Electro Static Power Coating Technology is a state-of-the-art technology invented by TS. Erwin Gemmer in the early 1950s. Through many innovations by scientists, manufacturers of equipment and paint powder has made the coating technology more complete in quality and design better. .
There are two types of electrostatic coating technology:
– Dry Powder Coating Technology (Powder Coating): Used to paint metal products: iron, steel, aluminum, stainless steel …
– Wet Powder Coating (solvent): Used to paint metal products, wood resin, …
Each technology has different advantages and disadvantages:
– For wet-electrostatic paint technology, it is possible to paint on more materials, but the amount of solvent that does not stick to the paint will not be recovered for reuse, causing environmental pollution due to the amount of solvent used. Remainder, high paint costs.
– For dry paint technology, only metallic paint is applied. However, paint powder that does not stick to the paint will be recovered (over 95%) for reuse, low paint cost, less lip contamination. bare.
Powder coating equipment line. The main equipment is spray guns and automatic controllers, other equipment such as paint spray booths and paint powder recovery; Steam room with infrared rays (autoclave temperature control and timer automatically turn off). Air compressors, compressed air compressors. The chemical tanks for surface treatment before painting are made of composite materials.
Process map of electrostatic painting process:
Surface Treatment Steamed Spray Painted Finished Products
– Surface treatment: The surface must be treated before painting by following steps: degreasing, rinsing, bleaching, bleaching, shaping, zinc phosphate, washing water.
– Steam: Dry the paint after surface treatment.
– Spray paint: Apply static effect during spray painting with gun control, can adjust the amount of powder spray or adjust the spray mode according to the shape of the paint.
– Drying: Painted objects are put into the drying chamber. Depending on the type of specifications of the paint powder, the appropriate automatic drying mode (drying temperature 150oC – 200oC, drying time 10 – 15 minutes).
– Finally, inspection, packaging finished.
Because of the good surface treatment process, the zinc phosphate process is firmly attached to the metal surface, the product after electrostatic paint has high corrosion resistance under the influence of the environment.
The color of the electrostatic powder coating is varied and rich, such as lacquer or abrasive, hammer or silver abrasive … Therefore, the powder coating product can meet the demand in many fields of degrees. High durability and aesthetics, especially for civil items, interior decoration, equipment in education, health, construction, electricity, …
WHAT IS A POWDER POWDER:
The concept of powder coating:
Powder coating powder is a material used in electrostatic coating technology, consisting of three main ingredients are resins, pigments and additives.
Electrostatic Powder Coating: Powder coatings now consist of four popular types: Gloss, Matt, Sand, Wrinkle for both indoor and outdoor use.
Storage conditions: As mentioned above, the condition for preserving static powder is very safe because it is not afraid of fire because it is a dry powder which does not contain solvent and does not cost much, just meet the following conditions. Is that we can preserve paint powder safely and effectively – Keep in dry, cool place. – Storage temperature below 33C (very suitable with weather and climate of Vietnam). – Only up to a maximum of 5 layers.
WHAT IS THE PAINT TECHNOLOGY?
The concept of static painting:
Most scientists in the world have acknowledged that it is rare for modern technology to be invented and used in production, replacing old technology with high quality and lower prices. The product but the initial investment cost is the same old technology – that is electricity painting. Electrostatic paint is also called dry paint because of its powder coating properties and when used it will be charged with a charge when passing through a device known as an electrostatic paint gun. It will also have a charge (-) to create the adhesion effect between the paint powder and the paint. Electroplating is a technology that not only provides economic advantages but also meets the current and future environmental concerns because of its solvent-free nature. Therefore, the problem of environmental pollution in air and water is absolutely not as in water.
History of powder coating:
The principle of organic polymer powder is heated and coated on the metal surface was studied and put into trial in Europe by scientist. Erwin Gemmer in the early 1950s, but until about 1964, the new and commercially successful Electrostatic Powder Spray process has been used extensively today. Through decades of contribution, improved by scientists and manufacturers on the processing of paint powder has helped the technology of electrostatic paint more complete in quality and design better.
Here is a summary of decades of Electrical Coating as well as its extensive influence:
The four starting chemicals – Epoxy, Hybrid, Polyurethane, and TGIC – were introduced in the market. Some types of melamine and acrylic have not been successful. Early 1970s Electrostatic coatings developed rapidly and were widely used in Europe.
Early 1980s Fast-growing and widely used in North America and Japan.
In the mid-1980s, rapid development and widespread use in the Far East (continental shelf Pacific).
1985 – 1993 New paint powder is introduced in the market. There are all kinds of acrylic and a mixture of paint powder is launched.
Advantages of Powder Coating Technology:
– 99% of paint is thoroughly used (residual powder applied during paint spraying is recovered for reuse).
– No primer required.
– Easily cleaned areas affected by spraying or unsatisfactory paint spraying.
– Save time to complete the product.
b. About the usage characteristics:
– The paint process can be done automatically with ease (using automatic paint spraying system).
– Easy to clean when powder applied to the operator or other equipment without the use of any solvent, as in water-based paints.
