RU2283008C2 - Method for applying of protective coating - Google Patents

Abstract

FIELD: manufacture of protective working clothing, in particular, individual protection of worker's hands, more particular, production of gloves and mittens with polymer coating for operation under reactive medium or low temperature conditions with the use of oil field equipment.

SUBSTANCE: method involves the steps of wetting fabric base; dipping it into polymer solution; washing; drying. Fabric base is wetted in aqueous solution of surfactant at temperature of 20-25 C during 0.5-1 hour. Washing operation is successively performed in running water within at least two independent baths in different temperature modes for running water during 40-60 min.

EFFECT: reduced labor intensity and improved quality of articles.

3 cl

Description

The invention relates to protective work clothing, to personal protective equipment for human hands and can be used for the manufacture of mittens and gloves with a polymer coating for working in aggressive environments, at low temperatures, with oilfield equipment.

A known method for producing coatings by applying to the substrate an adhesive layer based on nitrile rubber and rezol phenol-formaldehyde resin and a coating layer, which is used as a composition based on a copolymer of trifluorochlorethylene and vinylidene fluoride. The method increases the elasticity, heat and chemical resistance of the coating used as a vibration-absorbing material (Copyright certificate No. 292012, D 06 n 3/18, 44 d 1/14. Publ. 06.01.1971, Bull. No. 4).

A known method of manufacturing protective gloves and mittens, in which a form with a cloth substrate put on it is dipped into a latex mixture with a relative viscosity of 30-60 s in a funnel B 3-4 to a depth of not more than 10 cm. The form is removed from the latex mixture and kept over it surface for a time sufficient to recombine the molecules of the surface layers of the latex. Then the mold is again immersed to a depth of 6-8 cm, greater than with the previous immersion, repeating the operations of immersion in the latex mixture, removing from it and holding until the entire substrate is dipped. After which, the excess latex mixture is allowed to drain for 5-15 minutes without air blowing, and then dried at a temperature of 90-95 ° C with air blowing at a speed of 0.5-3.0 m / s for 60-90 minutes (Patent RF No. 2178257, class A 41 D 19/04, published on January 20, 2002 Bull. No. 2).

The disadvantages of the known methods include their complexity.

The closest in technical essence is the method of applying a protective coating to the gloves, including wetting the fabric base, dipping it in a polymer solution, washing and drying (RF Patent No. 2104663, A 41 D 13/10, A 62 B 17/00. Publ. 02/20/98, Bull. No. 5).

However, this method is laborious. In addition, it is not environmentally friendly enough, it does not allow to obtain high-quality products (mittens) in mass production at various thicknesses of the protective coating.

The task to which the invention is directed is to reduce the complexity of the method, preserve the ecology of the environment, obtain in mass production products of high quality and presentation with different thicknesses of the protective coating.

The specified technical problem is solved in that in the method of applying a protective coating, including wetting the fabric base, dipping it in a polymer solution, washing and drying, the fabric base is wetted in an aqueous solution of a surface-active substance (surfactant), and washing is carried out with running water for at least in two autonomous bathtubs at various temperature conditions of running water.

In this case, the fabric base is wetted for 0.5-1.0 hours at a temperature of 20-25 ° C.

Wetting the fabric base in an aqueous surfactant solution leads to better film formation, ensures the integrity of the coating, improves the tightness of the protective coating, thereby increasing the life of the product (gloves, gloves).

Rinsing with running water speeds up the process of washing the product from the solvent, improves the appearance of mittens, gloves.

And washing in several (at least two) bathtubs makes it possible to reduce the solvent content to the required maximum permissible concentration (MPC) in the main volume of wastewater, preserving the ecology of the environment.

Washing in autonomous baths also improves the process of washing the product from the solvent, reduces the solvent content to the required MPC values in wastewater.

Washing of the product under different temperature conditions between the bathtubs, i.e. at various temperatures of running water, reduces the total washing time, improves the washing of the product from the solvent, allows the mass production of products with different thicknesses of the protective coating, increases the comfort of the product during operation.

The protective coating is applied using a cassette-type line developed and manufactured by SPE Spectr-TP LLC. In this line, forms (frames) are assembled into cassettes rotating relative to their axis, on both sides of which forms (frames) from 32 to 48 pieces are installed. The line is equipped with one dipping bath, four washing baths and a chamber for drying products.

The method is implemented as follows.

A polymer solution is prepared at a temperature of 20-25 ° C with a viscosity of 2000-3000 MPa · s of the following composition, wt. %: polyether urethane (for example, Vitur P0512, TU 6-55-221-1085-89, solution in NN dimethylformamide) 12.0-20.0; a plasticizer (e.g. dibutyl phthalate) 0.2-0.6; inorganic filler (for example, chalk, titanium dioxide, zinc oxide, etc.) 5.0-15.0; polymer filler (for example, rubber crumb from vulcanized waste 1.5-2 mm in size, TU 38.105590-91) 5.0-10.0; a solvent (for example, NN dimethylformamide, GOST 20289-74, s.1) - the rest.

