Three-layered wound dressing and method of manufacturing the same

Abstract

A three-layered wound dressing, including: a first layer, a second layer, and a third layer. The first layer includes a blend of first hydrophilic fibers and first hydrophobic fibers, the second layer includes a blend of second hydrophilic fibers and second hydrophobic fibers, and the third layer includes hydrophobic fibers. The second layer is disposed between the first layer and the third layer. In use, the first layer contacts a wound.

Claims

1. A method of manufacturing a three-layered wound dressing, the three-layered wound dressing comprising a first layer, a second layer, and a third layer; the first layer comprising a blend of first hydrophilic fibers and first hydrophobic fibers; the second layer comprising a blend of second hydrophilic fibers and second hydrophobic fibers; and the third layer comprising hydrophobic fibers; the second layer being disposed between the first layer and the third layer; and the first layer being adapted to contact a wound; the method comprising one of the following three steps: 1) manufacturing the first layer, the second layer and the third layer separately using a heat binding method, or a needle punching method or a hydro entanglement method; then laminating three layers together by heat bonding, or needle punching or chemical bonding, followed by cutting, packing and sterilization; 2) manufacturing the first layer, the second layer and the third layer separately using a heat binding method, or a needle punching method or a hydro entanglement method; laminating the first layer and the second layer together by heat bonding, or needle punching or chemical bonding; and then manufacturing the third layer onto the laminated first/second layer directly, followed by cutting, packing and sterilization; and 3) manufacturing the second layer and the third layer separately using a heat binding method, or a needle punching method or a hydro entanglement method; laminating the second layer and the third layer together by heat bonding, or needle punching or chemical bonding; and manufacturing the first layer onto the laminated second layer/third layer directly, followed by cutting, packing and sterilization.

2. The method of claim 1, wherein the first layer comprises a blend of the first hydrophilic fibers and the first hydrophobic fibers, and a percentage of the first hydrophilic fibers is 75% or less by weight of the first layer.

3. The method of claim 1, wherein the second layer comprises the second hydrophilic fibers and the second hydrophobic fibers, and a percentage of the second hydrophobic fibers is, by the weight of the second layer, 75% or less.

4. The method of claim 1, wherein the third hydrophobic fibers of the third layer are selected from polypropylene (PP) fibers, polyester (PET) fibers, Polyamide (PA) fibers, polyethylene (PE) fibers, hydrophobic chitosan fibers, PP/PE bi-component fibers, PA/PE bi-component fibers, PET/PA bi-component fibers, or a mixture thereof.

5. The method of claim 1, wherein a weight of the first layer is between 50-500 gram per square meter (gsm), and/or a weight of the second layer is between 80-500 gsm, and/or a weight of the third layer is between 51-100 gsm.

6. The method of claim 1, wherein the hydrophilic fibers and/or hydrophobic fibers of the first layer and/or the second layer comprises antimicrobial agents selected from the group consisting of silver, silver compound, silver complex, Polyhexamethylene biguanide (PHMB) and honey.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention is described hereinbelow with reference to accompanying drawings, in which the sole FIGURE is a schematic diagram of a three-layered wound dressing according to one embodiment of the invention.

(2) In the drawings, the following reference numbers are used: 1. First layer; 2. Second layer; and 3. Third layer.

DETAILED DESCRIPTION OF THE EMBODIMENTS

(3) To further illustrate the invention, experiments detailing a three-layered wound dressing and a method of manufacturing the same are described below. It should be noted that the following examples are intended to describe and not to limit the invention.

Example 1

(4) The three layers are made separately in the following method.

(5) First layer: contains 75% by weight of polypropylene fibers (PP), fiber linear density 2.0 dtex, fiber length 38 mm; and 25% of alginate fibers, fiber linear density 2.5 dtex, fiber length 75 mm. The above two fibers are mixed evenly and then processed by opening, carding, crosslapping and needle punching. The needling density is 80/cm.sup.2. The finished fabric has a weight of 310 gsm.

