WO2013017074A1

WO2013017074A1 - Production process for electro-statically coating wood door

Info

Publication number: WO2013017074A1
Application number: PCT/CN2012/079442
Authority: WO
Inventors: 徐永忠
Original assignee: 颂润有限公司
Priority date: 2011-08-01
Filing date: 2012-07-31
Publication date: 2013-02-07
Also published as: CN102266846A

Abstract

Disclosed in the present invention is a production process for electro-statically coating a wood door, which comprises the following steps: loading material, removing dust, humidifying, spraying, leveling and preheating, solidifying, and unloading material. The process is characterized in that, in the step of removing dust, a conveying chain is used for conveying a workpiece into a sealed dust-removing chamber, a rotating brush is used for removing dust from the two sides of the workpiece, and an air drafting cover is used for absorbing and collecting the dust swept from the workpiece into a dust collecting box which is filled with water; in the step of spraying, an electro-static spraying mode is adopted for spraying a polyurethane ultraviolet light solidifying coating on the workpiece. The spraying mode can be used for promoting the use ratio of the coating, reducing the VOC emission, and obtaining a more uniformly coated layer.

Description

Production process of electrostatic coating of wooden door

Technical field

The invention relates to a wood production process, in particular to a production process of a wooden door coating.

Background technique

The traditional wooden door spraying method is mainly the coating method using an air spray gun. Due to the high air pressure in the air spraying method, the paint on the surface of the workpiece rebounds severely, resulting in a low paint lacquering rate and uneven coating. The corners of the door leaf cannot be effectively covered. When using automatic air spraying, the amount of refilling is large. Especially for wooden doors, the coating is thicker and requires multiple spraying. The production efficiency is low, the running cost is high, the coating waste is large, the VOC pollution in the coating environment is serious, and the wooden door is polished. The staff is dense and has a high workload.

In addition, the coating used in the traditional wooden door spraying method is a PU coating, which has the following disadvantages: the VOC organic compound is produced, the solid content is low, generally between 45 and 50%; the curing time is long, generally 4 to 8 hour.

Summary of the invention

The object of the present invention is to provide a production process for electrostatic coating of wood doors with energy saving, environmental protection, high efficiency and reduced consumption.

In order to achieve the above object, the technical solution adopted by the present invention is:

The production process of the electrostatic coating of the wooden door includes the steps of: feeding, dusting, humidifying, spraying, leveling, preheating, solidifying, and blanking, wherein: in the dust removing process, the workpiece is conveyed to the airtight by the accumulation chain. In the dust removing chamber, dust is removed from both sides of the workpiece by a rotating brush, and the dust swept from the workpiece is sucked and concentrated by the suction hood into a dust box containing water; in the spraying process, In the electrostatic spraying method, the polyurethane ultraviolet curing coating is sprayed on the workpiece by using a Lan's electrostatic rotating cup.

In the feeding process and the blanking process, the upper and lower line areas of the workpiece are designed in the accumulation area of the accumulation chain, and the manual auxiliary positioning and the automatic feeding of the workpiece by the accumulation chain are adopted.

The loading process includes the following steps: A. placing the workpiece on the turnover car according to the hanging distance of the workpiece in the accumulation area, placing four pieces in each car; B, pushing the turnover car onto the lifting platform and simultaneously pressing The platform rises the switch and raises the turnover car; C, manual assists to connect the workpiece to the hanger; D, presses the platform down switch to push the cycle car away; E, pushes the next car that carries the workpiece, continues material.

The blanking process includes the following steps: a. Pushing the turnover car onto the lifting platform, and pressing the platform ascending switch to raise the turnover car; b. automatically placing the workpiece according to the workpiece hanging distance in the accumulation area On the turnover car, and fixed; c, manual assistance to disengage the workpiece from the hanger; d, press the platform down switch to push the cycle car away; e, push the next car that carries the workpiece, continue to cut.

In the spraying process, the paint that does not adsorb the workpiece is first collected by the paint collecting system; the multi-level water curtain is collected for the micro-paint that is not collected completely, and the paint mist is washed into the water tank after meeting the water curtain; For the non-hydrophilic organic substance not collected through the multi-stage water curtain, the non-hydrophilic organic substance is subjected to adsorption treatment using an activated carbon adsorption device.

