RU2700730C1 - Method of producing nonwoven material with low inflammability - Google Patents

Abstract

FIELD: nonwoven materials.

SUBSTANCE: invention relates to production of nonwoven materials and can be used for noise insulation in automotive industry and low-rise construction. Method of producing non-woven material with low inflammability, in which the technological process consists of the following stages: supply of fibrous mixture, canvas formation, compaction of fibrous canvas on aerodynamic installation, thermal bonding and calendering of web, cutting and winding of web in rolls or workpiece. Fiber mixture used is a mixture of regenerated fiber, natural fiber in the form of jute, linen or hemp and synthetic fiber with a substance additive based on phosphorus-containing fire retardant in amount of 5–10 % of the weight of the mixture. In the process of supply, the mixture is moistened with an aqueous lubricating emulsion in amount of 4–6 % of the mixture weight till moisture content is not lower than 2 % at room humidity not lower than 50 %. Prepared mixture is fed into prefill chamber for can formation, where fibrous mass is uniformly distributed over aerodynamic canvas formation, in which air flow temperature is maintained within 18–24 °C, thermal bonding of the web is carried out in a furnace with a temperature mode of 170–175 °C, and calendering – at temperature of up to 220 °C and linear pressure up to 12 N/mm (= 5 t).

EFFECT: material has the required level of non-combustible properties.

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Description

The invention relates to a technology for the production of nonwoven materials and can be used for noise thermal insulation in the automotive industry and low-rise construction.

A known method of producing non-woven material with reduced combustibility, in which the technological process consists of the following stages: feeding the fibrous mixture, canvas formation, compaction of the fibrous canvas on an aerodynamic installation, thermal bonding and calendering of the fabric, cutting and winding the fabric into rolls or blanks (RF patent No. 2667359, C. D04H 1/549, publ. 09/18/2018). In the known method, the non-combustible properties of the obtained material are not sufficiently provided.

The technical problem, the solution of which is provided by the invention, is the elimination of the noted drawback. The technical result consists in increasing the required level of non-combustible material properties.

The problem is solved, and the technical result is ensured by the fact that in the method of manufacturing a non-woven material with reduced combustibility, in which the technological process consists of the following stages: feeding the fibrous mixture, canvas formation, compaction of the fibrous canvas in an aerodynamic installation, thermal bonding and calendering of the web, cutting and winding of the web in rolls or preforms, as a fiber mixture, a mixture of regenerated fiber, natural fiber in the form of jute, flax or hemp and synthetic fibers with the addition of a substance based on a phosphorus-containing flame retardant in an amount of 5-10% by weight of the mixture, moisten the mixture with an aqueous oil emulsion in an amount of 4-6% by weight of the mixture to a moisture content of at least 2% with a room humidity of at least 50%, in the process of feeding the mixture is fed into the pre-filling chamber for canvas formation, where the pulp is evenly distributed along the working width of the aerodynamic canvas formation unit, in which the air flow temperature is maintained at 18-24 ° C, thermally bonded e web is carried out in an oven with temperature control 170-175 ° C, and calendering - at temperatures up to 220 ° C and a line pressure of 12 N / mm (t = 5). As a flame retardant, a polymer phosphorus-containing concentrate CESA or aflammit can be used.

The technological process for the production of non-woven material with reduced combustibility consists of the following stages: a) Supply of the fibrous mixture. b) Canvas formation. c) Sealing the fibrous web in an aerodynamic installation. d) Thermal bonding and calendering of the canvas. e) Cutting and winding the web into rolls or blanks.

A mixture of regenerated fiber, natural fiber in the form of jute, flax or hemp and synthetic fiber with the addition of a substance based on a phosphorus-containing flame retardant in an amount of 5-10% by weight of the mixture is used as a fiber mixture. As a flame retardant, a CESA polymer phosphorus-containing concentrate was used, for example, CESA ^TM -f / flam NBAADS - active substance concentration - 50% (manufactured by Clariant, Switzerland) or aflammit, e.g. Aflammit MV 1277 (4%) (manufactured by THOR, Germany).

Examples of the composition of fiber mixtures:

- option 1 (the preferred option for the automotive industry): regenerated fiber - 70 wt.%, synthetic fiber - 20 wt.%, natural fiber in the form of jute, flax or hemp - 10 wt.%,

- option 2 (the preferred option for heaters in low-rise housing construction): natural fiber in the form of jute, flax or hemp - 75 wt.%, synthetic fiber - 20 wt.%, regenerated fiber - 5 wt.%,

- option 3: regenerated fiber - 40 wt.%, natural fiber in the form of jute, flax or hemp - 40 wt.%, synthetic fiber - 20 wt.%.

It is advisable to use at least 50% of fusible fiber (by weight of the synthetic fiber) as a synthetic fiber, since it provides thermal bonding of the fibers in the mixture when the material passes through the furnace.

In the supply process, the mixture is moistened with a water sizing emulsion Duron 3176 (3184) in an amount of 4-6% by weight of the mixture to a moisture content of at least 2% with a room humidity of at least 50%. The fiber mixture is fed into the pre-filling chamber, where the pulp is distributed over the working width of the installation, which is a key link in the formation of fleece with high rates of uniform distribution of fiber along the length and width. Uniform fiber supply to the aerodynamic installation ensures uniform material weight at the exit.

After the pre-filling chamber with the help of a power unit, consisting of a feed pair and a whipping drum, the pulp is fed into the shaker zone, where it is compacted, removing excess air to supply the mass to the weight conveyor (belt).

