A four-layer construction medical dressing and a method of making the same

Abstract

The application discloses a four-layer structure medical dressing, which comprises a contact layer, a lower absorbing layer, an upper absorbing layer and an isolation layer attached in sequence from inside to outside, and the left and right sides of the four-layer structure are connected through a selvedge tissue, wherein the contact layer is made of seaweed fiber / polyester blended yarn, the lower and upper absorbing layers are made of degreasing cotton yarn, and the isolation layer is made of Cool Plus / degreasing cotton blended yarn; during preparation, the warp yarns in the contact layer, the lower absorbing layer, the upper absorbing layer and the isolation layer are divided into upper and lower layers to be interwoven with weft yarns of corresponding layers, and the four-layer structure and the selvedge tissue are integrally woven and formed. The design not only has a one-way wetting performance to quickly guide the wound exudate to the outside, but also has a certain ability to keep the wound moist, has strong air permeability, has strong external pollution blocking effect, does not cause secondary damage to the wound, has high mechanical strength, and is especially suitable for scenes with less wound exudation but high mechanical performance requirement.

Description

Technical Field

[0001] This invention relates to a medical dressing, belonging to the field of textile dressings, and particularly to a four-layer medical dressing and its preparation method. Background Technology

[0002] Traditional medical dressings mainly include gauze dressings and non-woven fabric dressings. Gauze dressings not only have poor exudate absorption, making it difficult to absorb wound exudate and increasing the frequency of dressing changes, but also have poor moisture retention, making them prone to drying out. This is not conducive to wound healing and also results in poor adhesion between the gauze and the wound, causing friction and irritation to the skin around the wound and increasing patient discomfort. In addition, gauze has limited microbial barrier effect and is insufficient to prevent external microorganisms from invading the wound.

[0003] In contrast, while traditional nonwoven dressings possess some moisture-absorbing properties, their quick-drying performance is poor. This makes them prone to accumulating exudate on the dressing surface when dealing with large amounts of exudate. This not only soaks the skin around the wound, increasing the risk of recurrent infection, but also hinders air circulation, impairing breathability. Furthermore, the lack of sufficient permeability and deformability in nonwoven dressings can result in poor adhesion between the dressing and the skin around the wound, increasing patient discomfort.

[0004] The information disclosed in this background section is intended only to enhance understanding of the overall background of this application and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0005] The purpose of this invention is to overcome the defects and problems of poor moisture wicking performance, inability to simultaneously absorb and retain moisture, and poor breathability in the existing technology, and to provide a four-layer medical dressing with better moisture wicking performance, which can simultaneously absorb and retain moisture and has strong breathability, as well as its preparation method.

[0006] To achieve the above objectives, the technical solution of the present invention is: a four-layer medical dressing, wherein the four-layer medical dressing comprises a contact layer, a lower absorbent layer, an upper absorbent layer, and an isolation layer that are sequentially attached from the inside out, and the left and right sides of the four layers are connected by edge tissue;

[0007] The contact layer is woven from seaweed fiber / polyester blended yarn as warp and weft, the lower absorbent layer and the upper absorbent layer are both woven from degreased cotton yarn as warp and weft, and the isolation layer is woven from Cool Plus / degreased cotton blended yarn as warp and weft. The moisture absorption capacity of the lower absorbent layer and the upper absorbent layer is greater than that of the contact layer and the isolation layer.

[0008] The four-layer medical dressing has a unidirectional transport index greater than or equal to level 4, a liquid water dynamic transport index greater than or equal to level 4, and an air permeability of 3800-3900 mm / s. Preferably, the four-layer medical dressing has a unidirectional transport index greater than 275 and a liquid water dynamic transport index greater than 0.61.

[0009] The moisture absorption capacity of the lower and upper absorption layers is greater than that of the contact layer and the isolation layer: within 12 hours after liquid is dropped onto the contact layer, the moisture content of the lower absorption layer is 2.91-3.08 times that of the contact layer, and the moisture content of the lower absorption layer is 3.08-4.51 times that of the isolation layer; the moisture content of the upper absorption layer is 2.90-3.01 times that of the contact layer, and the moisture content of the upper absorption layer is 3.09-4.51 times that of the isolation layer.

[0010] The liquid water diffusion rate of the isolation layer is greater than or equal to level 4.

[0011] In the four-layer medical dressing, the liquid diffusion distance of the contact layer and the isolation layer in both the warp and weft directions is less than 1.5 cm, provided that 1.5 ml of liquid is dropped onto the contact layer and the diffusion time is 30 s.

[0012] The seaweed fiber / polyester blended yarn is made of seaweed fiber and polyester fiber blend, wherein the mass ratio of seaweed fiber to polyester fiber is 30%-40%: 60%-70%.

[0013] The medical dressing has a warp tensile strength of 640-700 N and an elongation at break of 14.1%-15.5%, and a weft tensile strength of 640-700 N and an elongation at break of 14.4%-14.9%.

[0014] The pH value of the contact layer of the medical dressing is 6.52-6.84.

[0015] The contact layer, lower absorption layer, upper absorption layer, and isolation layer all use plain weave as the basic structure. The warp arrangement ratio of the contact layer, lower absorption layer, upper absorption layer, and isolation layer is 1:1:1:1, and the weft arrangement ratio of the contact layer, lower absorption layer, upper absorption layer, and isolation layer is 1:1:1:1. The warp density of each layer is 120 threads / 100 cm, and the weft density is 120 threads / 100 cm.

[0016] The thickness of the four-layer medical dressing is 1.9-2.2 mm, and the weight per square meter is 182-188 grams / square meter.

