Baidu Encyclopedia Spray and Bake Paint Room

The spray booth mainly refers to the place where objects' surface is sprayed with paint and dried. Depending on different objects, such as furniture and sheet metal, color or gloss products are added to their surfaces. Here is the working principle of the furniture spray booth:

1. Working Principle of Spray Room:

When spraying, external air passes through the primary filter at the inlet and is then sent into the spray room by the blower. After passing through the secondary filtration via the top filter cotton, the airflow uniformly flows into the working space of the spray booth, forming an air curtain around the workpiece from top to bottom. At this time, the wind speed inside the spray booth is 0.3 m/s, so the paint mist generated during spraying will not linger in the operator's breathing zone but quickly descends with the airflow. The airflow is then filtered by water at the bottom and discharged through the exhaust duct.

2. Working Principle of Paint Booth:

Infrared Heating: Most organic coatings have a strong absorption capacity for infrared rays, especially far-infrared rays. Therefore, infrared rays have a very significant effect on drying the coating layer. It promotes the rapid curing of the coating layer, ensuring good quality without defects such as pinholes or bubbles.

3. Air Purification System:

The filtering system device adopts two layers of filtration. The coarse filtration layer effectively captures dust particles with a diameter greater than 10um, while the high-efficiency precision filtration layer has multiple structures that can effectively capture dust particles with a diameter greater than 4um. The entire filtration system has a large dust holding capacity, low resistance, long service life, and a filtration efficiency of more than 98%.

4. Wind Circulation System:

The wind circulation system consists of a complete set of equipment. The unit is equipped with a group of fans, powered by two 3KW fans, with a total wind volume of 24,000 square meters, ensuring the loaded wind speed inside the room is 0.3m/s. This ensures rapid indoor air circulation without residual paint mist, guaranteeing the health of the operators and the spray painting results. The fan uses Siemens technology produced specialized air conditioning-style fans for spray booths, which are compact, energy-efficient, and performance-stable.

5. Paint Mist Treatment System:

Paint mist treatment adopts water filtration, with low usage costs, ideal paint mist adsorption, and good effects. The indoor noise complies with GBJ87-85 "Industrial Enterprise Noise Control Design Standard," not exceeding 85 decibels.

Current Development Status and Working Structure Principle of Spray Booths in China:

The prices of mid-to-low-end domestic spray booths range from 22,000 to 60,000 yuan, while high-end ones cost between 60,000 and 150,000 yuan, with various product types. The main circulating types include outdoor rainproof type paint booths, fuel-type high-temperature paint booths, teaching type spray-paint booths, large passage-type paint booths, environmental protection type paint booths, infrared paint booths, and standard type paint booths, each with different functions. Generally, paint booths adopt a modular structure, with the body made of plug-and-play insulated spray-plastic wall panels, offering excellent sealing and insulation performance. The side of the body is equipped with a work door for easy access by staff, and aluminum alloy doors with observation windows in the middle allow real-time monitoring of the interior dynamics. Auxiliary equipment inside the paint booth includes fans, burners, lights, base plates, filter cotton, electrical control boxes, generator rooms, paint lamps, high-efficiency heat converters, etc., with specific configurations and models depending on the overall planning of automotive service institutions.

Spray Booth - Structure Principle:

The whole spray booth is a modular structure, with the body made of plug-and-play insulated spray-plastic wall panels, providing good sealing and insulation performance. Aluminum alloy doors are installed, with observation windows in the middle for real-time monitoring of interior dynamics. The side of the body is equipped with a work door for easy access by staff. High-quality stainless steel heat exchangers offer high efficiency and long service life. Imported, low-noise, high-volume fans ensure perfect spray painting results.

The spray booth provides for workpiece spraying:

(1) A clean working environment;

(2) Adequate collection of paint mist.

The configuration of the spray booth depends on the size, shape, weight, and production guidelines of the workpieces, with various methods including open and closed types, continuous and intermittent types, rotating or fixed workpieces, single-sided and double-sided spraying.

Recent developments include oil curtain spray booths and down-spray booths.

Structurally, it should include:

Supply air filtration system, workpiece hanging (conveyance, rotation) devices, water curtain system, water washing system, exhaust system, water tank, lighting fixtures, and room body.

Principle of Paint Mist Recovery:

Paint mist recovery can be divided into two parts:

1. During spraying, the paint mist collides and mixes with the water curtain. Part of the paint mist dissolves in the water curtain and falls into the water tank.

2. The remaining paint mist enters the water washing room through the gap at the bottom of the water curtain board, fully mixing with the water mist sprayed by the atomizing nozzles. After air-water separation and settling, it flows into the water tank. In the water tank, paint mist coagulant is regularly added to form paint sludge.

Airflow Direction Classification:

Three types based on airflow direction:

1. Cross-flow paint booth: Airflow moves from one end of the booth to the other. This model is cost-effective and easy to install. However, the mist moves along the side of the vehicle, and the mist cannot be removed from around the operator's face, making the working environment less satisfactory. Uneven baking temperature affects quality.

2. Side-down draft paint booth: Air enters the paint booth through the ceiling filter and exits through the side wall roots. This is a mid-priced paint booth. Since the mist is away from the vehicle and can be removed from around the operator, both the spray effect and the working environment are relatively ideal.

3. Full-down draft paint booth: Represents the latest technology. Air enters from the ceiling and is discharged through underground pits or basements. This exhaust method achieves a cleaner spray process and a safer working environment but comes with high costs and requires more space.

Heating Method Classification:

Diesel paint booth, electric heating paint booth, steam heating paint booth, far-infrared paint booth, waste engine oil paint booth, quantum heating paint booth, etc.

Paint Mist Treatment Method Classification:

Dry-type paint booth and wet-type paint booth (water treatment).

For normally used paint booths, dry treatment is most common, so the filtration system (mainly referring to primary and secondary filter cottons) needs regular inspection and replacement; otherwise, it may affect the paint quality or even cause a fire. With further development in science and technology, the way to handle excess paint mist becomes increasingly advanced. Now many high-end cars use water-treated paint booths, dissolving the excess paint mist in water, achieving significant progress in handling paint mist.