WO1982004456A1

WO1982004456A1 - Grid-shaped armature coated with thermoplastic material and device for the manufacturing thereof

Info

Publication number: WO1982004456A1
Application number: PCT/AT1981/000014
Authority: WO
Inventors: Werner Vogel
Original assignee: Werner Vogel
Priority date: 1981-06-12
Filing date: 1981-06-12
Publication date: 1982-12-23

Abstract

The grid-shaped armature is obtained from wires of which the strands (2) are coated with one or two layer(s) of plastic material (3', 3''). At the crossing points, the wires of the grid are welded to each other by thermowelding at least their outer coating (3'').

Description

Reinforcement in the form ^'of a plastic coated thread lattice and apparatus for producing

The invention relates to a reinforcement in the form of a plastic-coated thread grid.

Characteristic of the known prior art.

It is known for aring purposes, e.g. for wall plaster, lattice-shaped fabrics or scrims, the threads of which are made of glass fibers. These lattice-like fabrics or scrims are either dipped or with the help of a sponge roller with plastic or

Impregnation coating coated, to which alkali-repellent additives are added, and then dried. These measures attempt to make the individual threads resistant to sliding against one another and to protect the glass fibers against attack by alkaline substances. Reinforcements of this type have the disadvantage, however, that the protective layer on the glass fibers can be easily damaged by mechanical stress, or that due to their subsequent application they often have flaws at which the

O PI Glass fibers are exposed and are therefore exposed to the attack of alkaline substances. In addition, the impregnation size or the plastic coating is not always sufficient to avoid thread displacements under mechanical influences. Such thread displacements could, for example, impair the uniform penetration of the reinforcement mesh with the plastering mortar when applying the plastering mortar, which can result in the formation of cracks in the plastering of the wall. Thread shifts can be made in the known lattice-shaped

Reinforcement fabrics or layers also occur when tension occurs in the wall plaster, which in turn can lead to the formation of cracks. Thread shifts can also destroy the protective layer against the attack of alkalis, which further destruction (the

Reinforcement and finally the wall plaster).

Object of the invention

In other cases of reinforcement, it is important that the reinforcing lattice threads are protected against chemical attacks and mechanical stresses, in particular against displacement of the lattice threads.

Explanation of the nature of the invention

This is achieved according to the invention in that the threads of the reinforcing mesh are individually sheathed with thermoplastic material and are thermally welded over the sheath at least at the crossing points.

The coating of the lattice threads with thermoplastic plastic offers optimal protection against attacks by chemical substances, while the thermal welding of the individual threads at their crossings score, which is carried out by heating the grid above the melting point of the thermoplastic material, greatly improves the mechanical strength of the grid and, in particular, practically excludes thread shifts.

While at least two different types of thread had to be used in the previously known lattice-shaped fabrics or fabrics (e.g. leno weave), in particular to limit the extent of the thread displacements, which can never be completely avoided, the sheathing of the individual threads is not only thanks to the inventive welding a thread displacement is reliably avoided, but also enables the use of only one type of thread or thread thickness for the longitudinal threads and transverse threads. As a result, the reinforcement grid according to the invention — in the case of a square mesh field — has the same strength in the longitudinal and transverse directions.

The reinforcing mesh according to the invention can be loaded up to breaking strength without thread displacements, i.e. very high tensile loads can occur in the reinforcement grid, which - because there are no thread displacements associated with them - do not lead to crack formation in the reinforced material. On the other hand, in the conventional reinforcement fabrics or layers, thread displacements already occur at a third of the breaking strength, which result in crack formation in the reinforced material. In particular, this affects the fabric edges.

Depending on the application of the reinforcing mesh according to the invention, the core material of the threads can be made of glass fibers, metal, polyester fibers and the like. exist, the Kern¬ material essentially the strength, extensibility and - 4 -

and elasticity of the reinforcement.

The choice of the thermoplastic material for the sheathing primarily depends on the necessary chemical resistance. So e.g. Reinforcements for most building materials (plaster mortar, concrete) must be alkali-resistant. Glass fibers are not alkali-resistant, which is why a reinforcing mesh with glass threads must be coated with an alkali-resistant thermoplastic. PVC (polyvinyl chloride) is particularly suitable for this. PVC is also suitable in other cases as a material for sheathing the lattice threads, e.g. for covering polyester threads of a reinforcement grid for asphalt.

The sheathing according to the invention of the individual threads of the reinforcing mesh is also advantageous for the adhesion between the reinforcing mesh and the material to be reinforced, namely when the nozzle with which the sheathing is carried out has a cross section which causes small grooves in the surface of the sheathing .

