RU2346100C1 - Method for manufacture of molded products - Google Patents

Abstract

FIELD: textile fabrics, paper.

SUBSTANCE: method is intended for manufacture of nonwoven articles of three-dimensional configuration from fiber mass. In process of method realisation fibers are deposited on surface of solid-state shapes with production of moist product in lower solid-state shape on mesh insert. Growth of fiber material by water filtration from fiber mass is done due to pressure difference, moisture removal, and vacuum pumping from upper solid-state shape. Simultaneously to drying product is prepressed. Lower and upper solid-state shapes are perforated. Fiber mass used is natural textile fabrics with separated fibers 5-75 mm long and short cellulose fiber in ratio of wt % (65-95):(5-35) accordingly. After drying article is treated by urethane oligomer in solution of hydrocarbon chloride or mixture of hydrocarbon chlorides with concentration of 1-65 wt %.

EFFECT: production of cheap molded nonwoven articles of three-dimensional configuration with high-quality surface, which possess high strength and noise absorption and low heat conductivity, which may be widely used for vehicle cabin and in construction.

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Description

The invention relates to the industrial production of products from aqueous pulp and directly relates to the manufacturing process of the manufacture of non-woven products of volumetric configuration.

A known method of forming bulk products from an aqueous suspension of cellulose fiber by its deposition on mesh forms, in particular on a mesh matrix, under the action of a pressure drop on the deposited layer created by the hot compressed air acting on the suspension, and drying the deposited layer with this air passing through it after displacement of free water. Drying of the deposited fiber layer is carried out by blowing hot compressed air through it until the product is completely ready only in cases of relatively thin-walled products (up to 4 mm), and with a larger wall thickness, drying is carried out only to a certain humidity, followed by drying in a special drying chamber. As a result of this, in the manufacture of relatively thick-walled products (more than 4 mm), this method is not sufficiently productive and relatively energy intensive, see the All-Union Scientific Research Institute of Pulp and Paper Industry, Handbook of a Technological Wallet, Volume III, Goslesbumizdat, Moscow-Leningrad, 1961, p. 229 ... 233, Fig. 5.

A known method of manufacturing molded products from a fibrous suspension by deposition of fiber on mesh forms hydraulically. The method provides relatively quick molding of small and medium-sized relatively thick-walled products having a wet wall thickness of up to 60 mm, but subsequently pressing is required to a final wall thickness in special hot molds and final drying in a special drying chamber. This limits the total productivity of the process and increases energy costs, see the All-Union Research Institute of the pulp and paper industry. Handbook of a technology wallet, Volume III, Goslesbumizdat, Moscow-Leningrad, 1961, p. 227-229, Fig. 4.

A known method of manufacturing molded products from a fibrous suspension, including the deposition of fiber on a mesh matrix under the action of a pressure drop on the deposited layer created by the hot compressed air acting on the suspension, and drying the deposited layer with this air passing through it after free water is displaced, while in the process drying the layer of fiber deposited on the mesh matrix makes it hot pressed by means of a mesh punch heated by passing hot compressed air.

The preferred embodiment is when during the drying and hot pressing of the fiber layer deposited on the mesh matrix, a vacuum is created under it, see RU Patent 2129630, IPC 6 D21J 7/00, 1998.

In the known method of forming a product from a fibrous suspension, a step of hot pressing is provided at the stage of drying the wet product by means of a mesh punch heated by passing hot air, alternatively, under the product, they can simultaneously create a vacuum. In this case, the product "works" as a permeable membrane. Excessive pressure of hot air applied from one of the sides of the product cannot but affect the structure of the material of the product and its porosity, which in many cases is not acceptable from the point of view of consumer properties of the finished product.

The closest in technical essence is a method of manufacturing molded products from pulp, including the preparation of an aqueous suspension of the desired concentration from fibrous materials, molding a wet product by depositing fibers on a forming base and removing residual moisture by drying. Liquid and solid modifiers are metered into the prepared aqueous suspension. The deposition of fibers is carried out on the surface of solid forms made of porous material. The formation of a wet product is carried out on the lower surface of the forming base by increasing the fibrous material by filtering water from the suspension through the pores of the forming base due to the pressure drop created on it. Simultaneously with drying, the product is subjected to prepressing, and the product is dried in a heated, detachable solid-state form with simultaneous removal of water vapor due to vacuum pumping from the upper and lower parts of this form, see RU Patent 2270895 C1, IPC D21J 7/00, 2006.

The disadvantages of this method is that in the implementation of the method, liquid and solid modifiers are fed into the prepared aqueous suspension, as a result of which chemical reagents contaminate the technological equipment, which leads to disruption of its function and the production of poor-quality products, in addition, the molded products obtained by the known method have high density, which reduces its sound-absorbing properties, and increased thermal conductivity.

An object of the invention is the manufacture of molded non-woven products of volumetric configuration with a high-quality surface, with high strength, sound-absorbing properties and low thermal conductivity, which can be widely used, such as, for example, for a car interior.

