GB2476230A

GB2476230A - Acrylic lamination process

Info

Publication number: GB2476230A
Application number: GB0921413A
Authority: GB
Inventors: Raimund Aloys Liiv
Original assignee: Individual
Current assignee: Individual
Priority date: 2009-12-07
Filing date: 2009-12-07
Publication date: 2011-06-22
Also published as: GB0921413D0

Abstract

Designs made out of an acrylic medium 3 such as paint are laminated between two or more acrylic sheets 1, 5. The acrylic paint can be as a continuous area, as a series of strips, any desired shape or set of shapes and can be painted over with additional layers. Adhesive 2, 4 which may be allowed to flow out of the side of the acrylic sheets, may be present between the acrylic paint and the sheets, the adhesive dissolving the polymers to be bonded.

Description

DESCRIPTION

Process One 1. The acrylic paint is painted on to a surface which will allow it to be removed when dry, or nearly dry. A suitable material for this would be a smooth sheet of polypropylene.

a) The acrylic paint can be as a continuous area.

b) The acrylic paint can be as a series of strips.

c) The acrylic paint can be any desired shape or set of shapes.

d) The acrylic paint can be painted over with additional layers.

2. When the water content of the acrylic paint has evaporated sufficiently it is then peeled from the sheet of polypropylene. If the acrylic paint starts to tear then wait until more water has evaporated.

3. The dried acrylic paint is then cut out and arranged into the desired design. It is necessary to do this as the dry paint pieces will have to be placed quickly onto the acrylic sheet once it has been coated with adhesive. (By adhesive I mean any adhesive which has the property of dissolving the polymers to be bonded. When the polymers are dissolved they can be manipulated and modified. In this process the key element which is manipulated and modified is the acrylic paint. The curing of the adhesive is achieved by the removal of the solvent dissolving the polymers and a stable bond is achieved. The key characteristic of the finished bond is that it is clear and unblemished. In industrial bonding the presence of air bubbles is considered a blemish however in this process the addition of air bubbles creates an aesthetic effect.) 4. Once the desired effect has been produced two sheets of acrylic are cut, larger than the desired final size. For example, if the desired final size is 500mm x 500mm, then cut out two pieces approximately 520mm x 520mm. This will allow a margin of error when the acrylic is laser cut to size when the process is completed. It is not necessary to do this. It might be deemed preferable to have a piece which has an unfinished look. It is not necessary to cut out a square as any shape is will do.

5. The device which provides the pressure to enable lamination is prepared. This can be anything which enables a force to be applied to the laminates. For example, a vacuum bag, a veneer press or merely a set of weights, amongst others. You can use anything which will be able to provide enough force to push the laminates together. It is advisable to prepare it beforehand as the adhesive can rapidly becomes viscous.

6. The polythene protective cover is removed from one side of the base sheet of acrylic. The selection of the colour of the base sheet is important as if enough adhesive is used then the colour of the base sheet can spread through to the upper side of the acrylic paint and will be visible through the top sheet of acrylic which is predominantly clear, transparent, acrylic sheet. Sometimes the top sheet may be a coloured translucent acrylic sheet depending upon the desired effect.

7. The adhesive is applied to the base sheet of acrylic on the side which has had the protective, polythene covering removed. (Fig.1)(Fig.2) There is no fixed amount which is to be applied.

For the paint to bond to the base sheet it is necessary for the adhesive to be between the paint and the base sheet.

8. The design prepared in dry form is then arranged on top of the adhesive on the base sheet. The paint will become plasticised by the adhesive. By that I mean it will become possible for the paint to be shaped. In fact the paint will often deform itself when it comes into contact with the adhesive. (Fig.3) 9. As the adhesive plasticises the acrylic paint it will be possible to shape the paint through a wide range of techniques and implements. For example, sgraffito would be one of these techniques, though any technique or implement for reshaping plasticised paint could be used.

10. The base sheet will now covered with a mixture of adhesive and paint. The paint cover does not have to be 100% because where there is no paint then the colour of the base piece will be visible and incorporated into the design. (Fig.3) 11. Another layer of adhesive is now applied on top of the acrylic paint on the base sheet, covering the whole surface. (Fig.4) Special care must be taken to ensure that there is plenty of adhesive at the edges. If this is not done then it is possible that when the process is completed the two sheets are not completely bonded to the paint. As a result dirt or dust could enter or, when cutting, swarf could enter into the resulting space and be seen through the front sheet. This could also happen when polishing and cleaning the piece.

