UA152012U - A method of producing porous filter material for purification of liquid and gaseous media - Google Patents

Abstract

A method for obtaining porous filter material for purifying liquid and gaseous media includes the formation of filter material from a 0.2-1.4 % aqueous suspension containing cellulose and filler, its subsequent dehydration by gravity and vacuuming at a residual pressure of 0.2-0.8 kgf/cm2, pressing under pressure, and drying under heating. Thermoplastic polymer powder with a particle size of no more than 0.4 mm in the amount of 0.5-25 wt. % by weight of cellulose, wherein the molded material is pressed under pressure with a force of 0.6-6.0 kgf/cm2, followed by drying at a temperature of 90-120 °C for 15-30 minutes, after which the molded material is heat treated with air or steam at the melt temperature of the thermoplastic polymer for 15-20 minutes. In this case, 0.5-65.0 wt. % by weight of cellulose mineral filler with a particle size of no more than 0.074 mm is used as a filler.

Description

The utility model belongs to the field of obtaining porous filter materials for the purification of liquid and gaseous media, which are used as filters for the purification of liquid and gaseous media, and can also be used in the production of materials for encapsulating repellents, poison chemicals, odorous substances, containers, shoe insoles, which prevent the development of mold and fungal diseases.

The closest analogue is the method of obtaining porous filter material for the purification of liquid and gaseous media by forming it from a 0.2-1.4 95th aqueous suspension containing cellulose and a filler, then dewatering it by gravity and vacuuming it at a residual pressure of 0.2- 0.8 kgf/sme, pressing under pressure and drying under heating.

The technological process of manufacturing the porous material of filter cardboard consists of: - pre-dissolution of cellulose of the CA brand or cellulose of cordwood; - or viscose, sulfate, or sulfite, or sulfite for the production of sodium carboxyl cellulose, or sulfate, sulfite bleached refined; - preliminary dissolution and grinding of cotton pulp; - preliminary dissolution (cutting) of the filler - chrysotile asbestos of normal strength or iron-free asbestos.

Pre-prepared components are mixed in the ratio: 12 wt. 95 cotton cellulose, 68 wt. 95 cord or viscose, or acetate, or bleached refined cellulose, 20 wt. 96 asbestos per 100 wt. 95 of absolutely dry porous material, and prepare an aqueous suspension of the mixture with a concentration of 0.2-1.4 95.

Next, on the K-14A cardboard machine, a casting of a cardboard canvas is made - material, for example, from the above-mentioned composition (mixture). First, dehydration takes place at a residual pressure of 0.2-0.8 kgf/cm2, followed by pressing at a pressure of 0.5-1.0 kgf/cm and drying at 80-140 "С | see "Encyclopedia of Polymers", vol. 2 , M., 1974, pp. 549-555).

The disadvantages of the known method are the low strength of the porous material and its resistance to abrasion, especially in a wet state, excluding the shape stability of the material and the possibility of adjusting the pore structure. In addition, the porous material is toxic. This is explained by the fact that when in contact with an aqueous environment, cellulose fibers swell and

Because the filter loses its shape and strength, it is not excluded that asbestos fibers, which have carcinogenic properties, are poured into the filtrate.

Due to the swelling of the porous material and its loss of shape, its regeneration is impossible, which determines its one-time use.

The reason that prevents the obtaining of the technical result of the useful model, which is claimed to be the closest analogue, is the following: when forming a porous material from an aqueous suspension that contains cellulose with its preliminary dissolution and grinding and a filler for which chrysotile asbestos of normal strength or iron-free asbestos is used, pressing the material after casting the cardboard canvas at a pressure of 0.5-1.0 kgf/cm? and drying it at 80-140 "C. Cellulose fibers swell when in contact with an aqueous environment and the filter loses its shape and strength, as well as resistance to abrasion, and it is not excluded that asbestos fibers, which have carcinogenic properties, are poured into the filtrate.

The task of a useful model is the development of a method of obtaining porous filter material for cleaning liquid and gaseous media, in which, while ensuring the shape stability of the porous material with a regulating pore structure, it is possible to increase its strength and resistance to abrasion, especially in a wet state, with the exception of toxicity.

