DE19961240B4 - Process for the preparation of a thermally bonded nonwoven fabric - Google Patents

Abstract

method for producing a thermally bonded nonwoven fabric with in cross-section arranged fibrous binding elements in that the fiber layer to be supplied to a pile or web-forming agent (2) a binding surface (3) is applied, which consists of a splittable film, a slotted Foil or an adhesive fleece made of fibers or filaments and those used in the mechanical pile or pneumatic web formation Dissolving elements (8, 9, 18) into individual fibrous Binding elements (13) divided and with the fibers (12) of the fiber layer (2) mixed evenly and form the batt (10) and the random web (23).

Description

The The invention relates to a method for producing a thermal solidified nonwoven fabric, in particular a thermobond, Needle, stitchbonded or Wirbelvliesstoffes, with for a thermal bonding contained binder fiber elements, preferably to be used in technical applications.

It is already known, nonwovens with a mass-based share from 5 to 50% of so-called binder fibers. These binding fibers exist Completely or partially from a low melting polymer and yield with appropriate heat in the pile, fleece or nonwoven fabric the points of contact solid adhesive or connection points with each other or with the other fibers. The binder fibers are used in nonwoven production in the field the fiber resolution and fiber blend mixed with the other fibers. About the work steps pile formation, nonwoven laying and / or mechanical consolidation by needles, stitching or Verwirbeln with air or water jets causes the binder fiber use with subsequent thermal treatment, an additional solidification or the pile or fleece is directly subjected to a thermal treatment supplied in the form of the so-called thermobonding and thus the nonwoven fabric solidified.

The DE 88 07 017.4 U1 describes a cushion part for seating, reclining furniture or the like., In which the padding filling consists of a bulky nonwoven fabric containing thermofusible, selectively interconnected binder fibers. When heat is applied, the binder fiber nonwoven fabric is press-formed to form a cushion molding, wherein the binder fibers deformed in the interior of the nonwoven fabric form thermofused connection points with one another and permanently fix the cushion molding. According to the features of claim 3, this nonwoven fabric consists of a homogeneous mixture of binder fibers and normal fibers, which are thermofusion-connected with each other.

disadvantaged are the material and time required in this binder fiber use for the Preparation of the binding fibers themselves and for the additional mixing passages. Furthermore lets this classic Binder blending no functional arrangement of binder fibers in one or more layers of the nonwoven cross section.

Known are also thermoplastic adhesive surfaces in the form of films or Fleece, which is flat Bonding of z. B. nonwovens are used with each other. Thus, for example, in the utility model 29 701 077 a stitchbonded nonwoven fabric with superficial Adhesive fleece incorporated by sewing threads for the Connection with leather for Decorative parts in the car interior equipment described. However, they are herewith no hardening effects within the nonwoven cross section reachable.

In the patent DD 128 958 the production of a textile composite of fissile film and a nonwoven fabric is described, wherein both components are connected by needling. In this case, due to the sandwich-like arrangement of the splittfähigen film despite the needle composite no binding fiber effect can be achieved. The same applies to the in DD 128 958 described composite

In the DE 198 59 782 A1 a strip-shaped planar binding element is placed on the batt. As a result of the transverse wainscoting of the fibrous web to the non-woven fabric, a nonwoven cross-section is formed by a two-dimensional bonding layer, from which fibrous binding elements in the nonwoven cross section are mechanically arranged during the subsequent solidification of the nonwoven fabric to the nonwoven fabric, for example by needling or jetting. However, in the transverse paneling of the fibrous web to the nonwoven at the reversal points of the Florlegewalzen small Florverdoppelungen, which also apply to the analogous laying of Bindeelementstreifens to the planar bonding layer and cause undesirable stronger bonding especially in a few pile layers in the web. In addition, this effective introduction of fibrous binding elements usually requires a mechanical nonwoven, which is not in any case a uniform distribution of the fibrous binding elements over the entire nonwoven fabric cross-section achievable in many piles in fleece and consequently high nonwoven weight.

According to the invention the object of the invention therein, while eliminating the aforementioned disadvantages a thermally consolidated nonwoven fabric in the binder fiber-like Elements for the thermal solidification are introduced and distributed to simple To make a cost-saving way. The solution of the task requires According to the invention a special binding surface and the suitable delivery point for the binding surface in the field of mechanical fiber pile or pneumatic web formation.

Is solved the object by the features described in Anpruch 1 inventive features. Advantageous developments are described in the subclaims.

The main advantage of the invention is the fact that the steps for the manufacturer tion of binder fibers and their mixture with conventional fibers omitted. Also achieved is a good distribution into fibrous binding elements and their uniform arrangement in the entire fiber web surface and thus also in the entire nonwoven fabric cross-section.

In addition, the Invention, the binding elements targeted, based on the amount and spatial Arrangement to arrange in the fiber web cross-section. This can be done thermally bonded nonwovens with different cross-sectional areas in terms of strength and structure, which are the most diverse technical applications is important.

embodiments

in the The following is the invention with reference to embodiments in connection described with the drawings. Show it:

1 the schematic representation of the pile formation with supplied binding surface on a card,

2 the schematic representation of the pneumatic web formation with supplied binding surface on a random web formers,

3 the cross section of a fibrous web with distributed throughout the cross section fibrous binding elements,

4 the cross section of a nonwoven fabric with two differently distributed in the nonwoven cross section zones with predominantly fibrous binding elements.

