Product Introduction of PPGI
PPGI is pre-painted galvanized steel, also known as pre-coated steel, color coated steel, etc. Using Hot Dip Galvanized Steel Coil as the substrate, PPGI is made by first going through surface pretreatment, then coating one or more layers of liquid coating by roll coating, and finally baking and cooling. The coatings used include polyester, silicon-modified polyester, high durability, corrosion resistance, and formability. We are a PPGI & PPGL manufacturer in China. Our PPGI (Prepainted Galvanized Steel) & PPGL (Prepainted Galvalume Steel) are available in a variety of specifications. We could also provide the product life length lasts for decades as customers required.
Color Coated Steel Coil Co
Promotional Price Color St
Top Sell Ppgi Color Coated
600-1500mm,according to customer’s requirement
softy，half hard and hard quality
Type of substrate:
hot dipped galvanized,galvalume,electro-galvanized
oiling/passivstion or chromium free passivation /skin pass
3-5MT per coil
export standard package or as request
Terms of price：
FOB, CIF, CFR, EXW
TT, Irrevocable LC at sight, Western union, Ali trade assurance
Color-coated Roll Coating Type :
Polyester (PE),Good bacteria, little color, wide range in formability and outdoor, medium chemical resistance, low cost.Silicon modified polyester
Namely (SMP), the coating film has good abrasion resistance and heat resistance, good external appeal and anti-spongification, maintenance and retention, weak and moderate, and the cost is medium.High acceptance polyester.
Namely (HDP), excellent color retention and impact resistance, excellent outdoor reflection and resistance, good paint film resistance, obvious color, and appearance.Polyvinylidene fluoride
Namely(PVDF),appearance color and resistance, appearance, appearance appearance and chalking resistance, excellent solvent resistance, good styling, resistance, limited color, and high cost.
Coating Structure Type:
Apply twice on the upper surface, once on the lower surface, and bake twice.
The upper and lower surfaces are coated twice and baked once.
The upper and lower surfaces shall be coated twice and baked twice.
Use of different coating structures:
The single-layer back paint has poor corrosion resistance and scratch resistance, but it has good adhesion. mainly used in sandwich panels.
The back paint has good corrosion resistance, scratch resistance and processing formability, and has good adhesion.Applicable to single-layer profiled plate and sandwich plate.
The double-layer back paint has good corrosion resistance, scratch resistance and processing formability. Most of them are used for single layer Laminated plate, but its adhesion is poor, so it is not suitable for sandwich plate.
Color coated substrate classification:
Hot dip galvanized substrate
The product obtained by coating organic coating on hot-dip galvanized steel plate is hot-dip galvanized color coated plate. In addition to the protection of zinc, the organic coating on the surface of hot-dip galvanized color coated plate also plays the role of isolation protection and rust prevention, and its service life is longer than that of hot-dip galvanized plate. The zinc content of hot-dip galvanized substrate is generally 180g / m2 (double-sided), and the maximum zinc content of hot-dip galvanized substrate for external use is 275g / m2.
Hot dip aluminum zinc substrate
The hot-dip aluminum zinc steel plate (55% Al Zn) is used as the newly coated substrate, and the aluminum zinc content is usually 150g / ㎡ (double-sided) The corrosion resistance of hot-dip aluminum zinc plate is 2-5 times that of hot-dip galvanized plate. It will not be seriously oxidized or scale when used continuously or intermittently at temperatures up to 490 ℃. The ability to reflect heat and light is twice that of hot-dip galvanized steel plate, and the reflectivity is greater than 0.75. It is an ideal building material to save energy.
Electro galvanized substrate
The product obtained by baking with electro galvanized sheet as the substrate and coated with organic coating is electro galvanized color coated sheet. Because the zinc layer of electro galvanized sheet is thin and the zinc content is usually 20 / 20g / m2, this product is not suitable for making walls and roofs outdoors. However, due to its beautiful appearance and excellent processing performance, it can be mainly used for household appliances, audio, steel furniture, indoor decoration, etc.
- good durability, corrosion resistance and longer life compared to galvanized steel;
- good heat resistance, and galvanized steel sheet compared to the more difficult to change color at high temperature;
- It has good thermal reflectivity
- it has similar machinability and spraying performance to galvanized steel sheet
- It has good welding performance.
With good performance to price ratio, durable performance and very competitive price. As a result, both architects, engineers and manufacturers have been widely used in industrial buildings, steel structures and civil facilities, such as garage doors, gutters and roofs.
