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Riba May 2010
- 3. Industrial Flooring: The Generic Resins and their Real Life Performance Assessment Report-Recommendations Riba Approved CPD – AcryliCon Web-site
- 6. Epoxy PU MMA Non-toxic Thermo-Set Plastics Thermo-Plast Plastics 8 – 10,000 PSI 24hrs dry 7-14 day cure ( p.33 ) Never fully cures (p .35 ) Up to 18% of uncured resin ( p.36-37) 3-5hrs dry - 3-5 day cure 9 – 11,000 PSI 1-2hr full cure 6-8,000 PSI ( var. comp. str.) Min. required comp. strength (P.24 ) 10-15,000 PSI( P.25 ) Mechanical Bond Chemical Bond Toxic Dust (un-cured epoxy) Risk of delamination Difficult to Repair –Mechanical Bond PINHOLES – Impossible to clean Repairs Loss of PLASTICISERS ( p.11-13 ) 1-2 hr full cure Wear resistance Non-porous Chemical Bond Non-toxic ( ISEGA ) ( CFIA ) Norwegian Labour Inspection NO Loss of PLASTICIZERS Looses Plasticizers -Brittle / Micropores Spongy and Porous (p . 14-15 ) and dramatically deduction of compressive strength and no chemical bond, anymore. Dangerous Isocyanides VOC ( VOC ) Acrylicon
- 7. Photo of PU - PINHOLES
- 8. Photo of PU – Repairs?
- 9. Photo of MMA
- 10. Photo of MMA
- 12. Photo of Acrylicon and MMA
- 13. Photo of Acrylicon and MMA
- 14. Photo of Acrylicon and MMA
- 67. Whole life pricing Year Acrylicon Epoxy PU MMA 1 150,000 75,000 120,000 100,000 2 0 0 0 0 3 0 8,000 4,000 2,000 4 0 10,000 6,000 0 5 5,000 15,000 8,000 100,000 6 0 20,000 8,000 0 8 0 75,000 120,000 0 7 0 20,000 10,000 2,000 9 10,000 0 0 0 10 0 5,000 2,000 100,000 Total 165,000 228,000 278,000 304,000
Editor's Notes
- Welcome to Acrylicon’s CPD about generic resins and their real life performance.
- In this CPD we will learn the following:
- The first question to ask is why do we specify an industrial floor? In 1978 a survey was carried out and found that almost all consumers of industrial flooring had the same needs - they are the following (click, read out each one, finish at long lasting) If these are the properties we require, then when do we consider a floor to have failed? (click) Absolutely, a floor has not failed simply when it is lifting, or has worn away, but actually when it fails to perform any or all of the above properties. For example if the Slip resistance has worn out, or if it is hard to clean, then it is not doing what it was bought for. For example, if the car you bought recently failed to start, then the car would have failed. It has not failed when it has rusted away! (Click) So how long should a floor last before it has failed? (click) 10 years would be the desired minimum, however in reality, most floors fail relatively quickly with some lasting only 2 or 3 years. Gravity might be keeping them there, but they are hard to clean or have become porous. (Click)
- So lets talk about the resins currently on the market. The first is Epoxy. The “Hoover” of industrial flooring. Often people wrongly refer to all resin floors as epoxy floors, but in fact there are several others. (Click) PU or polyurethane (Click) MMA or methyl methacrylate (Click) and Acrylicon. Now they are all plastic floors and all come from crude oil, however they are from 2 groups (Click click). Rather like petrol and diesel come from the same oil but perform in very different ways, so too do these groups. The Epoxy and PU are from the Thermo-Set family of plastics (click), and the MMA and Acrylicon are from the Thermo-plast Family (Click). The idea of the thermo-set’s is that they start out as a liquid, poured over the floor and set without joints. So as these begin to cure, the molecules come together very slowly and form a very strong bond. However this can never be reversed so each layer of the system has to be “stuck” to the layer below. Most systems consist of a primer, body coat and top coat. Once the primer has cured, so the body coat is “stuck” to the primer, and the top coat stuck to this. As you can imagine this leaves “Bond lines” with in the system that are now prone to delamination. Should any damage penetrate the system, then these bond lines are exposed and water/dirt can get between the layers and delamination will occur. To repair this we need to cut the delaminated section out and replace the flooring, leaving cold joints – exactly the thing we were trying to eliminate!. These cold joints now themselves weaken the system and delamination will continue. We find that once damage has occurred the “patch” will itself fail, and then the repair made again, this time bigger and so on. So with the thermo-set’s, they only mechanically bond.