Plastic automatic coating equipment
Product introduction: The automatic coating equipment for plastic parts includes spray guns and control devices, dust removal devices, water curtain cabinets, IR furnaces, dust-free air supply devices and conveying devices. The combined use of these several devices makes the entire painting area unmanned, increases the product volume, greatly improves the production efficiency, reduces the consumption of raw materials, saves costs, improves the working environment of the employees, protects the health of the employees, and solves the problem of the external environment. Pollution problem; embodies the three characteristics of high efficiency, energy saving and environmental protection.
Components of coating production line
The seven major components of the coating line mainly include: pre-treatment equipment, powder spraying system, spraying equipment, oven, heat source system, electric control system, suspension conveyor chain, etc.
Pre-treatment equipment for painting
The spray type multi-station pretreatment unit is a commonly used equipment for surface treatment. Its principle is to use mechanical scouring to accelerate the chemical reaction to complete the process of degreasing, phosphating, and water washing. The typical process of spray pretreatment of steel parts is: pre-degreasing, degreasing, washing, washing, surface conditioning, phosphating, washing, washing, and pure water washing. A shot blasting machine can also be used for pretreatment, which is suitable for steel parts with simple structure, severe corrosion, and oil-free or low-oil. And there is no water pollution.
Powder spraying system
The small cyclone + filter element recovery device in powder spraying is a more advanced powder recovery device with faster color change. The key parts of the powder spraying system are recommended to be imported products, and the powder spraying room, electric mechanical lift and other parts are all made in China.
Such as oil shower spray booth and water curtain spray booth are widely used in the surface coating of bicycles, automobile leaf springs, and large loaders.
The oven is one of the important equipment in the coating production line, and its temperature uniformity is an important index to ensure the quality of the coating. The heating methods of the oven include: radiation, hot air circulation and radiation + hot air circulation, etc. According to the production program, it can be divided into single room and through type, etc. The equipment forms include straight-through and bridge types. The hot air circulation oven has good heat preservation, uniform temperature in the furnace, and low heat loss. After testing, the temperature difference in the furnace is less than ±3oC, reaching the performance indicators of similar products in advanced countries.
Heat source system
Hot air circulation is currently the most commonly used heating method. It uses the principle of convection conduction to heat the oven.
Electric control system
The electrical control of painting and painting line has centralized and single-row control. Centralized control can use a programmable logic controller (PLC) to control the host, and automatically control each process according to the programmed control program, data collection and monitoring alarms. Single-row control is the most commonly used control method in the coating production line. Each process is controlled in a single-row. The electric control box (cabinet) is set near the equipment, with low cost, intuitive operation and convenient maintenance.
Hanging conveyor chain
Suspension conveyor is the conveying system of industrial assembly line and painting line. The accumulation type suspension conveyor is used in L=10-14M storage rack and special-shaped street lamp alloy steel pipe coating line. The workpiece is hoisted on a special hanger (load-bearing 500-600KG), the entry and exit of the switch are smooth, and the switch is opened and closed by electric control according to the work order, which can meet the automatic transportation of the workpiece in various places of science and technology, in the strong cold room and the lower part area Parallel accumulating cooling, and setting up the identification and traction alarm and shutdown devices in the strong cold area.
The process flow of the coating production line is divided into: pretreatment, powder spray coating, heating and curing.
Before treatment, there are manual simple process and automatic pre-treatment process, the latter is divided into automatic spraying and automatic immersion spraying. The workpiece must be surface treated to remove oil and rust before powder spraying. There are a lot of chemicals used in this section, mainly including rust remover, oil remover, surface adjustment agent, phosphating agent and so on.
In the pretreatment section or workshop of the coating production line, the first thing to pay attention to is to formulate the necessary strong acid and strong alkali purchase, transportation, storage and use systems, provide workers with the necessary protective clothing, safe and reliable clothing, handling, equipment, and Formulate emergency measures and rescue measures in case of accidents. Secondly, in the pre-treatment section of the coating production line, due to the existence of a certain amount of waste gas, waste liquid and other three wastes, in terms of environmental protection measures, it is necessary to configure pumping exhaust, liquid drainage and three waste treatment devices.
The quality of the pre-treated workpieces should be different due to the differences in the pre-treatment liquid and the process flow of the coating production line. The surface oil and rust will be removed for the well-treated workpieces. In order to prevent rusting again in a short time, phosphating or passivation treatment should be carried out in the following steps of pre-treatment: before powder spraying, the phosphate should also be treated. The modified workpiece is dried to remove the surface moisture. Small batches of single-piece production are generally air-dried, sun-dried, and air-dried. For mass flow operations, low-temperature drying is generally adopted, using an oven or a drying tunnel.
For small batches of workpieces, manual powder spraying devices are generally adopted, while for large batches of workpieces, manual or automatic powder spraying devices are generally adopted. Whether it is manual powder spraying or automatic powder spraying, it is very important to control the quality. It is necessary to ensure that the workpiece to be sprayed is evenly powdered and has a uniform thickness to prevent defects such as thin spraying, missing spraying, and rubbing off.
In the coating production line, pay attention to the hook part of the workpiece. Before curing, the powder attached to it should be blown off as much as possible to prevent the excess powder on the hook from solidifying, and some of the remaining powder should be removed before curing. When it is really difficult, you should peel off the cured powder film on the hook in time to ensure that the hook conducts well, so that the next batch of workpieces is easy to powder.
Matters needing attention in this process are as follows: if the sprayed workpiece is produced in a small batch, please pay attention to prevent the powder from falling off before entering the curing furnace. If there is any phenomenon of rubbing powder, spray powder in time. Strictly control the process, temperature and time during baking, and pay attention to prevent insufficient curing due to color difference, over-baking or too short time.
For workpieces that are automatically conveyed in large quantities, check carefully before entering the drying tunnel for leaks, thinning, or partial dusting. If unqualified parts are issued, they should be shut down to prevent entering the drying tunnel. Remove and respray if possible. If individual workpieces are unqualified due to thin spraying, they can be sprayed and cured again after curing out of the drying tunnel.
The so-called painting refers to covering metal and non-metal surfaces with protective or decorative layers. The coating assembly line has experienced the development process from manual to production line to automatic production line. The degree of automation is getting higher and higher, so the application of coating production line is becoming more and more extensive, and it penetrates into many areas of the national economy.
Application characteristics of painting assembly line engineering:
Coating assembly line equipment is suitable for painting and spraying treatment on the surface of workpieces, and is mostly used for coating large quantities of workpieces. It is used with hanging conveyors, electric rail cars, ground conveyors and other transportation machinery to form transportation operations.
Engineering process layout:
1. Plastic spraying line: upper conveyor chain-spraying-drying (10min, 180℃-220℃)-cooling-lower part
2. Painting line: upper conveyor chain-electrostatic dust removal-primer-leveling-top coat-leveling-drying (30min, 80°C)-cooling-bottom part
Paint spraying mainly includes oil shower spray booths and water curtain spray booths, which are widely used in the surface coating of bicycles, automobile leaf springs, and large loaders. The oven is one of the important equipment in the coating production line, and its temperature uniformity is an important index to ensure the quality of the coating. The heating methods of the oven include: radiation, hot air circulation and radiation + hot air circulation, etc. According to the production program, it can be divided into single room and through type, etc. The equipment forms include straight-through and bridge types.
Post time: Oct-10-2020