Research on diamond wire saw with small diameter

Diamond rope saw has been widely used in stone mining, while the cutting of stone raw material big board mainly USES traditional disc saw, sand saw and frame saw. At present, Diamond rope saw is only used on the processing of special-shaped stone workpiece such as arc. The diameter of diamond rope saw of the existing processed stone arc plate is mostly 8~11mm. During the sawing process, there are large slitting joints, low stone completion rate and serious waste of resources. In addition, the sawing process has high energy consumption, loud noise, large waste discharge and serious environmental pollution. Therefore, a diamond rope saw with small diameter and high cutting efficiency is developed.

Its important significance is: on the one hand can increase the finished material rate of stone processing, increase the processing profit of stone processing factory; On the other hand, energy conservation and emission reduction can be achieved to create greater economic and social benefits.

1. Design scheme of diamond rope saw with small diameter

1.1 choose flexible multi-strand rope that is resistant to bending. The diameter of multi-strand rope is selected according to the tensile strength and the total outer diameter of the rope saw design. Diamond brazing work layer is fixed at intervals on flexible multi-strand rope. The diamond brazing working layer is the diamond working layer directly brazed on the flexible multi-strand rope.

1.2 diamond beads are pre-formed cylindrical self-supporting diamond beads (i.e. the inner wall of diamond beads is not supported by metal matrix) or diamond beads supported by metal matrix. A coating formed by rubber and plastic materials is fixed on the flexible multi-strand rope between each adjacent diamond beads. The diamond brazing work layer can be set into spiral shape, other regular shape or irregular shape.

1.3 the diamond abrasive particles distributed in the brazed diamond working layer may be single layer, multilayer or mixed unlayered-structure (i.e. the diamond abrasive particles are uniformly distributed in the diamond working layer).

1.4 the diamond brazing working layer can be sintered and formed by vacuum brazing furnace. The surface of diamond abrasive particles before brazing can be pre-metallized, that is, the overcoating layer containing carbide is formed on the surface of diamond in advance, which can enhance the bonding force between diamond abrasive particles and metal and shorten the sintering time.

1.5 rubber and plastic material layer is obtained by applying rubber and plastic material coating or injection molding to flexible multi-strand rope. The raw material of rubber and plastic material layer can be selected from rubber, plastic or binder. In order to increase the tensile strength, wear resistance or water resistance of the outermost elastic material, fillers such as fiber and abrasive can be added to the rubber material layer.

2. Manufacturing process of small-diameter diamond rope saw

2.1 direct brazing method:

A. After removing oil from the surface of flexible multi-strand rope, the high-temperature resistant inorganic glue shall be applied to the flexible multi-strand rope at intervals, and the insulating protective layer shall be formed after curing.

B. Take metal solder and add organic glue to make paste;

C. Smear or impregnate the empty space on the flexible multi-strand rope with paste metal solder, then arrange the diamond abrasive grains, and apply a paste metal solder after curing with organic glue.

D. The flexible multi-strand rope made in step c is dried and put into the vacuum brazing furnace for sintering. After sintering, the inorganic adhesive is removed and removed.

In the above method, as the inorganic glue can fill the gap of flexible multi-strand rope in the isolation layer, the molten metal solder will no longer diffuse into the isolation layer along the direction of flexible multi-strand rope in the brazing process, so that the flexible multi-strand rope can still maintain the original softness.

2.2 self-supporting diamond bead method, the steps are as follows:

A. Impregnate single steel wire with high temperature resistant inorganic glue, and dry and solidify the steel wire surface with a demoulding layer;

B. Take diamond abrasive grains and metal solder and add organic glue to make paste;

C. Separate the paste on the stripper layer, and then put the single-strand wire coated with the paste into the vacuum brazing furnace for sintering;

D. Exit the single wire in the central position after being baked, and obtain the ring diamond brazing layer.

E. Diamond beads shall be separated into flexible multi-strand rope, fixed with glue, and then coated with a protective layer of rubber and plastic materials at the interval. Diamond rope saw is made after curing.

In the above method, the diamond beads have been pre-brazed into shape and then fixed to the flexible multi-strand rope, so that the flexible multi-strand rope can still maintain the original softness.

2.3 metal matrix supporting diamond beads method, the steps are as follows:

A. Take diamond abrasive grains and metal brazing materials and add organic glue to make paste;

B. Smear paste on small diameter steel pipe, and then put it into vacuum brazing furnace for sintering;

C. Cut it into small sections of a certain length after being baked, and obtain diamond beads with metal matrix;

D. String the diamond beads to the flexible multi-strand rope, fix them with glue, and then apply a protective layer of rubber and plastic materials on the spacing part. After curing, diamond rope saw is made.