The technical problem is solved by a method of manufacturing molded products from pulp, including the deposition of fibers on the surface of solid forms and the formation of a wet product in the lower solid form on the insert, the surface of which corresponds to the shape of the future shell products, by increasing the fibrous material by filtering water from the pulp due to pressure drop and removing residual moisture in a heated detachable solid state form due to vacuum pumping from the upper solid state form at the same time, the product is subjected to pre-pressing simultaneously with drying, in which the lower and upper solid-state forms are perforated and the insert is mesh-like, fibrous natural textiles with a fiber length of 5-75 mm and short cellulose fiber in a ratio of wt.% are taken as fibrous mass ( 65-95) :( 5-35), respectively, and after drying, the product is subjected to treatment with a urethane oligomer in a solution of a chlorine derivative of a hydrocarbon or a mixture of chlorine derivatives of hydrocarbons with a concentration of 1-65 wt.%.

The solution to the technical problem allows you to get cheap molded non-woven products of volumetric configuration with a high-quality surface, with high strength, sound-absorbing properties and low heat conductivity, which can be widely used for the interior of the car.

The invention is illustrated by examples of specific performance.

Example 1

A method of manufacturing molded articles from pulp involves depositing fibers on the surface of solid forms and forming a wet article in the lower solid form on the insert by building up the fibrous material by filtering water from the pulp due to pressure drop. In this case, the lower and upper solid forms are perforated, and the insert is mesh. The surface of the insert matches the shape of the future shell product. To obtain molded products of different volume configurations, the deposition of fibrous material is carried out with replaceable solid-state inserts.

The pulp is prepared, for example, from a piece of cotton textile, which is previously chopped to a size of 5-75 mm, and then pulled on a pulper to the primary threads. Separately, a textile cutting is carried out, followed by grinding on a roll to a uniform short cellulose fiber.

After that, 95 wt.% Of the fiberized textile is mixed with 5 wt.% Of short fibers based on cotton textile obtained by grinding the textiles to a homogeneous mass, followed by homogenization in the aqueous phase with a concentration of 25% fibrous mass.

The formation of a wet product is as follows.

The lower solid-state form (matrix) with perforation, with a perforation diameter of 4 mm and a pitch of 15 mm, additionally equipped with a mesh insert, is immersed in a container with a working composition of aqueous pulp. The deposition of fibers lead to the surface of solid-state forms. A wet product is obtained in a lower solid state on a mesh insert, the surface of which corresponds to the shape of the future shell product, by building up the fibrous material by filtering water from the pulp due to pressure drop

After deposition of the required thickness of natural textile fibers and short textile fibers, the molded wet product is pressed and squeezed out of water by closing it with the lower solid-state form - the matrix with the upper perforated solid-state return mold and drying to a moisture content of 10% by supplying hot air (60-80 ° C) into the lower matrix and vacuum pumping from the upper (reciprocal) solid-state form. After drying, the product is subjected to treatment with a urethane oligomer in a solution of a chlorine-derived hydrocarbon - methylene chloride at a concentration of 1 wt.%.

Example 2

As the pulp, take 95 wt.% Fibrous cotton textiles, mixed with 5 wt.% Short fibers based on cotton textiles, the mass is homogenized in the aqueous phase with a concentration of 25% fibrous mass. After drying, the product is subjected to treatment with a urethane oligomer in a solution of a chlorine-derived hydrocarbon - methylene chloride at a concentration of 30 wt.%.

Example 3

As the pulp, take 95 wt.% Fibrous cotton textiles, mixed with 5 wt.% Short fibers based on cotton textiles, the mass is homogenized in the aqueous phase with a concentration of 25% fibrous mass. After drying, the product is subjected to treatment with a urethane oligomer in a solution of a chlorine-derived hydrocarbon - methylene chloride at a concentration of 65 wt.%.

Example 4

As the pulp, take 95 wt.% Fibrous cotton textiles, mixed with 5 wt.% Short fibers based on cotton textiles, the mass is homogenized in the aqueous phase with a concentration of 25% fibrous mass. After drying, the product is subjected to treatment with a urethane oligomer in a solution of a mixture of chlorinated hydrocarbons - perchlorethylene: methylene chloride (70:30) at a concentration of 30 wt.%.

Example 5

As the pulp, they take 65 wt.% Of fibrous cotton textile, mix with 35 wt.% Of short fibers based on cotton textile, the mass is homogenized in the aqueous phase with a concentration of 25% of the pulp. After drying, the product is subjected to treatment with a urethane oligomer in a solution of a chlorine-derived hydrocarbon - methylene chloride at a concentration of 65 wt.%.

Example 6

As the pulp, they take 65 wt.% Of fibrous cotton textiles, mix with 35 wt.% Of short cotton-based fibers, the mass is homogenized in the aqueous phase with a concentration of 25% of the pulp. After drying, the product is subjected to treatment with a urethane oligomer in a solution of a mixture of chlorinated hydrocarbons - perchlorethylene: methylene chloride (70:30) at a concentration of 65 wt.%.