12. The protective polythene is then removed from the top piece of acrylic. This then covered with a layer of adhesive. (Fig.5) Again, it is important to make sure that there is plenty of adhesive near the edges to make sure the lamination is thoroughly completed. This is then placed on top of the base sheet which is now covered with the acrylic paint and adhesive.

This must be carried out quickly while the adhesive on both surfaces is fluid. The polythene covered side of the top sheet will be face up. (Fig.6) The mixture between the two sheets now contains the following in a variable fluid state.

a) dissolved elements of the coloured base sheet of acrylic.

b) dissolved elements of the dried acrylic paint.

c) dissolved elements of the top acrylic sheet.

d) excess adhesive.

13. The top sheet can be used as a means of moving the paint by sliding it over the base sheet. The adhesive acts as a lubricant. This is another method whereby the plasticised acrylic paint can be manipulated to create distorting effects.

14. At this time it is possible to apply pressure physically to the acrylic sheets. This can be done in a variety of ways such as pressing with the hands, standing on the lamination or using any device or equipment which can be applied locally to a small area of the whole lamination.

This enables the plasticised paint to be manipulated and distorted in a more precise way. At the same time as moving the plasticised paint the less viscous elements of the adhesive will also be moved and as it flows between the plastic sheets further distortions will occur.

15. The acrylic sheets are placed in a jig so that when pressure is applied to the lamination then the two sheets will not slide apart. It is important that the jig allows space for any extruded acrylic paint and adhesive to flow away from the lamination. (Fig.7) If the jig is not designed to allow this to happen then the extruded acrylic paint and adhesive could be forced under the protective polythene covering of the top sheet, damaging it. This is another reason why when selecting the sizes of the acrylic sheets to be used they are larger than the desired finished size. (See point 4.) 16. The jig, with the acrylic sheets, is then placed inside the pressure providing device. The pressure is then applied. If the system for applying pressure is such that it is impossible to see the flat, top sheet of the lamination then experience will determine the effects of different pressures. It is possible to release the pressure so that the effects of the pressure can be seen and if desired localised pressure can be applied again as long as the acrylic paint and adhesive have not become too viscous. The lamination would then have to be returned to the pressure providing device.

If a device like a vacuum bag is used and the bag is made from a transparent or translucent material then it will be possible to see the effects of the application of pressure. This has obvious advantages and, again, localised pressure can be applied, though this time with the advantage of adding to the pressure applied by the vacuum pump. (Fig.7) 17. As the pressure is applied the main consequence, from an aesthetic point, is that the adhesive/acrylic paint mix is forced to move between the two acrylic sheets. This flow causes further manipulation of the original dried acrylic paint design. The flow of the acrylic paint and adhesive mix will cause different dissolved colours to blend with each other. The adhesive will dissolve portions of the coloured base acrylic sheet and this can often cause this colour to blend with other colours, or superimpose itself over areas of acrylic paint, thereby giving different visual effects.

18. As the original dried paint design was not of uniform thickness, the pressure applied has a tendency to level out the dried acrylic paint. In other areas the adhesive will act as a filler.

The result, again, is that distortion of the original dried acrylic paint design occurs.

19. It will also be noted that different acrylic paint colours and different acrylic paint brands will have differential deformations. The thickness of the original dried acrylic paint will also be a factor in differential deformation.

20. This effect (see point 19) is heightened because the adhesive is not laid down with a uniform thickness. Some areas will be relatively more fluid as there has been a greater amount of adhesive laid down on to the acrylic paint. If the process is carried out with sufficient speed there may also be pockets of fluid adhesive under the acrylic paint which were created when adhesive was laid down on the base sheet. (See point 7.) 23. The pressure is applied for a sufficient time to enable the bonding process to continue to completion. This will vary depending on the thicknesses of the paint and the amount of adhesive.

24. When a satisfactory time has elapsed the pressure is relieved and the jig and lamination are removed from the pressure device.

25. The article is chemically bonded but not all the adhesive solvent will have evaporated. The article can then be left to enable further evaporation to take place.

26. The production of the lamination is complete. (Fig.8) 27. Further sheets can be added to the original lamination. These sheets are ideally clear, transparent acrylic sheets. The effect is to create a series of layers to give a visual effect of depth as forms can be seen behind other forms.

