GB2176499A

GB2176499A - Article and method for tarnish removal

Info

Publication number: GB2176499A
Application number: GB08611601A
Authority: GB
Inventors: Howard Marc Gold
Original assignee: Individual
Current assignee: Individual
Priority date: 1985-05-14
Filing date: 1986-05-13
Publication date: 1986-12-31
Also published as: GB8611601D0; AU5819586A; SG71988G; HK9789A; WO1986006760A1; GB2176499B; GB8512122D0; EP0257037A1; DE3673420D1; AU580167B2; EP0257037B1

Abstract

An article useful for tarnish removal comprises a metal or alloy item such as a sheet of aluminium foil in combination with and preferably attached to a container of electrolyte(s), such as inorganic alkaline carbonate, the container either being water permeable as in the case of infusion web or capable of releasing its contents into water. the article is placed in water together with tarnished items, particularly silver-plated items, for removing tarnish by electrochemical action.

Description

SPECIFICATION Article and method for tarnish removal This invention concerns an article and its use for tarnish removal . "Tarnish" is used herein to embrace discolouration or oxidation of metal surfaces.

The invention is more specifically concerned with an article, such as a package or sachet, useful in cleaning tarnish from metal objects or objects at least having a metal-plated surface. Principally the invention provides an article for use in removing tarnish from silver or silver-plated objects.

One known method of removing silver tarnish requires use of abrasive polish substances by manual effort. This method includes the following disadvantages; (a) effort exerted in polishing is arduous; (b) polishing can take a long time; (c) intricate items such as jewellery or objects having sculptured or engraved surfaces may be impossible to polish in inaccessible areas. Conventional polish tends to get trapped in such areas and leaves an unattractive appearance; and (d) plated items eventually lose their plated surface by the repeated action of abrasive silver polish.

It is from a consideration of the drawbacks of known polishes and methods for removing tarnish that has led to the present invention.

The invention provides an article, useful for tarnish removal, comprising in combination a metal or alloy item, such as a folded or unfolded sheet, and a container of electrolyte(s) which can permit ingress of water.

Preferably the container is water-permeable or capable of releasing its contents by, e.g. opening or slitting the container. Most preferably the article useful for tarnish removal comprises in combination, a folded or unfolded sheet of metal to which a water-permeable container of electrolyte(s) is attached. The sheet can be in the form of gauze or foil, preferably aluminium foil, or other metal which is more electro positive than silver such as iron or zinc. Conveniently, the article may comprise a package in which the sheet is wrapped around the container, although this is not essential for embodiments in which the size of container in surface area approximates the size of the sheet.

To conform with current methods of sachet (container) production, the sheet can include a coating of heat sensitive adhesive substrate. It is preferred to use a sachet of water-porous material such as infusion web commonly employed in the production of tea bags. Such sachet may be formed on one side by the sheet, e.g. aluminium foil, and on the other side by infusion web which is stitched or adhered at or in the region of its periphery to the sheet.

Electrolyte in the form of inorganic salt may be used. This can be in powder or crystal form and the salt(s) selected may produce an alkaline solution in water. Carbonates such as sodium carbonate are preferred.

Use of an article as described herein for tarnish removal is included within the scope of the present invention.

In a process for removing tarnish from the surface of a metal or metal-plated object, an article according to the invention is placed in water preferably hot or boiling, the electrolyte(s) are allowed or caused to dissolve whereupon said objects are placed in the solution formed to contact the sheet.

Preferably the objects comprise silver or silverplated objects.

Use of the article in such a process provides an electrochemical means for tarnish removal wherein the object, e.g. a silver item, and a dissimilar metal are placed in an electrolyte solution such as a solution of common soda in hot water. When the two metals are in contact the tarnish is removed from the surface of the silver. Unlike an abrasive polish, silver is not physically removed in the process.

Advantages over conventional silver polish include; (1) No effort is required in polishing, as the process is self-sustaining requiring no manual effort.

(2) The process need only take little time and may even be almost instantaneous.

(3) Tarnish can be removed from manually inaccessible areas without special procedures.

(4) Since silver metal is not physically removed from the object or its plating, plated articles may retain their plated silver surface for longer.

The article can be presented as a convenient and ready-to-use package such as a disposable sachet which includes the metal or alloy sheet either integrally or separately.

Embodiments of the invention will now be described with reference to the accompanying drawings by way of example only, wherein; Figure 1 is a plan view of an article; Figure 2 is a side elevation; Figure 3 shows one form of article unfolded for use; Figure 4 shows the article in conjunction with a receptacle of hot water; Figure 5 illustrates ingress of water and diffusion of electrolyte; Figure 6 illustrates tarnish removal from silverplated objects; Figure 7 is a view of a more preferred form of article; and Figure 8 is a cross-section of Figure 7.