– Long life
– High gloss
– No corrosion by chemicals or chemical agents or weather.
– Rich color and accuracy …
And there are many other benefits that users in the process of applying static coating technology will find.
Benefits between static and oil painting:
Powder coating is the least costly method of painting on the cost of the product that is currently in use (including water-based powder coatings).
POWDER FUNCTION POWDER COATING WATER, OIL PAINT TECHNICAL REQUIREMENTS
High heat tolerance and less environmental impact (including hot and cold)
Ability to adjust the thickness of the paint.
Easily affected by the environment (it’s cold, the paint surface shrinks). Difficulty adjusting the thickness of the paint. Low coverage (can not paint complex angles)
Economy and reuse 99% High affliction (low rate of loss) Recovery only because of environmental problems, can not be re-used. Low grip (high loss rate of 60%)
Do not use solvents: do not pollute the environment. Applicable in many industrial fields (aviation industry, marine industry, construction industry …)
Easy automation saving labor costs
Easy to store Does not require skilled workers (when unsatisfactory can be easily remapped)
Must use solvents: polluting the environment Limit applications in many areas Difficult to build automation systems need more high-cost workers
Storage difficulties (potential for fire and explosion)
Requires highly skilled workers as they can not be repaired if the paint does not meet the requirements
Create fast finished product (about 10 – 15 minutes). Product life expectancy is high (4 – 5 years) Insulation ability Creates slow, time-consuming product (depends weather)
Product Life Expectancy Low Insect Resistance Through the comparison table, static coatings can save a lot of production costs, labor and product costs when using electrostatic powder. It is more advantageous to export than waterborne over Europe and America.
APPLICATION OF PAINT TECHNOLOGY PROVINCE:
Currently, electrostatic coating technology is widely applied in many industries such as maritime industry, aviation industry, car and motorcycle manufacturing industry … to such areas as decorative paint , Industrial construction, civil construction, …
PROCESS OF POWDER PROCESSING OF POWDER POWDER:
APPLIED PAINT TECHNOLOGY APPLICATION SYSTEM:
Surface treatment: Including 4 tanks: Chemical tank degreasing tank Rusting acid tank Reservoir chemical surface preparation Reservoir chemical phosphate surfactant And 3 treatment tanks The surface of the material is painted before being applied to the paint spray, in order to create a highly effective adhesive for the paint powder.
Spray equipment: including paint guns and controllers Guns: There are two types of paint guns:
– Hand paint guns
– Automatic paint guns
– Drying Kiln
– Spray Chamber
– Recovery Equipment
– Powder Feeder
Process technology powder coating system consists of the following four basic steps:
– Spray Painting
– Paint Baking
Detailed steps of the process:
Step 1: Surface treatment of the product before painting: Products (metal) before electrostatic paint must be treated surface. Usually the product is coated electrostatic is metal. We consider on the iron surface: The surface treatment of the product is to meet the following requirements: Industrial grease cleaner (due to mechanical processing) rust-free product. The product does not rust back in unpainted time. Creates a good coat for adhesion between paint film and metal. Due to the above requirements, the treatment of metal surface before painting is usually treated by the method of dipping the product into the chemical tank. The system of chemical tanks consists of the following tanks: chemical tank degreasing tank. Water tank Acid storage tank, usually H2SO4 or HCl. Water tank Tank surface chemical formulation. Photovoltaic surface chemical tank. Water tank These tanks are built and covered with plastic, or made of stainless steel. Painted objects are housed in stainless steel wire baskets, which are moved by the electric balancing system through the tanks in the order above.
Step 2: Dry the product surface before painting. The product after the chemical treatment must be dried before painting, drying oven products with steam drying function to quickly bring the product into the paint. Normally the kiln is in cubic form. The product is hung on the wagon and pushed into the furnace. The furnace is the main source of heat from the infrared kitchen stove or Burner, the burning material is Gas.
Step 3: Product paint Products after chemical treatment and drying are introduced into the spray chamber and paint recovery. Due to the characteristics of Powder Coat Powder coating, the adhesion of the coating to the surface of the metal is due to electrostatic force, so that the spray gun also plays an important role in recovering the powder. Excess paint, paint powder recovered is added to the new paint powder to reuse. This recovery is the preeminent economic feature of static painting.
Spray booths come in two types:
Type 1 spray gun: Use a spray gun, the paint is hung, hand-hooked into the spray chamber.
Type 2 spray guns: The paint moves on the conveyor belt into the spray chamber, two spray guns on opposite sides spray on two sides of the product. To paint and recover paint powder, we need an electrostatic paint sprayer, and an air supply system consisting of compressors and humidifiers.
Step 4: Drying and finishing of the product After spraying, the product is put into the oven. Drying temperature: 1800C – 2000C for 10 minutes. Furnace with main heat source by infrared stove or burner.
REMOVE POWDER AFTER PAINT:
a. Recovery System: Filter or cyclone
b. How to use the reclaimed powder: To be able to use the reclaimed powder most effectively we must mix the recovered powder with the new powder in a ratio of 1: 1. If the powder is impurities or weak electrodeposition, we must use a powder sieve.