28. It is not necessary to laminate two sheets first and when they have been completed go through the process again by adding one sheet at a time. Many sheets could be laminated at the same time. I outlined the process for two sheets as it is the simplest and it can be easily inferred how other sheets of acrylic could be added by following the same process.

Process Two 1. The polythene protective cover is removed from one side of the base sheet of acrylic. The selection of the colour of the base sheet is important as if enough adhesive is used then the colour of the base sheet can spread through to the upper side of the acrylic paint and will be visible through the top sheet of acrylic which is predominantly clear, transparent, acrylic sheet. Sometimes the top sheet may be a coloured translucent acrylic sheet depending upon the desired effect.

2. The adhesive is applied to the base sheet of acrylic on the side which has had the protective, polythene covering removed. (Fig.1)(Fig.2) There is no fixed amount which is to be applied.

This will be dependent on the desired effects. For the paint to bond to the base sheet it is necessary for the adhesive to be between the paint and the base sheet.

3. Using a paint brush, or any implement, acrylic paint is added to the adhesive. The acrylic paint used in this process is not dried but is the original acrylic paint with the pigments, dyes and additives suspended in an acrylic polymer emulsion.

4. When the paint is applied to the adhesive it is then mixed with the adhesive. This mixing ensures that the acrylic paint has elements which have been dissolved by the adhesive. As the adhesive has already dissolved elements of the base sheet this will ensure the acrylic paint becomes bonded to the base sheet.

5. If a large area is to be covered then it is advisable to do this by breaking down the area to be covered into smaller areas. Then by adding more adhesive to another area and then adding acrylic paint, and so on, the whole of the area can be covered. This is because the manipulation of the acrylic paint and the adhesive takes time to ensure there is a good mixture. The solvent evaporates quickly and the time taken to paint in the later areas may mean that too much of the solvent has evaporated and it impossible or difficult to mix the adhesive with the acrylic paints if the whole piece is covered in adhesive. If necessary then more adhesive can be added to the paint and adhesive mixture because the presence of the water ensures it has some fluidity though if left too long the mixture will become viscous and difficult to modify.

6. Once the desired design has been achieved then the base acrylic sheet with the adhesive and paint mixture is allowed to dry. The purpose of this is to allow the water from the acrylic paint to evaporate. Judgement is required to know how long to wait before the next step. This is because the biggest factor is the amount of acrylic paint used. Obviously the greater the amount of paint used then the length of time will be longer.

7. Once it is judged that sufficient water has evaporated then the process can continue in exactly the same way as in Process One, starting at point 11.

Process Three 1. Process three is a variation in that it is a combination of Processes One and Two.

2. Proceed by following the first seven steps of Process Two.

3. Once sufficient paint has been applied then pieces of dried acrylic paint, as achieved in Process One, can be added to the acrylic paint and adhesive mixture. More adhesive can be added to ensure the dried acrylic paint bonds with the underlying layers, whether this is the acrylic paint and adhesive mixture or any uncovered parts of the base acrylic sheet.

4. Once this has dried then continue as in Process One, starting at point 11.

Further processes Clearly there are a whole variety of processes where the variation arises from the method used to create a design from a medium containing acrylic, from the use of different adhesives, from the use of different types of acrylic paint containing different additives, from the inclusion of a variety of found objects, and so on. These are all obvious variations based on the fundamental three processes outlined above.

The same fundamental process would be followed if the design was airbrushed onto the base acrylic sheet, or computer images printed onto a thin acrylic substrate, or screen printed onto acrylic, and so on.

The same fundamental process would be followed if the adhesive were a solvent, like dichloromethane, or patented acrylic solvent cements developed as an alternative to dichloromethane based solvents, or an acrylic polymer dissolved in a solvent, and so on.

The same fundamental process would be followed regardless of the acrylic paint used as different manufacturers have different dyes, pigments and additives.

The same fundamental process would be followed regardless of what found object is included in the lamination as long as it could be compressed sufficiently.

Statement of Invention

The process described later allows designs to be made out of acrylic paints and for these designs to be laminated between two or more sheets of acrylic.

This process allows a designer/artist the opportunity of laminating their own acrylic artwork and designs to produce different visual effects. A designer/artist then has the possibility of incorporating this new process in all sorts of products which utilise acrylic.