[0017] A method for preparing the above-mentioned four-layer medical dressing, the method comprising the following steps:

[0018] First, design each layer of warp yarns to be divided into upper and lower layers to interweave with the corresponding layer of weft yarns. The warp yarns in the isolation layer are defined as follows: outer warp yarn 1 and outer warp yarn 2; the warp yarns in the upper absorption layer are defined as upper warp yarn I and upper warp yarn II; the warp yarns in the lower absorption layer are defined as lower warp yarn a and lower warp yarn b; and the warp yarns in the contact layer are defined as inner warp yarn ① and inner warp yarn ②. Then, the isolation layer, upper absorption layer, lower absorption layer, and contact layer are woven sequentially. Simultaneously, the edge weave is woven concurrently with each layer. The edge weave warp yarns include edge warp yarn 1, edge warp yarn 2, edge warp yarn 3, and edge warp yarn 4. The weft yarns of the edge weave are replaced by the weft yarns of each layer in rotation. The specific weaving steps are as follows:

[0019] Weave the isolation layer: lift the outer warp yarn 1, edge warp yarn 1, and edge warp yarn 3; lift the outer warp yarn 2, upper warp yarn I, upper warp yarn II, lower warp yarn a, lower warp yarn b, inner warp yarn ①, inner warp yarn ②, edge warp yarn 2, and edge warp yarn 4; and place the first outer weft yarn into the isolation layer.

[0020] Weave the absorbent layer: lift the outer warp yarn 1, outer warp yarn 2, upper warp yarn I, edge warp yarn 1, and edge warp yarn 4; lower warp yarn II, lower warp yarn a, lower warp yarn b, inner warp yarn ①, inner warp yarn ②, edge warp yarn 2, and edge warp yarn 3 are all submerged at the bottom; insert the first upper weft yarn of the absorbent layer;

[0021] Weave the lower absorbent layer: lift the outer warp yarn 1, outer warp yarn 2, upper warp yarn I, upper warp yarn II, lower warp yarn a, edge warp yarn 2, and edge warp yarn 4; lower warp yarn b, inner warp yarn ①, inner warp yarn ②, edge warp yarn 1, and edge warp yarn 3 are all submerged at the bottom; insert the first weft yarn of the lower absorbent layer;

[0022] Contact layer: outer warp 1, outer warp 2, upper warp I, upper warp II, lower warp a, lower warp b, inner warp ①, edge warp 2, edge warp 3 are lifted; inner warp ②, edge warp 1, edge warp 4 are all submerged at the bottom; the first inner weft yarn of the contact layer is inserted;

[0023] Weave the isolation layer: lift the outer warp yarn 2, edge warp yarn 1, and edge warp yarn 3; lift the outer warp yarn 1, upper warp yarn I, upper warp yarn II, lower warp yarn a, lower warp yarn b, inner warp yarn ①, inner warp yarn ②, edge warp yarn 2, and edge warp yarn 4; insert the second outer weft yarn into the isolation layer;

[0024] Weave the absorbent layer: lift the outer warp yarn 1, outer warp yarn 2, upper warp yarn II, edge warp yarn 1, and edge warp yarn 4; lower warp yarn I, lower warp yarn a, lower warp yarn b, inner warp yarn ①, inner warp yarn ②, edge warp yarn 2, and edge warp yarn 3 are all submerged at the bottom; insert the second upper weft yarn of the absorbent layer;

[0025] Weave the lower absorbent layer: lift the outer warp yarn 1, outer warp yarn 2, upper warp yarn I, upper warp yarn II, lower warp yarn b, edge warp yarn 2, and edge warp yarn 4; lower warp yarn a, inner warp yarn ①, inner warp yarn ②, edge warp yarn 1, and edge warp yarn 3 are all submerged at the bottom; insert the second lower weft yarn of the lower absorbent layer;

[0026] Contact layer: outer warp 1, outer warp 2, upper warp I, upper warp II, lower warp a, lower warp b, inner warp ②, edge warp 2, edge warp 3 are lifted; inner warp ①, edge warp 1, edge warp 4 are all submerged at the bottom; the second inner weft yarn of the contact layer is inserted;

[0027] ...

[0028] This process is repeated until the final product is formed in one go, resulting in a four-layer medical dressing.

[0029] The weaving diagrams for the isolation layer, upper absorbent layer, lower absorbent layer, contact layer, and the edge weave between the four layers include a weave diagram, a heddle pattern diagram, and a pattern diagram, which are shown below:

[0030] Tissue diagram: The tissue of the isolation layer, upper absorption layer, lower absorption layer, and contact layer is plain weave, while the tissue of the left and right sides is a 2 / 2 warp re-plain weave.

[0031] Heddle Threading Diagram: Use the forward threading method, threading only one warp yarn into each heddle frame, using a total of 12 heddle frames; first thread edge warp yarn 1 into the heddle frame on page 9, and edge warp yarn 2 into the heddle frame on page 10; then thread the corresponding outer warp yarn 1, upper warp yarn I, lower warp yarn a, inner warp yarn ①, outer warp yarn 2, upper warp yarn II, lower warp yarn b, and inner warp yarn ② into the heddle frames on pages 1-8 in sequence; then thread edge warp yarn 3 and edge warp yarn 4 into the heddle frames on pages 11 and 12 respectively;

[0032] Pattern diagram: Determine the pattern diagram based on the above tissue diagram and heddle diagram.

[0033] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0034] 1. In the present invention, a four-layer medical dressing and its preparation method are disclosed. The four-layer medical dressing comprises, from the inside out, a contact layer, a lower absorbent layer, an upper absorbent layer, and a separating layer, which are sequentially attached. The contact layer is woven from seaweed fiber / polyester blended yarn as warp and weft. The lower and upper absorbent layers are both woven from degreased cotton yarn as warp and weft. The separating layer is woven from Cool Plus / degreased cotton blended yarn as warp and weft. Furthermore, the moisture absorption capacity of the lower and upper absorbent layers is greater than that of the contact and separating layers. This medical dressing has the following advantages when used:

[0035] Firstly, seaweed fibers possess excellent hygroscopicity, biocompatibility, and gel-blocking properties. Upon contact with a wound, the gel-blocking effect of seaweed fibers prevents continuous exudation, reduces exudate formation, and partially inhibits blood diffusion. Simultaneously, the lower and upper absorbent layers have strong absorption and retention capabilities, absorbing a larger amount of exudate and preventing blood accumulation around the wound. This creates a gradient difference in hygroscopic capacity between the contact and absorbent layers, thereby continuously guiding exudate unidirectionally from the contact layer to the absorbent layer. In the absorbent layer, the outermost insulating layer has strong moisture absorption and quick-drying properties. Therefore, the insulating layer can continuously absorb and release the liquid seeping from the absorbent layer, causing the exudate to evaporate quickly and effectively preventing liquid diffusion. Ultimately, the dressing can effectively control the liquid diffusion distance and has a unidirectional moisture-wicking function. The liquid diffusion distance of the contact layer in both the warp and weft directions is less than 1.5cm, the overall unidirectional transmission index of the dressing is greater than or equal to level 4, and the comprehensive index of dynamic liquid water transmission is greater than or equal to level 4.

