What the curing oven looks like
Polymerization chamber is just necessary to carry out the process of powder coating, namely the polymerization of special paint used in this technology. In the curing chamber powder is applied to the product, which is then transported into the oven. Temperature of curing chamber is 180-210 °C, only in this mode you can perform the process.
Polymerization chamber is a modular prefabricated construction, which has good thermal insulation, so the outside surface of the furnace is heated only up to 40 ° C. The chamber itself is equipped with heating elements, which are located on the side walls and covered with heat reflective screens. Thanks to its design, in the thermoblock it is possible to carry out preventive maintenance of the heating elements and to replace faulty heating elements in a short time.
To allow air circulation, an air duct and fan are installed on the roof of the curing chamber.
the curing chamber is designed so that it has minimal heat loss, which keeps the temperature for a maximum period of time without heating the outside walls.
Loading of the parts into the curing chamber is carried out through an opening equipped with double-wing doors around the perimeter of which there are temperature-resistant rubber seals. Doors are locked with a locking mechanism. A special control cabinet is built into the side wall, which makes it possible to monitor compliance with certain parameters. The operator can modify them in the case of deviations. Polymerization chambers are available in various sizes.Depending on this criterion, the furnace is divided into several zones on the inside, each with its own fan and independent regulation of the heating elements. Forced air circulation is provided to keep the temperature uniform throughout the oven, as well as to quickly heat up the curing chamber after loading.
Everything you need to make your own curing chamber
Painting small parts at home can be done in several ways. One of the best materials for processing metal products is considered powder paint, but its use requires special conditions. The most difficult of them is drying at high temperatures. It is for this purpose a polymerization chamber is created, and equipped with their own hands, the cost of it will be much cheaper than purchased equipment.
Powder coating booth with their own hands drawings
When the room is found, you need to collect and prepare the necessary equipment:
In the work does not interfere with accuracy and a little experience. But if it does not exist. no problem, acting according to the instructions, you can avoid most mistakes and get quite a decent result.
Making a furnace
Polymerization. an important step in the curing of powder coatings. If this work item is omitted, the paint will not adhere to the metal surfaces. Therefore, such equipment as a furnace. it is also called a curing chamber. is necessary in the first place. This thing is expensive, so you can make it with your own hands, from whatever materials are at hand. We will need (the curing chamber will have the dimensions 2x1x1 m):
- profile pipe;
- non-combustible thermal insulation (basalt board);
- sheet metal (can be ordered to size)
- tangential fan;
- Heating elements.
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The instructions for assembling the oven consist of the following steps:
- Weld the frame from a profile.
- Put insulation in it.
- Sheet metal sew up the walls. Finish the outside of everything with fiberglass gypsum.
- For convection in the chamber install a tangential fan, welding him a narrow exit and a wide entrance.
- Insert the fan into the chamber. It will take the air at the top, drive it through the heating elements, blow it out at the bottom and then distribute it throughout the entire volume of the chamber.
- Install the heating elements along the parallel walls and connect them by the distribution per phase.
- Close the heating elements, leaving the fan open, the main part of which must be located outside the chamber (so as not to melt the winding).
- Install the electrical panel. True, it is better to entrust this work to a specialist.
The resulting equipment. a polymerization chamber. will have a capacity of 12 kW in preheating and 6 kW in operation.
The important thing is ! The energy carrier in such furnaces for drying powder paint can be not only electricity, but also natural gas and diesel fuel.
Painting tool. a gun
To apply powder paint to the product requires a special device. This is an electrostatic spray gun or a tribostatic powder sprayer. But buying expensive equipment for the sake of rare use is not reasonable. As in our case everything is made by our hands at home, such a device can be made in about 10 minutes. Such a gun is easy to use, cheap and practical. It takes a few seconds to change from one paint to another.
The design and construction of a powder-coating gun
How to make a powder paint gun:
- Take an ordinary plastic 1.5 liter bottle. The main thing is to keep it dry and clean.
- Fill it up to 1/3 full with powder paint and screw it on with a metal stopper.
- Make small holes in the cork. The more holes, the better the spray pattern. Deburr the outside of the cork from the piercing.
- Connect a plus wire from a high voltage source to the plug.
For this purpose, you need a converter that can deliver 25,000 volts of DC. These are used in stun guns, gas stove lighters, boilers, and boilers. They can run on batteries or rechargeable batteries, converting 3-6 volts to the necessary 25 kV.
Be careful when working with high voltages. It is better to entrust the assembling of the inverter to a qualified electrician.
After all the manipulation you get a pretty decent gun.
Little things you can’t do without
Before you start painting, you need to take great care to ensure that all operations take place under ideal conditions:
- Excellent lighting is essential. Use fluorescent lamps. Powder paint adheres very well to an ordinary lamp.
