RU1809781C - Disintegrating stone for supercolloid mill and method for its preparation - Google Patents

Abstract

Usage: for the production, in particular the working bodies of a supercolloid mill. SUMMARY OF THE INVENTION: a grinding stone and polymer composite for a supercolloid mill characterized in that the thermoplastic and thermosetting polymers are allowed to penetrate the free pores of the porous vitrified grinding stone for the supercolloid mill and fill them from the surface of the free pore walls within 30-60% total volume in said grinding stone, so as to leave 70-40% of the free pores in the grinding stone for a supercolloid mill and to ensure their volume fraction Vp in the range of 0.09-0.21. 1 s, p. crystals, 3 tablets, 2 ill.

Description

The invention relates to a composite of crushed stone and polymer for a supercolloid mill and methods for its processing and can be used for the production, in particular, of the working bodies of a supercolloid mill.

According to the invention, in a crushed stone, a thermoplastic or thermosetting polymer, expanding in the direction from the walls of the free pores filled by it, fills them by more than 30% so that the volume coefficient Vp of the remaining internal voids is final. the crushed stone composite material is in the range of 0.09-0.21, in the method for processing crushed stone, the monomer or oligomer of a thermoplastic or thermoset type or synthetic rubbers are forced into the free internal pores of a porous, vitrified crushed stone under the influence of reduced or increased pressure, accompanied by degassing by selecting a portion of the aforementioned monomer or oligomer filling said internal pores from the process control system so that after polymerisation, the polymer volume decreases to more than 30% with respect to the total volume of internal free pores in the crushed stone, and as a result of subsequent polymerization and / or condensation, the introduced monomer or oligomer has a volume coefficient of residual free pores in the final composite material and the crushed stone, reduced to values enclosed in the range of 0.09-0.21,

.. The stone consists of three elements: Ze; wren, a binder and connective pores. If proteinaceous substances adhere to areas of the pores, which are one of the three major elements, spoilage under the influence of undesirable bacteria will result in

s

come from these sites. Therefore, it is necessary to wash and remove adherents well with a wire brush and the like during use, but there is no means to wash off such adherents within the pores. In addition, since the distribution of such pores is not uniform, the appearance of cracks during expansion is caused by the heat generated by friction. If it is possible to fill these connecting pores artificially with a substance having the required properties, it becomes possible to use borazon and other materials more preferred than alundum (AlgO3) and carborundum (SIC), which are usually used as raw materials for the manufacture of grinders.

If grinding stone is made t; the use of such borazon, and; A supercolloid mill is manufactured using this grinding stone, grinding of materials having high hardness, grinding of dried materials and superfine grinding are also possible, and a great contribution to the grinding industry and to supercolloid grinding.

Figure 1 presents in section a diagram of a conventional crushed stone; figure 2 presents in section a diagram of the stone (composite with polymer content) in accordance with the invention.

The invention provides a composite of grinding stone and polymer for a supercolloid mill, characterized in that the thermoplastic and thermosetting polymers are allowed to penetrate the free pores of the porous vitrified grinding stone for the supercolloid mill and fill them from the surface of the walls of free pores in the range of 30 to 60% of the total volume in said grinding stone so as to leave 70-40% of the free pores in the grinding stone for the supercolloid mill, and to ensure their volume Vp within the range 0.09-0.21, and a method for producing a composite of grinding stone and polymer for a supercolloid mill, characterized in that the monomer or oligomer of thermoplastic and thermosetting plastics (free-flowing) inside the free pores of a porous vitrified grinding stone for a supercolloid mill resin) is forced to be introduced at reduced or applied pressure, and after the impregnated monomer is polycondensed in place using thermal energy, the final reaction is carried out Botko surface.

As described above, the main essence of the invention is that it is found

a grinding stone and polymer composite for a supercolloid mill and a method for manufacturing it, where the connecting pores present in the mass of vitrified grinder are filled

a fixed amount of thermoplastic polymer from the surface of the free pore walls towards the central part of the free pores.

Regarding manufacturing technology

5 of the composite in order to allow the polymer to fill the free pores of solid materials, the details were published in the outgoing Epoch of Plastic for five months from September 1978, but the technologies for manufacturing the composite of vitrified grinder with polymer were not affected. Since the impact resistance is reduced by allowing the polymer to be completely filled. The connecting pores of the vitrified grinder, it is important in what condition and how much polymer can be allowed to form in these pores.

