RU2103170C1 - Method for producing latex condoms - Google Patents

Abstract

FIELD: production of latex articles by dipping technique; may be used for production condoms from latex. SUBSTANCE: pre-cleaned condom-shaping moulds are twice dipped into latex mixture, followed by drying resulting film after each dipping procedure. Films are subjected to vulcanization, left to swell in solution, coated with wet powder, washed and dried. Novelty of the method is in that each time moulds are dipped into latex mixture at 33 ± 3 C for 40 ± 4 s, followed by drying film after each dipping procedure. Drying after first dipping is conducted at 110 ± 15 C for 80 ± 8 s, while drying after second dipping is effected at 90 ± 15 C for 35 ± 4 s. Film swelling treatment is effected at temperature 80 ± 10 C for 40 ± 4 s in aqueous solution containing 2.85-2.90% of sodium tripolyphosphate, 0.23-0.25% of sodium hydroxide and 0.46-0.50% of Volgonate emulsifier. Washing is conducted for at least 30 min in aqueous solution containing 4.1-4.2% of texturized starch, 4.88-5.0% of mixture consisting of calcium carbonate + calcium stearate + aluminium stearate, 0.17-0.19% of polymethylsiloxanic liquid and 0.013-0.015% of boric acid. Latex mixture has the following composition, parts by weight: sulphur, 1.8; zinc while paint, 0.77; basic zinc carbonate, 0.33; zinc ethylphenyl dithiocarbamate, 0.65; ethylcymate, 0.55; antioxidant agent, 1.0; dispersing agent, 0.61; potassium oxide hydrate, 0.47; aqua ammonia, 0.47-1.21; and pigmentary paste, 0.03-0.07 per 100 wt.pts of dry latex matter. Treatment of coating with wet powder is effected by dipping into 3.5-3.6-% texturized starch slurry. EFFECT: higher quality of consumer goods.

Description

 The invention relates to the production of dipped latex products and can be used for the manufacture of condoms.

 A known method of manufacturing condoms from latex, including dipping twice the pre-cleaned forms in a latex mixture, followed by drying the film after each dipping and heat treatment, using mixtures of various compositions containing latex biocidal additives [1].

 In the known method, it is indicated which film is to be obtained by double dipping the molds in latex, however, the process parameters are not indicated.

A known method of manufacturing condoms from latex, including dipping twice the pre-cleaned forms into a latex mixture, followed by drying the film after each dipping, vulcanization, swelling, dusting, washing and drying, dipping the molds into silicone, urethane or butadiene latex mixtures, drying the film carried out at 60-80 ^o C for 10-20 minutes, and swelling and washing is carried out in an alkaline solution [2].

 The disadvantage of this method is the instability of the physico-mechanical properties of the obtained products.

 The objective of the invention is the development of technology for the manufacture of high-quality condoms with stable physical and mechanical properties.

The problem is solved by a method of manufacturing condoms from latex, including dipping twice the pre-cleaned forms in the latex mixture at 33 ± 3 ^o C for 40 ± 4 cc by drying the film after each dipping, while drying after the first dipping is carried out at 110 ± 15 ^o C within 80 ± 8 s, and after the second dipping at 90 ± 15 ^o C for 35 + 4 s, vulcanization, swelling of the film at 80 ± 10 ^o C for 40 ± 4 s in an aqueous solution containing 2.85-2, 90% sodium tripolyphosphate, 0.23-0.25% caustic soda and 0.46-0.50% emulsifier Volgonat. After swelling, wet dusting is carried out, washing in an aqueous solution containing 4.1-4.2% structured starch, 4.88-5.0% mixture of calcium carbonate with aluminum stearate, 0.17-0.19% polymethylsiloxane liquid and 0.013 -0.015% boric acid for 30 minutes, and drying the product.

 It is preferable to use a latex mixture containing 100 parts by weight of dry matter, parts by weight: sulfur 1.8; zinc white 0.77; zinc, basic carbonate 0.33; zinc ethyl phenyldithiocarbamate 0.65; ethyl cimate 0.55; antioxidant 1.0; part of the dispersant 0.61; potassium oxide hydrate 0.47; aqueous ammonia 0.47-1.21; pigment paste 0.03-0.07.

 It is preferable to conduct wet dusting in a 3.5-3.6% suspension of structured starch.

 According to the proposed technology, condoms are made without dye or staining in the colors prescribed by the latex mixture formulation authorized by the Ministry of Health.

