RU2473572C1 - Method of polymer wastes processing - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to secondary stock processing and may be used fro grinding polymer wastes, including polymer composite materials. Proposed method comprises grinding polymer wastes by driving initial material by plunger through female die with through sharp-edges holes made in lengthwise direction to plunger axis at female die perforation factor of 0.35-0.55, cutting waste bundles coming out from female die by blade revolved at 60-200 rpm, dispersing produced semi-product to 0.2 to 2.0 mm in surfactant water solution, and processing at wave unit in resonance hydrodynamic mode at 5-40 kHz and oscillation amplitude of 0.05-2.0 MPa.

EFFECT: higher dispersity and quality, manufacturability and safety.

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Description

The invention relates to the field of chemistry and relates to the processing of secondary raw materials and can be used to grind polymer wastes, including rubber and other polymer composite materials, and is aimed at increasing the degree of dispersion and quality of the final product, improving the processability and the level of industrial safety, improving environmental security.

A known method of barodic destruction grinding of rubber waste and rubber crumb, including punching using a hydraulic press of pieces of rubber through a matrix with through holes [A.S. USSR No. 1728042; 04/23/1992] - (1).

The main disadvantage of this method is the high energy consumption necessary to create a high pressure, ensuring the optimal flow regime of the processed material.

From RU 2069623, 11.27.1996 (2), another method for processing polymer and rubber wastes is known. The essence of the known method lies in the fact that the grinding method includes forcing the processed material through a die, before entering which stress concentrators are applied to the surface of the material in the region of maximum normal stresses.

The known method is not technologically advanced, since it has a low degree of grinding of raw materials, is prone to clogging through-holes of the spinnerets with industrial waste, and does not provide an adequate level of industrial safety due to the high degree of dust formation.

From RU 2042511, 08.27.1995 (3), a method for processing rubber waste (worn tires reinforced with metal elements) is known, in particular for the destruction, grinding and separation of components of rubber cord products. The method includes the process of pressing tires, in which the rubber is separated from the metal reinforcing elements, the forcing of rubber waste (softened rubber) through the holes of the matrix; through holes formed in a matrix form of two intersecting conical surfaces with vertices directed towards each other, wherein the matrix is selected from the perforation coefficient ratio φ = ΣS _holes / S = 0.2-0.3 _mattresses where ΣS _holes - the total area of the openings matrix, S _mat - the area of the working surface of the matrix.

A disadvantage of the known method is that during tire extrusion during extrusion through the through holes of the matrix, pieces of rubber of various sizes are formed, or small rubber crumb, or hard rubber tows that are poorly separated from the matrix and thereby complicate the waste recycling process. In addition, this method relates only to the processing of rubber waste.

From RU 2147988, 04/27/2000 (4), another method for processing polymer waste, namely the processing of rubber waste in the form of used automobile tires, is intended for separating rubber from automobile tires. The method also includes grinding the waste by forcing it through a matrix with through holes. The method involves separating the rubber bundles emerging from the matrix after the end of the extrusion process, cutting and trimming the rubber bundles with knife devices.

The disadvantage of this method is its lack of effectiveness and the inability to obtain a final product of good quality, leading to the further use of various polymer (not only rubber) recycled waste.

The technical task of the claimed method of processing polymer waste as an invention is to increase the efficiency of waste processing in order to further efficiently use recycled waste.

The technical result of the claimed method is to increase the degree of dispersion and quality of the product, the manufacturability of the process and the level of industrial safety (reduce dust formation).

The stated technical problem and the technical result are achieved by the method of processing waste polymers and polymer composite materials, including grinding them by forcing the source material through a die with through holes having sharp (cutting) edges and made in the longitudinal direction to the axis of the plunger, the matrix perforation coefficient can reach 0.35-0.55, and after punching carry out the cutting of the waste tows at the exit of the matrix with the speed of rotation of the cutting tool 6 0-200 rpm to a size of 0.2 to 2.0 mm, followed by dispersion in a liquid medium upon wave exposure to a wave installation in the amplitude-frequency range, providing a resonant hydrodynamic regime (5-40 kHz, 0.05-2 , 0 MPa), and as a liquid medium use aqueous solutions of surface-active substances (surfactants) of ionic and non-ionic nature.

In the method according to the invention, surfactants use hydroxyethylated alcohols, sodium alkyl sulfonates (potassium, ammonium), sulfonated hydroxyethylated alkyl phenols (in particular, C-10), etc.

Polymer waste is pre-cut into pieces whose dimensions do not exceed the diameter of the matrix. The matrix perforation coefficient is defined as the ratio of the total area of the matrix holes to the area of the working surface of the matrix. According to the invention, it has values of 0.35-0.55.

A method of processing polymer waste is carried out, in particular, in a plant having a hydraulic press with a sealing plunger mounted on a power frame, a matrix with through holes.

The holes of the matrix have sharp cutting edges and are made in the longitudinal direction to the axis of the plunger.

As a wave setup, one can use devices (5) that allow one to excite nonlinear oscillations to intensify heat and mass transfer processes in multiphase media in the sound and ultrasonic frequency ranges. To create a resonant hydrodynamic regime, the wave installation contains a hydrodynamic oscillation generator and a resonant chamber.

Thus, the claimed technical result can be achieved by the totality of the essential features of the method, which are:

1) forcing the crushed material through a matrix with through holes with sharp cutting edges, while the perforation coefficient can reach values of 0.35-0.55;

2) cutting the pressed product at a speed of 60-200 rpm to a size of 0.2 to 2.0 mm;

3) dispersing the resulting product in a liquid dispersion medium in the presence of a surfactant;

4) wave processing of the obtained product in the amplitude-frequency range, providing a resonant hydrodynamic mode.

