GB2255030A - Simulated lead light - Google Patents

Abstract

The present invention provides a method of forming a simulated lead light in which opaque simulated lead cames are applied to the surface of a transparent or translucent carrier material, characterised in that the cames are built up by: a) applying an adhesive material to the carrier surface in lines or strips corresponding to the position of the cames wherein the adhesive material contains a cutting agent that acts to etch the carrier surface, and b) applying an opaque particulate material to the adhesive lines or strips, and c) removing unadhered particulate material, and d) applying adhesive material to the particulate material on the carrier surface, and e) applying opaque particulate material to the adhesive material applied in d), and f) repeating steps d) and e) if necessary until raised simulated lead cames have been built up as required on the carrier surface.

Description

This invention relates to methods of .rnanufctunng simulated lead lights1 including simulated stained glass windows.

Lead lights are used in windows, in decorative doors, in glass partitions, as back lit panels, and as parts of decorative articles, eg. in glass lampshades. Previously, the mamufactre of lead lights required the placement of small panes of glass bctween soft lead cames, which provide the bold outline for the lead light. If the small pieces of glass are stained, they can be put together to create a stained glass window.It will be appreciated that this age old practice is both expensive and time consuming and suffers from various disadvantages apart from the expense as: a) it is difficult to manufacture and install large lead lights as the resulting structure is unstable, and b) conventional lead lights have a tendency to leak between the lead cames and the pieces of glass, and c) the completed lead light is heavy, and d). copleted lead lights have a tendency to bow or distort with time, and e) it is difficult to use a conventional lead light in conjunction with aluminium framing as the lead came reacts with the aluminium.

Many attempts have been made to produce simulated lead light and or stained glass windows and the following US patent specifications illustrate the many different approaches that have been made to solving these problems.

U.S.Patent Specification No. 3183140 to Gibson, issued 11th May 1965.

U.S.Patent Specification No. 3420728 to Havistock, issued 7th January 1969.

U.S.Patent Specification No. 3713958 to McCracken, issued 30th January 1973.

U.S.Patent Specification No. 3815263 to Oberwagner, issued 11th Sune 1974.

U.S.Patent Specification No. 3900641 to Woodman, issued 19th August 1975.

U.S.Patent Specification No. 3931425 to Kuroda, issued 6th January 1976.

U.S.Patcnt Specification No. 409309 to Holt, issued 22nd February 1977.

U.S.Patent Specification No. 4127689 to Holt, issued 28th November 1978.

U.S.Patent Specification No. 4194669 to Bromberg, issued 25th March 1980.

.None of the above attempts proved to be commercially satisfactory. Some of the inventions involved the fixing of lead strips or cames to the outside of the glass sheet (eg.

Bromberg, US patent specification No. 4194669), whilst others involved the application of paint (Woodman, US patent specification No. 3900641), a paste (Havistock, US patent specification No. 3420728), or an ink (Kuroda, US patent specification No.

3931425).

The applicant addressed the aforementioned problems in European patent specification No. 0038681. The invention described in this specification overcame a number of the disadvantages of the prior art proposals by building up simulated lead cames by applying an adhesive material to the surface of a carrier sheet, such as a sheet of glass, and applying an opaque particulate material such as silicon carbide to the adhesive lines or strips, removing excess particulate material, and repeating the layers of adhesive and particulate material until a satisfactory simulated lead came is created.

Th particular, the above invention provided the following advantages: a) the ability to crcate a simulated lead came without the nted to apply a thick viscous paste, paint or ink, as the adhesive and particulate material were applied separately; b) the invention allowed the adhesive material to be applied to the carrier sheet by screen printing to ensure accurate registry of successive layers and/or registry between simulated lead cames on each side of the canier sheet, c) complicated curves and fine details could be created which would not be possible with conventional lead lights as the adhesive and particulate material were applied sepaiately;; d) large sheets of glass could be provided with simulated lead came on the surface thereof, and the sheets could then be cut to size as and when required.

Unfortunately, the above invention also had a few disadvantages associated with it. For instance, there have been problems in ensuring that the adhesive adhercs sufficiently to the carrier material. Furthermore, a gritty surface on the simulated lead camcs was formed by the process, unlike the smooth surface achieved with genuine lead lights.

It is an object of the present invention to address the above problems.

In the following description and throughout the specification, the description of screen and grit sizes are to be interpreted in accordance with the following. A screen described as "100" has 100 meshes per centimetre. If the letter "T" follows the numeral then the meshes are of medium quality material having a width of 123 microns. A particulate material which will pass through a "100" screen as described as being "100" grit. Other sizes described in the specification are to be similarly construed.