(6) The second layer: contains 35% by weight of cross-linked acrylates copolymer super absorbent fibers (SAF), fiber linear density 2.7 dtex, length 10 mm; 50% by weight of wood pump, fiber linear density 2.5 dtex, length 10 mm; and 15% by weight of PP/PE bi-component fibers, fiber linear density 2.0 dtex, length 10 mm. All three fibers are blended by hands or by an opener evenly, followed by opening and air laying and finally hot oven to form the fabric. The weight of the fabric is 180 gsm.

(7) The third layer: PP spun bond fabric, weight 30 gsm, beige color.

(8) The heat lamination method is used to combine the second layer and the third layer, then the needle punch method is used to laminate the first layer onto the above laminated layers.

(9) Samples are cut into 1010 cm, then packed into pouches, and sterilized by gamma irradiation. The finished dressing has a weight of 520 gsm, and an absorbency of 44 g/100 cm.sup.2.

Example 2

(10) The three layers are made in the following method.

(11) First layer: contains 50% by weight of hydrophobic chitosan fibers, fiber linear density 2.2 dtex, fiber length 51 mm; and 50% by weight of viscose fibers, fiber linear density 1.7 dtex, fiber length 51 mm. The above two fibers are mixed evenly and then processed by opening, carding, crosslapping and needle punching. The needling density is 100/cm.sup.2. The weight of the finished fabric is 100 gsm.

(12) The second layer: contains 35% by weight of SAF fibers, fiber linear density 2.7 dtex, length 25 mm; 15% by weight of viscose fibers, fiber linear density 2.5 dtex, length 51 mm; and 50% by weight of PP fibers, fiber linear density 2.0 dtex, length 38 mm. All three fibers are blended evenly, followed by opening, carding, cross-lapping and needle punched into nonwoven fabric. The needling density is 100/cm.sup.2. The weight of the fabric is 150 gsm.

(13) The third layer: hydro entangled Lyocell nonwoven, weight 40 gsm, white color.

(14) The first layer, second layer and the third layer are placed onto the conveyor belt of the cross-lapping machine, and fed into the needle loom and needled into laminated fabric. The needle density is 150/cm.sup.2.

(15) Samples are cut into 1010 cm, then packed into pouches and sterilized by EtO. The finished dressing has a weight of 290 gsm, absorbency 47 g/100 cm.sup.2.

Example 3

(16) The three layers are made in the following method.

(17) First layer: contains 10% by weight of hydrophobic chitosan fibers, fiber linear density 2.2 dtex, fiber length 51 mm; and 75% by weight of viscose fibers, fiber linear density 1.7 dtex, fiber length 51 mm; and 15% by weight of PP/PE bi-component fibers, fiber linear density 2.0 dtex, length 38 mm. The above three fibers are mixed evenly and then processed by opening, carding, and then heat processing to form the fabric. The weight of the finished fabric is 300 gsm.

(18) The second layer: contains 20% by weight of alginate fibers, fiber linear density 2.5 dtex, length 75 mm; 50% by weight of Lyocell fibers, fiber linear density 1.7 dtex, length 51 mm; and 30% by weight of PP/PE bi-component fibers, fiber linear density 2.0 dtex, length 38 mm. All three fibers are blended evenly, followed by opening, carding, and heat process to form the nonwoven fabric. The weight of the fabric is 150 gsm.

(19) The third layer: PP spun bond fabric, weight 30 gsm, pink color.

(20) The first layer, second layer and the third layer are placed together into a heat process to laminate the three layers.

(21) Samples are cut into 1010 cm, then packed into pouches and sterilized by EtO. The finished dressing has a weight of 480 gsm, absorbency 35 g/100 cm.sup.2.

Example 4

(22) The three layers are made in the following method.

(23) First layer: contains 70% by weight of polypropylene fibers (PP), fiber linear density 2.0 dtex, fiber length 38 mm; and 30% of Lyocell fibers, fiber linear density 1.7 dtex, fiber length 51 mm. The above two fibers are mixed evenly and then processed by opening, carding and crosslapping.

(24) The second layer: contains 25% by weight of CMC fibers, fiber linear density 2.2 dtex, length 50 mm; 75% by weight of PET fibers, fiber linear density 1.4 dtex, length 51 mm. All two fibers are blended evenly, followed by opening, carding, crosslapping and needle punching. The weight of the needled fabric is 200 gsm.

