What Are The Two Methods For Making Non-woven Fabrics?

The production methods of nonwoven fabrics are mainly divided into dry (mechanical consolidation) and wet (chemical consolidation) methods. There are significant differences between these two methods in process principle, equipment, product characteristics and application fields. Here are the details:
1.Dry (mechanical consolidation method)
Core Principle: Wrap or fuse fibers into a non-woven fabric fabric structure mechanical forces (such as needle punching, spurs, hot bonds, etc.).
Features: do not require chemical adhesive, good environmental protection, high product strength, good air permeability, flexible process, suitable for all kinds of fiber raw materials.
Common process types:
Acupuncture
Process flow: Combing machine or airflow molding machine → pre-needling → main needle punching machine (needle repeatedly piercing fiber web tangles) → roller.
Features: Thick, compact and sturdy, but with a rough finish.
Uses: carpet, geotextile, car interior, filter material, etc..
Water entanglement (a variation of the glue spray method, but based mainly on water entanglement)
Process flow: fiber web → hydroentanglement head spray high pressure flow (multi-fine water jets) impact fiber web → fiber tangle → dehydration → roll.
Features: The product is soft and breathable, absorbent and feels similar to textiles.
Usage: medical dressings, wet wipes, sanitary napkin surface, high grade napkins, etc.
Thermal bonding method
Process: combing double-bicomponent fibers (such as core structure and low-melting polymer core) into webs → heating (such as hot air or infrared) → bonding between fibers → cooling → solidifying → roll.
Features: The product is soft, fluffy and breathable, but slightly stronger than needle punching method.
Uses: Bathroom products (such as diapers, sanitary napkins absorption layer), insulation materials, filtration materials, etc.
Meltblown method
Process flow: Polymers (such as polypropylene) are randomly deposited on the receiving device → cooling high temperature and high speed air flow.
Features: Fine fiber diameter (0.5-10 microns), larger than surface area, high filtration efficiency efficiency, but low strength.
Uses: mask filter material, air filter material, insulation material, linoleum, etc..
2. Humidification (chemical consolidation method)
Core Principle: Disperse the fibers in water to form suspension slurry, and bind the fibers themselves (e.g., latex, polyvinyl alcohol) or their characteristics (e.g., hydrogen bonding for cellulose fibers) to form a non-woven fabric structure.
Features: good product uniformity, high softness, can produce thin material, but chemical adhesive requirements are higher, environmental protection performance is a little poor.
Common process types:
Bonding method (wet net + chemical bonding)
Process flow: fiber (such as wood pulp, chemical fiber) dispersed in water to form slurry → wet loom evenly spreads slurry on mesh curtain → dehydrates → formation of → sprays or dip chemical adhesive → dries curing → rolls.
Features: The product is soft and absorbent, but the strength is influenced by the distribution of adhesive.
Uses: Medical gauze, sanitary napkins, disposable tablecloth, industrial wet wipes, etc..
Papermaking method (wet net + fiber self-adhesive)
Process flow: Wood pulp fibers are dispersed in water, wet loom → dehydrates, pressing, drying, roller.
Features: Reliance on hydrogen bonds between fibers, no chemical binders, environmentally friendly products, but low strength products.
Uses: paper towels, toilet paper, disposable food packaging paper, etc..
Solvent bonding (special wet process)
Process: Dissolve fiber (such as polyester) in organic solvent → wet cloth → formation of fiber web → solvent volatilization or chemically reacts to bind fiber → roll.
Features: High strength, good water resistance, but high solvent recovery cost.
Applications: High-end filtration materials, industrial fabrics, etc..