KR19980701422A - PACKAGING PRE-STRAIGHTENED COPPER ALLOY WIRE IN DRUMS - Google Patents

Abstract

A pre-straightened metal wire consisting of a copper alloy and having a diameter of less than 6 mm and a mechanical strength of 400-750 MPa is packaged in a cylindrical drum in such a way that, when it is unwound, the wire is straight, with a sag of less than 5 mm per metre, and can be fed directly to a bar turning machine.

Description

Packing method of pre-straightened metal wire

It is already known to wrap pre-straightened steel wires for supply to automatic welders.

In today's welders, the wire is continuously fed through the sheath. To improve the automation of the machine, the wire is packed in a drum of 250 kg. Prior to placing the wire in the drum, straightening the wire in advance gives a product free of any residual spirals or windings as it is released. This can ensure the restriction of friction against the wire inside the sheath and the straightening of the free portion of the wire (stick-out approximately 30 mm in length) at the welding point.

The method of straightening in advance is achieved in the following manner (see FIG. 1).

The wire released from the reel passes through a series of straightening rollers, the large diameter capstan driving the wire, which maintains the straightening of the wire,

Thereafter, two unpowered rollers, disposed in two vertical planes passing through the axis of the wire and driven about the wire upon rotation, provide twisting to the wire, and the cylinder guides the wire to the bottom of the drum. The placement step of placing spirally on,

The drum is lowered while being filled so that the clearance between the free surface of the wire and the base of the cylinder remains constant;

After the drum is filled, a plastic washer is placed on the spiral at the top of the wire so that an elastic band is achieved in a holding step in which the washer can be attached to the bottom of the drum to hold the product in place.

This technique is typically used for welding wires made of strongly strain hardened steel having a mechanical strength in the range of 600-1,200 N / mm 2 and a diameter in the range of 0.8-1.6 mm.

The pre-straightening technique allows tens of millimeters in length to allow the pre-straightened wire to slide properly through the sheath and to feed from the stationary heavy wire storage unit to the movable welding unit.

The present invention relates to the packaging of pre-straightened copper alloy wire in coil form in drums, especially for various applications where it is necessary to straighten the wire before use.

The generic term wire is used hereinafter to refer to both long semi-finished products, even non-circular cross-section products, which can be supplied coiled.

1 is a schematic cross-sectional view of a device for pre-straightening the wire 1 to be straightened in advance.

FIG. 2 is a cross-sectional view of the final wrapped coil 15 of wire pre-straightened in the same manner as above to prevent any entanglement of the wire helix during transportation.

It is an object of the present invention, in particular, to improve today's technology for micro-lathing semi-finished products made of copper alloys, in particular brass.

In precision lathe machining, two kinds of machines or methods, namely

Type 1: Particularly machined by rotating tools but with a fixed type of material,

Type 2: There is a kind of use of a fixed tool in a rotating material, for example disclosed in the publication of patent application WO 81/01378.

In order to ensure optimum precision during high speed machining, the material is preferably in a rotating state while the tool is in a stationary state. This requires that the material be supplied in the form of a piece of relatively short length (typically 3-4 m) that is straight enough to rotate.

To produce these fragments, also referred to by the term bar, one of the following two methods is usually used.

Method A: The wire producer manufactures the bar using a stretcher-leveler (a device that stretches the material to make the height constant).

In this case, the precision lathe machine is equipped with a bar container known as a bar feeder for supplying the bar to the precision lathe tool.

This technique has the following advantages:

* Due to the current technology of bar feeders and lathes, the bar must be completely straight, otherwise the bar does not progress in the bar feeder, or the bar causes vibration during rotation, which causes It is a source of unacceptable geometric defects.

To ensure that the bar is perfectly straight, the producer of the brass bar has to use a relatively expensive special wire straightening machine (stretcher-leveler), and furthermore, the straightening speed is much slower than the drawing speed, which greatly increases the production capacity. Decrease. For these two reasons, this method incurs higher costs.

Since the capacity of the bar feeder is limited to tens of tons of bar, the automation of the lathe as a result is also limited. Therefore, it is necessary to reload the bar feeder regularly every few hours, which adversely affects the productivity of the lathe operator.

Due to space limitations during the transport and processing of the bar, its length is limited (about 4 m). This is disadvantageous for their use because, for each bar used, 5% of its length, or approximately 200 mm, is discarded.

