Nonwoven fabrics are divided into many kinds, each kind of nonwoven fabrics production process for:
A, hydroentanglement nonwoven fabrics: hydroentanglement process is a high-pressure micro-fine water jet to one or more layers of fiber network, so that the fibers are entangled with each other, so that the fiber network can be reinforced and have a certain strength.
(I), hydroentanglement non-woven process:
A.? Fiber raw materials → opening and mixing → carding → cross * laying network → drawing → → pre-wetting → positive and negative hydroentanglement → finishing → drying → winding ↑? ↑ water treatment cycle
B.? Fiber raw material→opening and mixing→combing and messy netting→→pre-wetting→positive and negative spunlace→post-finishing→drying→winding↑? ↑Water treatment cycle? Different netting methods affect the longitudinal and transverse strength ratio of the final product, process A is better for the fiber net longitudinal and transverse strength ratio adjustment, suitable for the production of spunlace synthetic leather base cloth; process B is suitable for the production of hydroentanglement sanitary materials.
(2), pre-wetting
The formed fiber mesh is sent to the spunlace machine for reinforcement, the first is pre-humidification.
The purpose of pre-humidification is to compact the fluffy fiber mesh, exclude the air in the fiber mesh, so that the fiber mesh into the hydroentanglement area can effectively absorb the energy of the water jet to strengthen the fiber entanglement effect.
Common pre-wetting methods:
1 Double net clamping type
2 Perforated roller and net curtain clamping type
(3), hydroentanglement
The pre-wetted fiber mesh into the spiked area, the spiked head of the water jet plate of the water spray holes sprayed out of the multi-flow micro-fine water jets, vertically shot at the fiber mesh. Water jets make part of the fiber network in the surface layer of fiber displacement, including vertical movement to the opposite side of the fiber network, when the water jets penetrate the fiber network, by the net curtain or drum rebound effect, in different directions scattered to the opposite side of the fiber network. Under the dual action of direct impact of water jet and rebound water flow, the fibers in the fiber network are displaced, interspersed, entangled, and embraced to form countless flexible entanglement points, so that the fiber network is reinforced.
The vertical jetting of the fiber network can prevent the destruction of the structure of the fiber network and maximize the use of water jet energy, which is conducive to the improvement of the performance of the hydroentanglement method of nonwoven materials.
Hydroentanglement mainly has a flat mesh hydroentanglement, rotary drum hydroentanglement and rotary drum and flat mesh combination of hydroentanglement in three forms.
To net curtain weaving structure and fiber mesh appearance structure effect? In the rotating drum hydroentanglement process, the hydroentanglement head is arranged along the circumference of the rotating drum, and the fiber mesh is adsorbed on the rotating drum to receive the water jet sprayed by the hydroentanglement head. Fiber mesh adsorption on the drum, there is no running phenomenon, conducive to high-speed production, while the fiber mesh in the hydroentanglement area was curved surface movement, accepting the hydroentanglement surface relaxation, the opposite side of the compression, which is conducive to the penetration of water jets, effectively entangled fibers.
The rotating drum is a perforated metal cylinder structure with a dewatering device inside, which has a good rebound effect on the water flow compared with the flat net hydroentanglement of the carrier curtain.
The combination of rotating drum and flat mesh hydroentanglement? In the hydroentanglement process, the combination of flat and rotary drum can be used to avoid the shortcomings of their respective advantages, usually the first level, the second level of the rotary drum type hydroentanglement, the third level of flat mesh type hydroentanglement. Number of spikes and water pressure? Hydroentanglement process commonly used in the number of hydroentanglement head 7 ~ 12, commonly used water pressure of 60 ~ 250Bar, depending on the quality of the unit area of the fiber network, production speed, etc., hydroentanglement head pressure is usually set to low → high → low.
Water jet structure analysis? According to fluid dynamics, the water is ejected from the water jet hole, which can be called a non-flooded free turbulent jet.? After the water jet is ejected from the water jet hole, it gradually transforms from a clustered jet to a dispersed water droplet due to the transverse pulsation of the turbulent jet and the frictional resistance of the air to the flow bundle.
(d), dehydration? The purpose of dewatering is to remove the stagnant water in the fiber network in a timely manner, so as not to affect the winding effect of the next water spikes. When the amount of stagnant water in the fiber network, will cause the dispersion of water jet energy, not conducive to fiber entanglement. After the end of the hydroentanglement process, the moisture in the fiber network is reduced to a minimum, which is conducive to reducing the drying energy consumption.
Five, water treatment and recycling
Hydroentanglement nonwoven production process of water consumption is very large, the output reaches 5 tons / day, the hourly water consumption of about 150m3~160m3. In order to conserve water, reduce production costs, it must be about 95% of the water through the water treatment and recycling.