In order to achieve a complete covering of the lattice threads, it is expedient if the single thread has a multiple, preferably double covering made of thermoplastic material. It is expedient if essentially only the outer sheaths of the crossing threads are thermally welded at the crossing points.

The reinforcement grid can preferably be produced as a fabric, in particular in plain weave. The weaving and the thread twists that usually occur in the process also have a favorable influence on the adhesion between the reinforcing mesh and the material to be reinforced. The size of the mesh openings or mesh size of the mesh depends on the application. An ar izing grid for fine plaster can, for example, have grid openings of 0.4 to 0.5 cm. For coarse plaster, a reinforcing mesh with mesh openings of, for example, 0.7 to 1.0 cm is more suitable. With an asphalt reinforcement grid, you can use grid openings of 1.5 cm, for example. Reinforcements for foams are usually equipped with smaller grid openings, for example 0.4 to 0.5 cm. In any case, however, it is the invention

Reinforcement mesh is not a fine-mesh mesh, as is the case with a fly screen, but a mesh or mesh fabric with mesh openings of at least a few millimeters up to several centimeters.

Further details of the invention are explained below with reference to the drawing figures.

Description of the drawing figures

1 shows a top view of a reinforcement grid according to the invention,

Fig. 2 is a cross section and

Fig. 3 is an enlarged detail of section A of Fig. 1;

Fig. 4 shows a cross section of a single thread and

Fig. 5 is an enlargement of section B of Fig. 4;

6 shows the cross section of a single thread with double sheathing,

Fig. 7 also shows the cross section of a single thread

OMPI with double sheathing,

Fig. 8 shows in section two crossing points of single threads with double sheathing;

9 shows the diagram of a device for producing a reinforcing mesh according to the invention.

Description of preferred embodiments

The lattice-like canvas-binding fabric shown in FIGS. 1 to 3 has warp threads 1 ^* and weft threads 1 ", which consist of a core 2 made of glass fibers and a sheathing 3 made of thermoplastic material. This fabric is caused by brief heating in the crossing points 4 the threads 1 ', 1 "welded. The casing is made of PVC, for example. Such a fabric is resistant to alkalis and is therefore particularly suitable for reinforcing external and internal plaster.

1 and 2 a lattice weave is shown in plain weave. The reinforcing mesh according to the invention can, however, also be produced in various other types of binding. The warp or the weft can also consist of a bundle of threads each consisting of two or more individual threads that are directly adjacent to one another and covered with thermoplastic plastic. The lattice openings «. in this case not limited by single threads but by bundles of threads. When thermally welding the individual f - provided per se according to the invention for the crossing point - if the warp or weft thread is the best from a thread bundle, the individual threads of the thread bundle can also be welded between the crossing point.

As can be seen from FIG. 4 and in particular from FIG. 5, - 7 -

envelops the sheathing 3 of a thread not only the core 2 in its entirety, but rather penetrates the plastic material. Sheathing 3 also between the single fibers 2 'of the core 2. This results in a particularly intimate connection between the core 2 and the sheathing 3, thus protecting the individual fibers 2 *, which the plastic material of the sheathing will also give good hold . This is a result of the application of the immersion process for applying the casing 3 to the ke

It is advantageous if, instead of threads with an e-fold sheath 3, those with a double sheath 3 " ^* and 3" made of thermoplastic material are used (FIG. 6.7). In a first step, the core 2 is provided with the inner jacket 3 'and in a second step, the outer jacket 3 "is applied to the inner jacket 3'. The outer jacket 3" represents a complete jacket of the single thread the double sheathing is equally valid if the core 2 is not exactly centered in the inner sheathing 3 'or is even partially exposed on the surface of the inner sheathing 3' because this defect is eliminated by the outer sheathing 3 " Sheathing 3 "also covers any fibers protruding from the core 2 or through air pockets in the manufacture of the inner sheathing in 'holes formed up to the core 2. The outer casing 3 "expediently has a lower thickness (layer thickness) than the inner casing 3 *.

6, the outer casing has a smooth surface. A particularly good adhesion between the threads of the reinforcing mesh and the material to be reinforced, for example plastering mortar, is achieved if - as can be seen in FIG. 7 - the surface of the outer casing 3 "has a roughening, for example in the form of a corrugation - δ -

points, which can be achieved, for example, by appropriate design of the nozzle with the aid of which the sheathing takes place.