That is, as shown in the sectional diagram of Fig. 1, the cross section of a conventional vitrified grinder has a porous structure, where the connecting pores are between grains 1, and when water pours onto the grinding surface 5 of the mat, water penetrates instantly. According to the invention, as shown in Fig. 2, the raw material, which is a monomer of thermoplastic plastics, is allowed to penetrate into the compounds. empty pores 2 along the surface of their walls, this impregnated monomer being polymerized in place, and the thermoplastic polymer 3 being used to fill to obtain the desired composite from

5 grinding stones and polymer for a supercolloid mill ..

Free pore content in stators and rotors made from AliOa stone grains No. 46, No. 80 and No. 120 (hardness T)

0 is presented in table 1.

If we take the free pores shown in Table 1 as 100, then, for example, from 40 to 60% and about 30 to 40% of the volume of free pores are filled with polymers in the surface layer and in the inner part of the grinding stone , respectively, so that the amount of filling-. of the polymer decreased from the surface layer, in the direction of the inner layer throughout the grinding stone.

Although a specific method is described later, it becomes apparent from experimental results that a polymer distribution gradient could be achieved by passing through a degassification process after impregnation of vinyl monomer.

Next, an explanation of the manufacturing process of the invention is presented in the following flowchart.

VM (vinyl monomer) impregnating (processing) liquid

ny

Loading in impregnation tank f

Pumping off at

reduced pressure

Vacuum

suction

Debugging process

Commodity Products

  It has been found that the manufacturing method is based on the above process diagram. Firstly, the grinding stone is roughly processed in a form suitable for a supercolloid mill and, after measuring the weight, it is placed in an impregnation tank, which is then pumped out using a vacuum pump. After a fixed suction value is reached at reduced pressure; in order to

 remove the air present in the: free pores of the grinding stone, the previously prepared impregnating stone. a substance, such as a vinyl monomer,

. is introduced into the impregnation container from the storage container through a pipe. The treatment fluid is brought in until the grinding stone is completely submerged, and then the valve on the vacuum suction pipe is closed. At this time, a pressure on the liquid level occurs under atmospheric pressure to introduce the treatment liquid into the free pores of the grinding stone.

. After the liquid level returns to normal pressure, the vacuum suction pipe is connected to the pressure vessel with gaseous Na using a coiled pipe and pressure is applied to the liquid level in the impregnation vessel. When a pressure value of 20 kg / cm2 is reached, the outlet of the pressure vessel containing Ma is closed so as to be able to maintain this state for several hours. ,

At the end of a certain amount of time, the internal volume of the tank for

The impregnation returns to normal pressure.

Extract (Wrapping), Product

water, and the treatment fluid in the tank is completely discharged. Thereafter, the suction inlet is again connected to a vacuum pump to suction under reduced pressure. The distribution of the treatment fluid is controlled in the grinding stone by reducing the pressure and the period of time, and the treatment fluid becomes abundant in the surface layer with a gradual decrease in its amount towards the inner layer.

After a new return to normal pressure, the grinding stone is removed from the impregnation vessel and carefully wrapped in cellophane. At this time, a weight measurement is taken to determine how much of the processing fluid has been impregnated with the grinding stone.

After the grinding stone, impregnated with vinyl monomer and wrapped in cellophane, is placed in a polymerization tank with hot air circulating, preheated to 60-70 ° C, polymerization is initiated for about 4 hours, and the temperature inside the grinding stone gradually

goes up. After reaching a temperature of about 160 ° C, the internal temperature gradually decreases to become the same as the temperature inside the polymerization vessel.

If the polymerization is complete at this time, the grinding stone is removed from the polymerization vessel and weight is measured. From the weight during the impregnation and the weight during the complete polymerization, the degree of conversion of the treatment fluid and the degree of polymer formation can be determined. The cellophane is removed and the grinding stone is sent to carry out the finishing process.

For finishing, a diamond stone processing machine is used. The hearth is poured on the surface and, in addition, the outer circumference is tightly tightened with a metal band. The finished product is used to make a mascolloid to produce a supercolloid mill. At this time, it is important to reduce the width of the grinding stone by a few millimeters both from above and from below.

As a specific example, below is presented as volume fractions a portion of the data on the grinding stone composite, where methyl grinding stone No. 49 (stator and rotor) made by Clemorton Co was impregnated with methyl methacrylate (MMA) and then polymerized. t

(No. 46 manufactured by Clemorton Co (see table, 2)

As processing fluids that are used for impregnation, vinyl monomer and vinilidene monomer are usually used independently or in combination, but if supplied. the purpose of obtaining high heat resistance, a monomer or oligomer of polycarbonate, polyimide and the like is used. Any commercial products may be used as initiating polymerization, but benzoyl peroxide (BPO) or azobisisobutyl nitrile (AIBN) is preferably used and less than 1% by weight of the monomer is added.