In the leveling preheating process, a five-stage temperature-controlled infrared preheating furnace is used for infrared radiation heating, the preheating temperature is 50-60 ° C, and the preheating time is five minutes.

In the curing process, the workpiece is irradiated with six sets of high-pressure mercury UV lamps having a dominant wavelength of 365 NM and a strength of 80 W/CM. Two groups are respectively distributed on both sides of the workpiece, and a group is respectively allocated above and below the workpiece.

The invention has the following advantages: 1. The design of the lower workpiece segment on the production line adopts the manual auxiliary positioning and the automatic upper and lower line of the workpiece, and the upper and lower line areas of the workpiece are designed in the accumulation area of the accumulation chain, so that the labor intensity can be reduced and the land can be saved. Area and improve the working environment. 2. The automatic dust removal part of the workpiece is designed with a brush rotating dust removal adsorption and concentrated to the central vacuum treatment system. The advantage of the previous air purge mode is that the dust can be concentrated and cleaned to improve the production environment. 3. The spraying area of the workpiece spraying area adopts a high atomizing electrostatic rotating cup system, and the rotating cup electrostatic spraying system is the core part of the entire production line. Compared with the current traditional air spraying method, the electrostatic rotating cup spraying system can increase the utilization rate of electrostatic spraying paint by 30%, improve the painting environment and reduce the pollution of paint and VOC emissions. The use of electrostatic spraying system has significantly improved product quality and production efficiency, while reducing the amount of sanding and polishing work for the next process. 4. At the same time, the spray area is designed with water curtain paint mist removal and paint recovery tank. The overspray paint can be recycled and reused to reduce energy consumption and save energy. 5. Spray room paint mist and exhaust gas discharge channel installation design has activated carbon filter adsorption treatment tower, the exhaust gas is discharged through the activated carbon filter adsorption treatment system. 6. The paint leveling section is designed with far-infrared preheating mode, which is more concentrated and energy-saving. The spray coating designed by the production line is UV environmental protection paint, and the paint curing is completely treated by UV ultraviolet light. The curing time is short, the efficiency is high, the energy consumption is low, and the production site is small. 7. Because of the high atomization electrostatic cup rotating system, the paint film on the surface of the workpiece is evenly distributed, which reduces the grinding process and the grinding personnel and the grinding workload, thereby greatly improving the grinding work efficiency and improving the grinding working environment. air.

DRAWINGS

The invention will be further described in detail below with reference to the accompanying drawings.

Figure 1 is a flow chart of the production process of the present invention.

detailed description

As shown in FIG. 1 , the production process of the electrostatic coating of the wooden door includes the steps of: feeding, dusting, humidifying, spraying, manual refilling, leveling preheating, solidifying, cutting, the feeding process and the blanking process. In the middle, the upper and lower line areas of the workpiece are designed in the accumulation area of the accumulation chain, and the manual auxiliary positioning and the automatic feeding of the workpiece by the accumulation chain are adopted. The accumulating conveyor chain is used to manually assist the automatic upper and lower door fans to realize the complete automation of the painting production line. The solid wood door leaf is heavier, and the weight of a single wooden door leaf is 35-100KG. At present, the labor intensity of the upper and lower lines of the workpiece is large, so the new process production line adopts accumulation and transportation. Chain suspension transport. The accumulation area is set in the upper and lower material sections, and the upper and lower parts lifting platform of the door leaf is equipped at the same time, the worker only needs to position the hook and the workpiece, which effectively reduces the labor intensity of the operator.

The workflow of loading is as follows:

(1) Place the workpiece on the turnover car according to the workpiece hanging distance in the accumulation area, and place 4 pieces in each car.

(2) Push the turnover car onto the lifting platform and press the platform ascent switch to raise the turnover car.

(3) Manually connect the workpiece to the hanger.

(4) Press the platform down switch to push the cycle car away.

(5) Push the next car that carries the workpiece and continue feeding.

(6) When the process speed of the production line is designed to be 3.5 m/min, the workpiece translation speed of the accumulation zone chain is 0.47 m/min.

The clock is loaded for 206 seconds per car, and workers can easily do the above.

In the dust removal process, the workpiece is transported into the closed dust chamber by the accumulation chain, and the two workpieces are rotated by the brush.

The side is dust-removed, and the dust swept from the workpiece is sucked and concentrated by the suction hood into the dust box containing water.

