1. Touch: Whether the texture is delicate and the particles are uniform. The quality of the tube does not solve the problem. If you touch it, the coarse particles are likely to be mixed with other impurities.
2. Burning: It is intuitive and useful when it is fired. Glass fiber tubes mixed with recycled plastics and other impurities in the raw materials will emit black smoke and have a pungent odor; after a good material is burned, it will not emit black smoke and odorless, and the molten liquid is still very clean after burning.
3. Smell: smell or not. Good pipes have no odor, and poor ones have strange odors. It is likely that they are blended with polyethylene (ie, PE) instead of polypropylene.
4. Smashing: A good fiberglass tube has good "resilience". It is too easy to smash because there are too many calcium carbonate fillers, which is naturally not a good fiberglass tube. The glass fiber tube that cannot be broken is not necessarily a good tube. The key is to look at the raw materials and processing technology.
5. Pinching: The glass fiber tube has considerable hardness, and it can be squeezed into a deformed tube at will. It is definitely not a PPR tube.
