Elastic spunlace Nonwoven Fabric Products

I. Process of Elastic Spunlace Nonwoven Fabric

The core of elastic water stitch nonwoven fabric lies in achieving the synergy of "elasticity + spunlace structure" through raw material selection and process optimization. Changshu Yongdeli Spunlaced Nonwoven Fabrics Co., Ltd. ensures stable elasticity and reliable performance through meticulous process control. The specific process is as follows:

Core raw material selection and ratio: Select high-quality elastic polyester fibers. The elastic polyester fibers use modified varieties with a high elastic recovery rate (elastic recovery rate ≥ 90%), which can quickly rebound after stretching;

Opening and mixing: Use a dedicated opening and mixing equipment to disperse the elastic polyester fibers. The equipment adopts a low-tension design to avoid the elastic fibers losing their elasticity due to excessive stretching; then it enters a biaxial blending machine, where multiple sets of mixing teeth achieve uniform fiber mixing to ensure the uniform distribution of elastic fibers in the fabric mesh, avoiding uneven elasticity in certain areas, laying the foundation for subsequent web formation and elastic shaping.

Combing and web formation (elastic orientation control): The elastic fibers enter a high-precision elastic fiber-specific combing machine. The combing machine uses special needle fabric (low-damage type needle fabric) and adjustable rollers to separate the fibers while controlling the fiber arrangement direction (mainly longitudinal elasticity, with lateral elasticity as a supplement), matching the elastic requirements of medical patches (such as longitudinal adaptation to limb movement direction). During the combing process, real-time monitoring of the thickness deviation (controlled within ±2%) ensures uniformity of the fabric mesh, avoiding uneven thickness that affects the subsequent coating and adhesion effects.

Elastic spunlace reinforcement (key process): This is the key step to give the product elasticity, using the "multiple progressive pressure water stitch" process:

The first low-pressure water stitch (pressure 5-8 MPa): Initially fix the fabric structure to prevent excessive fiber displacement caused by high-pressure water stitch, protecting the elastic structure of the elastic polyester fibers;

Medium-pressure directional spunlace (pressure 10-12 MPa): Through an inclined water jet head (at an angle of 30°-45° to the fabric mesh) to spray in a directional manner, making the elastic fibers form a "tangle - elastic reserve" structure along the preset direction (longitudinal), providing space for stretching and rebound;

High-pressure shaping spunlace (pressure 13-15 MPa): Use a high-density water jet head to fully reinforce the fabric mesh, ensuring the tight entanglement of elastic fibers with other fibers, while precisely controlling the pressure to avoid the fibers being crushed, ultimately forming a stable structure of "elastic fibers as the framework, water stitch entanglement as the support", with a longitudinal stretching rate of up to 15%-30% and a lateral stretching rate of up to 8%-15%, meeting the requirements of medical patches for limb movement adhesion.

Low-temperature dehydration and shaping: The wet elastic nonwoven fabric after water stitch reinforcement enters a vacuum dehydration equipment (dehydration rate 70%-80%), then enters a low-temperature hot air drying equipment (temperature 70-90°C), with a temperature lower than the conventional spunlace nonwoven fabric drying temperature (100-120°C), which can avoid the elastic polyester fibers losing elasticity due to high temperature. During the drying process, elastic shaping is carried out simultaneously. The tension of the fabric surface is controlled by temperature control rollers to ensure that the product maintains stable elastic recovery performance after drying, with the moisture content controlled within 5%.

Surface pretreatment (matching coating): For the subsequent coating requirements, the dried products are subjected to surface pretreatment: using plasma surface treatment technology to enhance the surface energy (surface tension ≥ 38 mN/m), improving the adhesion to hot melt adhesives, silicone gels, and other coating substrates, and avoiding "degluing" problems; at the same time, smoothness treatment is carried out, by lightly pressing the fabric surface with soft pressure rollers, ensuring the flatness of the fabric surface (flatness deviation ≤ 0.1 mm/m), providing a foundation for uniform coating.

Cutting and quality inspection: According to the roll width requirements of medical adhesive patch customers (common widths 0.5 - 2 m), the products are cut by high-precision cutting machines. The cutting process adopts tension closed-loop control to avoid elastic deformation of the products due to stretching; in the quality inspection process, in addition to routine appearance and strength tests, "elastic performance testing" (testing the elongation rate and elastic recovery rate with a tensile testing machine) and "coating compatibility testing" (simulating coating after testing the adhesion of the adhesive layer) are added to ensure that each batch of products meets the standards of medical adhesive patch substrates.

