Today we’re going to do something a little bit different, it’s time for a history lesson. In 2018 it’s easy to forget just how far we have come since the very early days of the finishing industry, it’s always humbling to look back to see how things have changed over time.
One of the most overlooked, and often underappreciated bits of kit in the finishing industries is the humble spray booth. It’s all too easy for us to see it as “just a clean room with some ventilation”, but in comparison to what the earliest professionals in the finishing industries had to deal with – it’s a spaceship.
The First Spray Booths
To be totally honest the very first spray booths that were ever used are barely worthy of the name. They were little more than a room with an open window or two. To give you an idea of the kind of technology available at this time – vehicles were painted with a brush…
The only innovation that was present during these times was to move the painting area to where the loading bay doors were. This provided much more ventilation and stopped workers getting too dizzy from the toxic fumes.
The First Proper Spray Booths
The first “proper” spray booths came along at the start of the 1900’s. It was around this time that the atomizer was invented for medical purposes (it wasn’t until a little later that it was used in the finishing industries). These earliest spray booths used an updraft ventilation system which was essentially a modified version of an exhaust hood that was designed to remove steam from a kitchen.
The inlet was enlarged and placed directly over the car to remove as many fumes as possible. It was a lot better than simply opening a window, but by the time the atomizer came onto the scene, it quickly became inadequate…
The crude updraft ventilation system simply could not handle the overspray that came with the use of the new atomization technology. Someone came up with the idea of combining the updraft ventilation with a fan pointing out of an open window. This would pull the particulate out of the room and was again an improvement upon existing technologies.
The problem with this, however, was that the blades of the fan would collect paint, and over time the motor would burn out. The solution was to place wooden slats in front of the fan to collect some of the overspray – a primitive version of a modern arrestor. It wasn’t completely effective, and innovative ducting designs were used to further remove the amount of paint on the blade – they were also quite a significant fire hazard.
By the time we reach the 1930’s we get into the world of prefabricated spray booths. They were 3 walled objects with a large fan on one side. Arrestors had been improved in some respects by this time too. Now a sheet of material (usually cotton wool or burlap) would be stretched over the inlet to collect much more of the overspray. While this collected more particulate, it was also much more flammable and fires were extremely common.
Several improvements were made in the 1940’s. The material of the booth was made of cement or metal to stop it burning down whenever there was a fire. Lights were enclosed to reduce the risk of one of the most common ignition sources too. Drive in spray booths became commonplace with closing doors on each side to again help contain the overspray. The cotton wool in the arrestors was replaced by a much less flammable spun fibreglass, further improving safety.
Downdrafts came onto the scene in the 1950’s and was a huge leap forward due to the reduced amount of overspray floating around the air. Electrostatic painting reduced overspray even further. More safety improvements like grounding and sprinklers again made the life of finishing professionals a little less like that of a fireman.
In terms of technological innovation not much changed in the 60’s, although small improvements were made. However, regulation really came into effect during this time and all new spray booths were required to be flame retardant and research started into the harm experienced by operators.
In the 70’s things really started to pick up. Manufacturers realised it was more efficient to keep spray booths clean than to polish out all of the dirt afterwards. Investment in spray booth technology was at an all-time high and the first robotic sprayers were utilised during this time too.
Downdraft airflow became pretty standard in the 80’s, it dried the paint quicker and kept dirt to a minimum. Prep stations became commonplace too, further removing the amount of potential debris that can get into the paint.
Downdraft technology improved significantly in the 90’s and there was an arms race in the new world of fired air-replacement furnaces. Manufacturers wanted to force more air, at a higher temperature, for a lower cost than their competitors. Of course, let’s not forget the ground-breaking introduction of waterborne basecoats that occurred in the early 90s.
The 21st Century
This brings us near enough up to where we are today.
Obviously, with the advent of computing designs have been refined, materials have improved, and automation has taken over. All we know is that we’re sure that we’ve not seen the end of the evolution of the spray booth.
And we’re excited to see what comes next…
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