Method B:

Producers form wires into coils, usually weighing 250 kg. The coil is placed in a cylindrical cardboard drum which is closed by a wooden floor at the bottom and with a removable wood or metal cover at the top.

To form such a coil, a brass wire producer applies a slight plastic deformation to the wire just before the wire is wrapped in the drum to give the wire a natural curvature of a diameter similar to that of the drum. This is entangled during transport and processing, so that the placement of the helix is required to be uniform in order to eliminate the risk of deadlocks during wire unwinding.

In a lathe plant, the wire is drawn from the drum by a special unwinding device, after which the wire passes through a rotating frame with rollers to straighten it and then cut into lengths by a shearing tool. Thus, a bar can be obtained which can be rotated for lathe machining.

Compared to method A, method B provides the following advantages:

The preparation of each bar is carried out simultaneously during the lathe machining of the preceding bar. Thus, even faster straightening than lathe does not result in any loss of productivity.

Approximately 10,000 m of wire is contained in the drum, which is equivalent to thousands of bars. Thus, the automation of the lathe is multiplied by a factor of 100 relative to that of method A.

Bar length limitations are no longer tied to the constraints of transport and packaging methods, but rather to the space available in lathing shops. Thus, at least in theory, longer bars can be machined to reduce consumption (less than 5% waste).

Thus, method B is preferred by, and increasing according to, precision lathe operators, especially those who work in bulk batches where the need for high productivity is essential.

However, method B has the following disadvantages, namely

a) Unlike in method A, the brass wire production unit is equipped with a limited number of stretcher-levelers to produce the bar, and the lathe operator must install a large number of it (all lathe stretcher-levelers). Thus, the stretcher-leveler must be a relatively simple model, otherwise it represents a significant investment.

b) However, due to the fact that it uses a simple stretcher-leveler, the straightening method is not much more precise than in method A, and the bar currently has a deflection value of a few centimeters. The lathe operator corrected this deflection by modifying the lathe's feeder in a way that the bar was enclosed in an oil-filled sheath, partly in the machining process. The oil reservoir allows the bar to be automatically centered during rotation. Nevertheless, the bar is not perfectly straight, so the precision of the lathe is not optimal (range of 10 μm: nominal value of +10 μm and nominal value of −10 μm, or nominal value depending on the circumference) ± 5 μm).

c) Method B is limited to wires that can be straightened relatively easily, and wires of high mechanical strength and large diameter cannot be precisely straightened. Thus, Method B cannot be used for wires with diameters greater than 3 mm, or wires with diameters smaller than those with high mechanical strength (typically around 700 N / mm 2).

d) In the case of machining of long pieces, especially in the case of rotating the tool, the utilization of the wire may result in excess residual deflection (the memory of brass to the skilled person). the brass, i.e. a deflection value of about 0.15 mm for a 40 mm long piece, will result in a tolerance of 0.07 mm. This problem occurs in both kinds of lathe machines in which the material is in a fixed state (Type 1) and in which the material is in a rotating state (Type 2). In this case, a precompensatory heat treatment consisting of partial recrystallization of the alloy needs to be carried out on the wire coil, which entails an additional cost which cannot be ignored. This heat treatment can yield fragments of long length (40 mm) with a deflection value of 0.05 mm.

It is an object of the present invention to provide a wire wrapping method made of copper alloy, usually brass, which eliminates the drawbacks indicated for methods A and B, in particular those shown a) to d) for method B, In other words

1) Eliminates the need for stretcher-levelers for all shelves

2) achieve of lathe machining operation with higher precision or faster speed,

3) to expand the range of available wires, including wires with larger diameters and / or higher levels of mechanical strength;

4) without any prior heat treatment, provides removal or very significant reduction of residual deflection values in long length fragments.

In addition, the packaging method according to the present invention eliminates the problems faced by the lathe operator and does not increase the perceived oppression to the wire producer.

Disclosure of the Invention

The first subject matter of the invention consists of a metal wire that is pre-straightened in a cylindrical drum, which wire is straight with a deflection value of less than 5 mm per meter when unwound and in such a way that it can be fed directly to a lathe machine, 10 Copper alloy wire having a diameter of mm or less and mechanical strength in the range of 400 to 750 MPa.

According to a second aspect for using this first subject matter of the invention, straight wires loosened with a deflection value of 5 mm or less are fed to a lathe machine equipped with an extension roller.