What are the characteristics of the color coated coil substrate:
Electro-galvanized substrate: The coating is thinner, and the corrosion resistance is not as good as the hot-dip galvanized substrate;
Hot-dip galvanized substrate: the thin steel plate is immersed in a molten zinc tank to adhere a layer of zinc to the surface. This galvanized sheet has good paint adhesion and weldability.
Hot-dip aluminum-zinc substrate:
The product is plated with 55% AL-Zn and has excellent corrosion resistance. Its service life is more than four times that of ordinary galvanized steel sheets. It is a replacement product of galvanized sheet.
- Poor bendability of color-coated coil (T-bend): When the steel is bent 180 degrees, the coating on the processed part will be cracked and the coating peeled off. Cause: Too much mastery of pre-processing. The coating thickness is too thick. Overbake. The bottom coating is different from the top coating manufacturer, or the thinner is used improperly.
- Poor hardness of color-coated rolls (pencil hardness): Use a drawing pencil to make a hard stroke on the surface of the coating, and leave a scratch on the surface after wiping it off. Cause: The furnace temperature is low, and the coating is not cured sufficiently. The heating conditions are inappropriate. The coating thickness is thicker than specified.
- The production process of the passivation board temperature is checked once every 2 hours. The reason is that the staff did not regularly track the passivation board temperature during the inspection. Especially in winter, the temperature change is relatively large within 2 hours, which will eventually cause the aging of the color-coated roll, and the phenomenon of scratching and peeling of the paint will occur during the pressing.
- During the production of color-coated rolls, there is dust on the exit inspection mirror, and there is also dust on some rollers. Dust will directly affect the surface quality of the color-coated rolls. The paint will explode when it grows longer or when exposed to the sun.
- Add passivation solution first and then water when matching the tank. Due to the density problem of the passivation solution, for example, when the density of the passivation solution is higher than that of water, the raw materials will be mixed unevenly, and the adhesion of the passivation layer and the substrate will be poor, which is very easy to cause the surface of the color coated roll to explode phenomenon.
As far as the current color-coated roll market is concerned, it is an emerging material respected in the world today. And with the advancement of science and technology, the enhancement of environmental awareness, and the improvement of people’s living standards, color-coated rolls increasingly show strong vitality and broad market prospects. One of the main advantages is that the color-coated roll has the properties of high mechanical strength of steel materials and easy forming, so as to have good decoration and corrosion resistance of the coating material.
Generally speaking, the color-coated coils currently on the market are made of cold-rolled substrates, hot-dip galvanized substrates, electro-galvanized substrates, and aluminum-zinc-plated substrates. In addition, it is a color-coated steel strip using hot-dip galvanized steel strip as the base material. In addition to the protection of the zinc layer, the organic coating on the zinc layer plays a role of covering and protection to prevent the steel strip from rusting, and its service life is longer than that of the galvanized strip. Long, about 1.5 times. With its many advantages, color-coated rolls in Shandong are widely used in construction, home appliances, automobiles, furniture and light industrial products and other industries.
Mainly affected by the physical and chemical properties and surface quality, and the understanding of various defects is also different, but the overall can be divided into poor quality of the substrate, changes in the surface tension of the coating, improper pretreatment, curing defects, coating defects and Scratched. In addition, we all know that the production process of color-coated rolls is continuous. Once there are quality defects, we need to cooperate closely with the whole line to gradually investigate, find out the cause of the defect and solve it.
The coating of color coated board not only plays a protective role, but also increases the decoration, and the color is durable and not easy to fade. Different types of color and surface structure of embossing and printing can also be added to the surface of different types of color coated board. Although the price of traditional steel plate is lower than that of color coated steel plate, the performance price ratio of color coated steel plate still has obvious advantages due to the decoration and protection process after forming.
Compared with traditional steel plate, color coated steel plate has the advantages of convenient installation, fast construction speed (no wet operation), firm and reliable connection, unlimited construction season and no secondary decoration. In order to achieve the same decorative effect of color coated steel plate, the traditional steel plate needs to be coated. Therefore, the construction speed of color coated plate is fast.
Color coated board also has a very favorable advantage in architecture and interior decoration, which can not only play a role in fire prevention. The coating surface can maintain luster even under high temperature baking, and the surface color has no change.
In terms of processing, the surface coating of high-quality color coated plate does not fall off after bending or stamping, and the coating quality is far more uniform, stable and ideal than that of monomer spraying on the formed metal surface.
In terms of service time, the color coated plate is obviously more durable than the traditional steel plate, and can maintain its luster and rust free for more than 20-30 years indoors.
