GB2034629A

GB2034629A - Making rubber gloves by dipping a hollow electroform

Info

Publication number: GB2034629A
Application number: GB7931660A
Authority: GB
Original assignee: BJS ELECTRO PLATING CO Ltd
Current assignee: BJS ELECTRO PLATING CO Ltd
Priority date: 1978-11-02
Filing date: 1979-09-12
Publication date: 1980-06-11

Abstract

A method for the manufacture of a rubber or similar glove comprising the following steps:- dipping a former that is an hollow electroform shaped to resemble the human hand into a suitable wet mix such as an aqueous rubber latex dip, withdrawing the former and subjecting the coating on the former to a latex spray process and curing it under heat, drying and stripping said coating from the former to produce the glove. A master pattern of the human hand conveniently made from one of the group of materials including wax wood, plaster, clay, metal and plastics, is made electrically conductive and plated with an electrodeposit of one or more metals (e.g. Cu, Ni) and the resulting electroform removed from the pattern or vice versa. The electroform may have a wall thickness of (0.010) inch (0.25 mm) to 0.020 inch (0.50 mm).

Description

SPECIFICATION Improved method for the manufacture of 'rubber' gloves and inter alia gloves when made by said method This invention relates to the manufacture of gloves forthe human hand of the kind that is made from a resilient material such as rubber or plastics; the rubber may be natural or synthetic and the plastics may be, for example, polyvinyl chloride. Such gloves referred to above are generally called 'rubber' gloves for industrial, household or surgical use, and are hereinafter referred to as gloves of the kind set forth.

It is known to form gloves of the kind set forth from natural rubber latex by dipping a former at least shaped to resemble the human hand into a suitable wet mix such as an aqueous rubber latex dip, withdrawing the former and subjecting the coating on the former to a latex spray process and curing it under heat after drying and stripping said coating when so formed from the former to produce a glove, such a method is hereinafter referred to as a method of the kind set forth. Such a method is shown in United Kingdom Patent Specification No. 1,326,102.

The method of the kind set forth may take a number of variations from that set out above but the use of a former is essential and said former takes the overall shape of a hand sometimes with thumb and no fingers or a thumb and four fingers. The former is generally of porcelain which in this art is referred to as a conventional material, but it may be of solid metal that is cast or fabricated.

In the method of the kind set forth a porcelain glove former is generally used and this is shown in the schematic of the single figure of the accompanying drawing which is a flow sequence for the manufacture of a glove of the kind set forth. To this figure is added a temperature gradient along the flow line. It will be seen readily that the time for the formation of a single glove is determined primarily by the raising of the former to a certain temperature at step II and cooling it, after heating at step IX, to a sufficiently low temperature at step Xforthe removal of the glove from the former, which operation is a manual operation and thus controlled by the susceptibility of the human hand of the operator of the process to an acceptable working temperature which varies in different persons.This important temperature may be arbitrarily set in a range of susceptibility that does not exceed for comfort about 40C to 60 C (1 04 F to 1 40 F).

We have surprisingly found that a method of the kind set forth can be speeded and the output of gloves per working hour produced by it increased.

According to one aspect of the invention we provide a method of the kind set forth in which the former is a hollow electroform.

According to further aspects of the invention we provide a method of making a hollow electroform and the electroform when so made.

According to yet another feature of the invention we provide a glove of the kind set forth whenever made by the method of the invention.

Electroforming is the art of producing metallic objects by a process of electrodeposition and an electroform is an electroformed metallic object.

Preferably the hollow electroform for the above is about 0.010 inch (0.25 mm) thick and is made from either copper or from nickel or from a copper nickel bi-plate deposit.

The advantage to be obtained from a hollow former is shown to some extent from a comparison of the heat conductivity of porcelain with that of copper and with that of nickel from Tables of Physical and Chemical Constants, Kaye & Laby 1959: Porcelain 0.015 expressed in Copper 3.85 Joule cm/cm2/s at 0 C.

Nickel 0.91 What is not clear from these figures is the advantage to be obtained from the use of a hollow thin metal former as against a solid ceramic former such as porcelain as long used in the glove making art or indeed against a solid metal former.

One method of making an electroformed hollow former for the glove is as follows: A master pattern of the human hand is made in one of a group of materials such as wax, wood, plaster, clay, metal and plastics. If wax is chosen a plastics two-part mould is made first from a pattern of a hand or stylized hand. Into this two-part mould is poured the molten wax. On solidification the wax is removed from the mould. By the term human hand is herein meant either an exact replica of the male or female hand of various sizes or a stylized form that resembles the human hand with or without fingers.

The wax form is now made electrically conductive by spraying with silver, and by electrolysis electro-deposits of a metal preferably copper or nickel or a biplate deposit of copper and nickel is plated onto the silver surface of the wax. The wax is finally melted out of the electroform leaving a hollow former in the shape of a hand with a metal wall thickness of about 0.010 inch (0.25 mm) to 0.020 inch (0.50 mm).

The advantage to be obtained from such a hollow former in comparison with a porcelain former is shown in the figure of the accompanying drawings in which temperature is taken along the ordinate and time along the abscissa. Clearly the times between steps II and Ill and between steps IX and X are much reduced with a hollow electroform owing to the exceptionally good heat conductivity of the thin metal over that of solid porcelain or solid metal.

Claims

1. A method of the kind set forth in which the former is a hollow electroform.

2. The method according to Claim 1, wherein the electroform is made from a deposit of copper.

3. The method according to Claim 1, wherein the electroform is made from a deposit of nickel.

4 The method according to Claim 1, wherein the electroform is made from a copper nickel biplate deposit.

5. The method of any one of Claims 2 to 4, wherein the thickness of the deposit is in the range 0.010 inch (0.25 mm) to 0.020 inch (0.50 mm).

6. An electroform for use in the method of any preceding claim, wherein said electroform is made by the following steps, a master pattern of the human hand as hereinbefore defined is made from one of the group of materials including wax wood, plaster, clay, metal and plastics, the master pattern is made electrically conductive and plated with an electrodeposit of one or more metals and the deposit removed from the pattern or vice versa.

7. The electroform according to Claim 6, wherein the electrical conductivity is provided by spraying a master pattern of wax with silver and melting out the wax from the electroform.

8. A glove whenever made by the method of any one of Claims 1 to 7.