GLOSSING OVER REGULATIONS?
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Complying with the requirements of the EPA costs money, sometimes a great deal of money. It was set up to regulate the emission of pollutants including VOCs (volatile organic compounds—solvents) from all types of industry in a bid to improve the environment.
Vehicle paint spraying has undergone particular examination and is regarded by the authorities as a significant source of these undesirable by-products. Both the automotive and commercial painting sectors of the trade have come under scrutiny By September 1992 all paint shops consuming more than two tonnes of VOCs a year (with the exception of body builders and vehicle manufacturers using refinish products spraying only their own production) were required to register with the local authority and gain permission to continue operating.
Following this improvement plans had to be drawn up within 12 months laying out exactly what had to be done to meet the EPA requirements—installing spray booths, improving vents and so on.
Towards the end of last year the threshold level for registration was reduced from two to one tonne of solvent use. Bodyshops using more than this were given two years to register. New or re-located businesses were required to register from day one.
Standards were demanded from the paint manufacturers too. By 1 Apri11995 VOC limits were set for each of the major products—top coats 480g/1, undercoats 540g11 etc. Some spe cialist products were made exempt due to manufacturing limitations The result is new ranges of VOC-compliant products from each major producer to meet the requirements. Ken Jones, of ICI Autocolor (For further details write No 51 on reader reply card), says that these products have led to some confusion: "Don't imagine that just by using VOC-compliant paints a bodyshop will automatically drop down below the threshold limit and so will not have to register. If you are registered then you must use compliant products."
Water-based paints have evolved as one potential answer to the emissions problem. Reducing the olganic content by replacing solvents with water seems the ideal solution but this can be a simplistic view. According to Jones: "The whole picture must be considered. The danger is you can simply exchange one environmental problem for another.
Some users may imagine that because the paint is water-based they can pour away any residues down the drain—not so. There are associated disposal problems which have to be considered." He adds: Also you must bear in mind the possibility of a higher energy requirement for the drying system."
The current two-pack base and clear-coat systems are not ideal for the commercial vehicle market. Jones says: "A base and clear system means that application times, product consumption and overall costs are too great for truck painting." Drying times can also be too quick making it hard to maintain that essential 'wet edge' when spraying large panel areas.
DRYING TIMES Water-borne paints rely on advanced chemistry to allow the pigments and resins to be dispersed within the water-based system but not remain water-soluble once they have dried. A consequence of this is that drying times are about the same as conventional products, although there is a more critical requirement for a combination of heat and air movement than with solvent-based systems.
The future from a paint point of view is unclear. A new VOC limit of 420g/1 or below will arrive in 1998 and basically there are two ways of achieving this. One is to go to an ultrahigh solids formulation, the other route is to develop a water-borne top coat product to be applied in one hit. Allied to this there would be various water-borne primers and undercoat systems.
As yet it is by no means certain which is the right course to take and some paint manufacturers, including ICI, are playing their cards close to their corporate chests.
Not so Spies Hecker (Write No 50 on reader reply card). Product manager Paul Casey says: "The most acceptable route for us is high solids for the foreseeable future, until 1998 at least. After this I imagine there will be a switch to water-borne base coats."
Herberts too has definite ideas (Write No 49 on reader reply card). Dave Kelly says: "We are firmly of the opinion that equal development of both options should continue before and after the 1998 deadline. We already have a high solid one-coat available and water-based glosses on test. I think a choice of paint types will prove important but have my doubts about the durability performance of any waterbased paint compared to solvent material," The constraints on paint manufacturers are tight. One of the underlying principles of the EPA is `BATNEEC' (best available technology not entailing excessive cost).
ICI's Jones says: "All this new development is going to create significant on-costs for the manufacturers. It seems very likely that the development work and cost of the raw materials will push prices to the user progressively higher."
Jones is unsure about what will happen to solvent levels after 1998. "It's hard to say The technology is going to become more and more difficult but I think it will become apparant that solvent emissions from the paint refinishing industry by then will be relatively minor in relation to other VOC sources take the vapour loss from petrol stations for a start."
Kelly's thoughts are that the UK has made things initially hard for itself by spearheading the regulations while the rest of Europe looks on. "We've certainly got the pain now", he adds, "but will feel the benefits later as the rest are forced into line By 1998, after the surviving paintshops have spent heavily on new equipment and the paint companies have exploited technology to its limits, there will be very little else in the short term to be done. Casey's opinion is: "After 1998 it will take some seriously innovative thinking to produce any further progress. A radical new approach would provide the only way forward."
Options for change include colour-impregnated plastics and powder coatings, but what of their practicality? Certainly, with powder coating there are no solvents required and almost 10000 transfer Aciency is achievable.
The advent of I RIP technology has produced some useful progress in spray transfer efficiency and associated cost savings. It is definitely working better now than it did initially but still has its doubters.
Prominent among these is Herberts Dave Kelly: "I believe the whole concept of HVLP really is questionable. The technique is fine for cars where everything is easily accessible but it's a different matter on large trucks—maintaining the vital gun-to-panel distance can be a real problem_ 'It is perfectly possible to achieve a 65% spray transfer efficiency using the likes of a JGA gun, if everything is set up properly," says Kelly.
Jones believes that very good results are now possible with an I IVLP gun but thinks that further work is required. If the industry moves towards ultra-high solids technology for 1998 there could be a question mark over HVLP's suitability to that. lie considers that airless spray equipment might provide an alternative for trailers and boxes.
Casey believes that the two technologies will develop hand-in-hand: "You only have to look at the new HVLP gun from Iwata to realise that spraying high solids with low pressure is already a practical reality. I'm sure that the gun makers will continue to develop their products to match paint technology. It's in their interests to do so."
As for business compliance to the EPA regulations, the problem is twofold, Operators know that compliance is probably going to cost them a lot of money and also that the regulations are being policed pretty inadequately Jones says: "EPA inspectors are expected to police every industry creating VOC emissions--a huge task. It will take time before they can hope to develop a working understanding so, in the meantime, the system relies heavily on the integrity of individual companies in complying."
POWERFUL URGE He has found that awareness is pretty good within the trade although there are some who are quite openly defying the legislation—driven by the powerful urge to save money and hassle.
Kelly's opinon is that the authorities have made a rod for their own back. "I can't understand why the enforcement is not imposed purely on the manufacturers, rather than the users. If VOC limits for paints were dropped much lower, which is perfectly possible based on our experience, then the user could do virtually what he liked and still create minimal pollution. Plus it would be far easier to police a handful of manufacturers rather than thousands of end users."
The bulk of the spray work these days is going through well-equipped large paint shops. The industry is becoming polarised with these highly-efficient outfits at one end and the tiddlers at the other. It's been suggested that many of the small operators are still probably breaking solvent threshold limits, not to mention Health and Safety and COSHH regulations, with little regard for the consequences.
If existing legislation was enforced effectively it is likely that by 1998 there would be very few small, polluting paint shops left. The reality is that such a tightening effect seems unlikely and the offenders know it.