The ideal way to move products safely through a paint facility is to install an overhead conveyor transportation system. Overhead conveyors are typically used for both wet paint and powder coating processes.
Using such systems can significantly improve productivity. Not only is there a reduction in manual handling, but overhead conveyors also allow you to control the flow of products through the various processes to suit specific throughput requirements.
Which is the right conveyor for your facility?
There are many different ways of transporting goods overhead, so you need to think carefully about which particular system would be best for your process. There are four main overhead conveyor types commonly used in surface finishing:
i) Power chain conveyors (monorails)
ii) Power and free
iii) Manual conveyors
iv) Trolley Conveyor
Heavy duty solution
A typical overhead conveyor is mounted above with products hung from it. Power chain conveyors or monorail systems utilise a continuous chain running in or on a track. JCB has a heavy duty, drop forged power chain conveyor providing transport for a range of fabrications in its powder coating plant at the Uttoxeter Heavy Products Division.
Flexibility with improved productivity
A power and free conveyor has a twin track arrangement where a powered chain is mounted above a free running trolley track. This design offers a great deal of flexibility, allowing products to be diverted for various processes and accumulated for buffer storage. CMK (Treatments) plant in Oldbury, Birmingham uses a power and free system which has enabled the company to increase its production capacity by more than 20%.
Manual conveyors – ideal for low throughputs
Designed around a track with trolleys that are pushed around by operators, manual conveyors are ideal cost effective solutions in situations where throughputs are relatively low. For example, when BAE Systems Global Combat Systems Munitions (previously Royal Ordnance plc) required a solution for paint processing of empty bomb shells prior to manufacture, a manual conveyor solution was perfect.
In floor solution saving space and time
A trolley conveyor is an inverted overhead chain conveyor. These systems are either mounted on or in the floor and are used to move products either directly from the chain on a jig or they can be used as a pushing or pulling medium for automatically moving products on work trolleys through various processes.
For Aston Martin, trolley conveyors were the ideal solution as the trolleys carrying the car bodies through the manufacturing process could pass seamlessly through the painting process. Each body was on a trolley and Aston Martin installed six individual trolley conveyors for the car body painting facility.
The selection process for an overhead conveyor
The first factor to consider when selecting an overhead conveyor is the type, dimensions (envelope) and weight of the goods that will be transported. This will establish the overall carrying capacity required and the size of conveyor needed to ensure that the load remains stable. A large but light product may need to be transported by a heavier duty system to optimise the stability of the moving load.
This is the next determining factor – where will the conveyor be located and what type of surface finishing facility is it, wet or powder coating? It is also important to take into consideration the different environments the system has to cope with.
In a paint facility the conveyor has to work in harsh conditions from corrosive chemicals in the pre-treatment plant to extreme heat in the curing ovens as well as paint or powder contamination in the paint booth.
Throughput – high or low?
Understanding the throughput of the goods to be carried is a vital element in the decision process regarding the speed and pitch of the conveyor. In some cases, different procedures in the production process require the conveyor to travel at varying speeds or indeed have elements where part of the conveyor remains stationary for periods of time.
Once the process and throughput requirements are established, a decision on the type of conveyor can be made. At this point it is necessary to consider the supporting structure for the system.
A roof supported conveyor is ideal as it keeps the floor area completely clear. The roof, however, may not be strong enough or sufficiently close to the system to bear its weight. In such circumstances, floor mounted steel work is installed to provide a supporting structure.
An overhead track will self-support over three metres, so a combination of columns, spine beams and brackets can be used to give optimum support with the least encumbrance at ground level.
Reduce the risks
Calling in experts right from the start of the decision process is a good way of avoiding possible problems. Here at LB Foster, we understand the key issues that have to be addressed.
Gary Bale, managing director of LB Foster Materials Handling comments, “We can provide a total project management service, designing, manufacturing and installing the entire conveyor and control mechanism or, at the other end of the scale, supply the conveyor only. Selecting a supply partner like us, with a UK base, means that lead times are kept to a minimum and we can react quickly when the goalposts change, which they inevitably do.
“The task of selecting the right overhead conveyor is not straightforward, but there are many advantages if you decide to use a transport system for your goods that runs not on the ground, but up in the air.”