RU2331726C1 - Fibrous filtering material - Google Patents

Abstract

FIELD: textile, paper.

SUBSTANCE: invention refers to cellulose-paper industry. Fibrous filtering material is formed in the air environment and contains a chemical fiber - viscose, polyester or polypropylene, as well as milled paper loss with polymerisation degree of 200-800 and surface area of 100-9000 m²/g. The material also contains bast fiber and/or cotton production waste. The milled paper waste is processed by silicone hydrophobisator on silane or siloxane basis (5-25% from dry paper waste weight) and dehumidified to dryness of 85-88%. This provides oil capacity increase of the filtering material, as well as enhancement of its hydrophilic properties, which, in turn, leads to filtering material service life prolongation.

EFFECT: prolongation of filtering material service life.

2 cl, 1 tbl, 2 ex

Description

The invention relates to the pulp and paper industry and relates to a fibrous filter material for deep cleaning of liquid media from oil products emulsified in it, as well as gaseous media and obtained by dry molding.

Known filter material used for fine purification of oil of automotive diesel engines and obtained by dry molding (SU 654718, CL D21H 27/08, 1979).

Known filter material contains two fibrous layers based on viscose fiber and a binder with a ratio of layer thicknesses from 0.7: 1.5 to 1: 1.

In this case, when forming the fibrous layers, viscose fibers are separated by any known mechanical method, for example, by means of a rotating gear drum. The degree of separation of the fibers for the two layers is different, which is achieved by varying the rotation speed of the feed shaft and the gear drum itself.

Such filter material is characterized by high filtering properties and a sufficiently high service life of the material.

However, a disadvantage of the known filter material is the technological complexity of its manufacture.

Known fibrous sheet filter material containing chemical fiber and formed in the air (SU 336395 A1, CL D21F 11/14, 1972). At the same time, viscose staple fiber is used as chemical fibers.

Known sheet filter material having a sufficiently high filtering properties, as well as the necessary moisture resistance, can be used to clean cutting fluids.

However, when using a known filtering material at the final stage of water purification from oil products emulsified in it with small concentrations of about 50-100 mg / l, the effectiveness of such a material will be negligible.

The closest analogue of the present invention is a fibrous filter material containing chemical fiber - viscose, polyester or polypropylene - and ground pulp with a polymerization degree of 200-800 and a specific surface of 100-9000 m ² / g, and molded in air (RU 2153035, cl. D21F 11/14, 2000).

In this case, the pulp milling product is obtained in a hammer mill with a frequency of mechanical impacts of 2000-6000 beats / min, a single impact force of 40.0-200.0 kgf / cm ² and a processing time of 0.1-0.5 s, and the ratio of components in the fibrous filter material the following (wt.%):

chemical fiber 5-50 waste paper product 50-95

Known material has satisfactory sorption properties in relation to oil and oil products, providing the possibility of deep purification of water and air at low concentrations of the above products.

However, the service life of the known fibrous filter material is insufficient due to the low hydrophobicity of the material itself, which contributes to a significant increase in resistance during its operation.

A new technical result is to increase the oil consumption of the filter material while increasing its hydrophobicity, which leads to a significant increase in the service life of the proposed filter material.

This result is achieved in that the fibrous filter material containing chemical fiber — viscose, polyester or polypropylene — and shredded waste paper with a polymerization degree of 200-800 and a specific surface of 100-9000 m ² / g, and molded in air, additionally contains production waste flax and / or cotton, and as crushed waste paper, it contains waste paper treated with silicone water repellent selected from the group containing silanes and siloxanes in an amount of 5-25 wt.% of the mass of absolutely dry waste paper, and dried to dryness 85-88%, in the following ratio of these components (in wt.%):

chemical fiber 10-40 shredded waste paper 30-80 flax and / or cotton production waste 10-30

In this case, the fibrous material contains flax and / or cotton production waste with a modal fiber length of 8-14 mm, which is a type of waste - tow produced in accordance with GOST 25133-82 and GOST 4644-77, respectively.

The proposed filter material, due to the introduction into the composition of crushed and treated with a hydrophobizing agent waste paper, as well as the introduction of waste from the production of flax and / or cotton, has high oil capacity while high hydrophobicity.

Such properties of the filter material provide in the aggregate the method of increasing the hydrophobicity of waste paper and increasing the proportion of long reinforcing fibers with high natural hydrophobic properties in the composition.

Achieving a certain hydrophobicity on the surface of the fibers ensures the absence of a water film on their surface (i.e., they are not wetted), which provides a significant increase in the sorption properties of the fibers with respect to oil and oil products and, as a result, a simultaneous increase in their oil absorption, since the surface of the fibers is completely absent blocking water film, which is necessarily formed, although to a lesser extent, and when filtering air with high humidity due to high hyd Ofilnogo properties of raw chopped waste paper.

In addition, hydrophobized fibers of shredded waste paper, consisting mainly of cellulose-containing fibers, do not swell due to the acquired water-repellent properties, therefore, their thickness does not increase, which usually leads to a decrease in the pore size of the filter material, causing a significant increase in its hydraulic resistance.

