KR20020071910A - Method and device for production of composite non-woven fibre fabrics by means of hydrodynamic needling - Google Patents

Abstract

Methods for producing mixed nonwovens made by applying at least one spun bonded fiber and subsequent wood pulp layers for the production of hygiene products are known. Thus, the spunbonded nonwoven is hydraulically needled before being applied to the wood pulp layer to increase fluid dispersion properties. As a result, when the pulp is washed through the nonwoven fabric, the pulp layer can no longer be needled. Bonding of the nonwoven is essential because of the required abrasion resistance. According to the invention the nonwoven is compressed or calendered with compressed air as a pre-bonding treatment before being coated with a strongly-absorbing material to solve the problem, and then the wood layer is applied and the The nonwoven fabric and the wood layer are joined by hydraulic needling and later subjected to a drying process. One calendaring may be added. One pre-bonded, in other words, a calendered spunbonded or carded nonwoven can be applied to the spunbonded nonwoven as a support layer or vice versa.

Description

TECHNICAL AND DEVICE FOR PRODUCTION OF COMPOSITE NON-WOVEN FIBRE FABRICS BY MEANS OF HYDRODYNAMIC NEEDLING}

EP-A-0 333 209 published the binding of endless elastomeric fibers and wood pulp fibers together and reinforcing mixed nonwovens. There is a risk in the method of reinforcing the nonwoven that large amounts of pulp fibers are washed out of the system, i.e., the fibers are lost. In addition, the tendency for the outermost layers of such mixed nonwovens to be small, as described in WO 90/04066, to pelpet is actually known as well. The modification, EP-A-0 540 041, proposed to handle hydraulically endless nonwovens before the application of the pulp fibers. This not only gives the nonwoven fabric greater strength but also improves the absorption and fluid distribution properties of the pulp fibers. According to this application, the pulp fibers are simply applied to a needless nonwoven and dried to a nonwoven or mechanically compressed into the nonwoven for bonding.

The production of this type of nonwoven product has not actually met the conditions. More particularly, complaints have been raised that the mixed nonwovens will be rounded outside the endless nonwovens.

The present invention relates to a method and apparatus for producing mixed nonwovens from at least one carrier nonwoven and wood pulp layer.

An apparatus for the implementation of the method is briefly described below.

1 is a side view of a continuous system for the production of mixed nonwovens with one carrier substrate,

FIG. 2 is a side view of the system in FIG. 1 supplemented with a supply of an additional covering layer made of a continuous nonwoven over the water needling; FIG.

FIG. 3 is a system in FIG. 2 but with a carding system at the inlet for the production of a card nonwoven as carrier layer.

It is an object of the present invention to relate to a method and apparatus that facilitates good surface wearability but nevertheless enables good bonding of the pulp fibers in a carrier nonwoven. Care should be taken to ensure that the applied pulp layer is not lost or is rarely lost where efficient bonding to the carrier nonwoven is possible.

The object of the present invention, which is more advanced than EP-A-0 540 041, is that the spun bonded nonwoven fabric is pre-reinforced, needled with air, and calendered before being coated with a strong absorbent material. ), The wood pulp layer is then applied, and the nonwoven and wood pulp layers are reinforced and dried by a hydrowater needling process. Enhancing the calendering of the endless nonwovens before the process not only improves the wear resistance of the final product but also reduces water needling and pulp loss in the nonwovens. However, it should be noted that the calendar should not be too strong. If the reinforcement is too large and the bonding points are too diverse, bonding the pulp layer to the calendered nonwoven is difficult through a water needling process. For this reason, in order to improve the tendency of pelpeting, the nonwoven can be calendered once again at the end of the bonding process after drying, which allows for a fixed bond of all surface fibers. Where the nonwoven product has only one spunbonded layer, the rollers adjacent to the spunbonded layer need to be heated.

However, it is advantageous to carry out a hot calendering process on the surface of the pulp layer where applicable. This creates so-called hydrogen bonds in the cellulose fibers so that a closed paper-like surface is made on the side of the wood pulp. Such products may also be used for medical purposes in the production of surgical garments or surgical covers, and the nonwovens should also be provided hydrophobically.

It should be established in the method of manufacture that the pulp layer should be hydraulically bonded to the nonwoven, otherwise the product may not actually be present due to layer formation. It is better if another pre-reinforced endless fiber or card nonwoven is applied to the pulp layer and the three layers are hydraulically needled together. Last calendaring is advantageous. It is advantageous to use calendered card nonwovens as carrier nonwovens instead of endless nonwovens, and spunbonded nonwovens as covering layers are applied to the continuous nonwovens.

