KR920009290B1 - Grindstone-polymer composite or super colloid mill and manufacturing method thereof - Google Patents

Abstract

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Description

Grindstone-polymer composite for super colloid mill and its manufacturing method

1 is a partial cross-sectional view of a conventional vitrified grinder,

2 is a partial cross-sectional view of the vitrification grinder (polymer composite) of the present invention,

3 and 4 are views showing a state in which the polymer composite vitrification grinder of the present invention is installed in a super colloid mill as a fixed grindstone and a rotating grindstone.

The present invention relates to a grindstone-polymer composite for a super colloid mill and a method for producing the same.

One of the uses of unused resources is paste meat without the lean meat of chickens, pigs and cows and lean meats, soybeans and crops in finely divided form and other raw materials in ultrafine form. Supplying them is a major development issue.

At present, various mills are commercially available, and as one of them, a super colloid mill (liquefaction mill) is preferably used for industrial purposes.

An example of these is a colloider (Masscolloider) which may be mentioned as a representative of the super colloid mill. The machine consists of two sets of upper grinder and lower grind, and the space between them is freely adjustable. When the upper grinder is fixed and the lower grinder is rotated at high speed, strong centrifugal force, impact milling and shear stress are generated between the upper grinder and the lower grinder. Ultra fine grinding is realized by the action of all of them. The grindstone materials used for this require adequate hardness and toughness.

For example, in using the above-described mass collider, the performance of a conventional vitrifide grinder (grinderstone) is described. First, the raw materials introduced into the hopper are first impeller and high speed at the tip of the shaft. The impact force and centrifugal force generated by the rotating lower grinder are supplied to the gap between the two upper and lower grinders, and are subjected to the strong shearing, compressive and milling forces caused thereby. As a result, the raw material is gradually released after being finely divided.

The life of the supercolloid mill depends on the life of the vitrified grinder. However, its biggest drawback is that the damage (breaking) of the grinder occurs easily, which may be related to the case of deformation due to thermal expansion resulting from a non-uniform distribution of frictional heat during operation. This is why conventional grinders need suitable toughnesses.

When using a high-strength material or a dry material as the raw material to be crushed, the frictional heat of the grinder is particularly high, and it is easy to cause damage (destruction). In order to prevent this, in the case of widening the gap between the grinders, pulverization becomes impossible. In order to solve the above problems, several improvement methods have been tried for many years, but have not been successful.

If the damage of the grinder is not caused by frictional heat as described above, the conventional method for pulverization can be completely changed, and the production capacity will be greatly increased. For example, until now, the generation of frictional heat on the grinder In order to suppress the speed of the grinder was reduced. Therefore, the decrease in productivity was inevitable. Also, because of the above reasons, manufacturers of vitrified grinders could not manufacture large diameter grinders for high-speed rotation, but if there is no fear of damage (destruction), the manufacture of super colloid mills by manufacturing large diameter vitrified grinders Will be available to them. As a result, if the diameter is increased by, for example, 50%, the output will be increased by 2.5 times. Therefore, the most important question is whether it is possible to secure stability in operation.

The advantages of the present invention will be described in detail in the following examples. The vitrified grinder consists of three members: grain, binder and connected pores. When protein material adheres to the pores, one of the three major members, decay by unwanted bacteria occurs in these parts. Therefore, in use, a metal brush or the like should be used to remove and clean the attached material, but there is no method for cleaning the material attached to the inner pores. In addition, since the distribution of these pores is nonuniform, expansion of cracks is caused by frictional heat. If the material having the desired properties can be artificially filled in these connecting pores, the raw material for grinders, Alundum type (Al ₂ O ₃ ) and Carborundum type (SiC) Better Borazom type can be used.

When grinderstone is manufactured using this borazone type, and super colloid mill is manufactured using this grindstone, it is possible to mill hard materials, finely pulverize and ultrafine pulverize dry materials, and fine and supercolloid milling. Will greatly contribute to the industry.