3. Compare and test two different kinds of rope saws

The no. 1 saw (developed independently) and no. 2 saw (commonly used in the market) were tested and compared on the special-shaped cutting machine. The equipment used for the experiment is; First reach the Rope saw cutting machine, the test used line speed of 30m/s, the test stone material is 2000*1000*1000 Spanish rice yellow stone raw material, each rope USES the same process to cut the radian for 1000mm, the cutting height is 950mm, the plate thickness is 20mm. The cooling liquid is tap water, and the cooling method is uniform with spraying.

3.1 the rope diameter, 1 Φ brazing wire saw 2 trials

Table 1 test data of no. 1 saw

During the test of no. 1 rope saw, there was little noise, but two beads turned during the cutting process. The rope was disconnected due to continuous grinding of beads. There is no change in the cutting process, only because the device jiggles into the rope part of the saw slit slightly larger.

Figure 1. Surface state of the no. 1 rope after testing

The tension of no. 1 rope is relatively small, and there will be no damage to the stone when the rope is broken. Before cutting, the rope was twisted counterclockwise for 3 turns /m. However, because the rope was thin, the self-torque generated was not large enough. In the process of cutting, one side consumed, and the diamond wear on one side was obviously larger.

3.2, 2 Φ 8.8 marble rope experimental conditions:

Table 2 test data of no. 2 rope saw

During the cutting process, the sound of cutting was loud. When the whole rope was cut, there was no beading rotation and peeling. When the rope was cut to about 45 square meters, the rope broke from the joint. The size of stone saw seams decreased with the change of rope outer diameter, and the average stone saw seams were around 10.5mm.

Figure 2. Surface state after rope 2 test

Before cutting, the rope was twisted 3 turns /m counterclockwise, and the outer diameter was measured with caliper after cutting. The overall rope consumption was relatively uniform, and there was no single side consumption deformation.

4. Result analysis and discussion

The following is a graphic analysis of the advantages and disadvantages of the new rope saw

FIG. 3 contrast of saws

Fig.4 bending degrees at different times

Figure 5 current change

Based on the above chart and test data, we made the following conclusions:

(1) figure 3 analysis; The saw sewing of no. 1 rope is about 8.0mm smaller than that of no. 2 rope saw. According to the conventional calculation of 20mm curved plate, the sampling rate of stone is increased by more than 30%.

(2) figure 4 analysis; Rope 1 is much less bent than rope 2 at the same cutting speed, which means that rope 1 has better sharpness than rope 2. Since the diamond of no. 1 rope is much higher than that of no. 2, the cutting depth is increased, and the cutting depth is also increased in the same time.

(3) figure 5 analysis; From the perspective of current, rope no. 1 has a thin rope and little cutting resistance, so the energy consumption of the rope itself is very small except the operation energy consumption of the equipment itself. In terms of the electricity consumption of the rope alone, the power consumption of the ordinary rope is five times that of the 2mm rope.

(4) according to the data in table 1 and table 2, the string has some deficiencies. Loose beads in the cutting process cause the rope to wear and break. Since a thin rope cannot twist itself in the cutting process even if it is twisted, it causes the rope to be sideways, and the rope's life can be greatly affected.

Existing problems and solutions:

(1) rope breaking problem: no matter the diameter of the rope, rope breaking will be generated in the tension-cutting process. Therefore, the rope saw joint can solve the problem of easy rope breaking by making it. In addition, effective design of joint structure and increase of wear resistance of joint surface can also reduce the rope breaking phenomenon.

(2) bead fixation: loose bead fixation will affect the cutting effect, and even cause the cutting cannot be continued. Therefore, the structural design of both sides of the beaded matrix tube, the structural design of the inner wall of the beaded beads and the spring of the beaded beads can effectively solve the problem of easy loosening of the beaded beads.

5 conclusion

The small-diameter diamond rope saw developed by the above brazing technology has the following beneficial effects:

(1) Φ 2 mm small diameter diamond wire saw cutting kerf is small, can be used for precious stone cutting and sheet cutting (can be cut into 1.5 2.0 mm thickness of stone material, greatly improve the yield of stone cutting, obtain good economic benefit.

(2) Φ 2 mm can greatly reduce the small diameter diamond wire saw cutting energy consumption and reducing emissions of waste stone, have the effect of energy conservation and emissions reduction, is worthy of popularization and application.

(3) further research and development of multiple combinations of rope saws and related rope saw equipment can greatly improve the cutting efficiency of diamond rope saws.

(4) small-diameter diamond rope saw can also be applied to silicon ingots and cutting square of sapphire, as well as more extensive applications such as magnetic material and composite material cutting.