RU2633890C1 - Method for producing hybrid reinforced complex composite low-combustible polyethylene plastic - Google Patents

Abstract

FIELD: technological processes.

SUBSTANCE: films are made of different materials and contain layers of polyethylene, cellulose fibre and aluminium. The method comprises mixing and simultaneously grinding polyethylene, aluminium, cellulose fibre with an agglomerating additive, mixing with the lubricant additive and the filler-antipyrene when heating to 130°C for 30-40 minutes. The prepared mixture is then extruded in a twin-screw extruder, in a feeding zone of which a temperature of 130-140°C is maintained to ensure the flow of polyethylene filling with cellulose fibre and aluminium globules. In subsequent zones of the twin-screw extruder, the temperature is sequentially increased, but not higher than 175°C, with the achievement of the maximum temperature in the unloading zone.

EFFECT: granulation of hybrid reinforced complex composite low-combustible polyethylene plastic.

2 cl, 3 ex, 1 tbl

Description

The invention relates to a technology for the production of a hybrid reinforced composite composite low-combustible polyethylene plastic with at least partial use of recycled materials, including multilayer packaging films made of various materials and containing layers of polyethylene, cellulose fiber and aluminum.

Recycling secondary plastic films is an urgent problem. Technologically the most difficult is the processing of films of multilayer laminated packaging materials made from polyethylene containing cellulose.

A known method of recycling a layered film (patent EP 2158182 B1) is as follows:

- the layered film is crushed, delaminated and the layers are separated from each other;

- layers are sorted and accumulated separately;

- each layer is processed separately.

This method is technologically complex, time consuming and expensive.

There is a method of joint recycling of polyethylene and aluminum (Von Zuben F., Neves F.L. RECYCLING OF ALUMINUM AND POLYETHYLENE PRESENT IN TETRA CANCER PACKAGES, 1999, Sao Paulo, Brazil

http://ww.ekopaket.si/upload/file/Recikliranje%20alu%20in%20polietilena%20v%20TP%20embalazi.pdf?phpMyAdmin=8f4aea4ea78343d51594e6196d6e3172), including the separation of the washed material and washing with the aid of the pulp and the pulp; polyethylene and aluminum, agglutination of polyethylene with aluminum, and the production of granules of a composite material by extrusion. In all areas of the extruder using temperature conditions characteristic of the extrusion of polyethylene. A temperature of about 120 ° C is maintained in zone I (or a loading zone), a temperature of 135 ° C to 140 ° C is maintained in zone II (or a compression zone), and a temperature of 150 ° C is maintained in zone III (or a homogenization zone). The die forming the tows operates at temperatures of about 170 ° C.

However, the known method is technologically complex and energy-intensive, and the authors themselves in their article indicate the need for complete removal of cellulose fiber from the material, since the presence of cellulose fiber can lead to tearing of the extrusion continuity, and drying of the material is necessary before extrusion. In addition, the known method does not allow the processing of materials that do not contain aluminum.

A known method for the production of composite polyethylene plastic reinforced with cellulose fiber and fiberglass (Patent US 7743567). A specific embodiment of the method (example 7 from the above patent) includes mixing dried and pre-ground to a size passed through a sieve of 20-150 (preferably 20-40) mesh (number of holes per 1 linear inch), cellulosic material (preferably wood) with polyethylene , fiberglass and cross-linking agent, grinding the mixture in a compounding device, followed by injection molding. This method is selected as a prototype (closest prior art). The resulting composite polyethylene plastic, reinforced with cellulose fiber and fiberglass, has a sufficiently high strength, comparable with the strength of the wood product it replaces.

However, the known method is technologically complex and expensive, since expensive cross-linking agents are used, it is necessary to thoroughly dry the cellulose fibers and then use special equipment to store the dried cellulose fibers. This method also does not reduce the combustibility of the finished material. In addition, the known method does not make it possible to recycle secondary polyethylene, from which aluminum is not separated.

The technical problem solved by the invention is to simplify and reduce the cost of production of a hybrid reinforced composite composite low-combustible polyethylene plastic with at least partial use of secondary multilayer raw materials without separation of its layers.

According to the proposed invention, a method for the production of hybrid reinforced complex composite polyethylene plastic includes the following operations:

- mechanical grinding of the starting materials of polyethylene, aluminum, cellulose fiber to a size of 3-5 mm.

The amounts of starting materials per 100 kg of their mixture are as follows, kg:

aluminum 5-15 cellulose fiber with a moisture content of 20-45% 5-30 recycled polyethylene 55-90

- mixing and simultaneous agglomeration in an agglomerator when heated to 80-160 ° C for 30-40 minutes of starting materials: 100 kg of a mixture of polyethylene, aluminum, cellulose fiber, at least partially secondary materials, with 20-30 kg of agglomerating additives moreover, the formation of aluminum globules also occurs in the sinter.