[0036] Secondly, based on the theory of wet healing, a moist environment is more conducive to wound healing, but excessive moisture is not conducive to wound healing. Therefore, as the contact layer closest to the wound, it must maintain a certain level of humidity but not be too wet. For this reason, this design uses a blend of seaweed fiber and polyester. Among them, seaweed fiber has a high moisture regain rate of about 15.4%, which is too high in water content. Polyester fiber, on the other hand, has the characteristics of being dry, high strength, and good abrasion resistance. Blending it with seaweed fiber can not only reduce humidity to maintain a suitable moist environment, but also improve mechanical strength, abrasion resistance, and dimensional stability. Thus, this dressing can have excellent liquid absorption performance, effectively absorb and conduct excess exudate from the wound, and provide a suitable moist environment for the wound, achieving both moisture absorption and moisture retention. For example, the contact layer still contains moisture within 24 hours after liquid is dripped onto it.

[0037] Thirdly: The contact layer in this design is made of seaweed fiber / polyester blended yarn. Seaweed fiber has high softness and a high degree of skin adhesion to the wound, which can improve the comfort of wound contact. At the same time, seaweed fiber has a large variation in length and fineness, while polyester fiber has better uniformity in length and fineness. Therefore, the use of polyester blend can effectively improve the yarn evenness and reduce yarn hairiness. In addition, the gel blocking effect of seaweed fiber can promptly prevent the continuous seepage of exudate, reduce exudate and residue in the wound, and improve the adhesion between the dressing and the skin.

[0038] Therefore, the present invention not only has excellent moisture-wicking properties and can also absorb and retain moisture, but also effectively prevents the spread of exudate and has a high degree of adhesion to the skin around the wound.

[0039] 2. In the four-layer medical dressing and its preparation method of the present invention, the absorbent layer includes a lower absorbent layer and an upper absorbent layer, both woven from degreased cotton yarn as warp and weft yarns. Its advantages include:

[0040] First, the moisture absorption capacity of a single absorption layer is greater than that of a contact layer. When two absorption layers are used together, the moisture absorption capacity is even stronger, which makes it easier to quickly create a gradient difference in moisture absorption capacity between the contact layer and the absorption layer.

[0041] Secondly, compared with a single absorbent layer of similar thickness, two independent absorbent layers have a larger surface area and stronger moisture absorption capacity. They also avoid the use of coarser yarns, which would cause the fabric to harden and make it difficult for wounds to adhere. In addition, they can avoid the use of tighter warp and weft densities, which would reduce the breathability of the fabric.

[0042] Thirdly, the air permeability of a single absorbent layer is still relatively high. When two opposing absorbent layers are used together, the impact on the air permeability is small, so as to avoid reducing the overall air permeability of the medical dressing.

[0043] Therefore, the present invention not only has better moisture absorption capacity, but also better air permeability.

[0044] 3. In the four-layer medical dressing and its preparation method of this invention, the seaweed fiber / polyester blended gauze in the contact layer not only provides gel blocking properties, effectively preventing liquid diffusion and avoiding dressing hardening and adhesion to the skin, thus preventing secondary skin damage during dressing changes, but also possesses excellent removability, preventing secondary damage to the wound during gauze changes. Furthermore, this dressing only appears pale purple under ultraviolet light, contains very little fluorescent material, and has very low skin irritation, preventing adhesion to the wound surface. This not only protects the wound surface and avoids damage to the mucous membrane, but also prevents secondary damage during dressing changes. Therefore, this invention, during dressing changes, will not stick to the wound and damage newly formed tissue, will not cause secondary damage to the wound, and can ensure the integrity of the wound and the continuity of the healing process.

[0045] 4. In the four-layer medical dressing and its preparation method of the present invention, the pH value of the medical dressing is 6.52-6.84, which is weakly acidic and conducive to wound healing. The reason is as follows:

[0046] Basic cellular processes and cycle activities, such as enzyme activity, macromolecule synthesis, metabolite transport, inflammation, collagen formation, and angiogenesis, are all significantly affected by pH. Maintaining an acidic environment in the early stages of wound healing, especially during hemostasis and inflammation, is crucial. An acidic environment helps reduce the load on the skin surface, inhibits bacterial proliferation, and promotes adipose tissue metabolism, thereby accelerating wound healing. Normal skin has a pH range of 4-6, which is acidic. However, after skin injury, the pH of the wound surface rises to nearly 7.4, becoming alkaline, which is detrimental to wound healing. This medical dressing has a pH of 6.52-6.84, which can lower the pH, returning it to a slightly acidic environment, promoting healthy wound healing. Therefore, the pH of this invention is acidic, which is beneficial for wound healing.

[0047] 5. In the four-layer medical dressing and its preparation method of the present invention, the contact layer is made of seaweed fiber / polyester blended yarn. The seaweed fiber produces gel blocking properties after absorbing liquid, has certain antibacterial properties, and also has excellent moisture regain. Polyester fiber has the characteristics of high strength, good abrasion resistance, and dryness. When polyester fiber and seaweed fiber are blended, the strength of the yarn can be improved, the mechanical properties and abrasion resistance of the yarn can be enhanced, the dimensional stability of the yarn can be guaranteed, the yarn quality can be improved, the yarn difficulty can be reduced, and thus the mechanical strength of the dressing can be improved and the moisture regain of the contact layer dressing can be reduced. Furthermore, the contact layer, lower absorbent layer, upper absorbent layer, and isolation layer in this design are molded in one piece, and the four-layer structure further enhances the mechanical properties of the final product. This results in a warp tensile strength of 640-700 N and an elongation at break of 14.1%-15.5% for the medical dressing, and a weft tensile strength of 640-700 N and an elongation at break of 14.4%-14.9% for the medical dressing. Therefore, the present invention has high mechanical strength.