PRI me R 1, Vitrified grinding (grain: AhOs) No. 46 manufactured by Cenorton Co (volume: 1652 cm3, weight: 3900 t, specific gravity: 2.36, true specific gravity: 4.99), was introduced under reduced pressure through an inlet on one side of the liquid impregnation tank by attaching a vacuum pump using a thick-walled rubber tube. The pressure was reduced to 10 mmHg by evacuation for about 1 hour.

Suction continued for more than 1 hour in this position, after which

“The wound was closed. On the other hand, the liquid obtained by adding 50 g of AIBM to 5 kg of MMA was prepared in a container, and MMA was introduced into a container for

impregnation. Since there was a vacuum inside the impregnation vessel, the MMA, when fed through the pipe, quickly entered the vessel. Upon completion, the supply of MMA to the container opened the valve to achieve

normal pressure. A suction inlet for reducing pressure was connected to a pressure vessel containing nitrogen gas, and, after all valves were closed, Na gas was introduced to apply pressure to the liquid level. When the pressure level in the impregnation tank reached 25 kg / cm2, the tanks were allowed to simply remain for about 3 hours, leaving

the taps are closed and maintaining the state as it was. The taps were then opened to return the internal volume of the tank to normal pressure, and the impregnating liquid MMA was completely removed from the tank. All taps were closed again for suction under reduced pressure.

After the internal volume of the container was returned to a pressure of about 100 mmHg, suction continued for about 30 minutes, at which time the taps were closed and the container was left for another 10 minutes. After that, all the taps were open. The grinding stone was removed from the impregnation tank and the mass was measured. It was found that the mass was 4625 g, so that the amount of MMA impregnated was about 275 g. (Apparently, 725 g - approx.

translator).

MMA impregnated crushing stone was wrapped three times in cellophane and placed in a polymerization vessel with

by circulating hot air, preheated to a temperature of 75 ° C. After about 3 hours, heat was gradually generated, and the internal central temperature reached 180 ° C. Then

the heat of polymerization was gradually reduced and equilibrium was established with the temperature in the polymerization vessel. It took about 5 hours for the complete polymerization to be achieved after being placed in the polymerization vessel. The grinding stone composite with the polymer was removed by removing the wrapper from cellophane, and a weight was measured which turned out to be equal to 4480 g. From 72G g of MMA; introduced as monomer, 580 g was

converted to a polymer with a conversion of 80%.

The total weight of 580 g of MMA polymer corresponds to 13%. According to the calculation, 19.2% of the voids were filled on average, based on the true specific gravity. However, when studying the cross section using an optical microscope, it was confirmed that the amount of polymer was large in the surface layer and gradually decreased towards the inner part.

The remaining voids determined by calculation were 80.8%. For the final processing of this grinding stone composite, a diamond stone processing apparatus was used and, when pouring cold water to the surface, leveling was carried out. The outer periphery of the product was tightly tightened with a metal bandage,

A mascolloider was made from the product, and when used in a supercolloid mill, excellent results were obtained.

PRI me R2. Place the vitrified grinding stone (grain: AlaOs) No. 46 manufactured by Clenorton Co (volume, 1749 cm, weight: 4130 g, specific gravity: 2.36, true specific gravity: 4.92) in an impregnation container and the impregnation was carried out in the same manner as in example 1. As a processing liquid, a mixture of MMA with styrene (St) was used with a ratio of the components of the mixture 1: 1 with the addition of 1.5% BPO. The weight after impregnation was 5142.5 g, and the amount of processing liquid impregnated with the grinding stone was 1012.5 g.

The weight after extraction at the end of the polymerization was 4940 g, which corresponds to a polymer weight of 810 g. The degree of conversion resulting from the polymerization was about $ 0%. The total polymer mass, equal to BTO g, corresponds to 16%. Of the voids determined by calculating from the true specific gravity, 61.4% of the voids were filled on average. However, when observing the cross-section surface using an optical microscope, it was found that the polymer filled in a large amount of the surface layer and the filling size became smaller towards the inside. From the observational results, the fact that the polymer propagated from the surface of the walls of free pores and the central parts remained free was obvious. According to the calculation, the amount of remaining voids not filled with the polymer was up to 38.6%. The final processing was carried out using the same method as in example 1,

Areas of use for conventional grounded grinding stones: almost all were used for planing and polishing; a portion was used for wet grinding, but indicated defects such as clogging of recesses and the like on the surface with organic materials.