As shown in Figures 1 and 2 of the drawings, the article comprises a sheet of aluminium foil 1 together with a porous sachet 2 containing sodium carbonate (soda crystals) 3. The sachet 2 is sealed or stitched at its edges 4 and is composed of water permeable material. The sachet is also attached to the surface of the aluminium foil at 5 by, e.g.

stitching or adhesive.

Figure 3 shows a sequence for unfolding the article supplied in "package' form. The folded aluminium sheet is partially separated from the porous sachet to become opened flat into a position corresponding to Figures 1 and 2.

Referring to Figure 4, the unfolded package is placed into a receptacle 6 containing hot (preferably boiling) water 7, the water-porous material fac ing downwards. Water seeps into the container and the soluble electrolyte contained in the sachet diffuses into the hot water 7 to form an alkaline solution 7a of sodium carbonate referred to in Figure 5. Diffusion may take 30-60 seconds.

Use of the article is shown in Figure 6, the receptacle 6 of electrolyte solution 7a includes the aluminium foil sheet 1 fully submerged and a plurality of silver or silver-plated objects 8-13 which are in contact with themselves and/or the aluminium foil providing at least one object contacts the foil. In this process, articles according to the invention can be positively retained at the bottom of the receptacle 6 by the objects undergoing tarnish removal.

Such objects rest on the aluminium foil as shown whereby at least one of them is in contact with the foil and the other objects are in metal-to-metal contact with each other and/or the foil.

Referring lastly to Figures 7 and 8, a more preferred embodiment of the invention is illustrated.

The upper surface of the article comprises a nonfolded sheet of aluminium foil 1 which acts as an electrode and one side of the container. The lower or under-surface is coated with a plastic, heat sensitive, adhesive 14. A sheet of infusion web 2 similar to tea bag paper forms the other side of the container. It may, if necessary, be also impregnated with heat sensitive adhesive in specific regions providing the web remains water-permeable.

Such adhesives are known in the art which are active at approximately 2000C and therefore unaffected by boiling hot water.

The web 2 is heat sealed at seams 4 to the underside of the sheet 1 and consequently traps and electrolyte, light sodium carbonate powder 3, between the web 2 and the foil 1. The foil need only be coated with adhesive substrate in specific regions where the edge seams are to be formed in the web. The heat sealed seams 4 extend around the sachet formed.

in order to use such an article for tarnish removal the same steps should be taken as previously described, although there is no need to unfold the sheet initially.

Tarnish removal may require some 2 to 5 minutes. Objects with extensive tarnish may require longer and may be gently brushed to assist the action. To keep the electrochemical process sufficiently active it may be desirable to add further boiling water.

Claims

1. Article, useful for tarnish removal, comprising in combination a metal or alloy item and a container of electrolyte(s) which can permit ingress of water.

2. Article as claimed in claim 1, wherein the metal or alloy item comprises a folded or unfolded sheet and the container is either water-permeable or capable of releasing its contents.

3. Article, useful for tarnish removal, comprising in combination, a folded or unfolded sheet of metal to which a water-permeable container of electrolyte(s) is attached.

4. Article as claimed in claim 3, wherein the sheet is in the form of gauze or foil made of iron or zinc or aluminium.

5. Article as claimed in claim 4, wherein the sheet is in the form of aluminium foil.

6. Article as claimed in any one of claims 3 to 5, wherein the sheet has a coating of heat sensitive adhesive medium.

7. Article as claimed in any one of claims 3 to 6, wherein the container is in the form of a package or sachet which is stitched or adhered at or near its periphery.

8. Article as claimed in any one of claims 3 to 7, wherein the container comprises water-permeable substrate.

9. Article as claimed in claim 8, in which the substrate comprises paper infusion web.

10. Article as claimed in claim 8 or 9, wherein the container is partly formed by the metal sheet and partly by water-permeable substrate.

11. Article as claimed in claim 3, comprising a sachet of electrolyte, one side thereof composed of aluminium foil, the other side composed of infusion web, the web being adhesively sealed to the foil at or near the periphery of the web by a heatsensitive adhesive coating on the foil.

12. Article as claimed in any one of the claims 3 to 11, wherein the electrolyte comprises inorganic salt.

13. Article as claimed in claim 12, in which the salt is in powder or crystal form.

14. Article as claimed in claim 12 or 13, in which the salt, in aqueous solution, is alkaline.

15. Article as claimed in any one of claims 12 to 14, in which the salt comprises a carbonate such as sodium carbonate.

16. Article useful for tarnish removal substantially as herein described with reference to any one of Figures 1 to 3 of the accompanying drawings.

17. Article useful for tarnish removal substantially as herein described with reference to Figure 7 or 8 of the accompanying drawings.

18. Use of an article as claimed in any preceding claim in a method of tarnish removal.