FIG. 8 illustrates the effect of the double sheathing at the crossing points of the threads. Accordingly, the outer sheathing 3 "is thermally welded at the crossing points, as a result of which the outer sheaths 3" of the crossing threads become homo ¬ merge a uniform layer. Preferably, the inner sheaths 3 'of the thread cores 2 are retained, i.e. there is expediently no (complete) welding of the inner sheaths 3 'to the outer sheaths 3 ", so that between the core and the core of two crossing threads there are three layers of thermoplastic synthetic material which completely surround the core 2.

The production of the reinforcing mesh according to the invention can advantageously e.g. in the following way or with the help of the facilities described below.

A system comprising the following functional parts can be used to sheath the individual threads:

- a creel for the withdrawal of the thread cores;

- a first diving device for diving and sheathing? the thread cores with thermoplastic (inner sheath);

a first gelling device for pre-drying the inner casing;

a second dipping device for dipping and sheathing the threads already provided with the inner sheathing with thermoplastic material (outer sheathing);

- a second gelling device for gelling (drying) the outer casing; - A winding system for winding the finished double-sheathed individual threads.

When the inner casing is predried, shrinking can result in an inaccurately smooth surface of the inner casing, which can be an advantage for the adhesion of the outer casing to the inner one.

The second immersion device and the second gelling device are dispensed with if the thread cores are only coated.

A third dipping and gelling device would be required for triple sheathing of the thread cores, but in general a single or double sheathing is sufficient.

FIG. 9 shows a weaving machine for producing the lattice fabric according to FIGS. 1 to 3. The weaving machine consists in a known manner of a warp beam 5, creel or the like, which contains the PVC-coated glass fibers, an oiling roller 6 , the shed 7, the drawer 8 and the breast tree 14. The finished fabric is then wound up on the take-off roller 15 onto a fabric tree 16 or otherwise processed. A heating device 10 is arranged between the spreader 9 arranged after the drawer 8 and the breast tree 14. This heating device consists of a heat radiator 11 and a reflector 12 arranged on the opposite side of the fabric 20. The heat radiator 11 is covered by an extraction trough 17, which ensures the removal of toxic vapors produced during welding. A protective shield 13 can be inserted between the heat radiator 11 and the fabric 20 and prevents damage to the fabric when the machine is at a standstill or when starting up. Instead of pushing in the protective shield 13, the heating device can 10 be designed to pivot away from the fabric 20. The lattice fabric according to the invention can be produced with this loom without any time delay. As it passes through the heating device 10, the fabric 20 is heated to a temperature above the melting point of the thermoplastic material for about 5 to 20 seconds, as a result of which the sheathing 3 of the warp and weft threads 1 ^* and 1 "in the crossing points 4 weld to one another.

OM

Claims

- 1 1 -

P a t e n t a n s r u c h e:

1. Reinforcement in the form of a plastic-coated thread grid, characterized in that the threads (1 ',

1 ") of the reinforcement grid individually encased in thermoplastic and over the encasement (3; 3

3 ") are thermo-heavy at least at the crossing points.

2. Reinforcement according to claim 1, characterized in that the core material of the threads consists of glass fibers.

3. Reinforcement according to claim 1 or 2, characterized gekenn¬ characterized in that the single thread has a multiple, preferably double sheath (3 ', 3 ") made of thermoplastic material.

4. Reinforcement according to claim 3, characterized in that the inner casing (3 ') has a greater layer ^• thickness than the outer casing (3 ").

5. Reinforcement according to claim 3 or 4, characterized gekenn¬ characterized in that at the crossing points essentially only the outer sheaths (3 ") of the crossing threads are thermofused.

6. Reinforcement according to one of claims 1 to 5, characterized in that the outer surface of the sheathing (3; 3 ") of the individual threads has a roughening, e.g. in the form of a corrugation.

7. Reinforcement according to one of claims 1 to 6, characterized in that the sheathing (3; 3-, 3 ^π ) of the individual thread consists of PVC.

- 1 2 -

characterized in that the reinforcing grid is a preferably canvas-bound, grid-shaped fabric.

9. Device for producing a reinforcing mesh according to one of claims 1 to 8, characterized in that the individual threads, which are preferably coated in a diving device with thermoplastic plastic, or the like from a warp beam (5), spool gate. withdrawn, bound to a fabric in a loom and welded by means of a heating device (10) at the bonding points by heating above the melting point of the thermoplastic material, the heating device (10) being arranged in a self-supporting section of the fabric (29) and is designed as a heat radiator (11) which is expediently covered by an air extraction trough (17), and that a protective shield (13) which can be inserted between the heat radiator (11) and the fabric (20) is preferably provided.