II. Compatible coating types and advantages

The elastic spunlace non-woven fabric is suitable for the four commonly used coating substrates for medical adhesive patches. Through raw material and process optimization, it achieves efficient compatibility, solving problems such as "uneven coating, delamination, and impact on drug efficacy" of traditional substrates. The specific advantages of compatibility are as follows:

Compatible with hot melt adhesive coating: Hot melt adhesives (such as EVA type, SBS type) are commonly used for plaster patches and pain relief patches. After surface pretreatment, the surface tension is enhanced, and the hot melt adhesive coating can be evenly spread, with the thickness deviation of the adhesive layer ≤ 5%; at the same time, the elastic structure of the fabric surface matches the flexibility of the hot melt adhesive, and the adhesive layer is less likely to crack when stretched, ensuring that the adhesive layer remains intact during limb movement, avoiding drug efficacy loss.

Compatible with silicone gel coating: Silicone gel has low allergenicity and high adhesion, often used in fever relief patches and special patches for sensitive skin. The elastic polyester fibers of the product have excellent compatibility with silicone gel, without chemical interactions; the fine spunlace structure of the fabric surface enables the silicone gel to evenly penetrate the fiber gaps, forming a "gel - fabric" closely combined structure, with an adhesion improvement of more than 25% compared to ordinary spunlace non-woven fabric, avoiding "edge lifting and delamination" of the patch during use.

Compatible with oil adhesive coating: Oil adhesives (such as rubber type oil adhesives) have high viscosity and aging resistance, suitable for long-term use plaster patches. The elastic structure of the product can buffer the internal stress of the oil adhesive during stretching, reducing "fatigue cracking" of the adhesive layer caused by limb movement; at the same time, the breathable structure of the fabric surface is not affected by the oil adhesive coating, still maintaining good breathability (breathability ≥ 300 L/m²·s), avoiding skin discomfort caused by heat during use.

Compatible with water gel coating: Water gel has high hygroscopicity and coolness, being the core adhesive type of fever relief patches and band-aids. The adhesive fibers matched with the product can enhance the fabric's ability to hold water gel, avoiding loss of water gel due to gravity; the elasticity of the fabric can adaptively adjust with the swelling degree of the water gel, providing a non-tight feeling when adhering to the skin, and the moisture in the water gel will not affect the elastic recovery performance of the product, ensuring the stability of the patch's elasticity during the usage period (usually 8 - 12 hours).

III. Core advantages of elastic spunlace non-woven fabric

Excellent elasticity and adhesion: The longitudinal elongation rate of the product is 15% - 30%, the lateral elongation rate is 8% - 15%, and the elastic recovery rate is ≥ 90%. It can closely adhere to human joints (such as knee joints, elbow joints), necks, and waists and other movable parts, stretching and rebounding synchronously with limb movement, avoiding problems such as "wrinkling, falling off, and pulling skin" of traditional non-elastic substrates patches, and improving the wearing comfort and stability of medical adhesive patches. High adaptability and durability: Through surface pretreatment and raw material optimization, it can perfectly adapt to four mainstream coating substrates such as hot melt adhesive, silicone gel, oil-based adhesive, and water-based gel. The adhesion strength of the adhesive layer is ≥ 5N/2.5cm (tested according to GB/T 2792-2014), and there is no risk of delamination during use; at the same time, the wear resistance (Martin-Dale abrasion ≥ 500 times without damage) and aging resistance (temperature range -20℃ - 60℃, meeting the requirements of medical environment) of the elastic polyester fibers ensure the stability of the adhesive patch during storage and use.

Skin-friendly, breathable and environmentally friendly: The elastic polyester fibers have a soft texture, and there is no irritation when in contact with the skin, making them suitable for sensitive skin groups; the water-stitch structure retains uniform pores, with a ventilation rate of ≥ 300L/m²・s, which can promote normal skin breathing and reduce the feeling of heat and allergic risks during use of the adhesive patch; the production process does not add chemical adhesives, only through physical water-stitch reinforcement, and the product complies with GB 18401-2010 "National Textile Product Basic Safety Technical Specifications" and YY/T 0334-2022 "Medical Deaerated Cotton", without formaldehyde or heavy metal residues, and is safe for medical scenarios.