- mixing the agglomerate with lubricating additives and filler-flame retardant in the mixer-mixer. Materials from the sinter are fed into a mixer-mixer, in which the material is heated from the action of friction, lubricants are added in an amount of 0.2-3 kg and filler-flame retardant in an amount of 15-40 kg per 100 kg of a mixture of aluminum, cellulose fiber with humidity 20-45% and secondary polyethylene.

- extruding the prepared mixture in a twin-screw extruder, in the loading zone of which a temperature of 150-170 ° C is maintained to ensure the reaction of filling polyethylene with cellulose fiber and aluminum globules, in the subsequent zones of the twin-screw extruder, the temperature is first lowered by 20-25 ° C, and then raised again to the temperature maintained in the loading zone;

- granulation of a hybrid reinforced composite composite low-combustible polyethylene plastic.

The used ratios of the starting materials — polyethylene, aluminum, cellulose fiber — were established experimentally. The introduction of cellulose fiber of more than 50 kg per 100 kg of the mixture of starting materials (more than 50 wt.%) Leads to the formation of a defect in the extrusion bundle of a hybrid reinforced composite composite low-combustible polyethylene plastic, namely the appearance of the so-called "Palm trunk". The increase in the introduction of aluminum into the mixture of starting materials above 15 mass. % leads to the fact that there is a clogging of the dies of the injection machine during the molding of products from a hybrid reinforced composite composite low-combustible polyethylene plastic. The decrease in the amount of cellulose fiber below 5 mass. % and aluminum below 5 wt. % is impractical, since important consumer properties of the finished product are lost - the “shrinkage” parameter - the finished product will be soft, will not keep its shape, etc.

Agglomerating additives are selected so that during extrusion they interact with polyethylene, contributing to its clumping, resulting in the formation of a polyethylene agglomerate filled with aluminum globules. Agglomeration, formation of aluminum globules and primary filling of polyethylene with aluminum in the proposed method

- these are three combined stages occurring in the same agglomerator. In the proposed method mainly use agglomerating additives that cause agglomeration of polyethylene with aluminum globules.

Agglomerating additive is the following product in the following proportions, mass. %:

- secondary polyethylene-polyamide composite film, with a polyamide content of not more than 25% - 25.

The following lubricating additive is introduced into the mixer-mixer, mass. %:

polyethylene wax 12-15 stearic acid 20-22 ethylene bis stearamide 20-22 maleic anhydride grafted polyethylene 12-15 boric acid 25-30

At the same time, filler-flame retardant is introduced into the mixer-mixer in the amount of 15-40 kg per 100 kg of finished material.

In the loading area of the twin screw extruder, a lubricant is opened.

Hybrid reinforced composite composite low-combustible polyethylene plastic produced by the proposed method has good mechanical properties, does not absorb moisture and does not emit an unpleasant odor during processing.

The following are specific examples of the implementation of the proposed method for the production of a hybrid reinforced composite composite low-combustible polyethylene plastic, however, which are not the only possible ones.

Example 1

Wastes from the production of juice packaging, consisting of cellulose fiber in an amount of 15 kg (with a moisture content of 35%), aluminum foil, weighing 5 kg, and 80 kg of a polyethylene film of complex composition based on high-pressure polyethylene, are crushed into fragments of 3-5 mm in size. The resulting mixture of starting materials is placed in an agglomerator, to which an agglomerating additive is added, which is a crushed to a particle size of 3-5 mm polyethylene-polyamide composite film in an amount of 25 kg. All ingredients are mixed and crushed at the same time by heating to 130 ° C for 35 minutes. The prepared mixture is fed into a mixer-mixer, into which a lubricating additive and a filler-flame retardant are fed. A lubricant additive in an amount of 2.225 kg is supplied immediately after the agglomerate is fed into the mixer. After three minutes of stirring, 22.5 kg of a flame retardant filler are added, which is ground brucite treated with stearic acid with a particle size of not more than 3 microns.

The resulting mixture is fed into a twin-screw extruder, in the loading zone of which a temperature of 135 ° C is maintained to ensure the primary combination of materials and primary softening, in subsequent zones of the twin-screw extruder, the temperature is gradually increased, but not higher than 175 ° C, with the maximum temperature in the discharge zone being reached. Forming granules of a hybrid reinforced complex composite low-combustible polyethylene plastic is carried out on a granulating device that is usual for high-pressure polyethylene.