In this case, the wire has a deflection value of 0.5 mm or less per meter when the wire leaves the stretching roller, and the level may be necessary for high precision machining.

Because of the use of the pre-straightened wire (lathe machining operation) of the first subject matter, brass is preferably selected as the copper alloy, but other alloys with hardness or more brittleness than brass may also be used, as described below. have.

The maximum limit on the diameter and mechanical strength of the pre-straightened wire is in particular due to the need to limit the energy accumulated by the pre-straightened wire while placing the pre-straightened wire in the drum. If a certain threshold is exceeded, the accumulated energy is so large that it cannot be accommodated by the armature of the drum and even becomes dangerous in the event of a drum break which causes a total release of the stress.

The Applicant was surprised to find that the following could be selected by the method of wrapping the wire according to the present invention.

Should the frame be fed to a lathe machine according to method B without using a rotating stretcher-leveler, which results in a substantial reduction in investment and substantial simplification of the repair and adjustment of these machines,

Should the frame be rotated using a stretcher-leveler to be fed to a lathe machine according to Method B, which has a large diameter of at least 10 mm instead of 3 mm and a mechanical strength of at least 750 MPa instead of 650 MPa? The use of wires not only expands the range of wires that can be used according to Method B, but also nominal values of +5 μm, nominal values of -5 μm, or nominal values of ± 2.5 μm depending on the circumference. Machining accuracy can be substantially improved within the range of 5 μm, which reduces the wear and bit breakage rate of the tool. Increased from 2,000 kg to 5,000 kg.

In any case, the present invention solves the problem of economically important productivity and / or quality levels. Furthermore, the solution of this problem has never been expected or suggested by the means mentioned in the prior art for wrapping welded steel wires.

In fact, for the expert in the technical field of brass lathe work, straightening the wire is inseparable from the machining according to Method B and is recognized as an essential work. The possibility of eliminating the straightening of the wire never arises for these experts.

On the other hand, such an expert is different from the person skilled in the art of welding, and the means known in the field of steel wire welding cannot be made in general or in the relevant field of the expert on the machining of brass wire lathes.

After all, due to the differences in the problems to be solved, the lathe expert knows the use of pre-straightened wires in the field of welding, but he believes that the means used to allow the steel wire to slide through the sheath is I never thought it was enough to mold the bar while eliminating the straightening operation.

Another subject of the invention consists of a pre-straightened wire in a cylindrical drum, the wire having a diameter in the range of 0.15 mm to 0.35 mm and 500 MPa, in such a way that when unwound it is straightened with a deflection value of less than 30 mm per meter. A Cu-Zn alloy having a mechanical strength in the range of ˜1,100 MPa is an electrical discharge machining wire formed of an outer layer.

The structure of the wire for electrical discharge machining is disclosed in a number of patents, for example in the publication of European Patent No. 526 361-A1 issued in the name of the applicant.

The Applicant has observed that the solution found using the wire for lathe machining also applies to the wire for electrical discharge machining. In this case, the technical problem that can be solved is as follows, because when the wire is broken, the wire must be automatically reattached to itself, so that the electrical discharge machining can be continuously processed without any requirement of manual interference. have.

For this reason, the wire for electric discharge machining certainly does not have any memory value which causes the tendency to form a ring by winding the end of the wire, which was originally coiled on the spool, by itself.

Thus, after the break of the wire, the end of the wire must maintain its trajectory, although there was no break of the wire at all.

Up to now, the problem has been solved by heat treating the wire and / or straightening it before winding. The present invention makes it possible to eliminate this heat treatment and avoids the use of spools and the constraints associated with them. In practice, the use of spools limits the amount of wire per coil (standard weight of 5 kg), although this amount tends to increase. On the other hand, if it is 15 kg or more, the spool must be mounted on a motor driven release device, which generates vibrations and additional costs that are unsuitable for the precision of electrical discharge machining.

Finally, the task of recycling such spools made of plastic is becoming increasingly serious. Due to the significant stress received during the winding, it cannot be used up to three or four times more, and the stress tends to break up the spool, after which the spool is clearly destroyed.

Packaging in drums according to the present invention presents a considerable solution to these problems, in particular

* Larger drums can be used per unit weight without the motor-mounted loosening device.

* In the packaging operation, the drum can be reused over and over again because it does not generate any substantial mechanical stress,

The drum may consist of recyclable materials such as cardboard and steel, for example.

