Fabrics Used in Medical Textiles
Fabrics play a crucial role in the medical textiles, offering a wide range of applications that enhance patient care, hygiene, and overall healthcare efficiency. A wide range of fabrication techniques including weaving, knitting, braiding, and nonwoven has been adopted in the manufacturing of medical textiles for different applications. Like the role of fiber composition on the potential characteristics of textiles, the fabrication methods also play a crucial role. The structural as well as functional characteristics of the fabrics can alter the requirements of a medical textile.
This section details different fabrication methods and their specific application in the field of medical textiles. The common fabric types used in medical textile products are provided in below Figure.
Knitted Fabrics
Knitting is the fabrication method where the yarns are inter-looped or intra-looped to form the fabric structure. In general, knitted fabrics were noted to have better advantage over other fabrics like woven and nonwoven structures in terms of higher elasticity, conformability, absorbency, and so on. Knitted fabrics are typically more extensible than woven fabrics, because rather than the yarns being tightly interlaced under and over one another as in woven fabrics, they consist of rows or columns of interlinked loops of yarn. Knitted fabrics have notable applications in the field of medical textiles which includes bandages, surgical stockings, and orthopaedic equipment like braces and supports, and also knitted fabrics were found in implants. Different uses of knitted fabrics in medical textiles are briefly described below.
Pressure/compression bandages and garments
Compression garments are the type of medical textiles that are mainly developed from the elastane yarns. These garments are developed in the shape of the body and are lesser than the actual measurement. Hence, in the applications, the garments can impart certain pressure on the applied area. The applications of such pressure on the affected area can increase the pressure on the inflammation along with higher blood flow. For the compression garment application, warp and weft-knitted fabrics are most commonly used. The stiffness of the material and the elasticity of the compression garment are the most important properties.
Pressure bandages/garments are the materials that should be able to maintain pressure on the scar area as per the requirements. These are very effective in the treatment of different problems including chronic venous ulcers and varicose vein disorders. The main role of these bandages/garments is that they apply pressure on the skin which in turn can help in the healing of the wound by increasing the blood pressure. The performance of these fabrics is highly dependent on the stress relaxation behavior and interfacial pressure of the fabrics.
In addition to weft-knitted structures, warp-knitted techniques were also used in medical applications. Pressure bandages were made with the multi-axial warp knitting technique with the combination of soybean, polyester, and elastomeric yarns and bamboo, polypropylene, and elastomeric yarns with different degrees of yarn directions (+45°, 90°, −45°). Knitted spacer fabrics are one of the key players in medical textiles. These fabrics show lesser bulk density with more volume.
Wound dressings
The knitted structures hold a predetermined position in the wound dressing applications because of their greater extensibility, elasticity, and flexibility. For wound dressing applications, spacer-knitted fabrics are getting more popular. Spacer fabrics are well suited for replacing the absorbent layer of the wound dressing due to their better permeability, absorbency, thermal conductivity, and cushioning properties.
Warp-knitted spacer fabrics were developed with 100% polyester, and their potential to serve as an absorbent layer of wound dressing was analyzed against commercially available wound dressings which were mainly focused on the management of exuding wounds like burns, ulcers, and surgical wounds.
In the medical textiles, spacer fabrics are used to create artificial vessels, innovative compression bandages, and for pressure-sore management.
Apart from spacer fabrics, knitted gauze is currently replacing the traditional woven gauzes which are being used in wound dressing. The better absorbency of knitted structure than woven structure paved the path for using knitted gauze in the place of woven gauze.
Implants
Artificial blood vessels:
Knitted fabrics are often used as artificial blood vessels to replace damaged ones. Though both woven and knitted structures are being used, the knitted structure has the advantage of better elasticity than the woven. These knitted structures are capable of replacing the larger diameter vessels (diameter of more than 6 mm).