In the present invention, the thermoplastic polymer and the thermosetting polymer in the inner pores of the porous vitrified grindstone for the super colloid mill, 70 to 40% of the pores in the grindstone for the super colloid mill, and the volume fraction Vp thereof is 0.09 to 0.21 Providing a grindstone-polymer composite for a super colloid mill characterized in that it is filled from the walls of the pores within a range of 30 to 60% of the total pore volume in the grindstone to a range of; Also, into the inner pores of the porous vitrified grindstone for super colloid mill, monomer or oligomer of thermoplastic and thermosetting plastics (synthetic resin) is forcibly injected under pressure or pressure, and then the impregnated monomer is applied with thermal energy. It provides a method for producing a grindstone-polymer composite for a super colloid mill, characterized in that the polycondensation in the in-situ to perform the surface processing.

As described above, the main point of the present invention is a grindstone-polymer composite for super colloid mill, in which a certain amount of thermoplastic is fixed in the connecting pores present in the structure of the vitrification grinder and filled from the wall surface of the pores toward the center of the pores. And a method for preparing the same.

The method for producing a composite article in which the polymer is filled into the pores of a solid material is described in detail in the plastic age issued from September 1978 to 5 months. However, no method of making vitrified grinder composites containing polymers is mentioned. Since the impact strength decreases when the polymer is filled in the entire connecting pores of the vitrified grinder, it is important to determine how many polymers are formed in these pores in what state.

That is, as shown in the partial cross-sectional view of FIG. 1, the cross section of a conventional vitrified grinder has a porous structure, wherein the connecting pores 2 are located between the grains 1, and water is deposited on the surface of the grinder. When poured, water is immediately penetrated. In the present invention, as shown in FIG. 2, the monomer of the thermoplastic plastic, which is a raw material, is impregnated into the connecting pores 2 along the wall thereof, and the impregnated monomer is polymerized in-situ and the thermoplastic polymer 3 is Gradient filling produces a grinderstone-polymer composite for the desired supercolloid mill.

The following description is an example of the present invention. Table 1 shows the processing rates of stators and rotors prepared from grains of emulsified Al ₂ O ₃ No. 46, No. 80 and No. 120 (hardness: T).

TABLE 1

When the porosity shown in Table 1 is 100, the polymer is filled in about 40 to 60% and about 30 to 40% of the pore volume, respectively, in the surface layer and the inner part of the grindstone, respectively. It gradually decreases from the surface layer toward the inner layer.

The method for this will be described later, but it is demonstrated from the experimental results that the polymer distribution gradient can be obtained by impregnating the vinyl monomer and then treating it with a degassing method.

The manufacturing method of this invention is as showing in the following block diagram.

The manufacturing method is based on the above configuration diagram. First, the grindstone is roughened into a form usable for a super colloid mill, and then weighed, placed in an impregnation bath, and evacuated with a vacuum pump. After a certain amount of suction is carried out under reduced pressure to remove the air present in the grindstone pores, a preprepared impregnate, for example a vinyl monomer, is introduced into the impregnation bath from a storage tank through a pipe. The treatment liquid is supplied until the grindstone is completely locked, and then the coke of the vacuum suction pipe is opened. At this time, the level of the liquid is pushed by atmospheric pressure, and the treatment liquid is introduced into the pores of the grindstone.

After the liquid level returns to the normal pressure level, the vacuum suction pipe is connected to the N ₂ gas bomb and pressure is applied to the liquid in the impregnation tank. When the gauge pressure reaches 20 kg / cm ² , the outlet of the N ₂ bomb is closed off and maintained for several hours in this state.

After a certain time has elapsed, the inside of the impregnation tank is returned to normal pressure, and the treatment liquid in the impregnation tank is completely discharged. Then, the inlet of the vacuum smoker is connected to the vacuum pump again to reduce the pressure to perform suction. The distribution of the treatment liquid is controlled in Grindsonton by pressure-reducing conditions and elapsed time, so that the treatment liquid is large in the surface layer and gradually decreases as it goes to the inner layer.

After returning to normal pressure, the grindstone is removed from the impregnation bath and well wrapped with cellophane. At this time, the weight is measured to determine the amount of the treatment liquid impregnated into the grindstone.