This positive effect and the increase in oil absorption of waste fibers lead to a significant increase in the service life of the filter material.

In addition to hydrophobicity, the processing of crushed waste paper by silicone hydrophobizators increases the strength and water resistance of the filter material.

Processing the crushed waste paper with a silicone hydrophobizing agent is carried out by impregnating it using a special device by immersing it in the form of a layer between two nets in a bath with silicone hydrophobizing organosilicon emulsions (Penta-820 or Penta-822 type) or with hydrophobizing silicone liquids (Penta-801 A or Penta-804), followed by squeezing the excess hydrophobizing agent in a roller press and drying in a fluidized bed dryer or in an aerial dryer.

If necessary, after drying, the treated waste paper before dry molding can be dissolved in a disk mill to dissolve small lumps, that is, to increase the sorption surface of the cellulosic material.

In this case, before processing, the waste paper is crushed in a hammer mill so that the crushed waste paper has the following indicators:

degree of polymerization - 200-800;

specific surface area is 100-9000 m ² / g.

To achieve such grinding of book and magazine waste paper, for example, with the following technological parameters of the operation of a hammer mill:

beat frequency - 6000;

single strike force - 200 kgf / cm ² ;

processing time - 0.5 s.

The use of chemically and mechanically treated waste paper as part of the proposed filter material in the mode of the declared parameters provides the material with high sorption properties, and when used together with the use of chemical fiber (up to 40%) and waste products from flax and / or cotton (up to 30%) with a modal fiber length of 8-14 mm, the filter medium provides high throughput with a significant increase in its service life.

The proposed filter material can be made in the form of a sheet material, as well as in the form of granules.

The proposed fibrous sheet filter material is obtained as follows according to the examples below.

Example 1. A fibrous sheet filter material is obtained by dry molding on a paper machine from aerial suspension containing 10% viscose fibers 12 mm long, 80% fiberglass pulp mill product and 10% linen waste with a modal fiber length of 8-14 mm. At the same time, the grinding product is obtained in a hammer mill by processing newspaper waste paper with a beat frequency of 2000 beats / min, a single strike force of 40 kgf / cm ² and a processing time of 0.1 s. The resulting product of grinding paper is characterized by the following indicators:

specific surface area is 100 m ² / g;

the degree of polymerization of the fibers is 800,

and the processing of ground waste paper is carried out with a silicone hydrophobizing agent based on alkyltriethoxylan (Penta-820) until the latter is contained in an amount of 25% by weight of the mass of absolutely dry cellulose after pressing the excess water-repellent agent and subsequent drying of the waste paper in an aerial dryer to 88% dryness.

The formed fiber layer is compressed between the shafts. The quality indicators of the obtained filter material are shown in the table.

Example 2. A fibrous sheet filter material is obtained analogously to example 1 with the only difference that the air suspension contains 40% polypropylene fibers, 30% of the product from the grinding of book and magazine waste paper in a fibrous state and 30% of waste from the production of flax and cotton (1: 1) with modal fiber length 8-14 mm, the mode of processing waste paper in a hammer mill - the beat frequency is 6000, the force of a single blow is 200 kgf / cm ² , the processing time is 0.5 s, the quality indicators of the waste paper grinding product are as follows:

specific surface area 8000 m ² / g fiber polymerization degree 250,

and the processing of the crushed waste paper is carried out with a silicone hydrophobizing agent based on polyfunctional siloxane (Penta-822) until the latter is contained in an amount of 5 wt% of the mass of absolutely dry cellulose after pressing the excess hydrophobizing agent and subsequent drying of the waste paper in an aeropontane dryer to dryness of 85%.

The quality indicators of the obtained filter material are shown in the table.

Analysis of the table shows that the proposed filter material has high sorption performance, which provides the possibility of deep water purification at low concentrations of oil products in it at the same time a high service life of the proposed material.

Example No. Quality indicators of filter material Thickness mm Density g / cm ² Specific throughput, cm ³ / cm ² , s Breaking force, kgf The amount of petroleum products captured, 1 g of FM upon reaching saturation The degree of purification from oils,% Life time Water absorption in 24 hours, the number of water absorption, g per 1 g of mater. one 56.0 0.7 4000 1,1 2,5 99.8 150 1.05 2 55.0 0.65 5000 1,2 3.2 99.9 200 1.15 3 prototype 55.0 0.7 2780 0.92 0.2 96.0 80 12

Claims (2)

1. A fibrous filter material containing chemical fiber - viscose, polyester or polypropylene and shredded waste paper with a polymerization degree of 200-800 and a specific surface area of 100-9000 m ² / g, and molded in air, characterized in that it additionally contains flax production waste and / or cotton, and as crushed waste paper it contains waste paper treated with silicone hydrophobizing agent based on silanes or siloxanes in an amount of 5-25 wt.% from the mass of absolutely dry waste paper and dried to dry ti 85-88% with the following ratio of these components, wt.%: chemical fiber 10-40 shredded waste paper 30-80 flax and / or cotton production waste 10-30 2. The fibrous material according to claim 1, characterized in that it contains waste from the production of flax and / or cotton with a modal fiber length of 8-14 mm