Q: I am searching for a way to double our production for powder coating division. Presently, we have a capacity of 3 tons per shift. We have an overhead conveyor with a speed of 1 m/m, and we are using 3 + 3 automatic spray guns, both sides, to produce 6-meter profiles for our clients.
I just want to know that can we hang double line profiles in the same flight bar so we can increase the production simultaneously. Both sides of the two layers can be coated with both the side guns, but what about the between areas of both the profile lines? And what should be the minimum distance to be kept between the profile and the spray guns. We are using automatic spray guns.
A: This is an interesting challenge. There are a few ways to increase production of your finishing line.
By increasing your throughput, you not only have to deliver more powder coating to more parts but you must also ensure that your pretreatment/cleaning system can handle the increase and – just as important – you must ensure that your oven can cope with the additional load.
First, let’s talk about mechanically increasing throughput. You can increase part density by hanging more parts per length of conveyor. It is essential that the conveyor can take the added weight. Otherwise, you may encounter abnormal wear and failure of the conveyor bearings and frictional surfaces.
Another approach is to increase line speed. This may be a better option, as you will not be adding more stress caused by weight. If you choose to increase the line speed, it is vital to make adjustments in your cleaning/pretreatment process. This may involve installing extra spray nozzles and certainly accommodations for higher consumption of chemicals and waste generation.
A higher line speed will also tax the output of your application system. I recommend that you add a couple guns for additional powder delivery.
Most critical to an increased line speed is ensuring that the powder coating receives adequate time and temperature in the oven. This can probably be accomplished by increasing your oven temperature about 15-20°C. It is important to measure the actual part temperature of a fully loaded oven to accurately ascertain powder cure conditions. Most powders can cure with shorter times at higher temperatures. For example, a powder that cures at a stoving schedule of 20 minutes at 180°C will cure with a 10 minutes at 200°C schedule. Please check with your powder supplier to verify this.
Congratulations on the increase in your business.