[0048] 6. In the four-layer medical dressing and its preparation method of the present invention, during preparation, an isolation layer, an upper absorbent layer, a lower absorbent layer, a contact layer, and edge tissues on the left and right sides of the four layers are woven simultaneously and formed as a whole in one step to obtain the final four-layer medical dressing. In specific applications, an appropriate length is cut as needed for application or bandaging of wounds (similar to wrapping with tape). This preparation method not only allows for the smooth application of the isolation layer, upper absorbent layer, lower absorbent layer, and contact layer layer by layer to form a whole, making the medical operation process smooth, but also enhances the application effect. That is, the inner and outer contact layers and isolation layers tightly wrap the upper absorbent layer and lower absorbent layer, which facilitates the subsequent unidirectional moisture wicking effect and improves the unidirectional transmission index, so as to promptly conduct wound exudate outward while the contact layer maintains a certain degree of wettability. In addition, it can also improve the overall mechanical strength of the medical dressing, making it easy to bandage and less prone to breakage. Therefore, the present invention not only has low operation difficulty, but also improves moisture wicking effect and mechanical strength. Attached Figure Description

[0049] Figure 1 This is a three-dimensional structural diagram of the invention from a top view, with the topmost layer being the isolation layer.

[0050] Figure 2 This is a cross-sectional schematic diagram of the present invention.

[0051] Figure 3 This is a schematic diagram of the textile of the first isolation layer in Embodiment 1 of the present invention.

[0052] Figure 4 This is a schematic diagram of the textile of the first upper absorbent layer in Embodiment 1 of the present invention.

[0053] Figure 5 This is a schematic diagram of the textile of the first lower absorbent layer in Embodiment 1 of the present invention.

[0054] Figure 6 This is a schematic diagram of the textile of the first contact layer in Embodiment 1 of the present invention.

[0055] Figure 7 This is a schematic diagram of the textile of the second isolation layer in Embodiment 1 of the present invention.

[0056] Figure 8 This is a schematic diagram of the textile of the second upper absorbent layer in Embodiment 1 of the present invention.

[0057] Figure 9 This is a schematic diagram of the textile of the second lower absorbent layer in Embodiment 1 of the present invention.

[0058] Figure 10 This is a schematic diagram of the textile of the second contact layer in Embodiment 1 of the present invention.

[0059] Figure 11 This is a schematic diagram of the structure of the four-layer medical dressing finally spun in Example 1 of the present invention.

[0060] Figure 12 This is a radial schematic diagram of the liquid diffusivity test performed in Example 1 of this invention.

[0061] Figure 13 This is a latitudinal schematic diagram of the liquid diffusivity test conducted in Example 1 of this invention.

[0062] Figure 14 This is a schematic diagram of the machine setup in Embodiment 2 of this invention. Detailed Implementation

[0063] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0064] See Figure 1 — Figure 14 A four-layer medical dressing, comprising a contact layer, a lower absorbent layer, an upper absorbent layer, and an isolation layer attached sequentially from the inside out, with the left and right sides of the four layers connected by edge tissue;

[0065] The contact layer is woven from seaweed fiber / polyester blended yarn as warp and weft, the lower absorbent layer and the upper absorbent layer are both woven from degreased cotton yarn as warp and weft, and the isolation layer is woven from Cool Plus / degreased cotton blended yarn as warp and weft. The moisture absorption capacity of the lower absorbent layer and the upper absorbent layer is greater than that of the contact layer and the isolation layer.

[0066] The four-layer medical dressing has a unidirectional transport index greater than or equal to level 4, a liquid water dynamic transport index greater than or equal to level 4, and an air permeability of 3800-3900 mm / s. Preferably, the four-layer medical dressing has a unidirectional transport index greater than 275 and a liquid water dynamic transport index greater than 0.61.

[0067] The moisture absorption capacity of the lower and upper absorption layers is greater than that of the contact layer and the isolation layer: within 12 hours after liquid is dropped onto the contact layer, the moisture content of the lower absorption layer is 2.91-3.08 times that of the contact layer, and the moisture content of the lower absorption layer is 3.08-4.51 times that of the isolation layer; the moisture content of the upper absorption layer is 2.90-3.01 times that of the contact layer, and the moisture content of the upper absorption layer is 3.09-4.51 times that of the isolation layer.

[0068] The liquid water diffusion rate of the isolation layer is greater than or equal to level 4.

[0069] In the four-layer medical dressing, the liquid diffusion distance of the contact layer and the isolation layer in both the warp and weft directions is less than 1.5 cm, provided that 1.5 ml of liquid is dropped onto the contact layer and the diffusion time is 30 s.

[0070] The seaweed fiber / polyester blended yarn is made of seaweed fiber and polyester fiber blend, wherein the mass ratio of seaweed fiber to polyester fiber is 30%-40%: 60%-70%.

[0071] The medical dressing has a warp tensile strength of 640-700 N and an elongation at break of 14.1%-15.5%, and a weft tensile strength of 640-700 N and an elongation at break of 14.4%-14.9%.

[0072] The pH value of the contact layer of the medical dressing is 6.52-6.84.

[0073] The contact layer, lower absorption layer, upper absorption layer, and isolation layer all use plain weave as the basic structure. The warp arrangement ratio of the contact layer, lower absorption layer, upper absorption layer, and isolation layer is 1:1:1:1, and the weft arrangement ratio of the contact layer, lower absorption layer, upper absorption layer, and isolation layer is 1:1:1:1. The warp density of each layer is 120 threads / 100 cm, and the weft density is 120 threads / 100 cm.

[0074] The thickness of the four-layer medical dressing is 1.9-2.2 mm, and the weight per square meter is 182-188 grams / square meter.