Vascular implants:
Vascular grafts/stents are the substitutes for damaged or diseased arteries. The main requirements of a vascular graft are mechanical and biological mimicking of natural arteries. Knitted fabric structures made of 100% polyester yarns were used as reinforcement of polyurethane vascular grafts. The elasticity and strength of the grafts were noted to improve with the knitted fabrics. Similarly, fabrics made out of polyester/spandex blend also showed better properties.
Woven Fabrics
Weaving is a technology that produces fabrics by means of the interlacement of two sets of yarns (warp and weft). These woven structures are better in stability when compared to the knitted structure. In the field of medical textiles, woven fabrics are widely used in hospital bedding, clothing, wound dressings, gauzes, and in some hygiene products. In tissue engineering processes, woven fabric structures are notably used as scaffolds and also as a reinforcing material for hydrogels. 3D woven fabric applications in healthcare are mostly to be found in wound dressings, implants, and in items intended for regenerative medicine.
Some uses of woven fabrics in medical textiles are briefly described below.
Artificial blood vessels
Artificial blood vessels of larger diameter are the well-known application of woven structure in medical textiles. The effect of structural parameters of PET fabrics to alter the biocompatibility to serve as artificial blood vessels. The cell adhesion of the developed blood vessels depends on the coarseness and pores of the surface. Woven structures were developed with different weft yarn densities to alter the surface characteristics, thereby altering the cell adhesion and proliferation. The detailed analysis showed that the endothelialization can be improved in the woven structure with a flatter surface and pore size among yarns should be less than 20 μm.
Vascular grafts
Woven structures are used in grafts because of their unique characteristics of higher stability, higher strength, and lower porosity. This makes it suitable for high flow arteries, and high-stress locations like the thoracic aorta. Seamless woven polyester grafts were developed with texturized polyester yarns by means of tubular weaving. The clinical trials revealed better results for the developed vascular prosthesis.
Wound dressings
In terms of wound dressings, woven gauzes are very popular. A wide range of commercial dressings is developed with woven structures.
Nonwoven Structures
In the field of medical textiles, nonwoven fabrics find a major role, especially as disposable products. Surgical masks, gowns, drapes, pads, medical filters, wound dressings, and so on are well-known medical applications that largely use nonwoven structures. The major advantages of nonwoven fabric structures that facilitate the potential of nonwoven in medical textiles include:
- Higher flexibility
- Easy and quick production process
- Low production cost
- Absorbency
- Breathability
- Excellent barrier properties
- Lightweight
Out of several nonwoven manufacturing methods, spunlace, spunbond, and meltblown are the most desirable techniques for the manufacturing of nonwovens in the area of medical textiles. The primary drawback of nonwoven over woven and knit structures is the absence of interlooping or interlacing of yarns which ends up in lower mechanical strength. However, all the nonwoven manufactured through different methods are given below.
Spunlace nonwovens
These are one of the most efficient methods of nonwoven production, where highspeed water jets are used to bond the fibers inside the structure. Spunlace nonwovens are found to be applied in wound dressings, surgical fabrics, baby diapers, and other sanitary products. The only disadvantage that is reported in the case of spunlace nonwoven production is higher water consumption.
Spun-laid nonwovens
Spun-laid nonwovens are known for their structural uniformity and mechanical property. These products are usually manufactured using calendaring process. Hence, the main disadvantage of the nonwoven is the lack of bulkiness and softness compared to other production methods. Instead, the calendaring process might melt the Structure and reduce the permeability characteristics.
Spunbond nonwovens
Spun-bonded fabrics play a vital role in health and hygiene-related products like baby care, feminine hygiene, and medicine. Due to their higher porosity and other structural characteristics, spun-bonded fabric helps in keeping the wearer’s skin dry and comfortable. Further, spun-bonded fabrics work better with hygiene products due to their smooth and soft nature. Spun-bonded fabrics had better air permeability properties. These fabrics are cheaper to produce and hence widely used in disposable products like surgical masks and surgical gloves. Spun-bonded structures are also used in wound dressing material due to their breathability and absorbency. Out of all, spunbonded nonwovens are mostly used in the applications like baby and feminine hygiene products.