(click) The Thermo-plast’s however work in a different way. When the floor cures, the molecules come together much quicker but form a weaker bond. The advantage is that this bond can be reversed. By applying wet resin to cured resin, the new resin actually solves the old resin, and chemically fuses with it forming a chemical bond between layers. So now we lay our primer which, incidentally, actually penetrates the substrate and chemically bonds to that, then we lay our body coat which chemically bonds to the primer and the top coat bonds to that. Now we have a monolithic block, which cannot delaminate. Even if damaged there are now no bond lines and no delamination even if the damage goes through to the substrate. To repair this all we need to do is to fill the whole, and the resin will chemically bond into the floor and leave an effective repair. So the Thermo-plast’s chemically bond (click). Now lets look at each resin in more detail with a good ol’ plus and minus chart (click) Epoxy was the first to be developed and was used because it could be poured out wet, and cure without having joints. But in order to be easy to clean, it needed to be hard. If you imagine glass, it is very easy to clean because it is hard enough that dirt cannot penetrate the surface. Dirt remains on the surface and can therefore be easily wiped away. So the higher the compressive strength the better, the epoxy has 60 – 70 Newton’s per mm squared. This is about double the strength of a good concrete. (Click) However the down side was the time it took to cure. Epoxy’s can take 24 hours to dry (Click) – the point they can be walked on, but take much longer to cure – up to 14 days depending on temperature. (Click) Cure is defined as the point at which it can stand chemical attack, including water. So although the floor appears dry and cured, any water that touches the floor within this curing time will disrupt the cure and weaken the floor. This is often displayed as “blooming”. The floor turns white and opaque. This is because water in the substrate is now attacking the primer and weakening the cure – at the place where you need the best adhesion. This is why epoxy’s seem to fail so readily and delaminate easily. They are rarely left to cure properly. But in fact Epoxy’s never fully cure. In 1985 the solvents used in Epoxy’s were banned. With this essential thinner removed, the resin would be too thick to lay and impossible to trowel. Therefore the manufacturers changed the chemical composition of the resins to make them easier to work with again. This composition however, used more of the thinner but toxic “low density” Epoxy molecules. About 16 – 18% of epoxy remains uncured in these systems, and uncured Epoxy is toxic. Many reports state that sanding dust can damage the respiratory organs and cause eczema in persons allergic to Epoxy. But of course sanding dust is the same as abrasion dust. When a floor wears from 3mm down to 2mm, where has that floor gone? It has not been stolen! But it has turned to dust and gone into the atmosphere, or into the food that is made, or the workforces’ lungs. There are many reports of this being a contributory factor in sick building syndrome. (Click) It is also hard to repair as we discussed earlier (click) Because of these reasons, Epoxy is not widely used in the UK (apart from as paints or sealer systems) and the majority of industrial floors are PU. This actually has a higher compressive strength, and is therefore easier to clean than the epoxy. (Click) And it has a much quicker curing time, even though it is still too long to be a positive factor, it dries in 3-5 hours (click) and cures in 3-5 days (click). This again means that any moisture present in the substrate has 3-5 days in which to attack the curing process. And being a thermo-set repairs are hard and often short lived (click). But, the biggest problem by far with PU’s is that they Pinhole. In 1995 CFC’s were banned, and these were used heavily in the production of PU’s. When they cure, they gas-off and CFC’s were added to the resin to prevent this. Once banned, no alternative was found and so now this gassing off process is inherent with ALL PU’s. As the bubbles rise to the surface they create pinholes and craters in the surface that are easily visible to the naked eye. Even though the installers now back roll the top seal over to cover them, this seal quickly wears off and the pinholes and craters are exposed. Dirt and bacteria is then pushed into these holes and is impossible to remove. The floor is now porous, un-hygenic and impossible to clean. (Click) Lets move onto the thermo-plast’s. MMA as discussed earlier cures very quickly (Click). In fact it is fully cured within 1-2 hours. Also because of the chemical bond it is also easy to repair (Click). MMA is also non-toxic, the material is used for a variety of medical purposes like contact lenses, tooth fillings and is even injected into bones to strengthen them. (Click) But unfortunately as mentioned earlier they are not very strong (Click). In fact they are only between 20 to 45N/mm.sq. This is already too low to be an effective industrial floor, with dirt being easily pushed into the surface. They tend to scratch and damage easily and become hard to clean. However this already too low compressive strength in fact gets worse with time. All