[0075] A method for preparing the above-mentioned four-layer medical dressing, the method comprising the following steps:

[0076] First, design each layer of warp yarns to be divided into upper and lower layers to interweave with the corresponding layer of weft yarns. The warp yarns in the isolation layer are defined as follows: outer warp yarn 1 and outer warp yarn 2; the warp yarns in the upper absorption layer are defined as upper warp yarn I and upper warp yarn II; the warp yarns in the lower absorption layer are defined as lower warp yarn a and lower warp yarn b; and the warp yarns in the contact layer are defined as inner warp yarn ① and inner warp yarn ②. Then, the isolation layer, upper absorption layer, lower absorption layer, and contact layer are woven sequentially. Simultaneously, the edge weave is woven concurrently with each layer. The edge weave warp yarns include edge warp yarn 1, edge warp yarn 2, edge warp yarn 3, and edge warp yarn 4. The weft yarns of the edge weave are replaced by the weft yarns of each layer in rotation. The specific weaving steps are as follows:

[0077] Weave the isolation layer: lift the outer warp yarn 1, edge warp yarn 1, and edge warp yarn 3; lift the outer warp yarn 2, upper warp yarn I, upper warp yarn II, lower warp yarn a, lower warp yarn b, inner warp yarn ①, inner warp yarn ②, edge warp yarn 2, and edge warp yarn 4; and place the first outer weft yarn into the isolation layer.

[0078] Weave the absorbent layer: lift the outer warp yarn 1, outer warp yarn 2, upper warp yarn I, edge warp yarn 1, and edge warp yarn 4; lower warp yarn II, lower warp yarn a, lower warp yarn b, inner warp yarn ①, inner warp yarn ②, edge warp yarn 2, and edge warp yarn 3 are all submerged at the bottom; insert the first upper weft yarn of the absorbent layer;

[0079] Weave the lower absorbent layer: lift the outer warp yarn 1, outer warp yarn 2, upper warp yarn I, upper warp yarn II, lower warp yarn a, edge warp yarn 2, and edge warp yarn 4; lower warp yarn b, inner warp yarn ①, inner warp yarn ②, edge warp yarn 1, and edge warp yarn 3 are all submerged at the bottom; insert the first weft yarn of the lower absorbent layer;

[0080] Contact layer: outer warp 1, outer warp 2, upper warp I, upper warp II, lower warp a, lower warp b, inner warp ①, edge warp 2, edge warp 3 are lifted; inner warp ②, edge warp 1, edge warp 4 are all submerged at the bottom; the first inner weft yarn of the contact layer is inserted;

[0081] Weave the isolation layer: lift the outer warp yarn 2, edge warp yarn 1, and edge warp yarn 3; lift the outer warp yarn 1, upper warp yarn I, upper warp yarn II, lower warp yarn a, lower warp yarn b, inner warp yarn ①, inner warp yarn ②, edge warp yarn 2, and edge warp yarn 4; insert the second outer weft yarn into the isolation layer;

[0082] Weave the absorbent layer: lift the outer warp yarn 1, outer warp yarn 2, upper warp yarn II, edge warp yarn 1, and edge warp yarn 4; lower warp yarn I, lower warp yarn a, lower warp yarn b, inner warp yarn ①, inner warp yarn ②, edge warp yarn 2, and edge warp yarn 3 are all submerged at the bottom; insert the second upper weft yarn of the absorbent layer;

[0083] Weave the lower absorbent layer: lift the outer warp yarn 1, outer warp yarn 2, upper warp yarn I, upper warp yarn II, lower warp yarn b, edge warp yarn 2, and edge warp yarn 4; lower warp yarn a, inner warp yarn ①, inner warp yarn ②, edge warp yarn 1, and edge warp yarn 3 are all submerged at the bottom; insert the second lower weft yarn of the lower absorbent layer;

[0084] Contact layer: outer warp 1, outer warp 2, upper warp I, upper warp II, lower warp a, lower warp b, inner warp ②, edge warp 2, edge warp 3 are lifted; inner warp ①, edge warp 1, edge warp 4 are all submerged at the bottom; the second inner weft yarn of the contact layer is inserted;

[0085] ...

[0086] This process is repeated until the final product is formed in one go, resulting in a four-layer medical dressing.

[0087] The weaving diagrams for the isolation layer, upper absorbent layer, lower absorbent layer, contact layer, and the edge weave between the four layers include a weave diagram, a heddle pattern diagram, and a pattern diagram, which are shown below:

[0088] Tissue diagram: The tissue of the isolation layer, upper absorption layer, lower absorption layer, and contact layer is plain weave, while the tissue of the left and right sides is a 2 / 2 warp re-plain weave.

[0089] Heddle Threading Diagram: Use the forward threading method, threading only one warp yarn into each heddle frame, using a total of 12 heddle frames; first thread edge warp yarn 1 into the heddle frame on page 9, and edge warp yarn 2 into the heddle frame on page 10; then thread the corresponding outer warp yarn 1, upper warp yarn I, lower warp yarn a, inner warp yarn ①, outer warp yarn 2, upper warp yarn II, lower warp yarn b, and inner warp yarn ② into the heddle frames on pages 1-8 in sequence; then thread edge warp yarn 3 and edge warp yarn 4 into the heddle frames on pages 11 and 12 respectively;

[0090] Pattern diagram: Determine the pattern diagram based on the above tissue diagram and heddle diagram.

[0091] The supplementary technical features of this invention are as follows:

[0092] In this invention, the preferred mass ratio of seaweed fiber to polyester fiber in the seaweed fiber / polyester blended yarn is 30%-40%:60%-70%, and more preferably 35%:65%. The reason is that a yarn with a 35%:65% ratio has good strength, hairiness, evenness, and softness. It not only has a moderate moisture regain to ensure wettability, but also good softness. At the same time, it has greater strength during spinning, making it less prone to breakage, which helps to improve the uniformity of the yarn.

[0093] In the Cool Plus / degreased cotton blended yarn of this invention, it is preferably made by blending 50% by weight of Cool Plus fiber and 50% by weight of degreased cotton. Cool Plus fiber has moisture-absorbing and quick-drying properties, and the addition of degreased cotton enhances the moisture absorption of the gauze. Thus, the Cool Plus fiber / degreased cotton blended gauze can absorb and release excess fluid from the wound in a timely manner, maintaining the dryness and wetness balance of the wound.

[0094] The reason for limiting the thickness of the dressing to 1.9–2.2 mm and the weight per square meter to 182–188 g / m² in this invention is that the areal density and thickness of the dressing affect its liquid absorption performance; thicker dressings generally have a larger absorption capacity. Similarly, areal density and thickness also affect the moisture permeability and breathability of the dressing; thinner dressings have better breathability and moisture permeability. Furthermore, the liquid's penetration and diffusion performance is also affected by areal density and thickness; thicker dressings will hinder the rapid diffusion of the liquid.

