HPL is an abbreviation for high-pressure-laminate and a simple name for phenolic compact laminate. There are many problems that international buyers are worried about when purchasing HPL, but the main ones are as follows:
- Quality of HPL sheet
- The color of the HPL plate
- Delivery time
- Tariff rate
- Transportation costs
Among them, the buyer is most concerned about the quality of HPL plates. So how can we distinguish high-quality and low-quality HPL sheets from the HPL industry with diverse prices and uneven quality without a professional laboratory? Next, let me talk to you about my experience.
There are many kinds of surface colors for HPL, and many manufacturers also accept custom HPL surface color customization. Therefore, we can not judge the quality of HPL sheet by the surface color of HPL sheet, because that is only the color of the surface, the factor that really affects the quality of the sheet comes from its core. The core quality of HPL sheets determines most of the resistance to bending and acid and alkali corrosion.
Most international buyers do not send HPL products to the laboratory for testing every time they purchase, which requires buyers to have a simple way to identify the quality of the product.
How do we know the core of the HPL sheet? We need to visually observe the color of the HPL plate sample incision to determine the core quality of the HPL plate. The core of HPL sheets generally has two colors, one is brown – this is the true color of phenolic compact laminates. Another color is black – this is the color of the phenolic resin board with black carbon added.
As for why black carbon is added, the HPL board has a black edge for two reasons: one reason is the aesthetic need, and the black edge is liked by customers. Black edges may be better matched to the environment. Another reason is that HPL sheet producers are deliberate. Some HPL sheet producers do not produce HPL sheets with 100% phenolic resin and 100% natural wood kraft paper. Instead, they use partial urea-formaldehyde resin and recycled kraft paper to produce, so the color of the edge of the HPL sheet cut is turbid brown or gray. This color is not aesthetically pleasing, and it can be intuitively judged that this is a cheap product. In order to make the edge of the phenolic resin board look better, most of the manufacturers of such HPL sheet added black carbon in the process of producing the board, which makes the edges appear black and mask the ugly color of the cut.
So is it that we can’t determine the quality of the board by observing the color of the edge of the HPL sheet? The answer is that we can also judge the quality of the raw materials of the board by carefully observing the details of the black edges. If the raw material for making HPL sheets contains recycled kraft paper, the edges of the black cuts will generally have scattered white dots. These white dots come from recycled kraft paper. We know that recycled paper is remanufactured from a variety of waste papers, so it contains a lot of impurities, some are bleached white paper slag, these ingredients are left in recycled kraft paper. The recycled kraft paper is the raw material for the cheap HPL sheet, which is of course reflected in the incision of the HPL sheet. Therefore, the HPL sheet with black edges can also judge the quality of the raw material kraft paper used by the naked eye. Thereby determining the quality and price of the board.
In addition to visually observing the color of the HPL sheet incision to judge the quality of the product, we can also judge the quality of the product by touching and bending. In general, the edge of the HPL sheet of 100% phenolic resin is smooth and round, without roughness. Of course, the large streaks caused by the sawing saw are not considered rough. If the quality of the HPL sheet is not judged by the smoothness of the edge of the cut, we can also judge it by bending experiments. In general, high-quality HPL sheets have good toughness and are not easily broken during bending. However, inexpensive HPL sheets are less resilient than high-quality HPL sheets and are more susceptible to breakage during bending.
If we want to know more about the quality of HPL plates, we can also judge by boiling test. A 10*15 cm HPL plate sample was placed in boiling water. After 2 hours of boiling, the deformed or cracked panels are relatively low-quality HPL sheets. Plates that are not significantly deformed or cracked are high-quality HPL sheets. Because water resistance is an important property of HPL sheets, the 2-hour boiling water cooking experiment is a simulation of long-term reality.
There is also a poor quality HPL sheet that we can visually recognize. This kind of board is called “second generation HPL” in China, which is actually a derogatory term. This plate should not be called HPL in my opinion, because it is not at all. In this type of sheet, it is almost impossible to find the composition of the phenolic resin, which is almost entirely made of a part of urea-formaldehyde resin or other chemical components. This kind of board is soft and very crisp, and the incision can feel obvious roughness. Its density is generally less than the density of HPL sheets, but the price is very low, only 1/3 of the price of the HPL sheet. This “fake HPL sheet” is generally used for low-grade toilet partitions. The demand for such boards in Southeast Asia is rising because it is too cheap.
If you want to know more information about HPL made in China, you can send an email to me: [email protected]