7 Way Judgment Method for HDPE Recycled Materials
More and more plastic pipes are used in our drinking water projects, such as PVC pipes, HDPE pipes, etc. Because drinking water needs very safe materials to transport, there will be higher requirements for the raw materials of the pipes.
As for the judgment of recycled plastics, we have always been concerned about it. There are various methods for judging recycled plastics and new material pipes.
Some of these methods are intuitive and simple, easy to operate, and can be judged intuitively from mechanical property data (such as melt index, impact, density, etc.); some are relatively complicated, requiring specific instruments and analysis (such as thermogravimetric analysis, infrared spectroscopy, DSC, etc. ), trace the root cause from the mechanism of the degradation of recycled plastic quality. Both methods play an important role in different application scenarios.
Today we will discuss some simple judgment methods, which are also widely used in daily engineering and are the mainstream methods in the current market. It is mainly judged from the results of physical and morphological characterization. Roughly from these seven aspects:
The closer to the raw material color, the more transparent the better the quality. As for the black recycled plastic material, the source of the base material is a mixture, and the price is relatively low.
The more vivid the color, the better the quality. The less miscellaneous the higher the vibrancy, those dull, dry recycled plastics are not of good quality.
3.Physical And Mechanical Properties
The aging degradation of recycled plastics, multiple high-temperature processing and melting plasticization, under the action of light, oxygen and high temperature, some polymers are oxidized, and the macromolecular chains are broken and degraded, which reduces the physical and mechanical properties, and the more regeneration times The performance drops more and more.
Judging from the length of the drawn wire after burning, the state of the smoke, and the speed of dripping, whether the shape of the wire is uniform, after a few times of drawing, overlap the wire, and pull it apart again to see if it is elastic. However, the smoke generated by combustion is harmful and this method is not recommended.
For recycled plastics with a density lower than water, you can use the principle of buoyancy to judge the amount of filling inside with water. However, it is difficult to judge plastics with a density greater than water, and it is necessary to adjust the density of the flotation liquid for judgment.
The more pores, the worse the quality of the material. Many pores are generally caused by too many mixed components, which lead to the volatilization of low-melting point materials or additives during processing. Some people may say that high moisture will also cause many pores. No, you must know that recycled plastics basically use double-stage For granulation, the moisture wrapped in the feed will be drained after it comes out of the first stage granulator.
Subjectively judge the pungentness of the particle smell, the bigger the smell, the worse the quality. Many pores are generally caused by too many mixed components, which lead to the volatilization of low-melting point materials or additives during processing. Some people may say that high moisture will also cause many pores. No, you must know that recycled plastics basically use double-stage For granulation, the moisture wrapped in the feed will be drained after it comes out of the first stage granulator.
Generally speaking, HDPE pipes produced from %100 Original Raw Material are smooth inside and outside, without pungent smell, and such pipes will be safer to use Pipes mixed with waste materials will have air bubbles on the surface, and the price is relatively cheap, so when selecting materials, you should verify it in many ways, and then confirm after actual inspection. （The Puhui HDPE Pipe Sample is attached below- %100 Original Raw Material）