SUMMARY OF THE INVENTION

So, the technical result of the invention is to increase the degree of dispersion and quality of the crushed material as a raw material for subsequent physicochemical processes and disposal. The technical result is achieved by the fact that the product being squeezed after being cut to a predetermined size at the exit from the through holes and then dispersed in a liquid medium containing a surfactant is subjected to nonlinear wave vibrations in the resonant mode [5].

The process is accompanied by the excitation of both shear stresses and cavitation effects, contributing to the deep destruction of the structure of raw materials.

Rubber wastes and solid wastes of other polymers have a viscosity of more than 10 ¹² Pa · s. Their movement along the channel (die) in the high-pressure zone occurs in the regime of viscous plasticity, which creates conditions for gross destruction of the viscoelastic material. In this method, the crushed material (the size of the pieces should be no more than the diameter of the matrix with through holes) is forced through the through holes, at the exit of which it is cut to a predetermined degree of dispersion (from 0.2 to 2.0 mm). This degree of dispersion is ensured by the interval of rotation of the cutting knife, which is selected taking into account that clogging of holes and the formation of dust are prevented, worsening working conditions and lowering the level of industrial safety. The resulting intermediate is mixed with an aqueous solution of a surfactant (dispersion medium) and then subjected to wave processing in a resonant hydrodynamic mode. The last stage is carried out at the installation for generating nonlinear wave oscillations [5], after which the finished product enters the receiving tank.

Examples of specific implementation of the method, illustrating the invention, but not limiting it

Example 1. Pieces of crushed material, such as rubber, is pressed through a matrix with through holes (by a known method). The dispersion of the obtained product is from 3 to 7 mm. Clogging of the holes of the matrix and high dust formation are observed.

Example 2. Pieces of material to be crushed are pressed through a matrix according to the invention, then they are cut with a rotating knife at a rotation speed of 60 rpm. The obtained intermediate with an average degree of dispersion of 2.0 mm is dispersed in a 5% aqueous solution of a surfactant (for example, sodium alkyl sulfonate) and is subjected to wave processing in a resonant hydrodynamic mode with a frequency of 40 KHz and an oscillation amplitude of 0.05 MPa. The dispersion of the obtained product is 100 μm. No dust is observed.

Example 3. Pieces of crushed material according to example 2 are pressed through the matrix of example 2 and cut using a rotating knife with a rotation speed of 200 rpm The resulting intermediate with an average degree of dispersion of 0.2 mm is dispersed in a 1% surfactant solution (for example, sulfonated hydroxyethylated alkylphenol C-10) and subjected to wave processing in a resonant hydrodynamic mode with a frequency of 15 KHz and an oscillation amplitude of 2.0 MPa. The dispersion of the obtained product is 30 μm. No dust is observed.

Example 4. Pieces of crushed material (for example, plasticized polyvinyl chloride, linoleum) are pressed through the matrix in example 2, cut in accordance with example 3, the resulting intermediate is dispersed in a 10% aqueous surfactant solution (for example, OS-20 ethoxylated alcohol) and then subjected to wave processing in resonant hydrodynamic mode with a frequency of 5 KHz and an amplitude of 0.5 MPa. The dispersion of the resulting product is 50 μm. No dust is observed.

Industrial safety was assessed by the level of dust formation in the working area of the installation, and manufacturability by the degree of plugging of the matrix holes with a polymer product (data are shown in the table).

Table N example The average size of the final product, microns Dust formation The degree of plugging holes,% 1 (control by a known method) 3000-7000 > MPC >> 50 2 one hundred << MPC 2-3 3 thirty << MPC 1-2 four fifty << MPC 1-1.5

As can be seen from the table, the final polymer product obtained by the method according to the invention is characterized by a significantly higher degree of dispersion. Moreover, in the process of its production, the clogging of the through holes of the installation matrix is significantly reduced. The use of an aqueous dispersion medium helps to reduce dust formation, which in turn ensures the fire safety of the process and the improvement of sanitary and hygienic working conditions. The use of surfactants contributes to the production of more stable and stable polymer disperse systems, i.e. improving their quality.

Thus, the achieved technical result allows us to recommend the use of this method, in particular, upon receipt of bitumen emulsions, various mastics and other materials. The method is environmentally sound, fireproof.

Information sources

1. "Collection of reports of the scientific and practical seminar" Environmental aspects of the production, operation of tires and rubber products. The problems of their secondary use and recycling. "M:" Maxima ", March 13-16, 2000; Installation for the isolation and grinding of rubber from used tires. USSR author's certificate No. 1728042 A1, 04/23/92, Bull. No. 15.

2. RF patent No. 2069623, 11/27/96, bull. No. 33.

3. RU 2042511, 08.27.1995.

4. RU 2147988, 04/27/2000.

5. Ganiev R.F. Wave machines and technologies (Introduction to wave technology). - M .: Scientific and Publishing Center "Regular and Chaotic Dynamics", 2008, pp. 41-48, 69-81.

Claims (1)

A method for processing polymer wastes, including rubber wastes and wastes of polymer composite materials, including crushing them by forcing the source material using a plunger through a matrix with through holes with sharp cutting edges made in the longitudinal direction to the axis of the plunger, with a matrix perforation coefficient of 0, 35-0.55, subsequent cutting of the waste bundles emerging from the matrix with a knife rotating at a speed of 60-200 rpm, dispersing the resulting intermediate with a degree of dispersion differences from 0.2 to 2.0 mm in an aqueous solution of a surfactant and processing on a wave installation in a resonant hydrodynamic mode with a frequency of 5-40 kHz and an oscillation amplitude of 0.05-2.0 MPa.