Meltblown nonwovens
Meltblown layers are very much beneficial in the filtration process. These layers are used in medical protective wear like masks to filter bacteria and other microorganisms. In general, meltblown fabrics are comprised of more number of lower diameter fibers which ends up in reduced pore size and pore volume. This leads to reduced air permeability in the case of melt-blown than spun-bonded fabrics. However, as far as the applications are considered, the meltblown nonwoven fabrics are also highly used in hygiene products along with spun-bonded nonwoven. Due to their higher softness and lower thickness, they are highly used in baby and adult diapers, napkins, and other hygiene products.
Airlaid nonwovens
Compared to other nonwovens, Airlaid nonwovens have higher absorption and moisture transfer capacity. These nonwovens are one of the main materials for the diapers and feminine hygiene products as a core absorbent material. Due to their higher absorbency, they help the product to remain thin with higher absorption. Researchers reported that the control of pore size is the main advantage of air-laid nonwovens. A smaller pore size helps in gaining better distribution of moisture and rewetting characteristics. Instead, a larger pore size gives a higher water absorption and less distribution.
Thermal-bonded nonwovens
These are the structures developed via heat and pressure directly applied on the fiber web, to produce nonwoven by passing through the metal calendaring rollers. Thermal- bonded nonwoven is mainly used in the disposable products as a top and bottom layer of the disposable products. The fabrics are also used in wet wipes, breast pads, diapers, napkins, and also in surgical apparel.
Nonwoven Composites
Nonwoven composites were developed using elasticated spun-bonded and meltblown fabrics incorporated with cotton fibers. The hydroentanglement process has been adopted to develop the composite. The combined action of synthetic webs and incorporated cotton fibers in the composite resulted in the achievement of desirable properties for application in medical textiles such as absorbency, air permeability, hydrostatic head, tensile strength, stretchability, and barrier properties. Other than this, different structures of the nonwovens can also be bonded together to get the composites with different properties. The most popular structure is spunbond–meltblown–spunbond (SMS), spunbond–meltblown–meltblown–spunbond, and spunbond–spunbond–meltblown– meltblown–spunbond in different weight ranges. Out of these, the SMS structure is the most successful combination as it showed a higher barrier against microorganisms due to the microporous structure of meltblown layer. SMS fabrics are also used as cover stock for diaper and sanitary napkins. Further, to add, the higher tensile strength and hydrophobic nature of the spun-bonded layer act as a liquid barrier. Based on the requirements, all the above-mentioned structures are used in both hygiene and medical products.
Braid Fabrics
A braid (or plait) is a narrow fabric made by interlacing three or more threads diagonally to create flat, tubular, or solid constructions. Braid fabric is used in medical textiles for surgical sutures, vascular grafts, ligament repair, orthopedic implants, hernia mesh, and catheters/stents. Its flexibility, strength, and biocompatibility enhance durability, tensile strength, and structural stability, making it essential for modern medical applications like ACL reconstruction, blood vessel replacement, and bone fixation.
Conclusion
Medical textiles are a vital component of the healthcare industry, encompassing a wide range of applications from simple bandages to complex implants. The role of fabrics in medical textiles is multifaceted and critical to modern healthcare. From wound care to implantable devices, these textiles play a vital role in patient safety, comfort, and recovery
References
[1] Adak, B., & Mukhopadhyay, S. (2023). Smart and functional textiles. Walter de Gruyter GmbH & Co KG.
[2] Morris, H., & Murray, R. (2021). Medical textiles. CRC Press.
[3] Medical textile materials. (2016). In Elsevier eBooks. https://doi.org/10.1016/c2014-0-04473-5
[4] Bartels, V. T. (2011). Handbook of medical textiles. In Woodhead Publishing Limited eBooks. https://doi.org/10.1533/9780857093691
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Founder & Editor of Textile Learner. He is a Textile Consultant, Blogger & Entrepreneur. Mr. Kiron is working as a textile consultant in several local and international companies. He is also a contributor of Wikipedia.