Plastics loose plasticiser over time. Plasticiser is used as the medicine for plastics, and is usually put in to stop them from being too brittle. (click) Plasticiser loss is caused by the environment – air, water, sunlight and heat. If you imagine a light switch, it starts life white and flexible, but over time goes brown and brittle. Plastic sunglasses bounce when dropped initially, however when old they seem to break easily. This is because the plasticiser has left the plastic and it is now brittle. So with the Epoxy, (Click) over time the compressive strength effectively goes up and it becomes brittle and map cracks at the surface. Micro pores also develop. With the PU, it too becomes brittle, map cracks and the resin goes brown and discoloured. (Click). The MMA however has plasticiser added not to keep it elastic – as you can see it is already a very soft plastic – but to stop it shrinking. MMA’s were originally developed for the aviation industry as a replacement for the glass window in pressurised Aircraft. Often called Plexi-glass. And when they tried to mould it, it would shrink when it cured. MMA actually has a 10% linear shrinkage. Now this is no problem as you simply make the mould 10% bigger, but for a floor it would be useless. So plasticisers were added to stop this shrinkage. You will often see them described as “low shrinkage Acrylic floors”. Now, when the plasticiser leaves the compressive strength actually goes down and the floor becomes spongy and porous and the dirt get squeezed into the floor very easily. (Click). This happens very quickly, and with regular washing with water, it can take as little as 3-4 years before they are completely washed out. The floor is now no longer chemically the same and therefore it does not chemically bond. It is now impossible to repair (click) and the only thing to do is to rip it out and relay the floor in its entirety. MMA floors have been around since the 60’s however you will never see one over 5 years old. Very quickly people realised the problems and went back to laying PU’s. In 1976, a chemical engineer in Norway had a factory making Distillators. If you’ve ever been to Norway you will know that it is very expensive to drink there! So he made these Distillators so that people could brew their own moonshine and get “half cut” before going out and save a small fortune! But next door to him was a fish processing factory. His neighbour had had many types of flooring, but none would ever work. Fish factories are the toughest on floors. They have constant ice water, heavy fork trucks, big stillages for the fish and ice, they wash down with thermal lancing to clean, the lactic acid in the fish blood and guts rots concrete and the building itself goes from -30 in winter to +30 in the summer. He said to Bjorn “your a chemical engineer, if you could invent a floor that worked, you’d be a millionaire”. Now with the government closing in on his distillator business, he took up the challenge and went to Germany – where the best MMA’s were being produced. Over two years he formulated Acrylicon. In 1978, he laid his first Acrylicon floor in his friends fish factory. So what is it? He realised that the best possible floor should combine the best of the Thermo-set’s and the best of the Thermo-plast’s. (Click) (Click). If he could combine short cure time and chemical bond with the high compressive strength of a PU, then you can see it would be a fantastic floor. With a lot of hard work and a bit of luck Acrylicon was born. Acrylicon is 84-104N/mm.sq. (Click) cures in 1-2 hours (Click) completely non-porous throughout the system (Click) and Non-toxic. You can see that the system performs all of the functions it is specified for. Easy to clean and hygienic it will therefore stay looking nice. Within a few years, Acrylicon was in 95% of all fish industry. After 5 years he expected to go back and relay the floors thereby giving him a nice pension! However when he went back to his first factory, the floor still looked as good as new. In fact they all did. 6 years, the same and so he took a core sample and tested it against one that was brand new. To his amazement he found that there was no loss of plasticiser. (Click). Now he has absolutely no idea why, because all plastics loose them eventually. The floor laid in 1978 is still there, still easy to clean and still looks good. It is now 30 years old! Maybe at the age of 31, all the plasticisers will jump out, but we can demonstrate 30 years. In 1990, with the company running out of floors in Norway and Scandinavia, it expanded into the UK, and on to Europe, America, Canada, Middle East and so on. Our oldest floor here is now 15 years old, and is still performing well. Lets look at some photos:
- This is a PU installed in a Dairy in 2003. The picture is taken just 2 years later and you can visibly see the pinholes and craters in the surface. These are now full of dirt and bacteria.