Throughout this specification, the carrier material will be referred to as glass, however it should be appreciated other carrier materials may be used in accordance with the present invention.

The applicant found that the poor adherence of the adhesive to the carrier material was due to two factors. One factor was that glass has a very smooth surface which does not lend to ready adherence by an adhesive.

In one aspect of the present invention, there is provided a method of forming a simulated lead light in which opaque cames are applied to the surface of a transparent or translucent canier material, characterised in that the cames are built up by: a) applying an adhesive material to the carricr surface in lines or strips corresponding to the position of the cames wherein the adhesive material contains a cutting agent that acts to etch the carrier surface, and b) applying an opaque particulate material to the adhesive lines or strips, and c) removing unadhered particulate material, and d) applying adhesive to the particulate material on the carrier surface, and e) applying opaquc particulate material to the adhesive material applied in d), and f) repcating steps d) and c) if necessary until raised lead cames have been built up as required on the carrier surface.

The adhsive applied over the particulate material may be different to that applied directly to the carrier surface.

By having a cutting agent in the actual adhesive, the surface of the glass to which the adhesive is applied becomes roughened, making for more ready adherence of the adhesive to the glass surface. The rcst of the glass surface which does not have the adhesive applied to it renains smooth as desired. A number of cutting agcnts may be used, for instance a acid or a strong base may be suitable. One adhesive material found which particularly suited to this purpose is an epoxy bascd ink sold under the name QUALAGE CATALINK CIM) by Croda Polymers NZ Urnited of 34 Lomo;ld Crescent, Pakuranga* Auckland, New Zealand.

The second factor the applicants found which led to difficulties in adherence of the adhesive to the glass, is that often moisture remained on the glass when the adhesive was applied. Previously, the shcets of glass were first washed with water and then allowed to dry. In the present invention the applicant has reduced the moisrure present on the glass surface after washing by firstly heating the glass after it has been washed. The adhesive has also had its formulation modified so that upon heating in the curing process later on, a wetting characteristic in the adhesive becomes apparent. This wetting characteristic allows the adhesive to flow more readily onto the glass creating full contact and thus ready adhesion.

The QUALAGE CATALIN:R (TM) adhesive readily passes through a coarse meshcd screen of 25T mesh size.

The meshed screen is provided with a suitable stencil in the usual screen printing manner enabling an appropriate pattern of lines or strips of adhesive to be applied through the screen onto the glass surface at a printing station.

After the adhesive had been applied to the carrier material, the printed sheet is conveyed to a dusting station. At the dusting station, a dry particulate material. such as silicon carbide is dusted onto the entire sheet so that it will adhere to the printed adhesive lines or strips. Surplus particulate material is removed from the sheet by lifting the sheet into a vertical position and bushing down the surface.

The dusdng station is preferably remote from both the washing and the printing station to avoid contamination by the particulate materials. Surplus particulate material is preferably removed by suction cleaners and filters to prevent dust build up in the air.

Previously, after dusting the sheets were stored until the adhesive had been set. The suggested drying period was in the order of 24 hours.

With the present invention, the additives to the adhesive means that a particular adhesive curing programme is required For the QUALAGE CATAUNK CIM) adhesive material, the glass sheets are required to be stood in vertical racks for approximately 2 to 4 hours and at a temperature of 60"C. There may be temperature fluctuations over the range of 5500 65QC although 60"C is the desired temperature. It should be appreciated that if other adhesive materials are used, different curing periods and temperatures may be required.

The cured sheets are then rcturned to the printing station, and subsequent layers of adhesive and particulate material are applied to the sheets and the adhesive until a sufficient thickness of material has been applied to the surface to simulate a lead came, in accordance with the end users requirements.

In one embodiment of the present invention, the applicant has found that the following combination of grit sizes and coatings provides a smoother surface to the lead cames to that previously obtained. A base layer of coarse particulate material in the order of 180 grit is used as a base build up on the adhesive material printed onto the glass. Next the adhesive material is cured as discussed before and then a second layer of adhesive is printed over the 180 grit base. Onto this adhesive is dusted a fine particulate material in the order of 400 t. This fine grit acts as a filler between the coarse particulate material and provides a relatively smooth surface. The adhesive is cured for a second time and then finally a sealing coat is screen printed over the layers of particulate material.

Preferably the sealing coat has the qualities of being dark in colour (so as to simulate the colouring of real lead light), provides a smooth coat and acts as a sealant to seal the particulate material away from the outside environment. One particular sealing coat which provides the desired colouring, surface characteristics and weatherability is the QUALAGE TOP COAT (TM) which is sold by Croda Polymers NZ Limited of 34 tomond Crescent, Pakuranga, Auckland, New Zealand.