(25) The third layer: PP spun bond fabric, weight 30 gsm, beige color.

(26) During the process to manufacture the first layer, the second layer and the third layer are placed in order (third layer at the bottom) onto the conveyor belt of the cross lapping machine, then fed into the needling looms. The needling density was 150/cm.sup.2. The needling has pushed the fibers of the first layer through the second layer and then into the third layer, thus laminating the three layers together.

(27) Samples are cut into 1010 cm, then packed into pouches, and sterilized by gamma irradiation. The finished dressing has a weight of 430 gsm, absorbency 39 g/100 cm.sup.2.

Example 5

(28) The three layers are made in the following method.

(29) First layer: contains 75% by weight of polypropylene fibers (PP), fiber linear density 2.0 dtex, fiber length 38 mm; and 25% of silver alginate fibers, silver content 2.1%, fiber linear density 2.6 dtex, fiber length 75 mm. The above two fibers are mixed evenly and then processed by opening, carding, crosslapping and needle punching. The needling density is 80/cm.sup.2. The weight of the finished fabric is 300 gsm.

(30) The second layer: contains 25% by weight of SAF fibers, fiber linear density 2.7 dtex, length 38 mm; 75% by weight of PET fibers, fiber linear density 1.4 dtex, length 51 mm. The two fibers are blended evenly, followed by opening, carding, cross-lapping and needle punched into nonwoven fabric. The weight of the fabric is 200 gsm.

(31) The third layer: PP spun bond fabric, weight 30 gsm, beige color.

(32) The first layer, second layer and the third layer are placed onto the conveyor belt of the cross-lapping machine, and fed into the needle loom and needled into laminated fabric. The needle density is 150/cm.sup.2.

(33) Samples are cut into 1010 cm, then packed into pouches and sterilized by Gamma. The finished dressing has a weight of 530 gsm, absorbency 42 g/100 cm.sup.2.

Example 6

(34) The three layers are made in the following method.

(35) First layer: contains 70% by weight of polypropylene fibers (PP), fiber linear density 2.0 dtex, fiber length 38 mm; and 30% of Lyocell fibers, fiber linear density 1.7 dtex, fiber length 51 mm. The above two fibers are mixed evenly and then processed by opening, carding, crosslapping and needle punching. The needling density is 80/cm.sup.2, the weight of the finished layer is 100 gsm.

(36) The second layer: contains 40% by weight of silver alginate fibers, silver content 2.1%, fiber linear density 2.6 dtex, length 75 mm; 60% by weight of PET fibers, fiber linear density 1.4 dtex, length 51 mm. All two fibers are blended evenly, followed by opening, carding, crosslapping and needle punching. The weight of the needled fabric is 100 gsm.

(37) The third layer: PP spun bond fabric, weight 30 gsm, beige color.

(38) The first layer, second layer and the third layer are placed onto the conveyor belt of the cross-lapping machine, and fed into the needle loom and needled into laminated fabric. The needle density is 150/cm.sup.2.

(39) Samples are cut into 1010 cm, then packed into pouches, and sterilized by gamma irradiation. The finished dressing has a weight of 230 gsm, absorbency 32 g/100 cm.sup.2.

Example 7

(40) The first layer and the second layer are the same as the ones from Example 6, feed both fabrics into the needle loom to laminate by needling. The laminated fabric is then placed before the calender rollers of the polypropylene spun bond line, ensuring the second layer facing the income polypropylene material so that spun bond polypropylene is laid onto the second layer, and all three layers are fed into the calender rollers together, thus making the spun bond polypropylene laminated onto the second layer/first layer.

(41) Samples are cut into 1010 cm, then packed into pouches, and sterilized by gamma irradiation. The finished dressing has a weight of 230 gsm, absorbency 30 g/100 cm.sup.2.

(42) Unless otherwise indicated, the numerical ranges involved in the invention include the end values. While particular embodiments of the invention have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from the invention in its broader aspects, and therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of the invention.