The grindstone impregnated with vinyl monomer and wound with cellophane is placed in a thermo-circulation polymerization tank previously heated to 60 to 70 ° C. and polymerization is initiated within about 4 hours, and the temperature inside the grindstone is gradually increased. After the temperature reaches about 160 ° C., the internal temperature is gradually lowered to be equal to the temperature inside the polymerization tank.

When polymerization is completed in this state, the grindstone is taken out of the polymerization tank and weighed. From the weight at the time of impregnation and the weight at the completion of polymerization, the conversion rate and the polymer formation rate of the treatment liquid are measured. The cellophane is released and the grindstone is introduced into the processing process.

In this processing step, a diamond dresser is used. Pour water on the surface and tie the outer peripheral surface tightly using a metal band. The processed product is fixed in a mass loader to produce supercolloids and goods. At this time, it is important to fix the grindstone reduced in width by a few mm on both the upper and lower.

As an example, data obtained by using a composite grindstone polymerized by impregnating methyl methacrylate (MMA) in Grindstone No. 46 (stator and rotor) manufactured by Glenorton Co. A portion of is described below based on the volume fraction.

＊ VM: Real part of grindstone

VP: polymer filled in pores of grindstone

Vv: Residual pores of composite grindstone

Note: It is advisable to judge the properties of a substance by the volume fraction of the component.

Although the vinyl monomer and the vinylidene monomer may be used independently as a treatment liquid for impregnation, in order to obtain heat resistance, monomers such as polycarbonate, polyimide, or olimere may be used. Although all commercially available products can be used as a polymerization initiator, it is preferable to use benzoic acid peroxide (BPO) or azobisisobutyl nitrile (AIBN) in the quantity of 1% or less based on the weight of a monomer.

Example 1

Using a rubber tube having a thick wall under reduced pressure for a vitrified grindstone (grins: Al ₂ O ₃ ) No. 46 (volume: 1652cm ³ , weight: 3900g, specific gravity: 2.36, specific gravity: 4.99) manufactured by Klenton. Connected to the vacuum pump and exhausted from the inlet at one side of the impregnated hydrogen. The pressure is reduced to 10 mm Hg for about 1 hour with an aspirator.

In this state, the coke which continued suction for 1 hour is closed. Meanwhile, a solution in which 50 g of AISM is added to 5 kg of MMA is prepared in a tank, and the MMA is introduced into an impregnation tank. Since the interior of the impregnation tank is a vacuum, the MMA flows violently through the pipe and is introduced into the tank. After the MMA is fully introduced into the tank, the cock is opened and changed to static pressure. Connect the suction inlet for pressure reduction to the nitrogen gas cylinder and close the coke completely and introduce N ₂ gas to apply pressure to the liquid surface. If the pressure value of the impregnation tank indicates 25 kg / cm ² , the impregnation tank is maintained for 3 hours with the cork closed. The cock is then opened to switch the interior of the bath to normal pressure and the MMA treatment liquid is extracted completely from the bath. All coke is resealed and released under reduced pressure.

After the inside of the bath has been converted to a pressure of about 100 mm Hg, suction is continued for about 30 minutes. At the same time, the coke is sealed and the bath is left for 10 minutes. Then, all the corks are opened, the grindstone is taken out of the impregnation bath and weighed. The center of gravity was 4625g, so that about 275g of MMA was impregnated.

The grindstone impregnated with MMA is wound in three layers with cellophane and placed in a hot-circulating polymerization bath previously heated to a temperature of 75 ° C. After about 3 hours, heat gradually develops and the internal center temperature reaches almost 180 ° C. The heat of polymerization is then gradually lowered to equal the temperature in the polymerization bath. After placing in the polymerization bath, it takes about 5 hours to complete the polymerization. The composite grindstone containing the polymer was unwound and taken out of the cellophane, and the weight thereof was found to be 4480 g. 580 g of 725 g MMA impregnated as monomer were converted to polymer, with a conversion of 80%.

580 g of MMA polymer corresponds to 13% by weight. Calculations from the abyss resulted in an average of 19.2% of pores. However, looking at the cross section under an optical microscope, it was confirmed that the polymer is rich in the surface layer and gradually decreases toward the inside.

Residual porosity derived from the calculation is 80.8%. In the processing of this composite grindstone, a diamond dresser is used, and cold water is poured onto the surface to make it flat. Tighten the outer circumference of the product with a metal band.

