DE2036879C3 - Mixed fiber fleeces, in particular for diaper covers and other hygienic purposes - Google Patents

Description

3 4

• A beneficial use has been found on the part by weight

Sn? ί ^Γ w ^ f ^^^ i? ' 5 ^ice P ^iel f: f "f viscose rayon staple fiber, 1.5 denier / 10 mm 25

Sleeves for diapers or sanitary napkins and similar viscose rayon 3 denier / 10 mm 25

Article: The new nylon fibers made by the wet process, 6 denier / 32 mm W

Mixed fiber fabrics meet all requirements 5 _bleached ; _not ground softwood

to such education: they feel soft, they are pulp 15

pleasant to look at have improved mecha- PolynosischV Vis'kose-ZeÜwoiie TYPEBX

Niche dry and wet strength, tensile strength grinding degree 83 ° Schopper 5

and burst resistance and are also cheap. Polyacrylics (binding agent) 20

The production of the new mixed fiber fabric takes place in io ' ^J

according to the general procedure used in papermaking

nen way of working. The French patent 1516 178 on the Fourdrinier is made from a latex

a paper machine accumulated pulp has been obtained dewatered, which is obtained from a mixture of methyl

sert, dried at temperatures of about 130 ° C acrylate, ethyl acrylate and acrylic acid homopoly-

and optionally a further heat treatment 15 mers and a terpolymer made of butyl maleate,

subjected at 130 to 180 ° C, which consisted, for example, of vinyl acetate and butyl acrylate,

a hot air oven, on new accordingly. The fiber dispersion was additionally with 0.6%

heated drums or between calender rolls in front of an aqueous solution of a cationic polyamide

is taken. The nonwovens can be added according to the usual epichlorohydrin resin, based on the

Process in various ways with heat with fiber mass.

for example, shrunk and / or mechanically treated. The fiber suspension is then placed on the long delt will. It has been shown that if you run the screen rather paper machine; the pulp usually used for impregnating fleece was dewatered, dried at about 130 ° C and The latex binder is replaced by polyacrylic fibrils undergoing a further heat treatment at 150 ° C and threw synthetic fibers into the fiber wet with 25.

high shrinkability such as polyamide fibers. The obtained mixed fiber nonwoven fabric had the following

Acrylic fiber absorbs the usual operations Properties:

the impregnation and subsequent drying, weight per unit area 20 g / m ²

skipped and if necessary dry immediately through the tear length 1800 m

a heat treatment with steam the textile intrinsic tearing length 'wet '. '.'. ". '.'. 700 m

Shafts of the mixed fiber nonwovens are formed Tear number Ό / G ........ IO

very flexible and soft crepe-like products that do not look rough feel. Running direction and in the transverse direction of the sheet

The following example is intended to elucidate the invention in more detail.

purify. The following were determined and measured: For comparison, a mixed fiber fleece was the same

length dry and wet according to the French norm of weight per unit area (20 g / m ² ) from the same fiber suspension

AFNOR NF Q 03 004 and the tensile strength according to sion but without the addition of polyacrylic fibrils and

ASTM D 2 261-64 T. cationic polyamide-epichlorohydrin resin

40 places. Those determined under the same conditions

Example properties of this fleece were as follows:

It was a mixed fiber fleece for bandages or

Diaper covers manufactured; the headbox of a Pa tear length, dry 800 to 1000 mm

The piercing machine contained a dispersion with 10 g / l of the breaking length, not measurable when wet

following mixture: 45 tensile strength not measurable

Claims (1)

