Improvements in or relating to the production of goods of or containing rubber

摘要

In the manufacture of rubber goods by deposition of rubber on a former from an aqueous dispersion, in which the deposition is effected by application of a rubber coagulant to the base, the thickness of the film is varied over the article by the application of a film of varying thickness or concentration, or both, to the base. The coagulant may be applied to portions only of the base. To produce a glove having a thick palm, a porcelain form is coated on the palm with calcium nitrate dissolved in acetone. When the solvent has evaporated, the form is dipped into a dispersion, and rubber is deposited on the palm. The form is then dipped in coagulant, dried, and immersed in latex for ten minutes. Alternatively, the form may be dipped in coagulant, dried, a second film of the same or another coagulant applied where required, and the deposition effected in one dipping. In sandblasting glass &c., parts to be protected are coated with coagulant, and rubber is deposited on these parts, while the remainder is coated with liquid latex which can be easily removed. If it is desired to provide a permanent coating of rubber, e.g. in a rack for supporting articles to be electroplated, an adhesive such as a solution of a rubber isomer as described in Specification 249,172*, [Class 70, Indiarubber &c.], may be applied to the former, before, or with the coagulant. Patterns, letters, &c. may be produced on paper, wood, &c. by printing with a thick rubber cement containing 5 per cent of acetic acid, and immersing in latex. The latex is washed from the untreated surfaces with weak soap and ammonia solutions. For providing rubber articles with raised lettering, a sheet of paper is printed with coagulant such as a solution of calcium nitrate in acetone or methanol, the sheet is immersed in latex, and when sufficient rubber is deposited thereon, is used as a transfer.