Example 1:

1 shows the formation of a non-woven fabric, which is produced by means of a web-forming and cross-lapper web forming apparatus. On top of the feed sheet 1 located fiber layer 2 becomes the binding surface 3 hung up. The feeding of the fiber layer 2 and the binding surface 3 to the carding takes place via the feed rollers 4 , When passing the drums 5 . 6 and 7 becomes the binding surface 3 through the dissolving systems of the work rolls 8th and the turning rolls 9 , which consist of different rollers with different fittings, in fibrous binding elements 13 divided up. At the same time, the uniform distribution of these fibrous binding elements takes place 13 with the fibers 12 the fiber layer 2 and the formation of both components to the batt 10 ( 3 ), via the feed belt 11 fed to a Quertäfler and laid there to fleece. The binding surface 3 will be in the same width as the fiber layer 2 fed.

The binding surface 3 According to the invention, it consists entirely or partially of thermoplastic polymers with a low melting point and is structurally a splittable film, a slotted film or an adhesive fleece of fibers or filaments. The weight of the binding surface 3 is chosen so that a fleece to laying fiber pile 10 with a weight of 5 to 40 g / m ² with a mass fraction of fibrous binding elements 13 from 5 to 50% is achievable.

According to a development of the invention, when using a splittfähigen binder film and a prefibrillation in coherent fibrous binding elements 13 in a separate fibrillator before laying on the fiber layers 2 respectively.

It is also possible to achieve a special solidification effect in one or more zones of the nonwoven cross section in the nonwoven fabric, the binding surface 3 as strips in any width ranges of the fiber layer 2 supply. The individual strip-shaped binding surfaces 3 can be used the same or different widths and of the same or different types of material, such as adhesive film or adhesive fleece, of the same or different polymers in the same or different thickness. This allows the arrangement of different areas with predominantly fibrous binding elements A, B ( 4 ) in different proportions in the nonwoven cross section, so that in the subsequent thermal consolidation different cross-sectional profiles, surface structures and strengths in the nonwoven fabric are achieved, which are for special applications, for example in the processing of moldings, of importance. Thus, for example, the average nonwoven cross section can be strengthened more strongly than the outer layers or vice versa, ie, at the edges become fibrous binding elements 13 on the fiber layer 2 hung up while in the middle of the fiber layer 2 no binding elements 13 available.

Example 2:

Another embodiment shows the 2 for a pneumatic web formation. In the illustrated pneumatic web forming device, the pre-dissolved fiber material becomes a box feeder 14 in one through the treadmill 15 and the baffle 16 transported limited bay. From there it is about a pair of rollers 17 guided and from the beater 18 detached, so that small fiber flakes arise. From the beater 18 become the detached fibers 12 by means of suction to the metering rollers 19 forwarded the fibers 12 to to unite a fleece. At the same time, immediately before the impact roller 18 the binding surface 3 from a roll 22 supplied and from the working organs of the impact roller 18 in fibrous binding elements 13 divided up. The width of the binding surface corresponds 3 the width of the random fleece to be formed 23 , The roller 20 is designed as a sieve drum, so that with the help of a suitable suction from the impact roller 18 discharged fibers 12 and those from the binding area 3 obtained fibrous binding elements 13 sucked together and a random fleece 23 is formed. The random fleece 23 is pulled off continuously and over the conveyor belt 21 fed to further processing.

As a binding surface 3 For example, as in Example 1, a splittable or slit film or an adhesive web of fibers or filaments may be supplied, which consist wholly or partly of thermoplastic polymers with a low melting point. The weight of the binding surface 3 should be chosen here so that a mass-related proportion of fibrous binding elements 13 from 5 to 50% in the fabric to be produced is achievable.

1

Zuführlattentuch

2

fiber layer

3

binding surface

4

feed roll

5, 6, 7

drum

8th

Stripper

9

turn roller

10

batt

11

infeed

12

fiber

13

fibrous binding element

14

hopper feeder

15

According band

16

baffle

17

roller pair

18

beater roll

19

metering

20

screen drum

21

conveyor belt

22

role

23

random web

A, B

zones predominantly fibrous binding elements

Claims (3)

Method for producing a thermally bonded nonwoven fabric having fibrous binding elements arranged in cross section, characterized in that the fibrous layer to be supplied to a pile or nonwoven former ( 2 ) a binding surface ( 3 ) is applied, which consists of a splittfähigen sheet, a slotted film or an adhesive fleece made of fibers or filaments and the release members used in the mechanical pile or pneumatic web formation ( 8th . 9 . 18 ) into individual fibrous binding elements ( 13 ) and with the fibers ( 12 ) of the fiber layer ( 2 ) are uniformly mixed and the batt ( 10 ) or the random web ( 23 ) form. A method according to claim 1, characterized in that the on the fiber layer ( 2 ) applied binding surface ( 3 ) is prefibrillated. Method according to claims 1 and 2, characterized in that the fibers ( 2 ) applied binding surface ( 3 ) as a broad strip on any width ranges of the fiber layer ( 2 ) is applied.