A two sided simulated lead light may be produced by building simulated cames on one side of a carrier surface as discusscd above. When the simulated lead cames have been built up on the surface of the glass, the glass sheet may be turned over and the process repeated Simulated stained glass is achieved by scren printing the colours in combination with the build up of the simulated lead cames as described above.

The carrier surface for simulated stained glass is preferably a rough textured glass such as cathedral glass to enhance the coloured effect.

The coloured layers are preferably screened printed onto the glass using a finer mesh than is utilised for the adhesive. A suitable mesh for the coloured areas is 120T mesh size, although other mesh sizes can be utilised The coloured areas are preferably applied to the glass prior to the application of the adhesive lines or stripes. The colours may be applied to one or both sides of the glass surface depending on the end use for the simulated stained glass.

Throughout the specification reference has been made to the particulate material as being silicon carbide. This has proved to be satisfactory, although it will be appreciated that other particulate materials can be utilised, such as black sand or New Zealand iron sand or aluminium oxides The preferred adhesive material has been referred to as an epoxy based screen printing ink, although it will be appreciated that other adhesive materials can be utilised provided the adhesive includes a carrier material cutting agent. The nature, setting bme and viscosity of the adhesive material will depend upon the method of application.

Although the Invention lends itself particularly to the use of screen printing and the application of adhesive lines or strips. it should be appreciated that other means of applying the adhesive may be utilised, eg by brush painting, spraying or by other printing processes.

It can be seen that the prescnt invention can be used to create complex curves in fine details which would otherwise be impossible to achieve with conventional lead lights.

Claims (15)

1. A method of forming a simulated lead light in which opaque simulated lead carnes are applied to the surface of a transparent or translucent carrier material, characterised in that the cames are built up by:: a) applying an adhesive material to the carrier surface in lines or scrips corresponding to the position of the cames wherein the adhesive material contains a cutting agent that acts to etch the carrier surface, and b) applying an opaque particulate material to the adhesive lines or strips, and c) removing unadhered particulate material, and d) applying adhesive material to the particulate material on tne carrier surface, and e) applying opaque particulate material to the adhesive material applied in and f) repeating steps d) and e) if necessary until raised simulated lead comes have been built up as required on the carrier surface.

2. A method as claimed in claim 1, characterised in that the adhesive material displays a wetting characteristic upon heating.

3. A method as claimed in either claim 1 or claim 2 in that the adhesive material is an epoxy bascd ink which is screened printed onto the carrier surface.

4. A method as claimed in any one of claims 1 to 3 wherein the ink is-that sold rsndcr the name QUALAGE CATALINK (EM) by Croda Polymcrs NZ Limited of 34 Lomond Crescent, Pakuranga, Auckland, New Zealand.

5. A method as claimed in any one of claims I to 4 wherein the adhesive material is cured by placing the carrier material with the adhesive on it in an environment of between 55 degrees and 65 degrees for approximately 2 to 4 hours.

6. A method as claimed in any one of claims I to S wherein the particulate material is silicon carbide.

7. A method as claimed in any one of claims 1 to 6 wherein there are two layers of particulate material applied to the came; material, wherein the firs: layer is of 180 grit size and the second layer is of 400 grit size.

8. A method as claimed in any one of claims 1 to 7 wherein a sealing material is placed over the top of the last layer of particulate material applied to the carrier material.

9. A method as claimed in claim'8 wherein the scaling material is sold under the name QUALAGE TOP COAT by Croda Polymers NZ Limited of 34 Lomond Crescent, Pakuranga, Auckland, New Zealand.

10. A method as claimed in any one of claims 1 to 9 charactensed in that the simulated lead cames are applied to both surfaces of the carrier material, the simulated lead cames on each surface being in register with each other.

11. A method as claimed in any one of claims 1 to 10 characterised in that one or both surfaces of the carrier material is or are coloured by screen printing,

12. A simulated lead light manufactured in accordance with any one of the preceding claims.

13. A simulated lead light consisting of a transparent or translucent carrier material having simulated lead cames on one or both surfaces thereof, wherein the simulated lead cames consist of a dense mass build up of alternative layers of an adhesive material and in a particulate material, a first one of the layers also adhering the mass to the carrier surface wherein the adhesive material applied to the carrier surface contains a cutting agent.

14. A method substantially as herein described with reference to the accompanying examples.

15. A simulated lead light substantially as herein described with reference to the accompanying examples.