The continuous fibers 2 appearing continuously from the device 1 are known in substance and need not be described in detail, and impact the conveyor belt 3 and flow in the direction of the arrow 4. The calender device is assigned to the conveyor belt 3, the calender device supplies the reinforced nonwoven fabric depending on the demand, and the nonwoven fabric is sharply compressed with force and heat where applicable. The calendar mechanism may be replaced with a device that enhances compressed air, although not shown here. The reinforcing effect is insignificant so that the pulp can enter internal bonds with a continuous fibrous nonwoven by the needling process. After the process, the pulp fibers are applied and use the apparatus 6 as known, for example according to EP-A-0 032 772. Since the hydraulic needling process is applied together to the nonwoven layer, it is possible to perform the hydraulic needlening process on the permeable drum in FIG. 2 instead of the conveyor belt in FIG. The drying process is followed by a sieve drum device 8, 9 through ventilation. In the case of the device 8 the ventilator is directly assigned to the sieve drum in front. Finally, another calendaring 15, 16 works, but one has greater force. The reinforcement strength is greater in the final product and has a satisfactory abrasion resistance. In the example in FIG. 1 only the rollers 16 in contact with the spunbonded nonwovens need heating.

The continuous system in FIG. 2 corresponds to FIG. 1, where only slightly pre-reinforced endless fiber nonwovens are produced with the device 10, and the nonwovens are also naturally made or premade using rollers (not shown). . This also applies to the carrier nonwoven with device 1-4 in FIG. The top covering nonwoven fabric 12 should always be reinforced in advance with the calendar 11. After the covering nonwoven 12 is deposited on the pulp layer, the pulp layer is applied to the basic nonwoven from the device 1, 5 using the instrument 6, and the above mentioned water needling process is carried out. This practice can take place from both sides and is applicable to a plurality of stages, the pulp layer being covered on both sides by a nonwoven fabric. The needling drums 13 and 14 for this purpose are one behind the other and move in a meander-shaped and each jet indicated by the arrow is allocated on the needling drum. The drying process that takes place later is carried out with another type of ventilation dryer 9, the ventilation device being allocated outside of the sieve drum 9 ′ of the dryer 9. As a result, the calendars 15 and 16 flow through them, but in this case both drums 15 and 16 must be heated.

So far, the production of spunbonded nonwovens has been discussed for the following calendering. Obviously, card nonwovens in place of spunbonded nonwovens can be produced as carrier nonwovens and can be reinforced in advance as they are calendered and the pulp layer 6 can be applied to the nonwovens. This is shown in FIG. 3. Cards 1'-4 'are used as nonwoven fabrics for placing devices. The card includes a box tank 1 'having a vibration chute 2' disposed under the card, the chute scraping and tearing the fibers spread evenly over the entire length. ) To the card using the roller 3 '. The conveyor belt 4 'described later transfers the card nonwoven fabric to the calendering device 5 described above. A spunbonded nonwoven is used as the covering layer 12 behind the pulp layer, and the spunbonded nonwoven is formed in the unit 10 shown schematically. There is a need to use spunbonded nonwovens as carrier nonwovens and card nonwovens are applied after the pulp layer. In this case, the unit 10 represents a device labeled 1'-4 ', while a spunbonded mechanism similar to reference number 1, 2 is disposed in place of the card.

Claims (11)

A method of producing a composite nonwoven from at least one carrier nonwoven, such as a spun-bonded nonwoven and a layer of wood pulp applied to the carrier nonwoven, for example for the production of hygiene products, The spun-bonded nonwoven fabric is compressed in a dry state to pre-strengthening before coating with a strong absorbent material, the wood pulp layer is applied, and the spun-bonded nonwoven fabric and wood pulp layer together hydraulic water needle A process for producing mixed nonwovens, characterized in that they are reinforced and dried in a hydrodynamic water needling process. The method of claim 1, Said pre-strengthening, pre-compressing is performed with compressed air. The method of claim 1, Wherein said pre-strengthening and pre-compressing are produced through calendering. The method of claim 1, wherein A covering layer is applied to the strongly absorbent material prior to the step of strengthening the water needling on the two-part blended nonwoven fabric. The method of claim 4, wherein Wherein said pre-strengthened, calendered spun-bonded nonwoven is provided as a covering layer. The method of claim 5, A pre-reinforced and calendered card nonwoven is provided as a covering layer. The method according to claim 1 to 6, Said pre-strengthening and reinforcing the calender is performed before said water needling binds only slightly to said carrier nonwoven fibers. The method of claim 1, wherein And said dried mixed nonwoven is calendered again with greater force. The method of claim 1, wherein A calendered card nonwoven is first formed as a carrier nonwoven, and a spun-bonded nonwoven is applied over the carrier nonwoven with the pulp layer followed by a covering layer. a) spun-bonding or carding device (1,2: 10,14 ') b) devices for strengthening or calendering compressed air (5,11) e) a device (6) directly connected where applicable to apply a layer of wood pulp onto said pre-hardened carrier nonwoven; f) a water needling device (7: 13,14), said water jet arranged in said wood pulp layer; g) dryers (8) (9) and h) sanitary articles comprising other pre-strengthening and calendering devices 15, 16, where applicable, and formed from spun-bonded nonwovens with a layer of strongly absorbing material for the practice of the method of claims 1-9 Device for production. The method of claim 10, The hydraulic water needling means 1, 2, 5 for forming a covering layer are c) spun-bonding or carding apparatus 10, d) behind the spun-bonding or carding apparatus and the water needling apparatus ( 13, 14, further comprising a strengthening and calendering device (11) above.