The device for straightening the wire 1 to be straightened in advance is provided with the following, i.e.

A system 4 for unwinding the pre-straightened wire 1 and a dancer 5 for adjusting the unwinding method,

Four planar continuum consisting of seven straightening rollers, the second continuum facing 90 ° from the first continuum, the third continuum pointing 45 ° to the right and the fourth continuum pointing 45 ° to the left. In FIG. 1 only the third continuum 6 is shown,

A large diameter (1,000 mm) capstan (7) for supplying a straightened wire at the outlet,

A pair of cylindrical rollers 8 having grooves mounted on the same rotating plate, which tighten the wire, twisting the wire back by the rotation of this plate,

A cylindrical body 16 driven in the same rotational motion as the plate, the cylindrical body forming a coil 15 of pre-straightened wires by allowing the pre-straightened wires to be guided to the drum,

A drum (3) with a lowering means for lowering the drum (9) in such a way that the base of the cylinder (16) is always located directly above the coil (15) of pre-straightened wires formed inside the drum, the cylinder The diameter of substantially determines the inner diameter of this coil 15.

The plastic washer 10 is pressed against the top of the coil 15 by a bracket 11, an elastic band 12, and a rigid rod 13 fixed to the bottom of the drum 3 by a ring 14. Is kept in a state.

The bracket 11, elastic band 12 and rigid rod 13 are arranged to hold the wire in place during preliminary transportation and storage. These members are removed during use of the wire so that the helix can be released.

Another object of the invention is to wrap the pre-straightened wires according to the invention for feeding the wires directly to machining machines, in particular lathes and lathes or cold forging machines, and to supply the wires to discharge machining machines. It consists of a method for wrapping pre-straightened wires according to the invention.

The present invention also relates to metal wires which have been pre-straightened in advance to feed the wires directly to machining machines, in particular lathes and lathes, or to cold forging machines, whether or not the wires are made of non-ferrous alloys or steel other than copper. It includes packing method. In fact, Applicant can demonstrate that it can be applied to steel wires of concept developed using copper alloys such as brass as described above.

First embodiment

The coil of the wire 2 which was previously straightened was manufactured.

The wire has the following characteristics:

Composition: Brass with 36% Zn and 3% Pb

Diameter: 1.825 mm

Mechanical strength: 620 MPa

The apparatus shown in FIG. 1 was used.

Four planar continuums 6 consisting of seven straightening rollers are used as straightening devices and are directed to each other as follows, ie (+ 90 ° / −45 ° / + 45 °).

The feed speed of the wire is 250 m / min and the rotational speed of the paired roller 8 and the cylinder 16 is 130 rpm.

This wire is wrapped in a suitable 250 kg drum 3 as shown in FIG. 2.

This drum must have a large diameter so as not to stress the wire against curvature that exceeds the elastic limit of the wire. Typically, this diameter is 510 mm for small diameter (1 mm) wire, 580 mm for medium gauge wire (diameter about 1.8 mm) and 620 mm for wire about 3 mm in diameter. .

The pre-straightened wire 2 obtained is tested in a TORNOS® stretcher-leveler, with or without a straightening device with a rotating frame.

If no rotating frame is used, a 4 m bar with a deflection value of 4 mm per meter is obtained. This deflection value is approximately equal to that obtained immediately according to method B after a straightening operation performed on a wire having the same composition and geometrical properties on a rotating frame with rollers.

After use of the rotating frame, a bar of 4 m with a maximum deflection value of 0.5 mm per meter is obtained, which roughly corresponds to the level of straightening of the bar obtained according to method A.

The lower the deflection value per meter, the less vibration during high speed rotation of the bar, the higher the precision of the machine, and optionally the faster the machining speed.

Typically, the current accuracy achievable with a bar with a deflection value of approximately 4 mm per meter is 10 μm, while the precision achievable with a bar with a deflection value of 0.5 mm per meter is as small as 5 μm.

Similarly, given the speed of machining to a certain level of precision, the gain in productivity is approximately 15% when a bar with a deflection value of 4 mm per meter is replaced by a bar with a deflection value of less than 1 mm per meter.

Applicants conducted a variety of other tests while varying the composition of the copper alloy and its geometrical or mechanical properties, as well as the machining techniques and the shape of the machined pieces.