Advantages of the Invention This process allows acrylic products to be designed with a visual aesthetic not previously possible. It does this by the addition of colour and tones in the lamination of acrylic.

Laminating acrylic paint between two or more sheets of acrylic creates a new form of acrylic sheet.

This new form allows colour to be added to the colours which acrylic already comes in. It is not only added but blends with, and is affected by, the colour of the acrylic itself.

This process will enable designers/artists greater choice when designing products in acrylic as they will now be able to incorporate their own visual elements.

Acrylic (poly methyl meth acrylate) is a material in common use in art and product design. One common type is acrylic sheet.

There is transparent, clear, acrylic sheet. There are also translucent and opaque,acrylic sheets that have various dyes, pigments and additives added to them to produce coloured effects.

The dye, pigment or additive is evenly distributed to produce an even colouring throughout the sheet. This is not universal as some sheets have their dye, pigment or additive concentrated, for example, towards one side of the sheet so that it can be seen from the other side of the sheet utilising the visual properties of acrylic.

What is important to note here is that the dyes, pigments or additives are added to the acrylic during the process for forming the acrylic sheet. They are not added afterwards.

A common process used with acrylic sheet is the lamination of two or more sheets. These can be of any combination to provide a variety of effects. Often clear sheets and coloured sheets are combined for effect, especially by creating visually interesting edges.

There are various methods for laminating acrylic sheet including using acrylic or acrylate adhesives, or ultraviolet curable resins with an acrylic base, amongst others. The adhesive acts as a solvent dissolving the surfaces of the acrylic sheets sufficiently to bond them. Pressure is often applied. The solvent then evaporates leaving a chemical bond between the two surfaces.

What is common with all methods is that when one of the laminates is a clear, transparent or coloured, translucent, acrylic sheet then the adhesive leaves a clear bond and is blemish free. This enables the other sheet to be seen through the transparent or translucent sheet. This is a very important characteristic of laminating acrylic.

Since its discovery acrylic has found uses in many areas. Acrylic paint is an acrylic resin (binding agent) suspended in water to which various pigments are added as well as other additives forming an emulsion. When the paint is used capillary action forces the water out of the emulsion which then evaporates and the acrylic binding agent is left, trapping the pigment. When fully dried this leaves a permanent, water insoluble coloured surface. These are key characteristics of acrylic paints.

When I began to work with acrylic I became interested in trying to add colour to the acrylic I was using so that it was somehow incorporated into the acrylic and not merely a surface decoration.

So for example I would use heat to soften a piece of acrylic and then use pressure to force another piece of acrylic into the softened piece and some interesting effects were created.

Another idea was to take a sheet and drill holes into it. Into the holes I inserted coloured, extruded acrylic rod.

From this came the idea that I could drill a piece of acrylic with holes and laminate this to another sheet of acrylic. After this I filled the holes with coloured matter and then laminated another sheet over the holes, effectively trapping the colour in a clear acrylic sandwich.

I was not too happy with the result. As I was preparing another piece and thinking about what I coutd put in the holes I saw a tin of paint and thought that would be good. The outcome was better than anything else I had tried. So I prepared another piece.

I visited an artist who was working with acrylic paints so I took some back with me. I repeated the lamination of the three pieces. My expectation was that the paint would form circles, when viewed from the top, conforming to the holes I had drilled. When the lamination was complete I was rather disappointed to see that the paint had smeared around the hole.

So I prepared another one but his time I decided to use two pieces and only drill down halfway through one of the pieces As well, I scratched two lines into the surface of the acrylic intending to smear paint in them and wipe off the excess. This time I let the paint dry on the premise that once the water had evaporated then the paint would remain where it was. I knew that once acrylic paint dried it was permanent.

When the lamination was complete I was annoyed to find that the paint had spread itself considerably between the two sheets of acrylic. The effect was as though the paint had been diluted.

It was then that I realised that the solvent had dissolved the acrylic which bound the pigment of the paint. This is the reason why acrylic is used and which gives the dried paint its fixed waterproof qualities. In effect the solvent had released the dye or pigment and the pressure exerted had forced it to flow away from its original position. As it was between two pieces of clear, transparent acrylic I realised I had added colour to acrylic that gave the appearance that it was intrinsic to the acrylic.