[0095] Example 1:

[0096] See Figure 1 and Figure 2 A four-layer medical dressing comprises, from the inside out, a contact layer, a lower absorbent layer, an upper absorbent layer, and an isolation layer, with the left and right sides of each layer connected by edge weave. The contact layer is woven from seaweed fiber / polyester blended yarn as warp and weft. The lower and upper absorbent layers are woven from degreased cotton yarn as warp and weft. The isolation layer is woven from Cool Plus / degreased cotton blended yarn as warp and weft. The moisture absorption capacity of the lower and upper absorbent layers is greater than that of the contact and isolation layers. The four-layer medical dressing has a unidirectional transport index greater than or equal to level 4, a liquid water dynamic transport comprehensive index greater than or equal to level 4, and an air permeability of 3800-3900 mm / s.

[0097] See Figure 3 — Figure 11 A method for preparing the above-mentioned four-layer medical dressing, the method comprising the following steps:

[0098] First, design each layer of warp yarns to be divided into upper and lower layers to interweave with the corresponding layer of weft yarns. The warp yarns in the isolation layer are defined as follows: outer warp yarn 1 and outer warp yarn 2; the warp yarns in the upper absorption layer are defined as upper warp yarn I and upper warp yarn II; the warp yarns in the lower absorption layer are defined as lower warp yarn a and lower warp yarn b; and the warp yarns in the contact layer are defined as inner warp yarn ① and inner warp yarn ②. Then, the isolation layer, upper absorption layer, lower absorption layer, and contact layer are woven sequentially. Simultaneously, the edge weave is woven concurrently with each layer. The edge weave warp yarns include edge warp yarn 1, edge warp yarn 2, edge warp yarn 3, and edge warp yarn 4. The weft yarns of the edge weave are replaced by the weft yarns of each layer in rotation. The specific weaving steps are as follows:

[0099] See Figure 3 Weave the isolation layer: lift the outer warp yarn 1, edge warp yarn 1, and edge warp yarn 3; lift the outer warp yarn 2, upper warp yarn I, upper warp yarn II, lower warp yarn a, lower warp yarn b, inner warp yarn ①, inner warp yarn ②, edge warp yarn 2, and edge warp yarn 4; and place the first outer weft yarn into the isolation layer.

[0100] See Figure 4 Weave the absorbent layer: lift the outer warp yarn 1, outer warp yarn 2, upper warp yarn I, edge warp yarn 1, and edge warp yarn 4; lower warp yarn II, lower warp yarn a, lower warp yarn b, inner warp yarn ①, inner warp yarn ②, edge warp yarn 2, and edge warp yarn 3 are all submerged at the bottom; insert the first upper weft yarn of the absorbent layer;

[0101] See Figure 5 Weave the lower absorbent layer: lift the outer warp 1, outer warp 2, upper warp I, upper warp II, lower warp a, edge warp 2, and edge warp 4; lower warp b, inner warp ①, inner warp ②, edge warp 1, and edge warp 3 are all submerged at the bottom; insert the first weft yarn of the lower absorbent layer;

[0102] See Figure 6 Contact layer: outer warp 1, outer warp 2, upper warp I, upper warp II, lower warp a, lower warp b, inner warp ①, edge warp 2, edge warp 3 are lifted; inner warp ②, edge warp 1, edge warp 4 are all submerged at the bottom; the first inner weft yarn of the contact layer is inserted;

[0103] See Figure 7 Weave the isolation layer: lift the outer warp yarn 2, edge warp yarn 1, and edge warp yarn 3; lift the outer warp yarn 1, upper warp yarn I, upper warp yarn II, lower warp yarn a, lower warp yarn b, inner warp yarn ①, inner warp yarn ②, and edge warp yarn 2 and edge warp yarn 4 to the bottom; insert the second outer weft yarn into the isolation layer;

[0104] See Figure 8 Add the absorbent layer: lift the outer warp yarn 1, outer warp yarn 2, upper warp yarn II, edge warp yarn 1, and edge warp yarn 4; lower warp yarn I, lower warp yarn a, lower warp yarn b, inner warp yarn ①, inner warp yarn ②, edge warp yarn 2, and edge warp yarn 3 are all submerged at the bottom; insert the second upper weft yarn of the absorbent layer;

[0105] See Figure 9 Weave the lower absorbent layer: lift the outer warp yarn 1, outer warp yarn 2, upper warp yarn I, upper warp yarn II, lower warp yarn b, edge warp yarn 2, and edge warp yarn 4; lower warp yarn a, inner warp yarn ①, inner warp yarn ②, edge warp yarn 1, and edge warp yarn 3 are all submerged at the bottom; insert the second lower weft yarn of the lower absorbent layer;

[0106] See Figure 10 Contact layer: outer warp 1, outer warp 2, upper warp I, upper warp II, lower warp a, lower warp b, inner warp ②, edge warp 2, edge warp 3 are lifted; inner warp ①, edge warp 1, edge warp 4 are all submerged at the bottom; the second inner weft yarn of the contact layer is inserted;

[0107] ...

[0108] This process is repeated until a final, one-piece molding is achieved, resulting in a four-layer medical dressing. Please refer to [link / reference]. Figure 11 .

[0109] The following tests were performed on the four-layer medical dressing fabricated above:

[0110] (I) Tensile breaking strength test:

[0111] The test was conducted according to YY 0331—2006, "Performance Requirements and Test Methods for Degreased Cotton Yarn and Degreased Cotton-Viscose Blended Yarn". Ten samples were prepared, five cut along the weft direction and the other five along the warp direction. When sampling, ensure a distance of at least 15 mm from the fabric edge and avoid any wrinkles or abrasion areas. Each sample should be precisely 50 mm wide and long enough to be securely clamped between two 10 mm apart clamps on the tensile testing machine. The samples were placed sequentially in the clamps of the tensile testing machine, and a tensile test was performed at a constant rate of 100 mm / min. The test results are as follows:

[0112] Table 1. Meridional Strength Test

[0113]

[0114]

[0115] Table 2, Weft Strength Test

[0116]

[0117] As shown in Tables 1 and 2, this medical dressing has strong mechanical strength, which is much greater than the minimum breaking strength requirement specified in the YY0331-2006 standard, namely, the warp breaking force is greater than 70N and the weft breaking force is greater than 60N.

