1、 "Look" appearance.
Good color. The PP-R water pipe produced by Shanghai gongjinniu has soft, uniform and uniform color without mottled color. PP-R pipes are mainly white, gray, green and yellow. Consumers often think that white is good. In fact, the color is not the standard to judge the quality. In fact, the quality of PP-R pipes has nothing to do with the color of PP-R pipes. Plastic particles are mainly white and transparent (there are also other colors added with color masterbatch). As long as the color masterbatch is added, any color can be produced, and the color masterbatch will not be decomposed and will not change the quality of pp-r. therefore, it doesn't matter what color the water pipe is. According to the regulations, PP-R water pipe should have good light closing performance. In this regard, gray or other light tight properties will be better. However, such advantages only exist in the open pipe installation and pipe well. All the water pipes of home decoration are buried, so there is no saying that gray is better than other colors
PPR water pipe is completely opaque, and pseudo PP-R pipe is slightly transparent or semi transparent. Generally, white products can only be produced with pure PP-R raw materials. For example, the color of products produced by adding recycled materials, waste materials and corner materials is neither soft nor uniform, while the color of other color products processed with color masterbatch will not be affected by adding recycled materials, waste materials and corner materials. This is why many manufacturers who pay attention to quality mainly focus on home decoration retail, and their products are mainly white; The internal and external surfaces of the product shall be smooth and flat, and there shall be no bubbles, obvious depressions, grooves, impurities and other defects.
2、 Touch texture.
Good PP-R pipes are 100% PP-R raw materials (without any additives). The texture is pure, the surface is smooth, and the feel is soft. The feel of pseudo PP-R pipes is smooth. Generally speaking, the coarse particles are likely to be mixed with impurities;
3、 "Smell" the smell.
The main material of PP-R pipe is polypropylene. Good pipe has no smell, while poor pipe has strange smell. It is likely to be mixed with polyethylene rather than polypropylene;
4、 "Pinch" hardness.
PP-R tube has considerable hardness. It can be easily pinched and deformed. It is certainly not PP-R tube;
5、 "Measure" wall thickness,
In addition, vernier caliper can be used to measure whether the pipe wall thickness meets the standard and is uniform. Generally, good pipes are produced in strict accordance with the national standard, but this method requires a certain understanding of the national standard of PP-R pipe.
6、 "Listen" to the sound.
The landing sound of PP-R tube is dull, and the landing sound of pseudo PP-R tube is crisp.
7、 "Smash" elasticity.
A good PP-R pipe has good "resilience" and is easy to break. Naturally, it is not a good PP-R pipe, but the best PP-R pipe can be broken when the temperature is lower than 10 degrees. However, strong hardness does not mean good elasticity. Some manufacturers improve the hardness by adding too many impurities such as calcium carbonate, which can not be broken and is easy to crack after long use; (due to the cold brittleness of PP-R raw materials, the properties are different in several temperature ranges: 10, - 5, - 23)
8、 "Burn" smoke smell.
The PP-R tube mixed with recycled plastics and other impurities in the raw materials will emit black smoke and pungent smell. Good materials will not emit black smoke and smell after combustion, and the molten liquid is still very clean after combustion. (you can also "pull" to see its "length")
9、 "Melting".
The normal welding temperature of PP-R pipeline during welding is in the range of 260-290 ℃, and the welding quality will be well proved during welding within this temperature range. If the product can easily enter the welding die head during welding under normal welding parameters, and the welding accumulation tumor is close to liquid, it indicates that the product is not produced by authentic PP-R raw materials, At the same time, if the welding accumulation tumor can be cooled and hardened quickly (generally within 10 seconds), it can also indicate that the product is not produced by authentic PP-R raw materials. This is because one of the characteristics of PP-R is that the thermal insulation effect is good, and its cooling speed will naturally be slow. See whether the inner diameter of the pipe is deformed and whether the pipe fittings are brushed. Good PP-R pipe cannot be brushed and the inner diameter is not easy to be deformed.
10、 "Check".
Use test instruments to detect and effectively distinguish the advantages and disadvantages of products. Several important test requirements data are specified in the national standard, such as pipe aging resistance test (the test that will not fail for 8760 hours when the ring stress is 1.9mpa and the test temperature is 110 ℃), pipeline system stability test (5000 cold and hot cycles) and impact resistance test. Therefore, users can ask manufacturers or businesses to provide the above test report for verification. In addition, it should be pointed out that the national standard also has an important requirement for the raw materials used for pipes and fittings, that is, the melt index. The national standard requires that the change value of the melt index before and after processing should not exceed 30%, and there is also a requirement in the industry that the melt index of raw materials should not be greater than 0.5g/10min