 The open end of the condom is rolled into a whisk. Condom weight 1.4 ± 0.3 g.

 Example. The manufacture of condoms is carried out on an automatic line.

 Before dipping, the forms are cleaned in soda solution, washed with hot water and dried with hot air.

 Pure dry forms are immersed in a dipping bath with a mixer containing a latex mixture of the composition, parts by weight: dry latex 100; sulfur 1.8; zinc white 0.77; zinc, basic carbonate 0.33; zinc ethyl phenyldithiocarbamate 0.65; ethyl cimate 0.55; antioxidant "Agidol-2" 1.0; dispersant "NF" 0.61; potassium oxide hydrate 0.47; aqueous ammonia 0.70.

Dipping forms into the mixture is carried out at 33 ± 3 ^o C for 40 ± 4 s.

It is dried in a tunnel type drying chamber at 110 ± 115 ^{° C.} for 80 ± 8 s.

Then the molds are re-dipped into the latex mixture at 33 ± 3 ^° C for 40 ± 4 s and again dried at 90 ± 15 ^° C for 35 ± 4 s.

 The molds with the dried film are fed to the seaming unit, where the edges of the film are rolled into the whisk using rotating brushes, after the seaming of the corolla, the forms enter the vulcanization chamber, divided into 4 sections, where vulcanization is carried out.

In the first and second sections, vulcanization is carried out at 115 ± 10 ^o C for 90 ± 9 s in each section. In the third section at 125 ± 10 ^o C for 105 ± 10 s, in the fourth at 125 ± 10 ^o C for 90 ± 9 s.

After exiting the vulcanization chamber, the molds with the products are immersed in a bath with a solution for swelling containing water, 2.89% sodium tripolyphosphate, 0.24% sodium hydroxide, 0.48% Volgonate. The molds are kept in a swelling solution for 40 ± 4 s at 80 ± 10 ^° C. Then the molds are immersed in a bath with a dusting suspension (3.55% suspension of Biosorb-structured starch in water).

 Powdered condoms are removed from the molds using two cylindrical brushes mounted at an angle and rotating towards each other. At the same time, a solution of Volgonate is fed to the brushes.

 Removed condoms are loaded into a washer and washed in an aqueous solution containing 4.15% structured starch, 4.89% Lipotex (a mixture of precipitated calcium carbonate and aluminum steorate), 0.18% polymethylsiloxane liquid and 0.014% boric acid. Washing is carried out for 30-40 minutes. Washed and centrifuged condoms from the washer are loaded into a drum-type dryer and dried in a stream of hot air. Dried products are polished and then carry out selective control.

As a result of the implementation of the method, high-quality condoms are stably obtained with the following physical and mechanical parameters:
conditional tensile strength of 20-25 MPa before thermal aging, 17-20 MPa after thermal aging;
elongation at break 700-800% before heat aging, 600-700% after heat aging.

Claims (2)

1. A method of manufacturing latex condoms, including dipping twice the pre-cleaned forms into a latex mixture, followed by drying the film after each dipping, curing, swelling of the film in solution, wet dusting, washing and drying, characterized in that each dipping of the forms into the latex mixture at 33 ± 3 ^o C for 40 ± 4 s with drying of the film after each dipping, while drying after the first dipping is carried out at 110 ± 15 ^o C for 80 ± 8 s, and after the second dipping at 90 ± 15 ^o C 35 ± 4 s, film swelling at 80 ± 10 ^o C for 40 ± 4 s in an aqueous solution containing 2.85 - 2.90% sodium tripolyphosphate, 0.23 0.25% sodium hydroxide and 0.46 0.50% emulsifier Volgonate, washing is carried out at least 30 min in an aqueous solution containing 4.1 4.2% structured starch, 4.88 5.0% mixture of calcium carbonate with aluminum stearate, 0.17 0.19% polymethylsiloxane liquid and 0.013 0.015% boric acid.  2. The method according to claim 1, characterized in that use a latex mixture containing 100 wt. including dry matter latex, parts by weight Sulfur 1.8
Zinc white 0.77
Zinc basic carbonate 0.33
Zinc Ethyl Phenyldithiocarbamate 0.65
Ethylcimate 0.55
Antioxidant 1.0
Dispersant 0.61
Potassium Oxide Hydrate 0.47
Ammonia water 0.47 1.21
Pigment paste 0.03 0.07
3. The method according to claim 1, characterized in that the wet dusting is carried out in a 3.5 - 3.6% suspension of structured starch.