A Wandering Mind...

Finishing Articles - HSE Finishing Industry

Malcolm Griffiths has been on his travels, but is now back and looks at what the HSE is doing to the finishing industry. Since joining the paint industry in 1963, Malcolm has worked for several leading coating manufacturers. He is a graduate in chemistry, Fellow of the Institute of Metal Finishing and a Chartered Member of the Institute of Occupational Safety and Health. He now runs the independent coatings advisory service Ad Qual Castech

It has been a while since I last wrote here. In the meantime, nothing much has happened. Amongst other more local projects, I have been on a couple of overseas business trips to the Sultanate of Oman and Ascension Island and … oh yes … the financial system suffering the non-nuclear equivalent of China Syndrome. Both overseas visits were extremely interesting since they involved some of the most aggressive environments I have seen. The sites were sited on marine shore lines, having high ambient humidity and temperature. Corrosion was rife and it highlighted to me the importance of the coatings industry in protecting equipment and minimising the effects of corrosion, so averting premature breakdown, structural failure and the need for frequent replacements. This trade-off is just one aspect of the industry that the environmental lobby fail to grasp in their drive for the Nirvana of “carbon neutral”.

Of course, I didn’t spend all of the time working. The trip to Ascension Island gave me a chance to play what I understand is formally recognised by the Guinness Book of Records as “the worst golf course in the world”, with ‘fairways’ of volcanic clinker and made of ‘greens’ of sand and tar mixture. In Oman, I had the opportunity to watch Green Turtles laying eggs and their young making a break for the safety of the Arabian Sea.

Anyway … back to work: in this issue, the magazine concentrates on two topics dear to my heart: powder coatings and extraction systems. I thought it would be a good time to review where we are and how we got here.

For a number of years, Mike Cowley and I have enjoyed presenting the twice-yearly Powder Coating Technology course on behalf of the PRA and more recently at their shiny new premises in Hampton. I first saw powder finishes in the late 60’s (yes, I am THAT old). As a paint technologist, I thought they were awful but over the first 20 years the quality of the products improved by leaps and bounds, easily replacing conventional stoving enamels. The environmental pressures on solvent-based materials also helped immensely to sway decisions when it came to new plant installations. The automotive industry added its weight to raising the standards through its drive for continuous improvements. The development of exterior durable and super-durable powder finishes for use on architectural sheet and extrusions was another great boost to the sector.

Powder application plant improved dramatically during the 70’s and 80’s. Gone were the spray guns that turned into flame throwers every time the electrostatic charge arced to earth. Who, of those of us who ever saw one, can ever forget the wonders of the early Brennenstuhl cabinets or the Estey powder booths?

In the early 90’s it looked as though improvements in resin technology might lead to combination IR melt + UV cured systems, allowing powders to expand into wood finishes and other thermally sensitive substrates. Some such powders do exist but are still very much work in progress. Low bake textured systems have been successfully applied to MDF. Thin film technology was the next big drive, though I could never see how that could work without massive improvements in pigment dispersion techniques. I recently came across a reference to an antimicrobial powder coating that had been developed. The idea isn’t totally new but this one contained a silver compound, probably silver oxide, which has been known for hundreds of years as a healing agent. Did you know that the phrase “born with a silver spoon in your mouth” referred to having been born healthy rather than wealthy?

In the late 90’s in USA, I came across the development of a method of applying powder to metal coil. New application techniques are all very well but, to make the process worthwhile the materials applied by coil need to have other, very special properties, such as rapid cure (say, under a minute) and extreme flexibility. The equipment was interesting and only exploded a couple of times during trials. There are a number of companies who now appear to be developing ideas similar to DSM’s patented electromagnet brush (EMB) application method for flat sheet and coil.

The complaints that our company Ad Qual are engaged to investigate are still mainly about colour match, contamination / haze / general appearance and corrosion problems. To be fair to the powder manufacturers, these are more usually due to problems of pretreatment or application but the point is that, in general, powder development has stagnated. It has become bogged down with overcapacity in both manufacture and application. Hopefully, somewhere in this issue, you will find the future of powder coatings unfolding. See you in Hampton.

On the Safety Health and Environmental front, we ran into a new phenomenon: As part of their remit, the UK competent authorities - surprisingly this includes the HSE and DEFRA - are required to consult stakeholders on likely changes to legislation proposed by the EU. In one particular instance, the EU proposed to prohibit the use of methylene chloride, which is a main constituent of most paint strippers. To their credit, the HSE did not consider this to be necessary, bearing in mind the potential risks against benefits. Nevertheless, they asked for opinions but mentioned that, whatever UK stakeholders thought, this prohibition would almost certainly go ahead because the majority in the EU would vote for it.

On another issue a little closer to home, in BS 8516 the British Standards Institute proposed that all trees be examined annually in a “Walk-by-inspection”. Chief executive of HSE, Geoffrey Podger, said they did not believe such action was needed because the risk of injury from a falling tree was low Even some environmental groups argued that this would lead to trees being felled unnecessarily – when the risk was less than 1 in 10,000,000 of actually being killed!

Nevertheless, the standard will be implemented and you JUST KNOW that some jobs-worth in each council will write into their bureaucratic rules for contractors and suppliers. In a few years, the rule will be as ubiquitous as the blessed ISO9001. The fact is that no-one has the guts to stop this relentless, self-perpetuating Health & Safety machine lest they be branded a killer. The Health & Safety at Work etc Act, 1974 is the inadvertent but direct cause of this, with the ragtag European Commission adding insult to injury.

Having berated them so often, both here and in the past, it is only fair that I should give great credit to the HSE for two current campaigns, both of which slot neatly in the need for well controlled extraction systems. Our lungs are the most sensitive areas of our body to pollutants in the air. It is estimated that, over the next 20 years or so, between 3,000 and 4,000 people per year will die from asbestos related diseases as a direct result of their employment. More workers will suffer from exposure to silica based materials. Thousands of others endure respiratory diseases that are directly related to exposure to dusts, solvents and aggressive chemicals in their workplace. All of these vastly outweigh the numbers who die annually from slips, trips and falls or farming incidents.

If you search for “Clear the air” on HSE’s website, you will find a large number of downloadable items that will highlight the issues in selecting and maintaining the right sort of local exhaust ventilation.

The HSE has also discovered that, in certain cases, the bacteria causing Legionnaires disease (Legionella) has been found in surface pretreatment plants. This is of particular concern when the chemical treatments are being spray applied. When inhaled, Legionella bacteria can initially cause symptoms that are similar to influenza but patients may quickly deteriorate and can often die from the disease.

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