- Here is the same floor but a different area. You can see they have tried to repair it with patches. Is it still a jointless floor?
- Here is a Standard MMA floor laid in a post office terminal. You will see it was installed in May 2005. The surface was so bad that the client condemned it and asked for it to be laid again. So in July it was re-done – only 3 months old! These photos were taken 3 months after that.
- As you can see, the floor is very dirty and impossible to clean. The heavy forklifts are pushing the dirt into the surface. Remember this floor is only 3 months old, and the plasticisers have not yet left – it will only get worse.
- Here we have a meat processing plant where the factory was laid with Acrylicon, and the extension done with a standard MMA. They were installed one day apart and the floors are now 3 years old.
- As you can see the standard MMA is now very dirty and impossible to clean. The Acrylicon floor is still good. The same traffic passes over these floors and the same cleaning routine applied to both. But look at the difference. As the floors age this difference will get greater.
- This is the real experience.
- Here is a floor from 1978. installed in a busy hospital kitchen in Trondheim Norway. In this photo the floor is 26 years old. You can see that the floor still has its shine from the top seal being intact. There has been very little wear or degradation, and no delamination. Even though hot water is present!
- You can see the type of trolleys that are pushed around. Also see how clean it is.
- This bit was done later and installed in 1993 into the same kitchen. It is only 11 years old, and again is easy to clean and nice looking. This is the pot wash area that is covered in water.
- Bjørn’s favorite, not because of the floor, but because she looked so kind and walked nicely…
- The only downside to Acrylicon is the installation cost. It is on average 20% higher than PU in resin cost. However if we look at the life cost over 10 years, you will see that Acrylicon is the cheapest floor you can buy for money. This is a 1000m.sq. Food factory. In year 1 you can see that we are the most expensive to install with PU next then MMA and epoxy is the cheapest. Year 2 there are no problems with any of the floors. But the MMA will be very hard to clean. By year 3 the epoxy will begin to delaminate in areas where the water has disrupted the cure. The PU as well. The MMA will also have some damage due to its low compressive strength and will be getting very dirty. In year 4, the epoxy now needs the first set of repairs doing again as they have failed. Same with the PU. The MMA floor repairs however have chemically bonded and been successful, but by now is very porous and is beginning to “bubble” with water going under the surface. Year 5, there are finally some repairs to do to the Acrylicon. Continual ongoing maintenance is beginning to cost with the epoxy and PU, but the MMA can no longer be repaired. It is now very black, very porous, and needs replacing completely. Year 6, Repairs done last year to the Acrylicon are effective and the floor continues to be easy to clean. The Epoxy and PU are now having continual repairs and the BRAND NEW MMA floor is ok, but already difficult to clean. Year 7 is the same. But now some repairs to the MMA are needed. Year 8, the Epoxy and PU now look like patchwork quilts and need replacing. Remember for their whole life they have been hard to clean and the PU has been full of dirt and bacteria. Year 9, there is a bit of damage to the Acrylicon which again can be effectively repaired. Year 10, so the cycle of repairs starts again with the Epoxy and PU and having done another 5 years, the MMA needs replacing completely. Over the 10 years the Acrylicon system works out at 16.50 per m.sq. Per year. Nearly half that of the MMA, and a lot less than the Epoxy and PU. This is the real life experience. Visit any floor that is over 5 years old to find out.
- Acrylicon can be recycled as it is an inert material once cured. It is completely non-toxic and has no impact on the environment But unlike PU and Epoxy which are very dangerous when burnt, Acrylicon (CH3) when combined with oxygen during the burning process combines to give off water steam and leave behind a black mush of carbon. PU will give off Nitrous gasses and more importantly Isocyanides. PU foam is now banned in the use of home and office furniture. Epoxy will also give of nitrous gasses. These nitrous gasses are the same as produced from your cars exhaust, and will asphyxiate people.
- As you can see we have learnt: