JPH0369537A - Manufacturing steel wire piece bundle - Google Patents

Abstract

PURPOSE: To improve a production speed and to save drying energy by using a molten state glue when steel wires are joined in bundle and solidifying the glue while cooling.

CONSTITUTION: When bundles joined with many steel wires in bundle are transversally cut and steel wire bundles for reinforcing of a building member is made to pieces, joining is done with a molten state glue, succcessively this glue is cooled/solidified. This method does not require drying, before the bundles are traversally cut to be made to a bundle, the bundle is slidified by simply/ quickly cooling. A method using a molten glue may totally or partially use a water soluble glue, this bundles are use for both cold cement mortar and hot bituminous concrete. In the case of the latter, a glue decomposable at a mixing temp. is selected.

COPYRIGHT: (C)1991,JPO

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing bundles of steel wire pieces for reinforcing building components, such as beams or road surfaces. For the above purpose, the wire piece is substantially rectangular and has a thickness of 0.3 to 1.0+nn+;
The length to thickness ratio is between 40 and 120, with the longest length being 120 mm. By "rectangular" we mean that the wire pieces are not so curved, positive or curled that there is no discernible general length direction that exerts a strengthening effect on the bituminous concrete. In this regard, the apparent length of the wire piece, ie the distance between the ends of the wire piece, is greater than or equal to 0.7 times the length measured along the wire piece. The thickness of a wire piece with a non-circular cross section is calculated as the diameter of a field with the same area.

The steel wire pieces are used to strengthen cement concrete and are mixed into a wet mix that, after being dumped, is deformed and compacted to harden into the desired shape. If the steel wire pieces are added to the mix without any precautions, the wire pieces will not be evenly distributed in the concrete and will clump together into balls. For this reason, bundles of steel wire pieces joined by such adhesive substances that lose their cohesive strength during mixing and disintegrate in whole or in part, especially in water Φ of cement mortar or cement concrete. into the wet mixture. This steel wire piece bundle preferably contains 5 to 40 wire pieces. This bundle of wire pieces does not have to be a bundle with a solid cross section, but can also be a flat bundle, which bundles are joined in parallel.

U.S. Pat. No. 4,284,667 discloses that a number of wires are bonded together in bundles using an emulsion or aqueous solution of an adhesive substance that can be decomposed and/or emulsified again in the concrete after drying, and then It is disclosed that a bundle of wire pieces is manufactured by drying the bundle in a drying oven and cutting the bundle in a cross section into wire pieces.

The object of the invention is to provide an alternative method to this method, which provides various advantages depending on the situation, eg the intended use, etc.

Although the present invention is known as a binding substance that must be wholly or partially soluble in water,
Therefore, it is based on the knowledge that it can be used in the form of an emulsion or aqueous solution, and can also be used in the form of a hot melt. This can even be applied to substances that are not completely water soluble and are adapted to decompose by melting.

This means that the steel wire pieces must be mixed into a hot mixture such as bituminous concrete;
It is of interest for applications where fiber bundles are decomposed by the mixing temperature. Applying the glue in the molten state has the advantage that there is no need for drying in a drying oven and that it can be solidified simply by rapid cooling before the bundle is cut cross-sectionally into pieces. In this way, production speeds are increased and drying energy is saved. The method of applying molten glue does not preclude the use of glues that are wholly or partially soluble in water;
Bundles of wire pieces can be used for both cold cement mortar and hot bituminous concrete.

A further manufacturing advantage is that glue applied by melting requires very little storage space and can be stored for an unlimited time.

The invention is therefore characterized in that the adhesion takes place by means of a molten glue, which is then solidified by cooling.

Glue in the "molten state" means that the glue loses its solidity and is applied to a wire bundle by heating above the melting point of the glue, which under the influence of temperature is not necessarily completely, but clearly defined. It should be understood that this means that it has lost sufficient solidity in order to

In the case of binding materials, such as synthetic resins, consisting of different molecules with different melting points, gradual softening in the softening temperature range causes a loss of solidity, and this viscous material becomes a material that is soft enough to be used as a glue. It is sufficient that In this bonded material, the temperature level of softening is determined by the softening point according to the ring and ball softening point test method. Also, in bonded materials with well-defined melting points, "softening" occurs at the melting point. This is hereinafter referred to as the softening point.

When the fiber bundle is used in bituminous concrete, the glue chosen is one that is adapted to dissolve by melting when mixed into the hot bituminous concrete. This means that the glue loses sufficient solidity under the influence of temperature to cause the bundle of wire pieces to disintegrate into individual wire pieces under the mixing action, and this loss of solidity results in a completely or partially solid state. This means that it is caused by a substance that changes from a molten state to a molten state. The mixing temperature of bituminous concrete is approximately 80 to 200
℃, with the mixing temperature preferably 3° below the softening point.
0-50'C high, so a glue with a softening point in the range of 50-170'C is chosen. If the softening point is lower than 50° C., there is an increased risk that the bundles will begin to stick together when exposed to light or warm weather conditions.

