Now more and more producers choose to co-extrude the hollow sheet with UV protection layer (UV layer). Many manufacturers now claim that their products are co-extruded with the UV layer. The UV layer and the anti-fogging layer can self-identify ultraviolet rays as a key factor leading to the aging of the board. But whether the UV layer can really exert its effect, consumers simply cannot investigate. The UV layer of a good plastic hollow board cannot be weighed by the thickness alone
The amount depends on the uniformity of the co-extrusion, and a hollow board with good UV layer thickness and uniformity should be selected. In view of the phenomenon that some UV materials are not added at all but are posing as co-extruded UV-layer hollow boards in the market.
According to Corrugated Plastic Bottle Boxes Manufacturers , if black spots or crystal spots appear on the plastic hollow board, it indicates that it contains impurities. It mainly depends on whether there are impurities in the hollow board. The more the impurity content, the more the old material content. A good plastic hollow board must be clean and translucent. The quality of the materials used can also be judged by investigating the fluidity of the hollow plate melt. Due to the long molecular chain of carbonate resin, its molecular structure will be destroyed when it is repeatedly melted at high temperature, and it will be degraded from large molecules to small molecules. The old material has to be re-melted at high temperature, and its molecular chain will be broken, thereby increasing its fluidity. Therefore, theoretically, the better the fluidity of the material in the molten state, the worse its quality. Although this method is easy to understand in theory, it is still difficult to operate. Users who do not have the testing conditions can send the hollow board materials to a professional organization for testing.