The rotating brush of the workpiece is mounted in a direction higher than the height of the workpiece and automatically rotated, and the dust cover is installed on the back of the brush. When the workpiece passes

When the brush is rotated, the brush cleans the surface of the workpiece, and the dust particles that are swept away are sucked away by the dust cover of the rotating brush system mechanism.

And sent to the central vacuum collection system to ensure that the environment is clean and not polluted, to protect the health of the staff.

After the workpiece is subjected to dust removal treatment, after humidification through the humidification chamber, an electrostatic spraying process is adopted, in which the spraying process is adopted.

In the electrostatic spraying method, the polyurethane ultraviolet curing coating is sprayed on the workpiece by using a Lan's electrostatic rotating cup. When spraying, the distance between the workpiece and the rotating cup and the height of the workpiece are detected by the encoder and the grating detecting device. When the workpiece passes the detecting device, the signal is sent to the control cabinet. When reaching the front end of the spray gun, the control cabinet will give the spraying valve. Signal, spray in the X direction or stop spraying. This real-time control is not affected by changes in conveyor speed.

A new technical method for electrostatic coating for wooden door spraying. The electrostatic coating technology maintains the coated workpiece at the positive electrode (grounded state), and the coating machine rotates the cup end at the negative electrode, thereby passing the supplied high voltage at the two poles. An electrostatic field is formed between which the atomized coating particles are negatively charged, so that the coating particles can be applied to the surface of the workpiece to be coated, wherein the side and back sides are also attached to the paint due to the electrostatic hazard, and the static electricity is adhered. The method saves paint, time and labor. More paint is attracted to and attached to the target, and less paint is wasted in the spray booth and the surrounding air. The electrostatic method also reduces the evaporation of solvent into the air because the amount of paint required to spray each part is reduced. Although the ring-packaging effect contributes to the efficiency of the electrostatic method, the hoop is not the main reason for the improvement of the transfer efficiency. In fact, the main advantage of electrostatics is that the transfer efficiency of the paint to the main surface is increased, less paint is wasted, and contamination of the spray environment is reduced.

The characteristics of the electrostatic rotating cup spraying system: high efficiency of paint spraying when the electrostatic rotating cup is sprayed; when the electrostatic rotating cup is sprayed, the surface quality of the workpiece is good, the film thickness is uniform, the coating fullness is high; the production efficiency is greatly improved and the factory production is greatly reduced. Energy consumption, fully automated spraying production process, reducing the labor intensity of operators, reducing production costs; effectively reducing the emission of VOC organic compounds and dust emissions. UV is used in the spraying process of the present invention Coating, UV is the English abbreviation of Ultra-Violet Ray. The full name of UV coating is Chinese polyurethane UV curing coating. UV The photocurable coating has the advantages of no volatile organic compounds (VOC), low environmental pollution, fast curing speed, energy saving, good curing product performance, and high-speed automatic production.

In the spraying process, the paint that is not adsorbed on the workpiece is first collected by the paint collecting system; the multi-level water curtain is collected for the micro-paint that is not completely collected, and the paint mist is washed into the water tank after meeting the water curtain; The non-hydrophilic organic substance is not adsorbed through the multi-stage water curtain, and the non-hydrophilic organic substance is adsorbed by the activated carbon adsorption device.

In the curing process, six sets of high-pressure mercury UV lamps with a dominant wavelength of 365 NM and a strength of 80 W/CM are used to illuminate the workpiece. Two groups are respectively distributed on both sides of the workpiece, and a group is respectively allocated above and below the workpiece. After curing for six minutes, it enters the grinding process. Because the electrostatic coating is uniform, the grinding work is reduced by 2/3 compared with the air spraying, and the fine sand can be lightly polished once.

After the curing is completed, the cutting process is entered, and the workflow is as follows:

(1) Push the turnover car onto the lifting platform and press the platform rise switch to raise the turnover car.

(2) According to the workpiece hanging distance in the accumulation area, the workpiece is automatically placed on the turnover car and fixed.

(3) Manually assisting in disengaging the workpiece from the hanger.

(4) Press the platform down switch to push the cycle car away.

(5) Push the next car that carries the workpiece and continue to cut.

(6) When the process speed of the production line is designed to be 3.5 m/min, the workpiece translation speed of the accumulation zone chain is 0.47 m/min, and the cutting time per car is 206 seconds, and the worker can easily complete the above operation.

