TECHNICAL FIELD

The present invention relates to a novel nonwoven fabric composite formed by binding nonwoven fabric onto cheesecloth, comprising airlaid fiber and other materials, in a single step with the help of latex and/or thermal process in airlaid machine by using nonwoven fabric, obtained by using water-jet binding technology (spunlace), as the lower or upper layer in airlaid technology, and relates to the production method of said composite.

PRIOR ART

Today, particularly in the industrial field (hygiene, medical, cleaning clothes, filtration, etc.), nonwoven fabrics, which have a wide usage area and whose usage increases every passing day, are obtained by means of binding of cheesecloth, formed by staple fibers or filament fibers, by means of various binding technologies (chemical, thermal or mechanical). The nonwoven fabric formation methods have been classified according to usage of staple fibers or filament fibers and according to the binding methods. Cheeseclothes, which are made of filament fibers, are separated into two types, namely dry laying and aqueous laying. Dry laying methods are also separated into three as mechanical laying, airlaid and mechanical airlaying. The methods of formation of cheesecloth from staple fibers are separated into four as infinite fiber laying, spraying from the melt, electrostatic laying and instantaneous laying. Binding methods used in obtaining nonwoven fabric from formed cheesecloth are separated into three as mechanical, chemical and thermal binding methods. The mechanical binding methods are classified as binding by means of needle, water-jet binding (spunlace) and vertical binding. Chemical binding methods are classified as impregnation, spraying, powdering, transferring the chemical by means of pattern and transferring by means of foam. The thermal binding methods are classified as binding by means of hot cylinders, gapped cylinders, sound waves, hot air and radiation.

Nonwoven fabrics have various usage areas as single layer. Besides, in order to provide utilization of nonwoven cheesecloth or fabrics, having different properties, within the same structure, nonwoven fabric composites are used. Nonwoven fabrics with composite structure are formed by joining layers of nonwoven cheesecloth or fabrics, obtained by using different technologies, by using different joining methods. Today, nonwoven fabrics formed by staple fibers are brought together by means of separate lamination and adhesion processes, and can be used in obtaining nonwoven fabric composites.

For instance, nonwoven fabrics, which are obtained by using airlaid technology and latex or by thermally joining, provide low extending and breaking values although sufficient liquid absorption and retention properties can be provided. In another application, in nonwoven fabrics produced by means of water-jet technology, while high resistance values can be obtained, said nonwoven fabrics have a limited liquid absorption and limited liquid retention property. Moreover, back-wetting values of nonwoven fabrics obtained by means of water-jet are weaker when compared with the nonwoven fabrics formed by means of airlaid method. Thus, in various fields like sanitary napkin, adult patient diaper and industrial cleaning cloth where high absorption and sufficient resistance and extension values are desired, nonwoven fabric composites may be used which are obtained by bringing together these nonwoven fabrics with different characteristics. However, obtaining these nonwoven fabric composites necessitates the usage of pluralities of technologies together. This leads to increase of investment costs and production costs.

An application related to nonwoven fabric composites is seen in document US20020168910 A1. In said application, a complex (having multiple-components) nonwoven fabric is described. The filaments obtained by means of drawing method from the melt form the first cheesecloth layer of the composite structure and the second cheesecloth layer is obtained by means of laying the short fibers by means of airlaid technology. The third cheesecloth layer has been obtained by means of drawing from the melt again. These three layers are connected to each other by using water-jet for forming nonwoven fabric composite. Obtaining of said nonwoven fabric composite structure necessitates an integrated line where airlaid and water-jet binding machines exist. Thus, investment and production costs of nonwoven fabric composites obtained through integrated systems in this manner and in a similar manner are substantially high.

As a result, because of all of the abovementioned problems, an improvement is required in the related technical field.

BRIEF DESCRIPTION OF THE INVENTION

The present invention relates to a nonwoven fabric composite production method and a nonwoven fabric composite produced from nonwoven fabric obtained by means of water-jet binding by using airlaid technology, for eliminating the above mentioned disadvantages and for bringing new advantages to the related technical field.

The main object of the present invention is to provide a production method which minimizes high investment and production costs which occur in production of nonwoven fabric composites.

Another object of the present invention is to provide a nonwoven fabric composite with high added value.

Another object of the present invention is to provide a nonwoven fabric composite and the related production method with high dry-wet resistance and with improved softness and with increased liquid absorption speed.

Another object of the present invention is to provide a nonwoven fabric composite and the related production method with lower fiber pilling.

Another object of the present invention is to provide a nonwoven fabric composite and the related production method with increased abrasion resistance.

In order to realize the abovementioned object and the objects which are to be deducted from the detailed description below, the present invention is a nonwoven fabric composite production method where the nonwoven fabric layer, obtained by means of water-jet binding process from a primary fiber group, is included. Accordingly, said production method is characterized by comprising the steps of:

a) Feeding said nonwoven fabric layer into an airlaid machine,

b) Joining a secondary fiber group and a nonwoven fabric layer in airlaid machine, c) Binding the nonwoven fabric layer and the secondary fiber group by means of a chemical and/or thermal binding process.

In a preferred embodiment of the present invention, in the chemical binding process in said step (c), preferably a latex binder is used.

In another preferred embodiment of the present invention, in the thermal binding process in said step (c), a bi-component (Polyethylene/Polypropylene - PE/PP, Polyethylene/Polyester - PE/PET, Polyethylene/Polyamide - PE/PA, etc.) fiber is used as binder. In another preferred embodiment of the present invention, said primary fiber is preferably formed by 0%-100% natural and/or by 0%-100% artificial fibers.