[0118] (II) Liquid Diffusion Test:

[0119] The simulated wound exudate was prepared according to YY / T 0471.1-2004 "Test Methods for Contact Wound Dressings - Part 1: Liquid Absorbency". 8.298g of sodium chloride and 0.368g of calcium chloride dihydrate were dissolved in 1L of deionized water. To enhance the observability of the experiment, a small amount of red ink was added to the solution. Five 5cm*5cm medical dressings were prepared and placed in a petri dish. 1.5ml of the simulated wound exudate was slowly added dropwise to the test sample, and the mixture was allowed to stand for 30 seconds after the liquid diffusion stabilized. The liquid diffusion performance of the sample was evaluated by measuring the maximum diffusion length formed by the liquid on the sample. The test results are as follows:

[0120] Depend on Figure 12 , Figure 13 It can be seen that in the liquid diffusion test, the liquid diffusion of medical dressings in both the warp and weft directions is limited to a range of 1.5 cm, which shows better results.

[0121] (III) Breathability Test:

[0122] According to GB / T5453-1997 "Textiles: Determination of Air Permeability of Fabrics", five samples of medical dressings, each 100 square centimeters in size, were tested using a YG461E-III fully automatic air permeability meter. The test results are as follows:

[0123] Table 3. Results of air permeability test for four-layer medical dressings

[0124]

[0125] As shown in Table 3, the average air permeability of this medical dressing is 3860.8 mm / s, which indicates good air permeability. This allows for the expulsion of harmful gases generated during wound healing, ensuring a favorable environment for the wound and promoting faster healing.

[0126] Example 2:

[0127] The basic content is the same as in Example 1, except that:

[0128] See Figure 14 The weaving diagrams for the isolation layer, upper absorbent layer, lower absorbent layer, contact layer, and the edge weave between the four layers include a weave diagram, a heddle pattern diagram, and a pattern diagram, which are shown below:

[0129] Tissue diagram: The tissue of the isolation layer, upper absorption layer, lower absorption layer, and contact layer is plain weave, while the tissue of the left and right sides is a 2 / 2 warp re-plain weave.

[0130] Heddle Threading Diagram: Use the forward threading method, threading only one warp yarn into each heddle frame, using a total of 12 heddle frames; first thread edge warp yarn 1 into the heddle frame on page 9, and edge warp yarn 2 into the heddle frame on page 10; then thread the corresponding outer warp yarn 1, upper warp yarn I, lower warp yarn a, inner warp yarn ①, outer warp yarn 2, upper warp yarn II, lower warp yarn b, and inner warp yarn ② into the heddle frames on pages 1-8 in sequence; then thread edge warp yarn 3 and edge warp yarn 4 into the heddle frames on pages 11 and 12 respectively;

[0131] Pattern diagram: Determine the pattern diagram based on the above tissue diagram and heddle diagram.

[0132] The above description is only a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. Any equivalent modifications or changes made by those skilled in the art based on the content disclosed in the present invention should be included within the scope of protection set forth in the claims.

Claims

1. A four-layer construction medical dressing characterized by: The four-layer structure medical dressing comprises a contact layer, a lower absorbing layer, an upper absorbing layer and an isolation layer attached in sequence from inside to outside, and the left and right sides of the four layers are connected by edge tissues; The contact layer is woven by sea algae fiber / polyester blended yarn as warp and weft, the lower absorbing layer and the upper absorbing layer are both woven by degreasing cotton yarn as warp and weft, and the isolation layer is woven by Cool Plus / degreasing cotton blended yarn as warp and weft, and the moisture absorption capacity of the lower absorbing layer and the upper absorbing layer is greater than that of the contact layer and the isolation layer; The one-way transmission index of the four-layer structure medical dressing is greater than or equal to level 4, the liquid water dynamic transmission comprehensive index is greater than or equal to level 4, and the air permeability is 3800-3900 mm / s. The moisture absorption capacity of the lower absorbing layer and the upper absorbing layer is greater than that of the contact layer and the isolation layer: within 12 hours after liquid is added to the contact layer, the water content of the lower absorbing layer is 2.91-3.08 times that of the contact layer, and the water content of the lower absorbing layer is 3.08-4.51 times that of the isolation layer; the water content of the upper absorbing layer is 2.90-3.01 times that of the contact layer, and the water content of the upper absorbing layer is 3.09-4.51 times that of the isolation layer. The liquid diffusion distance of the contact layer and the isolation layer in the four-layer structure medical dressing in the warp and weft directions is less than 1.5 cm, and the condition is that 1.5 ml of liquid is added to the contact layer, and the diffusion time is 30 s.

2. A four layer construction medical dressing according to claim 1, wherein: The liquid water diffusion speed of the isolation layer is greater than or equal to level 4.

3. A four layer construction medical dressing according to claim 1, wherein: The sea algae fiber / polyester blended yarn is blended by sea algae fiber and polyester fiber, and the mass ratio of the sea algae fiber and the polyester fiber is 30%-40%:60%-70%.

4. A four layer construction medical dressing according to claim 1, wherein: The breaking strength of the medical dressing in the warp direction is 640-700 N, and the breaking elongation is 14.1%-15.5%, the breaking strength of the medical dressing in the weft direction is 640-700 N, and the breaking elongation is 14.4%-14.9%.

5. A four layer construction medical dressing according to claim 1, wherein: The pH value of the contact layer of the medical dressing is 6.52-6.

84.

6. A four layer construction medical dressing according to claim 1, characterized in that: The contact layer, the lower absorbing layer, the upper absorbing layer and the isolation layer all adopt plain weave as the basic organization, the warp arrangement ratio of the contact layer, the lower absorbing layer, the upper absorbing layer and the isolation layer is 1:1:1:1, the weft arrangement ratio of the contact layer, the lower absorbing layer, the upper absorbing layer and the isolation layer is 1:1:1:1, the warp density of each layer is 120 roots / 100 cm, and the weft density is 120 roots / 100 cm; The thickness of the four-layer structure medical dressing is 1.9-2.2 mm, and the square meter weight is 182-188 g / m2.