In particular, Applicants have found that when machining long lengths (typically 40 mm) of fragments, the pre-straightened wires according to the present invention can avoid heat treatment of coils previously required to remove the memory of brass. It was observed that it is possible to obtain a fragment having a deflection value of 0.05 mm with respect to a tolerance of 0.07 mm without heat treatment.

In addition, the applicant manufactures the fragments by cold forging as well as by machining using pre-straightened wires according to the invention. Here again, the Applicant has found that deflection problems still arise due to residual deformations generated during winding before placing them in the drum for long length fragments, typically in the range of 30 to 50 mm, and despite the repeated adjustment of the straightening device, The product may be defective. Also in this case, the pre-straightened wire of the embodiment can considerably limit its deflection value.

Typical examples of fragments obtained by cold forging are the cathodes of alkaline batteries in view of strict geometrical tolerances.

In addition, the test is carried out on wires with different diameters (tests on brass wires with a diameter of 3 mm and a diameter of 6 mm), and with different levels of mechanical properties, namely bronze with lead (Cu-Sn- Alloys with hardness and brittleness such as Pb) or lead-containing nickel-silver (Cu-Zn-Ni-Mn-Pb) have been successfully tested within the limits set forth in claim 1.

This limit is due to the need to obtain a deflection value of 5 mm or less per meter with respect to the bar which will be rotated for the purpose of machining (method B).

If too thick and / or too coarse wires are used, this wire leads to a residual deflection value of the bar which is larger than this limit of 5 mm per meter.

Example 2

The coil 15 of the pre-straightened wire 2 was manufactured for gas discharge discharge machining. This wire is comparable to that disclosed as an example in the publication of EP 0 526 361-A1 and has the following characteristics.

Composition: Cu-Zn37

Diameter: 0.25 mm

Mechanical strength: 910 MPa

Such wires according to the invention were tested for electrical discharge machines and compared with standard wires. Standard wires are subjected to mechanical straightening or heat treatment before winding.

According to the invention, the behavior of the wire in the drum is the same as the behavior of the wire heat treated or mechanically straightened on the spool according to the prior art.

The present invention solves the problems encountered by various types of users and machines of various types, such as lathe machines, electric discharge machines, as well as cold forging machines.

In each of these cases, the improvement relates to the production rate, and thus the productivity, or the best final quality of these fragments for all uses, for example electrical connections, and the low level of investment required to produce them or It is about a combination of these advantages. In the case of lathe machining, the present invention combines the known methods described above with Method A and Method B and then eliminates the disadvantages associated with each of these methods, i.e.

* As in method A, the customer performing the lathe should not worry about straightening the bar, and similarly the customer performing the electrical discharge machining should be aware of the presence of residual helix in the event of a wire breakage. Don't worry.

* On the other hand, as in Method B, the wire supplier must not use heavy means. Indeed, the pre-straightening straightening means that have been used do not reduce the production level for the draw or raise the cost of production, are easily incorporated at the end of the draw line and further require much less investment than an industrial stretcher-leveler. In general, straightening means for straightening in advance are still necessary for the wire producer, but on the other hand there is no longer a need for the lathe operator to have all lathe stretcher-levelers, which results in considerable savings.

Therefore, the straightening operation can be classified into two stages, that is,

One of them is a pre-straightening straightening step performed by the wire producer, which is carried out at high speeds (typically 4 to 9 m / s), consistent with the fast drawing speed necessary to ensure high productivity.

The other one is performed by the user but is an optional finishing straightening step, which is performed at low speed (typically 0.1 to 0.5 m / s) for high quality straightening with an inexpensive device. In this case, the low speed is not composed of disadvantages since the straightening operation is carried out simultaneously, and the limiting step only occurs at the level of machining.

In summary, as emphasized above, the straightening device is economical because the lathe operator must install everything he or she lathes with this type of device. By classifying the straightening operation according to the invention in this way, both quality and productivity are optimized because it allows two involved parties, producers and users, to work at their respective characteristic speeds.

Among the other advantages of the present invention, it is important to present below, namely

The possibility of using wires with very high mechanical strength, which is more suitable for lathes than softer wires, because the chips are fine (usually 0.05 mm instead of 0.5 mm) and easier to remove Because.

* Almost eliminated the risk of rupture during straightening of the wire, because on the average, 250 kg of one failure per drum was observed in the prior art, while no plastic deformation of the wire was present anymore.

