Fig. 1)

- Precision balance, dd = 0.01 g

- shallow bowl

- Stopwatch with seconds division

Reagents/indicators: - none

Chemicals/buffers/media: demin. Water Sample preparation:

Punch out samples

Before the measurement, place the sample material in a test climate of 23 ± 2 °C and 50 ± 4 %rH for at least 24 hours so that air has free access.

Test procedure: unless otherwise required, carry out n = 5 tests

- Determine the dry weight (= ml) of the sample by weighing it to the nearest 0.01 g

Note: if a single sample weighs less than 1 g, stack several samples into a sample stack that weighs at least 1 g.

- Place the sample in the wire basket and cover with the stainless steel plate

Note: for samples from e.g. medical records, place the test specimen in the wire basket with the foil side facing the sieve.

- Place the wire basket with sample and stainless steel plate in a bowl filled with demineralized water; The surface of the sample must be approx. 20 mm below the water level

Note: Avoid the formation of air bubbles under the sample or in the sample stack, for example by inserting the sample into the water at an angle.

- After 30 s, lift the stainless steel plate and place it on the wire basket, twisted by 45° is stated:

- Water absorption A in [g/g], rounded to a decimal

Ml = weight of test specimen, dry in g

M2 = weight of test specimen, wet in g

Note: in special cases the exposure time can be increased or decreased, but not less than 10 s

- After another 30 s, remove the wire basket with the sample from the water and let it drain over a corner for 120 ± 3 s

Weigh the sample again to the nearest 0.01 g (= M2)

Evaluation:

- Relative water absorption A _rei in [%], rounded to a decimal

Ml = weight of test specimen, dry in g

M2 = weight of test specimen, wet in g if desired:

- Water absorption per area AA.in [g/cm ² ], rounded to whole numbers

Ml = weight of test specimen, dry in g

M2 = weight of test specimen, wet in g - Number of tests, mean, minimum and maximum values, standard deviation

Reference to standards: - Method based on DIN 53923:1978-01

Deviations: slightly smaller wire basket, 2-part immersion time with additional load on the sample at the beginning, water temperature corresponds to room temperature

In particular, the requirements for wound treatment can be taken into account through the water absorption determined in this way.

Particularly preferably, the dressing material can be a gauze or a gauze material.

In the following figures, a corresponding dressing material, which is designed as a gauze or gauze material, is shown.

Show:

Figure 1 shows a first fabric for producing gauze,

Figure 2 shows schematically the structure of a gauze

Figure 1 with the warp threads 14 and the weft threads 16 and

Figure 3 shows an alternative fabric. In Figure 1 the fabric of a gauze can be seen, which has weft threads and warp threads. The gauze is cut from a large fabric in the desired width and then made into the appropriate products, such as swabs and compresses. It can be clearly seen here, in addition to the plain weave fabric 10, that open edges 12 are provided, at which the fabric 10 is partly cut through the thread courses. In contrast, a dressing material in the form of a tamponade bandage has closed selvedges and the dressing material is immediately produced in the appropriate width.

The dressing material according to Figure 1 thus consists of a grid-like fabric 10, the fabric being formed with cut open edges 12, the warp threads and/or the weft threads containing polyester threads and/or polyester blend threads.

Figure 2 illustrates the structure in which the warp threads 14 and the weft threads 16 are marked. The weft threads are preferably made from 100% polyester, while the warp threads are made from 100% cotton. In addition to this embodiment, which is a plain weave in which the threads are woven together, it can also be provided that the warp threads are replaced by a mixed thread made of cotton and polyester, for example 60% cotton and 40% polyester. It is also possible to use a design in which the weft threads consist of mixed threads made of cotton and polyester, for example 50% each. The mixed threads can consist of filaments, whereby filaments made of cotton and polyester or cotton and viscose can be provided, which are spun together to form a thread. Alternatively, bicomponent fibers are also possible.

It can also be provided that both the warp threads and the weft threads consist of polyester threads or polyester blend threads. For polyester blend threads, both cotton and viscose can preferably be provided as the second component.

Figure 3 now shows another possible design in which the warp threads are 14 cotton threads. Alternatively, mixed threads made of cotton and viscose, viscose threads or polyester threads as well as mixed threads with polyester can also be used as warp threads. The weft threads 16a, b are alternating polyester threads 16a and viscose threads 16b, each consisting of 100% of the respective materials.

By using polyester, the values of the DIN EN 14079 standard can be met with regard to density, but also water absorption capacity, as well as the other values of the standard. At the same time, improved or constant tear strength can be achieved. In particular, the polyester improves the tear resistance in the damp or wet state, which is close to an application of the bandage material.

Below is a table containing an analysis of both a 100% plain weave cotton fabric shown as well as a fabric that consists of cotton in terms of the warp threads and polyester in terms of the weft threads. Both materials are bandage material with open, cut selvedges.

For the experiments, the results of which are shown in the table, a monofilament made from 100% polyester (polyethylene terephthalate) was used, which was produced by polycondensation and can be purchased at

Name "40S polyester yarn" from the manufacturer "Jiujiang Xin Cheng Textile Co. Ltd., China". The thread has 14.76 tex+/-2.5%. It can be seen from the table that the tear resistance, especially when wet, is improved.

17fd = 17 thread count

MD = Machine Direction

CD = Cross Direction (perpendicular to machine direction)

Claims

Claims Bandage material comprising a grid-like fabric

(10) with a warp direction and a weft direction running perpendicular thereto, as well as with warp threads (14) running in the warp direction and weft threads (16) running in the weft direction, the fabric (10) being designed with cut, open edges (12), characterized that the warp threads (14) and/or the weft threads (16) contain polyester threads and/or polyester blend threads. Bandage material according to claim 1, characterized in that the weft threads (16) are polyester threads and/or polyester blend threads and in particular are polyester threads. Dressing material according to claim 1 or 2, characterized in that the polyester threads are monofilm ducks which are produced by polycondensation, in particular from polyethylene terephthalate (PET). Bandage material according to one or more of the preceding claims, characterized in that the warp threads (14) are cotton threads and/or cotton blend threads. Bandage material according to one or more of the preceding claims, characterized in that the fabric (10) is woven in plain weave. Bandage material according to one or more of the preceding claims, characterized in that the polyester threads and/or polyester blended threads are used either as weft threads or as warp threads, and in particular the weft threads comprise polyester threads and/or polyester blended threads. Bandage material according to one or more of the preceding claims, characterized in that the fabric (10) in the dry state has a tear strength in the warp direction of >50 N/50mm, in particular of >55 N/50mm and in particular of >60 N/50mm. Bandage material according to one or more of the preceding claims, characterized in that the fabric (10) in the dry state has a tear strength in the weft direction of >30 N/50mm, in particular of >70 N/50mm and in particular of >100 N/50mm. Bandage material according to one or more of the preceding claims, characterized in that the fabric (10) when wet has a tear strength in the warp direction of >50 N/50mm, in particular of >55 N/50mm and in particular of >60 N/50mm. Bandage material according to one or more of the preceding claims, characterized in that the fabric (10) when wet has a tear strength in the weft direction of >30 N/50mm, in particular of >70 N/50mm and in particular of >100 N/50mm. Bandage material according to one or more of the preceding claims, characterized in that the fabric (10) has a basis weight of at least 23 g/m2. Bandage material according to one or more of the preceding claims, characterized in that the fabric (10) has a water absorption of at least 5 g/g, in particular of at least 5.2 g/g and in particular of at least 5.4 g/g. Bandage material according to one or more of the preceding claims, characterized in that it is a gauze or gauze.