7. A method of making a four-layer construction medical dressing according to claim 1, characterized by: The preparation method comprises the following steps: The warp yarns of each layer are divided into upper and lower layers to interweave with the corresponding weft yarns, and the warp yarns in the isolation layer include the face warp yarn 1 and the face warp yarn 2, the warp yarns in the upper absorption layer include the upper warp yarn I and the upper warp yarn II, the warp yarns in the lower absorption layer include the lower warp yarn a and the lower warp yarn b, and the warp yarns in the contact layer include the inner warp yarn 1 and the inner warp yarn 2, and then the isolation layer, the upper absorption layer, the lower absorption layer and the contact layer are woven in turn, and at the same time, the selvedge is woven synchronously when each layer is woven, and the warp yarns of the selvedge include the selvedge warp yarn 1, the selvedge warp yarn 2, the selvedge warp yarn 3 and the selvedge warp yarn 4, and the weft yarns of the selvedge are replaced by the weft yarns of each layer in turn, and the specific weaving steps are as follows: Weave the isolation layer: the face warp yarn 1, the selvedge warp yarn 1 and the selvedge warp yarn 3 are lifted; the face warp yarn 2, the upper warp yarn I, the upper warp yarn II, the lower warp yarn a, the lower warp yarn b, the inner warp yarn 1 and the inner warp yarn 2, the selvedge warp yarn 2 and the selvedge warp yarn 4 are all sunk below; the first face weft yarn of the isolation layer is inserted; Weave the upper absorption layer: the face warp yarn 1, the face warp yarn 2, the upper warp yarn I, the selvedge warp yarn 1 and the selvedge warp yarn 4 are lifted; the upper warp yarn II, the lower warp yarn a, the lower warp yarn b, the inner warp yarn 1, the inner warp yarn 2, the selvedge warp yarn 2 and the selvedge warp yarn 3 are all sunk below; the first upper weft yarn of the upper absorption layer is inserted; Weave the lower absorption layer: the face warp yarn 1, the face warp yarn 2, the upper warp yarn I, the upper warp yarn II, the lower warp yarn a, the selvedge warp yarn 2 and the selvedge warp yarn 4 are lifted; the lower warp yarn b, the inner warp yarn 1, the inner warp yarn 2, the selvedge warp yarn 1 and the selvedge warp yarn 3 are all sunk below; the first lower weft yarn of the lower absorption layer is inserted; Weave the contact layer: the face warp yarn 1, the face warp yarn 2, the upper warp yarn I, the upper warp yarn II, the lower warp yarn a, the lower warp yarn b, the inner warp yarn 1, the selvedge warp yarn 2 and the selvedge warp yarn 3 are lifted; the inner warp yarn 2, the selvedge warp yarn 1 and the selvedge warp yarn 4 are all sunk below; the first inner weft yarn of the contact layer is inserted; Weave the isolation layer: the face warp yarn 2, the selvedge warp yarn 1 and the selvedge warp yarn 3 are lifted; the face warp yarn 1, the upper warp yarn I, the upper warp yarn II, the lower warp yarn a, the lower warp yarn b, the inner warp yarn 1 and the inner warp yarn 2, the selvedge warp yarn 2 and the selvedge warp yarn 4 are all sunk below; the second face weft yarn of the isolation layer is inserted; Weave the upper absorption layer: the face warp yarn 1, the face warp yarn 2, the upper warp yarn II, the selvedge warp yarn 1 and the selvedge warp yarn 4 are lifted; the upper warp yarn I, the lower warp yarn a, the lower warp yarn b, the inner warp yarn 1, the inner warp yarn 2, the selvedge warp yarn 2 and the selvedge warp yarn 3 are all sunk below; the second upper weft yarn of the upper absorption layer is inserted; Weave the lower absorption layer: the face warp yarn 1, the face warp yarn 2, the upper warp yarn I, the upper warp yarn II, the lower warp yarn b, the selvedge warp yarn 2 and the selvedge warp yarn 4 are lifted; the lower warp yarn a, the inner warp yarn 1, the inner warp yarn 2, the selvedge warp yarn 1 and the selvedge warp yarn 3 are all sunk below; the second lower weft yarn of the lower absorption layer is inserted; Weave the contact layer: the face warp yarn 1, the face warp yarn 2, the upper warp yarn I, the upper warp yarn II, the lower warp yarn a, the lower warp yarn b, the inner warp yarn 2, the selvedge warp yarn 2 and the selvedge warp yarn 3 are lifted; the inner warp yarn 1, the selvedge warp yarn 1 and the selvedge warp yarn 4 are all sunk below; the second inner weft yarn of the contact layer is inserted; …… The above steps are repeated in turn until the final one-time forming is completed to obtain a four-layer structure medical dressing.

8. A method of making a four-layer construction medical dressing according to claim 7, characterized in that: The weaving diagram corresponding to the isolation layer, the upper absorbing layer, the lower absorbing layer, the contact layer and the edge organization between the four layers includes an organization diagram, a draft diagram and a card diagram, which are respectively shown as follows: The organization diagram: the organizations of the isolation layer, the upper absorbing layer, the lower absorbing layer and the contact layer are all plain, and the left and right edge organizations are both 2 / 2 warp heavy plain structures; The draft diagram: the order of draft is adopted, only one warp yarn is drafted into each page of the heald frame, a total of 12 pages of heald frames are used; the edge warp yarn 1 is drafted into the 9th page of the heald frame, and the edge warp yarn 2 is drafted into the 10th page of the heald frame; then the corresponding face warp yarn 1, the upper warp yarn I, the lower warp yarn a, the inner warp yarn 1, the face warp yarn 2, the upper warp yarn II, the lower warp yarn b and the inner warp yarn 2 are drafted into the 1st-8th pages of the heald frame in sequence; then the edge warp yarn 3 and the edge warp yarn 4 are drafted into the 11th page of the heald frame and the 12th page of the heald frame respectively; The card diagram: the card diagram is determined according to the above organization diagram and the draft diagram.

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