The present invention is moreover a nonwoven fabric composite comprising a nonwoven fabric layer obtained by means of water-jet binding process from a primary fiber group. Accordingly, said nonwoven fabric composite is characterized by comprising a secondary fiber group provided on said nonwoven fabric layer by means of an airlaid laying machine, and at least one binding component for binding said secondary fiber group and said nonwoven fabric layer to each other by means of chemical and/or thermal methods.

BRIEF DESCRIPTION OF THE FIGURES

Figure 1 is a schematic flow diagram related to the production method of the nonwoven fabric composite.

DETAILED DESCRIPTION OF THE INVENTION

In this detailed description, the subject matter nonwoven fabric composite and production method are explained with references to examples without forming any restrictive effect only in order to make the subject more understandable.

With reference to Figure 1 , the flow schema, related to production of nonwoven fabric composite, is used in obtaining a nonwoven fabric composite from two different fiber groups. In this direction, a primary fiber group is turned into a nonwoven fabric layer in the water-jet binding machine. Said nonwoven fabric layer is preferably obtained in a gapped surface structure for providing air permeation. A secondary fiber group is also fed to an airlaid machine. Besides the secondary fiber group, the nonwoven fabric layer obtained from the primary fiber group as a result of water-jet binding process is fed to the airlaid machine. Thus, the airlaid process provides laying of the second fiber group onto the nonwoven fabric layer which has a gapped surface; and the composite structure is obtained. Said composite structure is also binded by means of a latex binder and/or by means of thermal process. This binding process provides binding of nonwoven fabric layer, obtained from the primary fiber group, and the secondary fiber group to each other. At the end of the binding process, the nonwoven fabric composite is obtained.

When examined basically, the water-jet binding technology provides the fibers to engage to each other by using high-pressure water. By means of the water-jet binding technology, products with low unit weight can be obtained with high production speeds and with low costs. In addition to these, the important characteristic of this method is that the binding process does not comprise any chemical. Thus, in the subject matter production method, the nonwoven fabric layer, obtained from the primary fiber group by means of water-jet binding, is produced by means of the abovementioned advantages. The airlaying process is a process where the fibers are brought into cheesecloth form by using air and where the fibers are binded to each other by realizing thermal binding in thermoplastic polymers or by realizing chemical binding by means of a binder like latex, etc. In airlaying, short fibers are used preferably in the range of 2-6 mm. The used fiber type is delimited and the high energy consumption has disadvantages like limited opening in fiber bundles.

By means of the subject matter production method, water-jet bidning technology and airlaid process are applied together, and the disadvantageous characteristics of these used technologies are eliminated and both technologies support each other and provide advantages. Thus, in the airlaid technology, the nonwoven fabric composite obtained in single-step will be a structure which collects the advantageous characteristics of both of the methods. Since the fibers, added to the nonwoven fabric layer formed by means of water-jet binding technology, are much longer than the fibers used in air-laying technology, increase can be provided in the dry-wet resistance of the nonwoven fabric composite. Increase will also be provided in the abrasion resistance. Thanks to the airlaid process, liquid absorption and retention will be improved. Moreover, low fiber hairiness will be provided and softness will be improved.

In a preferred embodiment of the present invention, in order to form the nonwoven fabric layer, the primary fiber group fed to the water-jet binding process comprises preferably 0%- 100% natural and/or 0%-100% artificial fibers. Since these fiber varieties are plenty, the fiber variety which is limited in airlaid process has been increased in the obtained nonwoven surface composite.

In a preferred embodiment of the present invention, the obtained nonwoven fabric composite can be used in various technical textile fields like sanitary napkins, baby diapers, adult patient diapers, industrial cleaning clothes, filter materials, surgery clothes and patient wound pad. In sanitary napkins, the liquid acqusition distribution layers and absorbant (core) layers produced by using airlaid technology can be produced as nonwoven fabric composite in a single structure by means of the subject matter production method. Thus, products with performance which is closer to finished product performance can be obtained. In case nonwoven fabric composite is used in industrial cleaning clothes, the dusting values will be eliminated by providing contact of the long fibers to the surface, which is to be cleaned, besides the high absorption characteristic and liquid retention effect.

In a preferred embodiment of the present invention, in the binding process applied following the airlaid process, in applications where latex is insufficient, preferably bicomponent fibers (PE/PP, PE/PET, PE/PA, etc.) are used as alternative to latex. While the thermoplastic polymer component (for instance, PE), which can melt at low temperatures and provided in the bicomponent fiber, shows binding characteristic, the other component (for instance PP, PET, PA, etc.), which needs higher temperature for melting, preserves its form without melting at process temperature and preserves its reinforcing effect, and increase can be obtained in the resistance of the obtained structure thanks to the effect of thermal binding and thanks to the contribution of the reinforcing component. Moreover, the nonwoven fabric layer obtained by means of the primary fiber group and the layer formed by the secondary fiber group in the airlaid process have different extension values along the transverse cross sections which are independent from each other. For this reason, when a force is exerted in the direction of the transverse cross-section, breaking occurs between the layers at different times. In order to prevent this, preferably bicomponent fibers are added to the nonwoven fabric layer, and the binding between the layers is reinforced, and the structure shows reaction against the load as a whole instead of showing reaction in an independent manner from each other.

The protection scope of the present invention is set forth in the annexed claims and cannot be restricted to the illustrative disclosures given above, under the detailed description. It is because a person skilled in the relevant art can obviously produce similar embodiments under the light of the foregoing disclosures, without departing from the main principles of the present invention.