Powder coating has long ceased to be a service that a metalworking company necessarily gives away. When the volume of painted parts grows, and the contractor's deadlines begin to shift their own shipping schedule, the question arises: isn't it cheaper to start your own site? The answer depends not only on the download, but also on how well the set of equipment is selected. An error at the selection stage is the most expensive: it has to be corrected already on the working line.
Let's look at which nodes the powder coating site consists of, how to select them for the dimensions of the parts and the volume of production, and where they are most often mistaken when starting.
How the technological process works
Any area of powder coating, from a small workshop to a conveyor line, repeats the same sequence of operations. Each operation needs its own equipment, and it is impossible to skip the stage without losing the quality of the coating.
- Surface preparation — removal of rust, scale, old paint and oils. Mechanically (sandblasting or shot blasting) or chemically (washing with degreasing and phosphating).
- Drying — after chemical preparation, the part must be completely dry, otherwise the powder will form defects.
- Powder application is carried out in the spray chamber, by manual or automatic spray.
- Polymerization — the powder melts in the furnace and forms a continuous coating.
- Cooling and control — checking the thickness and adhesion of the coating, packaging.
All this is connected by a transport system: a suspended conveyor or trolleys, through which parts move between sites without unnecessary overloads.
Plot composition: what is included in the package
A separate expense item that is often overlooked at the planning stage is air filtration. The spray chamber with cyclones or cassette filters allows you to return the non-settled powder to work, and with a large amount of painting, this is a noticeable saving in material.
How to start the selection process
The main mistake at launch is to choose the equipment according to the catalog, and not according to the details to be painted. The selection order should be reversed.:
- Dimensions and weight of the parts. The longest and heaviest part determines the internal dimensions of the spray chamber and furnace, as well as the load capacity of the suspensions. If a product longer than the oven arrives once a month, it will have to be painted on the side.
- Volume per shift. How many square meters of the surface need to be painted per shift. It depends on whether a dead-end chamber and a periodic furnace are enough, or whether a flow-through scheme with a conveyor is needed.
- The range of colors. If the color changes several times a day, the cleaning speed is important.