The goal of canvas formation is to form a fibrous canvas from textile fibers - a layer of fibers with a certain density of condensation and with a certain orientation thereof.

Canvas formation occurs by a mechanical method and is carried out at an aerodynamic canvas formation apparatus, in which the temperature of the air flow is maintained within the range of 18-24 ° C.

Thermal bonding of the web is carried out in a furnace with a temperature regime of 170-175 ° C. The temperature regime in the furnace is set in such a way (technical map) that the fabric can be thermally bonded by using fusible synthetic fibers, but at the same time maintain the surface properties of the flame retardant, which was used to process the initial fiber.

At the fiber preparation stage, a system for treating the pulp with an aqueous emulsion is used, which ensures the preservation of the mass moisture of at least 2% and the creation of a protective film at the fiber-fiber interface, which prevents damage to the protective layer of flame retardant on the surface during processing.

Calendering is carried out at temperatures up to 220 ° C and linear pressure up to 12 N / mm (= 5 t).

Further steps are carried out in the usual manner.

A roll of nonwoven fabric on the product shaft is mounted on a rolling device and, using the unwinding mechanism, enters a tray-type drive, where the fabric is accumulated, which ensures non-stop operation of the line when stitching the fabrics of one roll with another, and also ensures uniform feeding of the fabric into the impregnation zones.

The entry zone of the machine is designed taking into account the possible finish of any textile fabric. Therefore, there are many options for the location of tissue-guiding organs.

Finishing non-woven fabrics, depending on the quality indicators attached to the canvas, occurs in two ways:

- method of impregnation;

- a method of applying foam.

The impregnation of the canvas is carried out with the help of a dressing for dressing. The canvas, passing through a group of guide pulling shafts, enters the bath with the solution. Then, when leaving the bath, the canvas is squeezed using 2 rubberized shafts. The degree of extraction of the web is regulated by changing the pressure. The system provides manual pressure control.

Foam is applied to the wrong side of the web by installing a special device. Installation of the unit is carried out in the area of the input device. Foamed solution enters the bathtub through a hose line that reciprocates along the bathtub. The solution is distributed on the canvas using a leveling shaft, which is mounted on the support of the bath. The amount of solution applied is controlled by the gap between the blade and the leveling shaft. The latex solution is converted into foam using a mixer. The weight of the foam depends on the intensity of foaming, which, in turn, depends on the air velocity and the amount of binder supplied to the mixer.

After passing through the impregnation nodes, the web enters the stupid chain. Needle straps are attached to the chain to hold and transport the web in the drying chamber. The web is fed onto the needle bars using a lead device. Depending on the finishing method, the material may be pricked on the needles ahead or behind in relation to the feed shaft. The main body for reliable pricking is a pricking roller with a brush ring. With a pricking roller, the material is partially planted. The piercing roller and the piercing brush press the material all the way to the bottom of the needle bars.

The working width of the dummy chain is adjustable depending on the width of the web.

The canvas, fixed on the transport chain, enters the drying chamber, which consists of several zones. Each drying zone has two sections of air circulation lying opposite each other. Drying canvases can be carried out by two types of heating: steam and electric heating.

By means of axial fans, fresh air and air from the drying chamber are sucked in through steam or oil-heated heat exchangers and fed to the nozzles. Through the openings in the dies, the heated air enters the material to be dried at high speed. Air saturated with humidity is exhausted through exhaust fans.

When leaving the drying chamber, the material enters the cooling zone. The material, which is still on the chains, is cooled by an axial fan through the nozzles with ambient air.

Further, the material is pulled together with the width chain by two pulling shafts.

The material enters the winding device, where the finished web is wound on commodity shafts with sleeves. Commodity shaft with a sleeve for winding the web can be replaced at speeds of 40 m / min without stopping the finishing line using a rotary winding mechanism. A wound roll of web is removed from the winding device along with the commodity shaft, after which the commodity shaft is pulled out of the sleeve, and the roll is packaged.

The finished product is a composite multilayer nonwoven material with a width of 1000-2000 mm of high drapeability (up to 11%), air permeability of 145-155 dm ³ / m ² s, tear strength from 28 to 42 N, surface density 250-700 g / m ² The activity of the test substance cyclohexane is 130 mg / g.

Claims (2)

1. A method of manufacturing a non-woven material with reduced combustibility, in which the technological process consists of the following stages: feeding the fibrous mixture, canvas forming, densifying the fibrous web on an aerodynamic installation, thermo-bonding and calendering of the web, cutting and winding the web into rolls or preforms, characterized in that as a fiber mixture, a mixture of regenerated fiber, natural fiber in the form of jute, flax or hemp and synthetic fiber with the addition of a substance based on phosphorus is used containing flame retardant in the amount of 5-10% by weight of the mixture, moisten the mixture with an aqueous oil emulsion in the amount of 4-6% by weight of the mixture to a moisture content of at least 2% at room humidity of at least 50%, and the prepared mixture is fed into the pre-filling chamber for canvas formation, where the pulp is evenly distributed along the working width of the aerodynamic canvas formation unit, in which the temperature of the air flow is maintained within the range of 18-24 ° C, the fabric is thermally bonded in a furnace with a temperature mode 170-175 ° C, and calendering - at temperatures up to 220 ° C and linear pressure up to 12 N / mm (= 5 t). 2. The method according to p. 1, characterized in that as a flame retardant use a polymer phosphorus-containing concentrate CESA or aflammit.