The problem is solved by the fact that in the method of obtaining the porous material of filters for the purification of solid and gaseous media by forming it from 0.2-1.4 95-0 aqueous suspension containing cellulose and filler, its subsequent dehydration by gravity and vacuuming at residual pressure 0.2-0.8 kgf/cm, pressing under pressure and drying under heating, according to a useful model, thermoplastic polymer powder with a particle size of no more than 0.4 mm is used as a filler in the amount of 0.5-25 wt. 95 from the mass of cellulose, pressing of the molded material is carried out under pressure with a force of 0.6-6.0 kgf/cm7, and drying - at a temperature of 90-120 C for 15-30 minutes, after which the molded material is heat-treated with air or steam at the temperature of the melt thermoplastic polymer for 15-20 minutes, while 0.5-65 wt. is additionally used as a filler. 95 by mass of cellulose mineral filler with a particle size of not more than 0.074 mm, selected from the group containing talc, shungite, zeolite, apatite, diatomite, perlite, trepel or mixtures thereof.

The technical result of the use of a useful model is that the production of a porous material will increase its strength and resistance to abrasion, excluding toxicity while ensuring the shape stability of a material with a regulating pore structure, due to the fact that a powder of a thermoplastic material with a given particle size is used as a filler and quantity, additional use of mineral filler is possible.

Essential features of a useful model are: formation of material from 0.2-1.4 95-0 water suspension; the presence of cellulose and filler in the aqueous suspension; dehydration of the material by gravity and vacuuming at a residual pressure of 0.2-0.8 kgf/cm"; pressing of the material under pressure; drying of the material by heating; use as a filler of thermoplastic polymer powder with a particle size of no more than 0.4 mm in the amount of 0.5 -25 wt. 9o from the mass of cellulose; pressing of the formed material under pressure with a force of 0.6-6.0 kgf/cm; drying at a temperature of 90-120 "C for 15-30 minutes; heat treatment of the molded material with air or steam at the melting temperature of the thermoplastic polymer for 15-20 minutes; additional use as filler 0.5-65.0 wt. 95 by mass of cellulose mineral filler with a particle size of not more than 0.074 mm, selected from the group containing talc, shungite, zeolite, apatite, diatomite, perlite, trepel or mixtures thereof.

The new essential features of the useful model are: - the use as a filler of thermoplastic polymer powder with a particle size of no more than 0.4 mm in the amount of 0.5-25 wt. 95 from the mass of cellulose; - pressing of the formed material under pressure with a force of 0.6-6.0 kgf/cm; - drying at a temperature of 90-120 "C for 15-30 minutes; - heat treatment of the molded material with air or steam at the temperature of the thermoplastic polymer melt for 15-20 minutes; - additional use as a filler of 0.5-65.0 wt. 95 mass of cellulose mineral filler with a particle size of no more than 0.074 mm, selected from the group containing talc, shungite, zeolite, apatite, diatomite, perlite, trepel or their mixtures.

Due to the fact that thermoplastic polymer powder with a particle size of no more than 0.4 mm is used as a filler in the amount of 0.5-25 wt. 95 from the mass of cellulose or its mixture with a mineral filler in the amount of 0.5-65.0 wt. 95 by mass of cellulose with a particle size of not more than 0.074 mm, selected from the group containing talc, shungite, zeolite, apatite, diatomite, perlite,

For example, high-pressure polyethylene or low-pressure polyethylene, waste polyethylene, polystyrene, polyvinyl chloride in the form of powders and others are used as a thermoplastic polymer in a useful model, then when drying an aqueous suspension that also has cellulose of unequal grinding , the formation of a porous structure with a regulating pore size, both of the thermoplastic polymer particles and the size of the mineral particles and its concentration in the composition, occurs, and during heat treatment, the melting of the particles contributes to the bonding of cellulose fibers, as well as mineral particles (in the case of using their mixture ), which provides the cardboard filter with dimensional stability, strength in an aqueous environment, resistance to abrasion, especially in an aqueous environment, and prevents mineral and cellulose fibers from being removed into the filtrate. Obtaining the technical result is confirmed by the table.