Claim: Mixed fiber nonwovens, especially for diaper covers and other hygienic purposes, with high Dry and wet strength and improved tear strength, containing 15 to 25% thermoplastic Binder fibers, characterized in that they a) at least 45 Vo Viscose rayon, 15 to 20% bleached unground Softwood cellulose, 1 to 10% ground polynesian fibers and 5 to 15% polyamide fibers and b) contain the binder in the form of Fibr'.llen from an acrylic polymer. The invention relates to mixed fiber nonwovens produced by the wet route and staple fibers as well as a binding agent that binds the fibers together to form a coherent mass. Mixed fiber nonwovens are used below to refer to both individual nonwovens of any cut as well as continuous non-woven fabric of constant width, which can be wound on spools, understood. It has long been known to use different fiber materials, for example cellulose fibers, synthetic fibers and / or synthetic fibers, individually or in combination with one another for the production of nonwovens, and to connect them to one another with the aid of various processes. Usually, the nonwovens are produced either on textile machines dry using aerodynamic methods or by carding or on paper machines, in that the fibers are slurried in water and the slurry is applied to the fourdrinier wire of the paper machine. Regardless of the respective manufacturing process, the fibers must be connected to one another and to one another in order to ensure the necessary cohesion and to give the nonwovens the mechanical properties required for the intended use. Needling, a mechanical process in which the fibers are felted perpendicular to the direction of the web, as well as the connection of the fibers by impregnation with a suitably selected resin, was described in great detail for the dry process. In the wet process, it has already been recommended to add a binder, for example a latex, to the aqueous fiber dispersion or to impregnate the dewatered and dried nonwoven mass. Papers with improved wet strength, for example, be obtained by addition of about 20 ⁰ Zo polyacrylonitrile-fine fibers. In other binding processes, low-melting thermoplastic fibrils or fibers are introduced into the nonwoven mass, which melt with appropriate heat treatment and weld the fibers together; their share is at least 5%. However, all these binding processes lead to nonwovens, the properties of which are not always fully adapted to the intended uses, especially when high mechanical strength in dry or humid environments, better tensile strength, better burst strength, greater softness or flexibility, etc. are desired will. It has now been shown that mixed fiber nonwovens, which have a certain careful combination of synthetic fibers, Natural fibers and synthetic fibers contain and in which the fibers are made with polyacrylic fibrils bound, characterized by high wet and dry strength, improved tensile strength as well as flexibility, soft grip and high absorbency distinguish and therefore especially for diaper covers and other hygienic and medical Purposes are suitable. The mixed fiber nonwovens according to the invention for diaper and sanitary napkin covers and similar sanitary articles contain at least 45 parts by weight, preferably 50 to 55 parts by weight viscose rayon; 15 to 20 parts by weight bleached not ground Softwood pulp; 1 to 10 parts by weight milled polynosic fibers; 5 to 15 parts by weight of polyamide fibers and 15 to 25 parts by weight of polyacrylonitrile fibrils. The binder fibrils are made by precipitating a polyacrylic latex in a coagulating liquid in a manner known per se, for example as described in French patent specification 1516 178, obtain. The latex can be a latex made from homopolymers of acrylic acid, acrylic acid esters such as methyl acrylate, Ethyl acrylate, butyl acrylate or copolymers of the various acrylic compounds with one another and optionally with other ethylenic monomers such as vinyl acetate, butyl maleate etc. be. Mixtures of these polymers and / or copolymers are advantageously used. The use of fibrils made from an acrylic polymer as a binder in the manufacture of Nonwovens on the wet route offer special advantages: The added polyacrylic fibrils encase the nonwoven fibers not, as is the case with impregnation with a liquid binder, but they set preferably at the points of intersection of the fibers and stick them only here at one subsequent heat treatment. The fibrils do not disappear or run, but rather remain their structure of small particles. The disadvantages of the impregnation process, with the fibers completely Glue together and the gaps are blocked, so that the fleeces become rough feel, are not flexible enough and therefore often require mechanical post-treatment such as Creping must be subjected, sometimes reducing the mechanical properties of the Nonwovens are severely impaired, do not occur. The mixed fiber webs according to the invention have the textile properties of the fibers themselves of which they are composed, d. H. so grip, appearance, Flexibility or softness, high absorbency for liquids, all essential properties, which are aimed at with the nonwovens. In addition, the mechanical properties noticeably improved, especially when the nonwovens are used in a damp environment. In the end the fleeces are characterized by great flexibility and based on the homogeneous distribution of the fibers a good view from the fact that they are wholly or partially colored at will Motifs can be printed, creating the pleasing appearance and also the mechanical properties be improved.