Example: In the past, a piano factory required a film thickness of 700 um. The air gun was sprayed with 900-1000 um and then ground for about 300 um. After using the electrostatic painting equipment, only 750 um was sprayed. When a furniture factory uses air spraying, the number of people grinding is 165. Now, after using the electrostatic rotating cup spraying system, the number of grinding is only 50, the grinding workshop is reduced by 2/3, and the environment of the grinding workshop becomes clean. Through the successful cases of a piano factory and a furniture factory, it is concluded that the amount of sanding work is reduced significantly after using electrostatic painting equipment.

Under the same film thickness requirement, the electrostatic cup coating rate is 30%-45% higher than that of the air spray gun, which greatly reduces the waste of paint. When the paint waste is more serious, the waste paint produced is larger, and the treatment is more. When the amount of exhaust gas is generated, the environmental impact and energy use are greater, that is, when the paint utilization rate is increased by 30% - 45%, the environmental pollution and energy consumption are also reduced by 30% - 45 %; when the electrostatic cup is sprayed, the film thickness error is between 5% and -10%, and when using the air gun, it is between 20% and -30%. The larger the film thickness error is, the worse the surface flatness of the workpiece is. The amount of work caused by the grinding is large and the dust generated causes environmental pollution. On the contrary, the smaller the thickness error of the paint film, the smaller the amount of work to be polished and the less dust generated.

Claims

1. The invention relates to a production process of electrostatic coating of wooden doors, which comprises the steps of: feeding, dusting, humidifying, spraying, leveling preheating, solidifying and cutting, wherein: in the dust removing process, the workpiece is conveyed by using the accumulation chain In a sealed dust chamber, dust is removed from both sides of the workpiece by a rotating brush, and dust swept from the workpiece is sucked and concentrated by a suction hood into a dust box containing water; The electrostatic ultraviolet coating method is used to spray the polyurethane ultraviolet curing coating on the workpiece by using a Lan's electrostatic rotating cup.

2. The production process of the electrostatic coating of the wooden door according to claim 1, wherein in the feeding process and the blanking process, the upper and lower line areas of the workpiece are designed in the accumulation area of the accumulation chain, and the artificial auxiliary positioning is adopted. And the way of automatically feeding the workpiece by using the accumulation chain.

3. The production process of the electrostatic coating of the wooden door according to claim 2, wherein the loading process comprises the following steps: A. placing the workpiece on the turnover car according to the hanging distance of the workpiece in the accumulation area, each Put the car in four pieces; B. Push the turning car onto the lifting platform, press the platform ascending switch to raise the turnover car; C, manually assist the workpiece to connect with the hanger; D, press the platform down switch, turn the cycle Push the car away; E, push the next car that carries the workpiece and continue feeding.

4. The production process of the electrostatic coating of the wooden door according to claim 1, wherein the blanking process comprises the following steps: a, pushing the turnover car onto the lifting platform, and pressing the platform ascending switch to turn the turnover car. b. According to the workpiece hanging distance in the accumulation area, the workpiece is automatically placed on the turnover car and fixed; c, manual assists to disengage the workpiece from the hanger; d, press the platform down switch, push the turnover car Go; e, push the next car that carries the workpiece and continue to cut.

5. The production process of the electrostatic coating of the wooden door according to claim 1, wherein in the spraying process, the paint which is not adsorbed on the workpiece is collected by the paint collecting system first; and the multi-stage water is used for the trace paint which is not collected completely. The way the curtain is collected, after the paint mist meets the water curtain, it is washed into the water tank; for the non-hydrophilic organic matter not collected through the multi-stage water curtain, the non-hydrophilic organic substance is adsorbed by the activated carbon adsorption device. deal with.

6. The process for producing a wooden door electrostatic coating according to claim 1, wherein in the leveling preheating process, a five-stage temperature-controlled infrared preheating furnace is used for infrared radiation heating, and the preheating temperature is 50- At 60 ° C, the preheating time is five minutes.

7. The production process of the electrostatic coating of the wooden door according to claim 1, wherein in the curing process, the workpiece is irradiated with six sets of high-pressure mercury UV lamps having a dominant wavelength of 365 NM and a strength of 80 W/CM. Two groups are respectively distributed on both sides of the workpiece, and a group is respectively allocated above and below the workpiece.