* A substantial reduction in vibration associated with lower levels of bias, which also results in a lower breakdown rate of the tool, i.e. the consumption of bits with the present invention is between 1 bit and 5,000 kg of wire per 2,000 kg of wire. 1 bit per bit.

The wires from the drum not located at the bottom of the machine as in the prior art, but at a point remote from such a machine, for example a sheath arranged in a storage space in which the sheath guides the wire towards the machining device. Alternatively, as a possibility of supplying to the molding apparatus, it is also known that the wire which has been straightened in advance through the sheath is also known.

This type of construction reduces the space required for each machine, reduces the movement and handling of the drum, thus reducing the risk of shock and accidents.

The possibility of packing a hard or brittle alloy in the drum, which alloys are not suitable or unsuitable for any of the following reasons: during winding before placing into the drum, and during straightening followed by the unwinding process. Either because they have a yield strength and require substantial force to reach the elastic region, or because they have extremely narrow plastic deformations, so that even limited plastic strains, such as winding or straightening, can limit the elongation at break. May be sufficient to exceed locally, resulting in repeated breakage of the wire.

Thus, a pre-straightened wire made from an alloy having a composition of Cu-Sn-Pb (lead-containing bronze) and Cu-Zn-Ni-Mn-Pb (lead-containing nickel-silver) can be packaged in a drum.

In the case of electrical discharge machining, the advantages provided by the present invention are also important with respect to the following:

* Removal of heat treatment and mechanical straightening treatment,

Faster per unit weight, thus the possibility of better automation, the wire weight per spool is typically 5 kg, but the weight per drum is not limited.

The drum can be reused many times in a number of times because of the need for a powered release device, eliminating the spool that must be destroyed after a limited number of turns.

Finally, in all cases of the use of pre-straightened wires according to the present invention, the Applicant believes that the packaging method according to the present invention is equivalent to the amount of wires (previously known as 250 kg) for conventional wires According to the present invention, it has been observed that it is possible to double the 500 kg) even using the same drum size. This is due to the fact that in the conventional packaging method, the spiral must be relatively inflated to limit the problem of entanglement during unwinding, while in the present invention all spirals are extremely dense and densely stacked.

Claims (9)

In a packaging method for wrapping a pre-straightened metal wire in a cylindrical drum, The wire is straight, with a deflection value of 5 mm or less per meter when unwound, and copper alloy wire with a diameter of 6 mm or less and a mechanical strength in the range of 400 to 750 MPa, in such a way that it can be fed directly to a lathe machine. The packaging method of the pre-straightened wire, characterized in that the. The method of claim 1, wherein the copper alloy is brass. A packaging method of wrapping a pre-straightened metal wire in a cylindrical drum, The wire has a deflection value of less than 30 mm per meter when unwrapped and is straight, such that a Cu-Zn alloy layer with a diameter in the range of 0.15 mm to 0.35 mm and a mechanical strength in the range of 500 MPa to 1,100 MPa is outward. A method for wrapping pre-straightened metal wires, characterized in that the formed electrical discharge machining wires. 4. The drum according to any one of claims 1 to 3, wherein the drum is capable of inactivating other means (drying bag, ammonia) to avoid this risk, in order to avoid the risk of stress corrosion of the wire. And an impermeable drum which may comprise products, shielding products absorbed on the surface of the wire. The packaging method according to any one of claims 1 to 4, in order to obtain a metal wire which has been previously straightened in a cylindrical drum, a) the wire to be straightened in advance passes through a series of straightening rollers, the large diameter capstan driving the straightening of the wire to drive the wire, b) thereafter, the wire is placed in a vertical plane and subjected to twisting while passing through two unmotorized pairs of rollers driven about the wire as it rotates, c) circumferentially moving cylindrical bodies guide the wires and spirally place them at the bottom of the drum; d) the drum is lowered while being filled to maintain a constant gap between the free surface of the wire and the base of the cylinder. Packaging process characterized in that. Drum obtained according to claim 1 or 2, or according to claims 1, 2 and 4, for supplying the wire directly to a machine tool such as a lathe and a lathe or a cold forging tool. Use of the packaging method of the genus. Use of a packaging method in a drum according to claim 3 for feeding wires to an electrical discharge machining apparatus. Use of pre-straightened metal wire wrapping methods for feeding wires directly into lathes and lathes or machine tools such as cold forging tools. 9. The method of claim 8, wherein the metal wire is a wire made of steel or non-ferrous alloy.