Hot air non-woven fabric
Hot air non-woven fabric belongs to a type of hot air bonded (hot-rolled, hot air) non-woven fabric. Hot air non-woven fabric is produced by using hot air from a drying equipment to penetrate the fiber web after the fibers are combed, allowing it to be heated and bonded together.
Hot air bonding process
Hot air bonding refers to the production method of using hot air to penetrate the fiber mesh on drying equipment and melt it under heat to produce bonding. The heating methods used are different, and the performance and style of the products produced also vary. Generally, products made by hot air bonding have characteristics such as fluffiness, softness, good elasticity, and strong warmth retention, but their strength is low and they are prone to deformation.
In the production of hot air bonding, a certain proportion of low melting point bonding fibers or two-component fibers are often mixed into the fiber web, or a powder spreading device is used to apply a certain amount of bonding powder to the fiber web before it enters the drying room. The melting point of powder is lower than that of fibers, and it quickly melts when heated, causing adhesion between fibers.
The heating temperature for hot air bonding is generally lower than the melting point of the main fiber. Therefore, in the selection of fibers, the matching of thermal properties between the main fiber and the bonding fiber should be considered, and the difference between the melting point of the bonding fiber and the melting point of the main fiber should be maximized to minimize the thermal shrinkage rate of the main fiber and maintain its original properties.
The strength of bonding fibers is lower than that of normal fibers, so the amount added should not be too large, generally controlled between 15% and 50%. Due to its low thermal shrinkage rate, two-component fibers are highly suitable for use alone or as bonding fibers in the production of hot air bonded nonwoven fabrics, forming effective point bonding structures. The products produced by this method have high strength and soft hand feel.
Application of hot air non-woven fabric
Fiber webs composed of thermoplastic synthetic fibers can be reinforced by thermal bonding, such as polyester, nylon, polypropylene, etc. commonly used in non-woven fabric production. Due to the lack of thermoplasticity of fibers such as cotton, wool, hemp, and viscose, the fiber network composed solely of these fibers cannot be reinforced by thermal bonding. However, a small amount of fibers such as cotton and wool can be added to thermoplastic fiber webs to improve certain properties of non-woven fabrics, but generally should not exceed 50%. For example, hot-rolled bonded non-woven fabric made of cotton/polyester in a 30/70 mixing ratio can significantly improve moisture absorption, hand feel, and softness, making it very suitable for use in medical and health products. As the cotton fiber content increases, the strength of non-woven fabrics will decrease. Of course, for fiber webs composed entirely of non thermoplastic fibers, it is also possible to consider using powder spreading and hot bonding methods for reinforcement.
Hot rolled non-woven fabric
Hot rolling process and hot air process are both important production processes. The hot rolling process involves heating non-woven fabric raw materials at high temperatures and then compressing them into a certain thickness of non-woven fabric through a rolling process. Hot bonded nonwoven fabrics can be achieved through different heating methods. The bonding method and process, fiber type and combing process, and web structure will ultimately affect the performance and appearance of non-woven fabrics.
Hot rolling adhesive method
For fiber webs containing low melting point fibers or two-component fibers, hot rolling bonding or hot air bonding can be used. For ordinary thermoplastic fibers and fiber webs mixed with non thermoplastic fibers, hot rolling bonding can be used.
Hot rolling bonding method is generally suitable for thin products with a web weight range of 20-200g/m, and the most suitable web weight range is between 20-80g/m. If the web is too thick, the bonding effect of the middle layer is poor, and delamination is prone to occur.
Hot air bonding is suitable for products with a quantitative range of 16~2500g/m. In recent years, the development of thin hot air bonded nonwoven fabrics has been rapid, with a quantitative range generally between 16-100g/m.
In addition, thermal bonding is also commonly used in the production of composite nonwoven fabrics (such as melt laminated nonwoven fabrics), or as a supplementary means to other reinforcement methods. For example, mixing a small amount of low melting point fibers into the fiber web, reinforcing with needle punching, and then bonding with hot air can significantly improve the strength and dimensional stability of needle punched products.
Application of hot-rolled non-woven fabric
Hot air bonding products have the characteristics of high fluffiness, good elasticity, soft hand feel, strong warmth retention, good breathability and permeability, but their strength is low and they are prone to deformation. With the development of the market, hot air bonding products are widely used in the manufacturing of disposable products with their unique style, such as baby diapers, adult incontinence pads, fabrics for women’s hygiene products, napkins, bath towels, disposable tablecloths, etc; Thick products are used to make anti cold clothing, bedding, baby sleeping bags, mattresses, sofa cushions, etc. High density hot melt adhesive products can be used to make filter materials, sound insulation materials, shock absorption materials, etc.
Dongguan Liansheng Non woven Technology Co., Ltd. was established in May 2020. It is a large-scale non-woven fabric production enterprise integrating research and development, production, and sales. It can produce various colors of PP spunbond non-woven fabrics with a width of less than 3.2 meters from 9 grams to 300 grams.
Post time: Jan-06-2025