Maintain (wet) the fabric base of the product before dipping into a polymer solution in an aqueous surfactant solution (auxiliary substance OP-10) for 0.5-1 hours at a temperature of 20-30 ° C.

Then the fabric base is squeezed in a centrifuge at a speed of 2500-3000 rpm for 1.0-1.5 minutes, after which it is immersed on a wire frame (when applying a protective coating on the gloves) or on a porcelain, or metal, or glass form ( when applying a protective coating to gloves) into the polymer solution for 5-10 s in the "cuff up" position.

After immersing the products in a polymer solution, they are kept in air under normal conditions in the position of the molds (frames) "cuff up" for 1.5-3 minutes.

Then the cartridge is rotated 180 °, while the coated products are on top of the cartridge in the "cuff down" position, in which they are kept in air under normal conditions for 3-5 minutes.

Then the products located on the lower side of the cartridge are immersed in the polymer solution for 5-10 s in the "cuff up" position.

After which they are kept in air under normal conditions in the position of the molds (frames) "cuff up" for 1.5-3 minutes.

Then the cartridge is rotated 180 °, while the coated products are on top of the cartridge in the "cuff down" position, in which they are kept in air under normal conditions for 3-5 minutes.

Then periodically (at least 6 times per minute) for 10-15 minutes immerse the cassette, either the lower or the upper side, in the first stand-alone bathtub with running water having a temperature of 50 ± 5 ° C.

After washing in the first bath, immerse the cartridge in the next stand-alone bath with running water having a temperature of 40 ± 5 ° C, and the process is repeated.

Then the cartridge is immersed in the next, third, autonomous bath with running water having a temperature of 35 ± 5 ° C, and the process is repeated again.

And, finally, immerse the cartridge in the last, fourth, autonomous bath with running water having an ambient temperature (20-25 ° C), repeating the process.

The washing process with decreasing temperature of running water from bath to bath from a maximum temperature of 50 ± 5 ° C to a minimum of 20-25 ° C is advisable to carry out when placing the product (for example, mittens) on a wire frame. In this case, the maximum washing of the product (mittens) from the solvent in the first bath occurs, which preserves the ecology of the environment.

Due to its high concentration, the spent washing solution from this bath is poured into a separate container for further regeneration.

And the spent washing solution of other (second, third and fourth) baths, having a maximum permissible concentration, is discharged into wastewater.

When placing the product (for example, gloves) on the form (porcelain), it is preferable to carry out the washing process with increasing temperature of running water from bath to bath from a minimum of 20-25 ° C to a maximum of 50 ± 5 ° C. In this case, the porcelain mold with the product is suitable for the operation of drying already heated to a temperature of 50 ± 5 ° C, i.e. its heating in the drying chamber is not required, and thus the drying process is accelerated, energy costs are reduced.

At the same time, the spent wash solution from the first and second baths due to its high concentration (since the temperature of the wash water in these baths is not high enough) is poured into a separate container for further regeneration.

And the spent washing solution of other (third and fourth) baths, having a maximum permissible concentration, is discharged into wastewater.

In general, washing lasts 40-60 minutes (in the prototype method, products are immersed in water for 2-6 hours).

After washing, the products are kept in a horizontal position in air under normal conditions for 10-15 minutes, and then dried in a chamber at a temperature of 50-60 ° C for 2-3 hours (in the prototype method, dried at a temperature of 50-70 ° C within 10-12 hours).

The selected time intervals allow you to conduct the process of applying a protective coating on the product continuously.

At NPP Spektr-TP, using the proposed method, an experimental batch of mittens (1000 pcs.) And gloves (5000 pcs.) Tested in field conditions (LLC Nizhnevolzhskburnefte, Zhirnovsk, Volgograd Region and CJSC Stroykomplekt-Enamel ", Smolensk) with positive results.

Currently preparing the industrial production of protective gloves using the proposed method of applying a protective coating.

Claims (3)

1. The method of applying a protective coating, including wetting the fabric base, dipping into a polymer solution, washing and drying, characterized in that the fabric base is wetted in an aqueous solution of a surfactant at a temperature of 20-25 ° C for 0.5-1 h and the washing is carried out sequentially with running water in at least two independent baths at different temperature conditions of running water for 40-60 minutes. 2. The method according to claim 1, characterized in that the washing is carried out with a temperature of running water from bath to bath from a maximum temperature of 50 ± 5 ° C to a minimum of 20-25 ° C. 3. The method according to claim 1, characterized in that the washing is carried out with increasing temperature of running water from bath to bath from a minimum of 20-25 ° C to a maximum of 50 ± 5 ° C.