The product was fixed in a mass loader and the supercolloid mill was tested and excellent results were obtained.

Example 2

A vitrified grindstone (grins: Al ₂ O ₃ ) No. 46 (volume: 1749 cm ³ , weight: 4130 g, specific gravity: 2.36, specific gravity: 4.92) manufactured by Clentonton in the impregnation tank was placed and the same as in Example 1. Impregnated in a way. 1.5% BPO was added to MMA and styrene (st) mixture of the mixing ratio 1 as a process liquid, and it used. The weight after impregnation was 5142.5 g, and 1012.5 g of the treatment liquid was impregnated into the grindstone.

The weight taken out after polymerization was 4940 g, corresponding to 810 g weight of the polymer. The conversion through polymerization is about 80%. 810 g of polymer corresponds to 16% by total weight. An average of 61.4% of the pores were filled in the pores calculated from the specific gravity. However, when the cross section was observed under an optical microscope, the polymer was richly packed in the surface layer, and the amount of filling gradually decreased inward. The observations proved that the polymer grows from the wall of the pores and the core becomes the pores. The calculation showed that 38.6% of residual pores were not filled with polymer. Machining is carried out using the same method as in Example 1.

The range of use for ordinary vitrified grindstone is as follows. : 1) Almost all are used for grinding and polishing. 2) Some are used for wet grinding, but defects such as the filling of recesses on the surface are filled with organic materials.

The use range of the composite grindstone of the present invention is as follows. : 1) used for grinding and polishing, as well as 2) for aseptic hygiene grinding in food, chemical and medical industries, 3) for dry grinding, 4) for substrates of elastomers such as wood and cellulose materials. Can be differentiated.

In one embodiment of the wood material, it has been difficult to finely grind the wood material until now, but by using the composite grindstone, a yield of 80% or more with a particle size of 10 microns or less can be obtained. X-ray thinning analysis shows that the crystallization region of the woody material is amorphous in the case of normal grinding, whereas in the case of using complex grindstones, the particle size shows a distinctive property that finely crushes without destroying the crystal. It became.

In addition to the above-mentioned cases, in the case of using the super colloid mill incorporating the composite grindstone, there is no fear of destruction during operation, and all ultra-fine milling can be performed under high pressure. Therefore, the sorting of powder in milli microns becomes unnecessary, resulting in an increase in productivity.

This advantage is confirmed in that vitrified grindstone in which composite vitrified grindstone is used as a starting material is excellent in increasing durability and abrasion resistance, which contributes the greatest since the polymer assists the stability, holding strength, and bonding strength of the grain.

The following table summarizes the comparison of conventional grindstone products with the grindstone products of the present invention: Durability tests for the grindstones of the present invention and conventional vitrified grindstones

Experimental methods and results of milling MMA polymers using a masscoder equipped with composite grindstones are as follows: As shown in FIGS. 3 and 4, the grindstone-polymer composite of the present invention Used for fixed grindstone and rotary grindstone. The rotary grinder can be freely moved up and down by operating metal parts, and the gap is adjusted to the desired particle size in order to grind the raw material, thereby obtaining extremely stabilized ultra-fine particles without the need for long time sorting operation. .

Claims (3)

In the inner pores of the porous vitrified grindstone for the super colloid mill, the thermoplastic polymer and the thermosetting polymer allow 70 to 40% of the pores in the grindstone for the super colloid, and the volume thereof is 0.09 to 0.21. A grindstone-polymer composite for super colloid mill, characterized in that it is filled from the wall surface of the pores within the range of 30 to 60% of the total pore volume in the grindstone. Into the inner pores of the porous vitrified grindstone for the supercolloid mill, monomers or oligomers of thermoplastic and thermosetting plastics (synthetic resins) are forcedly injected under pressure or reduced pressure, and the impregnated monomers are then subjected to thermal energy. To polymerize in situ, and to perform surface processing, to prepare a grindstone-polymer composite for a supercolloid mill. 3. A method according to claim 2, characterized by enclosing the outer peripheral surface of the product with a metallic band, thereby producing a grindstone-polymer composite for a supercolloid mill.

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