- You need good ventilation with two motors (inlet and outlet). In addition, you will need to wear a gauze bandage, or better a professional respirator.
- You have to invent a way to collect the remnants of powder paint. Use an old powerful vacuum cleaner for the initial stages.
When everything is thoroughly prepared, you can begin to paint with your own hands the necessary parts.
The layout of the spray booth
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The powder spraying equipment is based on the booth itself and the curing oven. In the first one, the paint layer is applied; in the second one, the cladding process is carried out. The car is painted with a special electrostatic gun.
In the usual conditions of a small production process, paint that is categorized as powder paint can be applied with an ordinary hand gun, which has a compact size.
In the process of factory dyeing very often change the method of dyeing, so cartridge cleaning chambers may be applicable. The powder in this case is filtered in a special way from the air in a device such as a recuperator. In essence, it is a filter unit where automatic regeneration is carried out by pulse blowing.
A powder coating system has now been developed and established in the garage. A paint booth and other necessary elements must be purchased for this purpose. In addition, if necessary, it is possible to make a powder coating booth entirely by your own hands.
Requirements for powder curing chambers
When purchasing equipment, it is important to take into account the special process conditions and requirements for the technology:
- The working space of the curing booth needs to be heated completely and evenly with an even temperature growth rate in all areas;
- the permissible gradient is no more than 5 C regardless of the temperature measuring points in the curing oven;
- If necessary, controlled blowing of the parts must be provided;
- To use the room to its fullest potential, it is necessary to keep the wall thickness as small as possible while maintaining a low heat transfer coefficient.
The design of the curing ovens takes these features into account and the design allows the equipment to be adapted to different production scales.
Powder coating curing oven with your own hands
curing booths (also called drying ovens, melting boxes, etc).д.) for powder coating is designed to carry out the final stage of painting parts. In it the coating is heated and evenly distributed over the surface, so these devices are sometimes called fusion chambers and drying boxes. This type of equipment has a number of specific requirements related to the specifics of powder coating technology.
What is a curing oven and how does it work?
A smooth, firm and durable coating in powder coating is not only achieved by the quality of the materials used. It also acquires these properties when a special design, called a curing chamber, is used. This device allows you to complete the polymerization process of chemical compounds present in the powder paint in a short time. In essence, such a chamber is a furnace for a product on which a powder-type paint substance has been applied. Technical features of the device allow it to dial up the temperature inside up to 210 ° C. In normal conditions it is impossible to achieve such an effect, and in the room the gained temperature will spread throughout the room. Here, on the other hand, the air warms up quickly to the desired temperature in the minimum volume of space, which accelerates the processes of polymerization of substances in the paint.
Subtypes and their features
Now there are many subspecies of such chambers, and the range is only expanding. The structural components are such:
Let’s review the characteristics of some of them.
- Has a recuperator equipped with a single filter.
- Can handle up to 99% of atomized paint from the air.
- The filter is cleaned in the following way: by blowing manually or by automatic mode.
- Power of at least 3 kW.
- Working space (standard): 1700 x 1100 x 2000 mm.
- Weight. 390 kg.
Two-post (marking KO2):
- Pass-through type.
- Has two recuperators and two removable filters.
- Re-cleaning technology (up to 99% of sprayed paint goes back into operation).
- Filters can only be cleaned with pressurized air.
- Power from 5 kW.
- Working space of 1700 x 1100 x 4000 mm.
- Weight. 640 kg.
This type is most convenient when processing workpieces from more than one side. Products pass through spraying openings on both sides. Convenient for two operators at the same time.
The powder coating booth is equipped with a cartridge filter:
- Paint booth.
- Interchangeable filter system.
- Filter cartridges.
- With a strainer on a shaking mechanism.
- Paint collecting vessel with filters.
- Powder Injector.
- Scraper.
- Filter blowing system with compressed air.
- Absolute filter.
- System for clean air supply.
- Lattice.
There are special working points for this particular kind. They are as follows: by means of a draft air with powder paint is supplied. It all goes through the cartridges. The paint is sieved and falls into the receiver. This is then fed into a powder coating gun. Any surplus material left on the filter is removed with compressed air. And if there is not enough paint in the system, a sensor lights up.
often exactly the powder chambers models are bought and used because they are part of the painting line united in a common transport system.
The principles of the painting methodology
The part is cleaned and degreased before painting. In a bowl with a prepared detergent solution, with solvent (white spirit or acetone) added, at a temperature of 40-60 degrees above zero, several parts are degreased simultaneously. All contamination is removed by blasting and sandblasting.
The type of polymerization design dictates how the part is treated with powder dye. It is further processed in a thermal apparatus. The powder is heated, melted, and the polymer covers all the fine pores of the part’s surface. The high adhesion coating undergoes a sintering stage, which increases the strength of the layer and its adhesion to the substrate.
