How to buy Pre-painted Steel coil

There are many types of Pre-painted Steel coils on the market, and there are many Pre-painted Steel coil manufacturers with different levels. Therefore, when buying Pre-painted Steel coils, you can't just look at the price. Next, I will teach you how to distinguish the quality of Pre-painted Steel coils.

1. Observe the thickness of the substrate and the thickness of the coating

The Pre-painted Steel coil is composed of a substrate and a colored peritoneum or coating. We must first consider the thickness of the substrate and the peritoneal coating. The better Pre-painted Steel plate substrate is 0.02~0.05mm, and the thickness of the coating or coating is often only 0.15mm or less. Because from the perspective of affecting the use time of Pre-painted Steel plates, the thickness of the substrate is very important. Some manufacturers make changes in the coating or coating of the substrate and the Pre-painted Steel plate. They reduce the thickness of the substrate, but increase the thickness of the peritoneum to reduce the production cost of the Pre-painted Steel plate, which greatly reduces the service life of the Pre-painted Steel plate.

2. Observe the leakage edge of the Pre-painted Steel coil

When I get a Pre-painted Steel plate, I first observe whether the exposed steel of the Pre-painted Steel plate, such as the section, is finely crystallized, and whether it is gray, dark, or impurity. If the cut surface is a fine crystal, the quality is relatively superior.

3. Listen to the sound

Tap the Pre-painted Steel plate with your finger or with a hard object. If the material of the Pre-painted Steel plate is poor, the sound will be dull and the metal sound is not obvious. The metal sound of the Pre-painted Steel plate with better material is louder and crisper.

4. Check the quality certificate of the Pre-painted Steel plate

Whether there are inspection standards of relevant departments. If possible, try to visit the manufacturer of the Pre-painted Steel plate on the spot. See how the business environment is, whether it is formal or not. Find out what the reputation of this company is like in the market.

5. Look at the price

Everything is worth every penny. When we compare the quality of Pre-painted Steel plates, price is one aspect, but don't pay too much attention to price. If the price of a Pre-painted Steel plate is much lower than others, then we should pay attention.

The choice of the color of the Pre-painted Steel plate coating: The choice of color is mainly based on the matching with the surrounding environment and the owner's hobby, but from the technical point of view, the choice of pigments for light color coatings is large, and inorganic pigments with superior durability can be selected (such as Titanium dioxide, etc.), and the paint has a strong heat reflection (the reflection coefficient is twice that of dark paint). The temperature of the coating itself in summer is relatively low, which is beneficial to prolong the life of the coating.

In addition, even if the coating is discolored or chalked, the contrast between the light-colored coating and the original color after the change is small, and the impact on the appearance is small. Most of the dark colors (especially the brighter colors) are organic colors, which are easy to fade when exposed to ultraviolet rays, and change color in a short period of 3 months. For color-coated steel sheets, the thermal expansion rates of the coating and the steel sheet are usually different, especially the linear expansion coefficients of the metal substrate and the organic coating are quite different. When the ambient temperature changes, the bonding interface between the substrate and the coating will be Expansion or contraction stress occurs, and cracking of the coating can occur if it is not properly relieved.

In addition, I want to explain two misunderstandings in the current domestic market: one is that there are a lot of white primers in China. The purpose of using a white primer is to reduce the thickness of the topcoat, because normal architectural corrosion-resistant primers are yellow-green (hence the strontium chromate pigment) and must have sufficient topcoat thickness. The second is the color-coated steel plate used in construction projects. The same project uses color-coated steel plates from different Pre-painted Steel manufacturers and different batches. It seems that the color is the same during construction, but after several years of sunlight exposure, the color trends of different coatings and different manufacturers change. Different, resulting in serious chromatic aberration, there are too many such examples. Even for products from the same supplier, it is strongly recommended to place an order for the same project, because different batch numbers may use products from different paint suppliers, which increases the possibility of chromatic aberration.