Hybrid reinforced composite composite low-combustible polyethylene plastic produced by the proposed method has good mechanical properties, does not absorb moisture and does not emit an unpleasant odor during processing. We experimentally established that the obtained hybrid reinforced composite composite low-combustible polyethylene plastic has the following improved strength characteristics compared to conventional LDPE:

Example 2

Wastes from paper production, consisting of cellulose fiber, in an amount of 20 kg (with a moisture content of 28%), waste from the production of aluminum foil weighing 5 kg and 75 kg of waste plastic film based on high-pressure polyethylene are crushed into fragments of 3-5 mm in size. The resulting mixture of starting materials is placed in an agglomerator, to which an agglomerating additive is added, which is a crushed to a particle size of 3-5 mm polyethylene-polyamide composite film in an amount of 25 kg. All ingredients are mixed and crushed at the same time by heating to 130 ° C for 35 minutes. The prepared mixture is fed into a mixer-mixer, into which a lubricating additive and a filler-flame retardant are fed. A lubricant additive in an amount of 2.225 kg is supplied immediately after the agglomerate is fed into the mixer. After three minutes of stirring, 22.5 kg of a flame retardant filler are added, which is ground brucite treated with stearic acid with a particle size of not more than 3 microns.

The resulting mixture is fed into a twin-screw extruder, in the loading zone of which a temperature of 135 ° C is maintained to ensure the primary combination of materials and primary softening, in subsequent zones of the twin-screw extruder, the temperature is gradually increased, but not higher than 175 ° C, with the maximum temperature in the discharge zone being reached. Forming granules of a hybrid reinforced complex composite low-combustible polyethylene plastic is carried out on a granulating device that is usual for high-pressure polyethylene.

Example 3

Wastes from the production of milk packaging, consisting of cellulose fiber in an amount of 15 kg (with a moisture content of 34%), aluminum foil weighing 9 kg and 76 kg of a polyethylene film of complex composition based on high-pressure polyethylene, are crushed into fragments of 3-5 mm in size. The resulting mixture of starting materials is placed in an agglomerator, to which an agglomerating additive is added, which is a crushed to a particle size of 3-5 mm polyethylene-polyamide composite film in an amount of 25 kg. All ingredients are mixed and crushed at the same time by heating to 130 ° C for 35 minutes. The prepared mixture is fed into a mixer-mixer, into which a lubricating additive and a filler-flame retardant are fed. A lubricant additive in an amount of 2.225 kg is supplied immediately after the agglomerate is fed into the mixer. After three minutes of stirring, 22.5 kg of filler-flame retardant is added, which is ground brucite treated with stearic acid with a particle size of not more than 3 microns.

The resulting mixture is fed into a twin-screw extruder, in the loading zone of which a temperature of 135 ° C is maintained to ensure the primary combination of materials and primary softening, in subsequent zones of the twin-screw extruder, the temperature is gradually increased, but not higher than 175 ° C, with the maximum temperature in the discharge zone being reached. Forming granules of a hybrid reinforced complex composite low-combustible polyethylene plastic is carried out on a granulating device that is usual for high-pressure polyethylene.

The proposed invention makes it possible to simplify and reduce the cost of production of a hybrid reinforced composite composite low-combustible polyethylene plastic with at least partial use of secondary multilayer raw materials, without separation of its layers. The hybrid reinforced complex composite low-combustible polyethylene plastic produced by the proposed method has such good mechanical properties that the proposed method can also be used for joint processing of several types of secondary raw materials, selecting their quantities so that the ratios of the starting materials correspond to the ratio used in the proposed method.

Claims (10)

1. A method of manufacturing a hybrid reinforced composite composite low-combustible polyethylene plastic, comprising mixing dried and pre-ground polyethylene and cellulose fiber, characterized in that the production of a hybrid reinforced composite composite low-combustible polyethylene plastic is supplemented by the following operations: - grind the starting materials: polyethylene, aluminum, cellulose fiber, to a size of 3-5 mm, and the amounts of starting materials per 100 kg of their mixture are as follows, kg: aluminum 5-15 cellulose fiber with a moisture content of 20-45% 5-30 secondary or primary polyethylene 55-90 - mix and simultaneously grind when heated to 80-160 ° C for 30-40 minutes, the starting materials: aluminum, cellulose fiber, polyethylene, at least partially secondary material, with an agglomerating additive, agglomerating additive, lubricating additives and flame retardant are introduced in the following amounts per 100 kg of a mixture of starting materials, kg: agglomerating additive 20-30 lubricating additives 0.2-3 flame retardant filler 15-40 - extruded the prepared mixture in a twin-screw extruder, in the loading zone of which the temperature is maintained at 135-140 ° C to ensure the polyethylene filling reaction with cellulose fiber and aluminum globules, in subsequent zones of the twin-screw extruder, the temperature is gradually increased, but not higher than 175 ° C, with the achievement of the maximum temperature in the discharge zone; - granulate a hybrid reinforced composite composite low-combustible polyethylene plastic. 2. The method according to p. 1, in which a lubricating additive is used that causes the polyethylene to be filled with cellulose fiber and aluminum globules in the following proportions, wt.%: polyethylene wax 12-15 stearic acid 20-22 ethylene bis stearamide 20-22 maleic anhydride grafted polyethylene 12-15 boric acid 25-30