A grinding stone composite according to the invention: planing and polishing are possible, of course; aseptic, hygienic grinding is possible in the food, chemical and medical industries; possibly dry grinding; fine grinding of elastic materials, such as wood and cellulosic materials,

When implementing one example using wood material, it was difficult to finely grind it, but by using a composite grinding stone, more than 80% of the material with a particle size of less than -10 microns could be obtained. From the results of analyzes carried out by X-ray diffraction, it became apparent that a remarkable feature was that, in the case of conventional grinding, the crystalline state of the wood material was destroyed and amorphousness appeared, whereas, in the case of the use of the composite grinding stone, a thinner stone could be obtained particle size without breaking crystals.

In addition to the foregoing, when using a supercolloid mill with a composite grinding stone, there is no need to worry about the destruction of teo operating time, and super-fine grinding can be carried out with strong compression. Therefore, there is no need for screening powders on a micron scale, which leads to an increase in productivity.

The basis of these advantages was that the use of a composite vitrified grinding stone using vitrified grinding stone as a starting material contributed to abrasion resistance and increased resistance, since the polymer was used to hold and stabilize grains, and the binding forces became large.

Further, the results of comparing conventional products with products of the invention are summarized in Table 3.

Comparative test results for the resistance of a grinding stone according to the invention and a conventional vitrified grinding stone.

The experimental method and the results of grinding performed using a mascolloader with a composite grinding stone with an MMA polymer are as follows: composites of grinding stone and polymer according to the invention were used for stator grinding stone and rotor grinding stone. The rotary grinder can slide up and down freely with the metal nozzle of the regulator and, by adjusting the gap so that the particle size of the product meets the requirements for grinding raw material, extremely stable super-quiet particles can be obtained continuously over a long period of time, which do not need a screening process and excellent results are achieved.

Claims (2)

The claims Crushed stone for a supercolloid mill, obtained in the form of a composite material containing a porous vitrified crushed stone for a supercolloid mill, in which free pores are at least 70% filled with a thermoplastic or thermosetting polymer, characterized in that said thermoplastic or thermosetting polymer , expanding in the direction from .VM: the crumbling stone part is strong, VP: polymer filling the grindstone voids, Vv: remaining voids in the composite grinding stone. Note: The best way is to judge the characteristics of materials by volume fraction of the elements making up the materials. The volume of free pores filled by it, fills them by more than 30% so that the volume coefficient Yp of the remaining internal voids in the final milled stone composite is in the range 0.09-0.21. 2. A method of processing crushed stone for a supercolloid mill, in which a composite material is converted from a porous vitrified crushed stone for a supercolloid mill, in which the internal free pores are filled with less than 70% thermoplastic or thermoset polymer, characterized in that the monomer or oligomer is thermoplastic thermosetting type or synthetic rubbers are forced into the free inner pores of a porous vitrified crushed stone for super of an olloid mill under reduced or increased pressure, accompanied by degassing, by taking a portion of said monomer or oligomer filling the internal pores of the process control system so that the polymer volume after polymerization is reduced to more than 30% with respect to the total volume of internal free pores in the crushed stone, and as a result of subsequent polymerization and / or condensation, the introduced monomer or oligomer has a volumetric coefficient of residual free pores in the final Nominal composite material and crushed stone, reduced to values of 0.09-0.21. ... Table 1 Table 2 Vitrified Grinding Stone A strong dispersion arises between the respective products. The thermal compressibility is low, which is why the use of a leveling method for grinding stones is generally eliminated. Abrasion is great due to the effect of precipitation in experiments. In particular, this phenomenon is noticeable during the grinding of substances with high hardness. Resistance and resistance to high temperature are low. Cracks, damage and dispersion are possible. The grinding ability, i.e. the ability of the grinding stone to produce superfine particles of matter, is small. This characteristic makes up about one third of the right column. Table3 Crushing stone corresponding invention The issue of dispersion between products can be resolved since a homogeneous structure is obtained due to the chemical reaction of the filling polymer and processing. High compression resistance High abrasion resistance. Particularly high abrasion resistance is due to the prevention of grain loss, since the grains are constantly stabilized and there are no voids, The resistance and, in particular, the resistance to high temperature at high compressive loads are excellent. Cracking, damage and dispersion are completely absent. The grinding ability, i.e., the ability of the grinding stone to produce superthin particles of matter, is excellent. This characteristic is 2.5-3 left column.