I did another lamination with two pieces to confirm this and because the piece was small most of the paint was extruded but the surfaces of the two pieces bonded. The colours used had spread and merged.

There was one final thing to discover. One day when making a larger piece I left myself too little time to do it properly. So I hurriedly clamped the two sheets of acrylic together with the acrylic paint and the adhesive between them. They were approximately 450mm x 250mm in size. When I unclamped them later the effect was exactly as I had hoped but unfortunately within a couple of hours the two sheets began to separate.

I then realised that I had not left the paint long enough to dry properly and there was too much water in the acrylic paint as I had put it on rather thickly. This excess water had prevented the successful bonding of the two sheets.

I now knew that I needed to have dried or nearly dried acrylic paint for the process to work. It is not novel to paint acrylic with varying thicknesses onto a surface which the acrylic paint will not bond and then to let it dry so that it is removable, either in separate pieces or as a whole piece. After experimentation I found that high density polypropylene worked really well and this became my preferred material.

I later developed a range of techniques whereby I could utilize dried paint to realize my designs. For example, I stretched a piece of polyethylene cling film across a sheet of polypropylene and then reverse painted a design on it. In this method I had to paint the front of the design first and then I added further layers. This is the opposite of conventional painting where the backgrounds are painted first and succeeding layers are superimposed.

Once the design was completed it was allowed to dry. Then by turning it over I simply had to peel off the cling film and I had a dried acrylic paint design. I could add further acrylic paint, or dried acrylic pieces, or found material to this until my design was finished. I could then proceed to laminating the design between acrylic sheets.

Over many experiments I realised I could apply pressure and make the acrylic flow thereby modifying the design to create effects. These effects were dependent on the thickness of the dried acrylic paint, the brand of acrylic paint, the type and colour of the acrylic sheets, the type and amount of adhesive I used, the amount of pressure I applied and where I applied it, amongst others.

In industrial bonding of acrylic the presence of air bubbles is considered undesirable. This is often because the work is structural and will have various forces working on the piece. The presence of air bubbles is undesirable because it creates weakness in the joint.

In industrial laminating of acrylic the same applies, air bubbles are considered aesthetically undesirable. I was fortunate in that my pieces are non-structural. When I was experimenting with my process I found that air bubbles were not a problem. I could remove them if I wished. However, I found they gave depth to the work, allowed internal reflections of external light sources and enhanced the visual qualities of the piece. Moreover, when viewing the pieces from approximately a metre the bubbles were not readily noticeable.

In essence, now, the fundamental steps of the process had been worked out. I could produce a decorative laminated piece in acrylic which incorporated additional colour. The process could be controlled to various degrees and I could predict the outcomes of the process. In other words, it was

repeatable.

The description of the process will refer to the following drawings.

Figure 1: a plan view of the base sheet of acrylic (1) with a covering of adhesive (2).

Figure 2: a side view of the base sheet of acrylic (1) with a covering of adhesive (2).

Figure 3: a side view of the base sheet of acrylic (1), covered first with adhesive (2) and then acrylic paint (3).

Figure 4: a side view of the base sheet of acrylic (1), covered first with adhesive (2) and then acrylic paint (3) which, after drying, has another layer of adhesive applied (4).

Figure 5: a plan view of the top sheet of acrylic (5) with a covering of adhesive (6).

Figure 6: a side view of a base sheet of acrylic (1), layers of adhesive (2, 4, 6) and acrylic paint (3) and the top sheet of acrylic (5) before pressure is applied.

Figure 7: a side view showing pressure (8) being applied to the completed lamination and an excess of adhesive (2, 4, 6) and acrylic paint (3) being allowed to flow out of the side of the two acrylic sheets (1, 5).

Figure 8: a side view showing the completed two sheet lamination with the remaining adhesive and paint (7) forming a single layer between the two acrylic sheets (1, 5).

Figure 9: a plan view of the completed piece through which the artwork of the designer/artist would be seen after being finished with all residues and waste removed.

Claims

CLAIMS1. A process whereby designs produced with any acrylic medium can be laminated between two or more sheets of acrylic.
2. A process which allows the manipulation and distortion of said designs, if desired, during the preparation of the materials for laminating, as well as during the laminating process.
3. A process whereby the resulting laminations of the process can be utilised to produce products which give designers/artists more choice in the visual appearance of said products.