Cotton cellulose and various brands of coniferous cellulose are used as cellulose when preparing an aqueous suspension, such as, for example, aqueous and viscose cellulose, sulfate cellulose, sulfite acetate cellulose, bleached refined cellulose.

An aqueous suspension is prepared from cellulose and filler.

The mineral fillers used are known natural minerals: - talc or aqueous zeolite, in which water can be removed when heated and reabsorbed by the mineral in a moist environment; - shungite - a natural mineral, is an elementary carbohydrate, which differs from anthracite by a small content of volatile components, and from graphite - by the absence of a crystalline structure; - apatite - basic anhydrous phosphates; - diatomite - the remains of siliceous shells or skeletons, synthesized by diatom algae, racchloria or flagellate algae (diatom silica); - perlite - a natural silicate of the opal type; - trepel - opal silica, which is an extremely small, irregularly shaped body with a diameter of 0.002 to 0.02 mm.

Due to the fact that the molded material is pressed under pressure with a force of 0.6-6.0 kgf/cm", and drying at a temperature of 90-120 "C for 15-30 minutes and heat treatment with air or steam at the temperature of the melt of the thermoplastic polymer for 15 - for 20 minutes, the formation of a porous structure takes place, which has the properties of reaching maximum values for ensuring strength, dimensional stability, resistance to abrasion, especially in a wet condition, with the removal of toxicity, which is confirmed by the data given in the table.

Thus, as a result of the set of known and new essential features listed above, it became possible to establish a cause-and-effect relationship between them, which provides the possibility of obtaining a technical result of the claimed useful model.

As a thermoplastic polymer in a useful model, for example, high-pressure polyethylene or low-pressure polyethylene, waste polyethylene, polystyrene, polyvinyl chloride in the form of powders with a particle size of no more than 0.4 mm and others are used.

The porous material is obtained as follows:

When mixing an aqueous suspension of cellulose of unequal grinding and a thermoplastic polymer filler, or mixing it with a mineral filler, a porous structure is formed, the pore sizes of which are regulated both by the size of the mineral particles and its concentration in the composition, and by the particles of the thermoplastic polymer, which during heat treatment melts and bonds between are cellulose fibers, as well as mineral particles (in the case of using their mixture), which provides the cardboard filter with form stability, strength in an aqueous environment and prevents mineral and cellulose fibers from being removed into the filtrate.

In the process of mixing, a solution of aluminum sulfate can be introduced into a suspension that has cellulose and a thermoplastic polymer or cellulose, a thermoplastic polymer and a mineral filler, which contributes to the reduction of the electrokinetic potential, which leads to a significant increase in the retention coefficient of fillers when casting samples and the formation of a more uniform mixture components.

An increase in the concentration of components in an aqueous suspension also leads to this effect.

The advantages of the proposed useful model are as follows: - the material is stable in a wet environment, which prevents the removal of cellulose fibers and particles of mineral fillers in the filtrate; - the material does not contain toxic or carcinogenic substances.

The obtained porous cellulosic material has a wide purpose, in connection with 3 of it

With manufacturability due to the use of known natural minerals, non-toxicity, as well as the elimination of workers' contact with harmful secretions in the process of technological operations.

Claims (1)

USEFUL MODEL FORMULA The method of obtaining porous filter material for cleaning liquid and gaseous media, which includes the formation of filter material from a 0.2-1.4 95-0 aqueous suspension containing cellulose and a filler, its subsequent dehydration by gravity and vacuuming at a residual pressure of 0.2- 0.8 kgf/cm7, pressing under pressure and drying under heating, which differs in that thermoplastic polymer powder with a particle size of no more than 0.4 mm is used as a filler in the amount of 0.5-25 wt. 956 from the mass of cellulose, while pressing of the molded material is carried out under pressure with a force of 0.6-6.0 kgf/cm", after which drying is carried out at a temperature of 90-120 C for 15-30 minutes, after which the molded material is heat-treated with air or with steam at the temperature of the thermoplastic polymer melt for 15-20 minutes, while 0.5-65.0 wt.9% of the mass of cellulose mineral filler with a particle size of no more than 0.074 mm, selected from the group containing talc or shungite, is additionally used as a filler , or zeolite, or apatite, or diatomite, or perlite, or trepel or their mixtures.