If the use of ppgi is not appropriate, the result is not a high standard of materials, resulting in waste, is the material performance can not meet the use of requirements, the use of the need to choose according to the use of ppgi.
1.The choice of substrate
(1)cold-rolled substrate: poor corrosion resistance, can be used to make home appliances parts
(2) galvanized substrate: Corrosion Resistance Than cold-rolled plate, generally for home appliances shell, furniture, interior decoration.
(3)hot-dip (aluminum) zinc substrate: corrosion resistance, external construction.
(1)color: General Color for White Gray, sea blue, special color order to increase the price and order time.
(2)GLOSS: the Gloss of the film is high, medium and low. General Construction for 30-70 csomething O low gloss color coated roll
3.The choice of coating technology
general outer plate with 2/2 PPGI, field composite plate type can also use 2/1 PPGI, EPS composite plate must use 2/1 PPGI, in order to have better adhesion, aluminized zinc plate is generally used for roofing site composite plate, after some process can also be used aluminized zinc plate to do EPS composite plate.
4.Attention in the use of the problem
(1)PPGI used in a building, the use of the same manufacturer the same production line at the same time products, to avoid mixing.
(2)the necessary peritoneum during pressing forming, such as PVDF coated color coated sheet, aluminized zinc coated sheet.
(3)when the PPGI is sheared, the surface of the equipment in contact with the PPGI should be covered with rubber mat.
(4)remove the metal chips in time to avoid scratching the coating on the surface of the PPGI.
(5)zinc can be used as a sacrificial anode to protect the steel, but when in use, try to place the incised part of the PPGI in the hidden part, there are strict requirements of the project to protect the incisions.
(6) after the installation of the project, the welding spots and metal chips left over from
The quality of PPGI is mainly the detection of coating pretreatment and coating performance. The pretreatment detection of coating includes two aspects: degreasing and chemical conversion coating. Coating detection includes two aspects of coating detection technical performance (such as adhesion, weakness, impact strength, hardness, skin, etc.) and special properties with protective functions (such as weather resistance, acid and alkali resistance, and oil resistance) . Good performance, and the characteristic performance with protection function, can be tested according to different use requirements, and the above two performance tests can be performed internationally.
The so-called color coated steel plate refers to the color coated steel plate, which is a kind of steel plate with organic coating. At present, color steel plate is widely used in the walls and roofs of large public buildings, public factories, movable plank houses and integrated houses. Identify the advantages and disadvantages of color steel plate, and observe the thickness of substrate and coating. Color steel plate is composed of substrate and color coating or coating. We must first consider the thickness of substrate and coating. A better color steel plate substrate is 0.02-0.05mm, and the coating or coating thickness is often less than 0.15mm. Because the thickness of the substrate is very important in terms of affecting the service time of the color steel plate. Some manufacturers make changes on the substrate and color steel plate coating or coating. They reduce the thickness of the substrate, but increase the thickness of the peritoneum to reduce the production cost of color steel plate, which greatly reduces the service life of color steel plate. Observe the leakage edge of the color steel plate. Of course, I think observing the leakage edge of color steel plate is also a relatively simple method. When we get a color steel plate, we can first observe whether the exposed steel of the color steel plate has fine crystallization, gray, dark and impurities.
If the section is fine crystalline, the quality is superior. The method of listening to sound is also relatively simple, that is, knocking the color steel plate with fingers or hard objects. If the material of the color steel plate is poor, the sound is dull and the metal sound is not obvious; The sound of color steel plate with good material is loud and crisp.
Be sure to pay attention to the solubility and temperature of the applied cleaning solution during the removal step of PPGI. If the cleaning solution is too low, the oil stains on the surface of the board will not be cleaned, resulting in disadvantages in the subsequent chemical coating treatment and damage to the quality of the coating; The surface layer of the zinc and aluminum layers in the solution simply constitutes saccharate, which causes worrying corrosion and then damages the molecular biology coating effect behind it.
Organic chemical cleaning fluids generally contain surfactants. The best way for various surfactants to create high efficiency is that there are differences in temperature. If the temperature is too high, the credibility of the surfactant will be reduced, which will reduce the ability of the cleaning fluid to remove oil stains; if the temperature is too low, the saponification reaction speed is too slow to completely eliminate the oil stains, which will cause more foam damage and removal. In addition, the temperature of the cleaning liquid is too high to accelerate the corrosion of the zinc and aluminum layers when the liquid is exchanged.
PPGI will have bubbles due to external factors, which not only affects welding, but also affects the aesthetics. Therefore, we need to avoid this situation as much as possible during welding. What is the cause of the bubble phenomenon of PPGI?