Uniform coating and convenient processing: The surface flatness is high (flatness deviation ≤ 0.1mm/m), and the thickness is uniform (thickness deviation ±2%). During coating, the adhesive layer can evenly cover, without problems of excessive or insufficient adhesive layer in certain areas; at the same time, the product has good cutting performance, and during cutting, there is no fiber edge shedding, and can be precisely cut according to different sizes of medical adhesive patches (such as circular, rectangular, and irregular shapes), providing convenience for downstream customers' processing.

Ⅳ. Weight range of elastic spunlace non-woven fabric

The elastic spunlace non-woven fabric produced by Changshu Yongdeli Spunlaced Non-Woven Fabric Co., Ltd., with a focus on the requirements of medical adhesive patch substrates, covers a weight range of 70g/㎡ - 120g/㎡, which can be flexibly adjusted according to the type of adhesive patch (such as lightweight cooling patches, thick-type plaster patches); the characteristics and applicable scenarios of each weight range are as follows:

Ⅴ. Core application scenarios - Medical field medical adhesive patches

As the base material for medical adhesive patches, elastic spunlace non-woven fabric, with the advantages of "elastic adhesion, adaptability to multiple adhesive types, and safe skin-friendly", has been widely used in the following medical scenarios:

Plaster patch base material: Suitable for traditional Chinese medicine plaster patches, the elasticity of the product can fit the curves of the waist, shoulders, etc., avoiding the wrinkling of the plaster patch due to limb movement, which prevents the inability of the medicine to penetrate; compatible with hot melt adhesive or oil-based adhesive coating, with strong adhesive strength, ensuring that the plaster patch does not fall off within an 8-12-hour usage period, and the breathable structure can reduce the skin heat sensation caused by the drug components and reduce the risk of allergy.

Pain relief patch base material: For pain relief patches for muscle strain and joint pain, the elasticity of the product can stretch synchronously with the movement of the limb, without a pulling sensation at the pain site; compatible with silicone gel coating (low allergenicity), suitable for long-term pain patients, and the softness of the fabric surface can reduce the irritation to the skin at the pain site, improving the use comfort.

Cooling patch base material: As the core base material for children and adult cooling patches, the low-weight product (35-45g/㎡) is lightweight and breathable, compatible with water-based gel coating, which can quickly transfer the cooling sensation, reducing body surface temperature; the elastic structure can fit the forehead, neck, etc., and even when children are active, it is not easy to fall off, while the skin-friendly material avoids children's skin allergies.

Barb tape base material: Due to the presence of a large amount of water-soluble drug components in Barb tape, the absorption and strength requirements of the base material are high, the high-weight product (66-80g/㎡) can effectively bear the water-based gel and drug components, preventing component loss; the elastic structure can be adapted to joint and other movable areas, with no tight feeling during adhesion, and the breathable performance ensures the normal penetration of drug components, improving the efficiency of drug absorption.

Ⅵ. Company services and quality assurance Changshu Yongdeli Spunlaced Nonwoven Fabrics Co., Ltd. has established a complete quality control system for elastic nonwoven fabric products: at the raw material end, it collaborates with well-known elastic polyester fiber suppliers, and conducts elasticity recovery rate and purity tests for each batch of raw materials; at the production end, it is equipped with online elasticity detection equipment to monitor the stretching rate and rebound performance of the products in real time; at the finished product end, it undergoes aseptic treatment according to medical standards (providing EO sterilization or gamma-ray sterilization services), and is tested by third-party authoritative institutions (such as SGS, CNAS certification) to ensure that the products meet the requirements for use in the medical field.

At the same time, the company can provide customized services according to customer needs: it can adjust the fiber ratio to achieve different elasticity levels (such as high elasticity type, low elasticity type), can customize the width of the fabric (0.5 - 2m) and the length of the roll, and can also provide pre-coating testing services to assist customers in optimizing the adhesive layer formula and coating process, achieving a perfect fit of "material - adhesive".

Changshu Yongdeli Spunlaced Nonwoven Fabrics Co., Ltd. has always been "oriented towards the needs of the medical field", continuously optimizing the elasticity performance and adaptability of elastic nonwoven fabrics. In the future, it will further develop "antibacterial elastic nonwoven fabrics" and "ultra-thin high elasticity nonwoven fabrics", expand its application in high-end medical patches, wound care patches, etc., and provide more high-quality and professional material solutions for the medical health industry, working together with customers to safeguard health.