Hydroentanglement nonwoven process water requirements? <>? When the suspended solids content is high, it will shorten the service life of the filter bag and filter element.
Organic substances in dissolved or colloidal dispersion state tend to make the water turbid and produce color. These substances are easy to deposit in the water jet hole pore wall, adhere to the fiber, thus affecting the final whiteness of the product.
The rotting slurry formed by microorganisms, after being transported by high-pressure pumps, will quickly block the water jet holes, resulting in a sudden rise in the pressure of the spiked head, causing a stop in serious cases.
Inorganic salts dissolved in water, whether the anions or cations in them, have an effect on the hydroentanglement process. Calcium, magnesium ions in the pipeline and equipment to produce dirt, iron, manganese, copper and other ions are easy to generate colored substances, for the production of white sanitary materials, should be strictly controlled its content. Chloride ion content is more likely to cause equipment corrosion.
The combination of various fibers together, and is a combination of multi-layer fibers is the spunlace nonwoven, but this can not be formally known as the spunlace nonwoven, the reason why it is known as a nonwoven is because it does not go through the textile, but will be textile this process into an automatic jetting. Through the process of jetting the various fibers are combined together to strengthen the durability of the fabric, thus increasing the quality of the fabric.
Two, heat bonded nonwoven fabric: heat bonded nonwoven fabric refers to the fiber network in the addition of fibrous or powdered hot melt bonded reinforcing materials, fiber network and then heated and melted and cooled to reinforce the cloth.
Three, pulp into the net airflow nonwoven fabric: airflow into the net nonwoven fabric can also be called as dustless paper, dry paper nonwoven fabric. It is the use of airflow into the network technology of wood pulp fiber board open into a single fiber state, and then use the airflow method to make the fiber coagulation in the net curtain, the fiber network and then reinforced into the cloth.
Four, wet nonwoven: wet nonwoven is placed in the aqueous medium of fiber raw materials into a single fiber, at the same time to make different fiber raw materials mixed, made of fiber suspension slurry, suspension slurry conveyed to the netting mechanism, the fiber in the wet state into the net and then reinforced into cloth.
Fifth, spunbond nonwoven: spunbond nonwoven is in the polymer has been extruded, stretched and formed a continuous filament, filament laid into a network, fiber network and then after its own bonding, thermal bonding, chemical bonding or mechanical reinforcement methods, so that the fiber network into a nonwoven.
Six, meltblown nonwoven: meltblown nonwoven process: polymer feeding - - melt extrusion - - fiber formation - - fiber cooling - - into the network - - reinforcement into cloth.
Seven, needle-punched nonwoven fabrics: needle-punched nonwoven fabrics is a kind of dry nonwoven fabrics, needle-punched nonwoven fabrics is the use of felting needles puncture, the fluffy fiber mesh reinforcement into cloth.
Eight, sewing nonwoven fabrics: sewing nonwoven fabrics is a dry nonwoven fabrics, sewing method is the use of warp knitting coil structure on the fiber mesh, yarn layer, non-textile materials (such as plastic sheet, plastic thin metal foil, etc.) or a combination of them to reinforce, in order to make a nonwoven fabric.
Nine, hydrophilic nonwoven fabrics: mainly used in the production of medical and hygienic materials, in order to achieve a better feel and not scratch the skin. Like sanitary napkins, sanitary pads is the use of hydrophilic nonwoven hydrophilic function.
Expanded Information:
Non Woven Fabric (English name: Non Woven Fabric or Nonwoven cloth), also known as non-woven fabric, is composed of oriented or random fibers. It is called cloth because it has the appearance and certain properties of cloth.
Nonwoven fabrics are moisture-proof, breathable, flexible, lightweight, non-combustible, easy to decompose, non-toxic, non-irritating, colorful, inexpensive, recyclable and so on. Such as the use of polypropylene (pp material) granules as raw materials, high-temperature melting, spraying, laying the outline, hot pressing and winding continuous one-step production and become.
Nonwoven fabrics do not have warp and weft threads, cutting and sewing are very convenient, and lightweight and easy to shape, loved by handmade enthusiasts.
Because it is a kind of fabric formed without spinning and weaving, it is only the textile staple fibers or filaments are oriented or randomly arranged to form a fiber network structure, and then reinforced by mechanical, thermal bonding or chemical methods.
It is not interwoven and knitted together by one yarn after another, but the fibers are directly bonded together by physical methods, so when you get the sticky weighing in your clothes, you will find that it is not possible to draw a single thread. Nonwovens break through the traditional textile principles, and has a short process, fast production rate, high yield, low cost, wide range of uses, raw material sources and other characteristics.
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