If the welding surface of the PPGI is not cleaned, it is very easy to cause the appearance of bubbles, such as the presence of oil stains, moisture and other ingredients. In this regard, we can solve this problem by cleaning the surface to be welded. Impure shielding gas can also lead to the production of bubbles. For this, 99.99% argon can be used to deal with this problem. If the electrode tip is exposed to the air, bubbles will also appear. Therefore, we must keep the end of the electrode under the protection of the rare gas when welding the PPGI.
The three methods introduced above can prevent bubbles from being generated during electric welding of color-coated plates. For the bubbles that have already appeared, we can directly use an angle grinder to grind them away.
The corrosion resistance of stainless steel coils decreases as the carbon content increases. Therefore, the carbon content of most stainless steels is low, up to 1.2%, and some steels have a low ωC (carbon content) of even less than 0.03% (such as 00Cr12). The main alloying element in stainless steel coil is Cr (chromium). Only when the Cr content reaches a certain value, the steel has corrosion resistance. Therefore, the goods Cr (chromium) content of at least 10.5%. Stainless steel coil also contains Ni, Ti, Mn, N, Nb, Mo, Si, Cu and other elements.
Most of the requirements for use are to maintain the original appearance of the building for a long time. In determining which type of goods to choose, the main considerations are the required aesthetic standards, the corrosiveness of the local atmosphere and the cleaning system to be used. However, other applications are increasingly seeking structural integrity or impermeability. Examples include roofs and sidewalls of industrial buildings. In these applications, construction cost to the owner may be more important than aesthetics, and the surface may not be very clean. The use of 304 stainless steel coils in dry interior environments is quite effective.
Weldability. Different product uses have different requirements for weldability. A class of tableware generally does not require weldability, even including some cookware companies. However, most products require raw materials with good weldability, such as second-class tableware, insulation cups, steel pipes, water heaters, water dispensers, etc.
Corrosion resistance. Most stainless steel coil products require good corrosion resistance, such as Class I or Class II tableware, kitchen utensils, water heaters, water dispensers, etc.
Polishing performance. In today’s society, stainless steel coil products in the production process are generally polished, only a few products such as water heaters, drinking fountains, etc. do not need to be polished. Therefore, this requires raw materials with good polishing performance.
1. The need for pre-treatment
Pretreatment is an important treatment step before the surface of stainless steel coil parts enter surface treatment (including pickling, chemical polishing and electrochemical polishing, electroplating, passivation, black coating, coloring, chemical treatment, etc.). During the forming process of goods parts, the surface may adhere to oil stains, burrs, rough surfaces and oxides. Therefore, before surface treatment, oil stains, burrs, uneven surfaces and oxides must be removed in order to obtain subsequent satisfactory results through processing.
2. Treatment of removed dirt
Stainless steel coil surface pretreatment in the need to remove the dirt can be divided into two categories: organic and inorganic substances.
(1) organic dirt. Including mineral oil (such as diesel, oil, paraffin, gypsum, etc.) and animal oil, vegetable oil (such as soybean oil, camellia oil, rapeseed oil, lard, butter, etc.). These oils are mainly from the stainless steel coil zero cattle processing process used in the lubricant. , cutting oil, quenching oil, polishing paste and polishing paste, and fingerprints.
(2) Inorganic dirt. Including dirt, dust particles, oxides and other contaminants generated during the heat treatment process.
3. Pretreatment steps for stainless steel coil parts
(1) The surface is mechanically leveled. Eliminate the roughness of the stainless steel coil surface, through mechanical polishing and grinding to achieve a surface finish.
(2) Degreasing. Remove the surface oil and dirt.
(3) Acid washing. Remove the oxides on the surface.
(4) Weak corrosion. Activates the surface to be treated, removes the surface passivation film, and exposes the metal crystal structure.
Stainless steel is a high-alloy steel, with a large resistance to rolling deformation. In order to carry out high-efficiency and high-precision rolling, rigid rolling mills should be used, generally multi-roller cold rolling mill.
Special welding process is also a feature of cold-rolled stainless steel coil production.
In the production process of cold rolled stainless steel coil, the raw material (hot rolled coil) should be annealed, intermediate annealing should be carried out in the cold rolling process, and the final product should be annealed, so annealing is an important part of the production.
Cold-rolled stainless steel is a high-grade steel products, there are strict requirements for surface quality. Not only are metallurgical defects caused by the previous process not allowed, but also obvious defects caused by the cold rolling process.