Example 7

As the pulp, take 75 wt.% Fibrous cotton textile, mixed with 25 wt.% Short cellulose fibers based on waste paper, the mass is homogenized in the aqueous phase with a concentration of 25% fibrous mass. After drying, the product is subjected to treatment with a urethane oligomer in a solution of a chlorine-derived hydrocarbon - methylene chloride at a concentration of 30 wt.%.

Example 8

As the pulp, take 75 wt.% Fibrous cotton textile, mixed with 25 wt.% Short cellulose fibers based on waste paper, the mass is homogenized in the aqueous phase with a concentration of 25% fibrous mass. After drying, the product is subjected to treatment with a urethane oligomer in a solution of a mixture of chlorinated hydrocarbons - perchlorethylene: methylene chloride (70:30) at a concentration of 15 wt.%.

When using 100% fiberglass cotton textile as pulp, the product is destroyed when removed from the working surface of the matrix.

Noise and vibration absorption are important features for many trim parts in the car. As cars get smaller and lighter, noise becomes a major consumer issue. The combination of noise and vibration of the car creates discomfort for passengers. When sound falls to the surface, its energy is partially reflected, and partially absorbed. An important characteristic of sound-absorbing materials is the sound absorption coefficient, which is defined as the ratio of the energy absorbed by the surface to the energy incident on the surface. Samples cut from molded products obtained by the present method, were investigated for sound absorption at the research facility "Kundt pipe".

The essence of the method for determining thermal conductivity is to create a heat flux directed perpendicular to the largest faces of a flat sample of a certain thickness, measure the density of the stationary heat flux and temperatures on opposite sides of the sample according to GOST 7076-87. Building materials and products. Method for determining thermal conductivity. Moscow, Publishing house of standards, 1987, 12 p.

Testing samples of molded non-woven material for impact resistance at a temperature of minus (45 ± 2) ° C is carried out as follows:

the samples are placed in the freezer and incubated for (2 ± 0.1) h at a temperature of minus (45 ± 2) ° С. Then the samples are placed on a rigid horizontal surface and a sphere is dropped on them with a diameter of (60 ± 1) mm, weight (0.9 ± 0.09) kg from a height (150 ± 2) cm;

similarly, tests are carried out at a temperature of (20 + 5) ° C: the samples are placed in an oven and incubated for (2 ± 0.1) h at a temperature of (20 + 5) ° C. Then the samples are placed on a rigid horizontal surface and a sphere is dropped on them with a diameter of (60 ± 1) mm and a mass of (0.9 ± 0.09) kg from a height of (150 ± 2) cm.

The table shows the characteristics of the properties of the materials obtained by the prototype, the claimed object and the base. The Italian technology of the Keller company for the manufacture of “fibrous poroso” shaped products for the passenger compartment by hot pressing was adopted as the base object. The products are manufactured by JSC "BRT", Balakovo.

As studies have shown, products obtained by the claimed object are much superior to products obtained by the prototype in sound absorption. Moreover, the products have low thermal conductivity.

The inventive method allows to obtain molded non-woven products of different volume configurations from textile and paper wastes on simple equipment with a high-quality surface, having high strength and sound absorption and low heat conductivity, and can be widely used for the interior of the car, as well as in construction. Products obtained by the claimed method have properties at the level of products obtained by technology of the Italian company "Keller", requiring expensive equipment.

Table The name of indicators According to the prototype Basic - fiber poroso, production of JSC "BRT" (Balakovo) According to the claimed object Examples one 2 3 four 5 6 7 8 Name of material Pulp & Paper Natural fibers with polyester resins Urethane Oligomer Short Cotton Cellulose Fiber Textile Specific gravity, g / m ² 1200 800/600 600 600 600 600 600 600 600 600 Material Thickness, mm 20/12 Material Thickness, mm 12 12 12 12 12 12 12 12 12 Sound absorption coefficient (%) in the range of 1500 Hz 0.15 0.84 / 0.84 0.85 0.82 0.65 0.80 0.55 0.52 0.80 0.84 Thermal conductivity, W / m · K 0.058 0,048 / 0,045 0,045 0,044 0,038 0,036 0,042 0,042 0,048 0,048 Shock resistance No gap No gap No gap No gap No gap No gap No gap No gap No gap No gap

Claims (1)

A method of manufacturing molded products from pulp, including the deposition of fibers on the surface of solid forms and the formation of a wet product in the lower solid form on the insert, the surface of which corresponds to the shape of the future shell products, by increasing the fibrous material by filtering water from the pulp due to pressure drop and removing residual moisture in a heated detachable solid-state form due to vacuum pumping from the upper solid-state form, while simultaneously drying the product is subjected to prepressing, characterized in that the lower and upper solid-state forms are perforated and the insert is mesh-like, fibrous natural textiles with a fiber length of 5-75 mm and a short cellulose fiber in a ratio of wt.% (65-95) are taken as pulp. : (5-35), respectively, and after drying, the product is treated with a urethane oligomer in a solution of a chlorine derivative of a hydrocarbon or a mixture of chlorine derivatives of hydrocarbons in a concentration of 1-65 wt.%.