If the fiber bundle is mixed into bituminous concrete, a bitumen of a composition similar to that used in the bituminous concrete may preferably be chosen as the binding material. As is known, bitumen is a mixture of mainly hydrocarbons containing residual impurities obtained from the refining of coal or right-hand grains, such as pitch, tar or asphalt. These are hard at room temperature, fully solid at mixing temperatures, and bituminous concrete (in addition to filling materials such as sand, lime, and/or
Stone chips with a grain size of ~20+++n) flow into the other components and, after solidification, form the adhesive component for bituminous concrete.

As adhesive substances, thermoplastic polymers or copolymers can be used, preferably in the form of conventional hot melt glues, which, depending on the various manufacturers, can also contain waxes, softeners, stabilizers, etc. agents, and possibly fillers. Therefore, as a polyester polyurethane glue, for example, US Pat. No. 2.801. ．． As shown in No. 648, a glue whose softening point can be set by adding a large or small amount of diisocyanate during the production of the glue can be used. Furthermore, as EVA glue (ethylene-vinyl acetate copolymer) it is possible to use one whose softening point can be adjusted by the ethylene/vinyl acetate ratio. When it is necessary that the hot melt glue is capable of disintegrating or emulsifying in water, typical hot melt glues such as those used for paper or cardboard in the molten state can be used, which are then wetted with water. This will make it sticky again. In practice, this glue can be selected from a variety of hot melt glues available on the market, which are described in the book "Hot Melt Adhesives", 3rd edition, by Hari, L. BATEMAN, Noyes Data Co., Ltd.
published in 1999.

Glue can be applied in a variety of ways.

The wire bundle can be continuously passed through a bath of molten glue. Excess glue is wiped off at the exit of the bath before the bundle is cooled, for example in an air jet or in water if the glue is water insoluble.

When the glue is in powder form, another method consists of heating continuous wire bundles and passing the hot wire bundles through a fluidized bed of these powders. The powder then melts on contact with the wire bundle and the glue solidifies again at the outlet of the fluidized bed. It is also possible to use conventional equipment equipped with nozzles that continuously eject molten glue under pressure onto or around the wire bundles and wire pieces. It is also possible to first apply glue on the individual wires and then bundle the wires, which can then be glued together, for example by heating and cooling again.

Glue the wires in parallel to easily glue the wire pieces and then easily disassemble the wire pieces;
Preferably in flat bundles.

However, it is also possible to produce round bundles in which the glue does not penetrate completely towards the core of the bundle, but acts as a tight sleeve around the bundle so that all the wires is held. As a result, bonding the wires does not require that all wire pieces be in contact with the glue; it is only necessary that the wires be held in a bundle after the glue has solidified.

When the wires are led in parallel to be grouped into a smooth bundle in one plane, and when the wire pieces have corrugations or deformations and/or have hooks or bends at the tips, those deformations are preferably It is best applied to continuous bundles before cutting. This means that the rollers are such that the protrusion of one profile coincides with the recess of the other profile, and then the preferably smooth bundle forms two rollers with an undulating cross-sectional circle or other contour. This is done by being guided continuously between rotating rollers. In this way, a deformation is effected in a plane that includes the longitudinal direction of the bundle and is perpendicular to the plane of this bundle.

It is clear that this manufacturing method is very suitable for continuous manufacturing methods, in which a large number of wires are not wound on each spool, but after unwinding these wires The wires are gathered towards the entrance of the device where they are glued and bundled. In this device,
Pass the bundle first through the glue, apply glue at this glue,
The glue is allowed to cool to solidify and then optionally passed through a deformation section where the bundle is deformed between two rotating wheels and finally the bundle is cut into pieces and the bundle of wire pieces is placed in a container. accommodate.

Claims (5)

[Claims] (1) A method for producing a bundle of steel wire pieces for reinforcing building members, which includes the step of bundling and gluing a large number of steel wires, and then cutting the resulting bundle in cross section to form pieces. A method for producing a bundle of steel wire pieces for reinforcing building members, characterized by causing adhesion with a state glue and then solidifying the glue by cooling it. 2. Process according to claim 1, characterized in that it uses a glue adapted to decompose by melting when mixed into the hot bituminous concrete mixture. 3. Process according to claim 1, characterized in that it uses a glue adapted to be decomposed by water when mixed into cement concrete. (4) The manufacturing method according to any one of claims 1 to 3, characterized in that the wires are glued in parallel to form a flat bundle. (5) The manufacturing method according to claim 4, wherein the wire is deformed in a plane including the longitudinal direction of the bundle, perpendicular to the plane of the flat bundle.