PVC pipe

Features good tensile and compressive strength, but its flexibility is not as good as other plastic pipes, excellent corrosion resistance, the price is the cheapest in all kinds of plastic pipes, but the brittle connection at low temperature is bonding, inserting aprons Connection and flange thread connection are mainly used for residential life, industrial and mining, agricultural water supply and drainage, irrigation, gas supply, exhaust pipe, wire conduit, rainwater pipe, industrial anticorrosion pipe, etc.

CPVC pipe

Features outstanding heat resistance, heat distortion temperature of 100 ° C, excellent chemical resistance, joint bonding, flange thread connection, mainly used for hot water pipes

PE tube

Features light weight, good toughness, good low temperature resistance, non-toxic, cheaper price, high impact strength, but low compression and tensile strength. Connection method hot-melt welding, flange thread connection is mainly used for drinking water pipes, Rainwater pipes, gas pipes, industrial corrosion-resistant pipes

PP tube

Features Good corrosion resistance, good strength, high surface hardness, surface finish, and high temperature resistance. Connection method Hot-melt welding, flange thread connection is mainly used for chemical sewage, seawater, oil and irrigation pipelines. For indoor concrete floor heating system heating pipe

ABS tube

Features Excellent corrosion resistance, light weight, heat resistance higher than PE, PVC, but the price is more expensive. Connection type bonding, flange thread connection Mainly used for sanitary ware, down pipe, pipe, sewage pipe, underground cable pipe, high anti-corrosion industrial pipe, etc.

PB tube

Between the strength of PE and PP, the flexibility is between LDPE (LDPE: low density polyethylene) and HDPE (HDPE: high density polyethylene). Its outstanding feature is creep resistance (cold deformation), repeated winding Constant, temperature resistance, chemical properties are also very good. The way of hot-melt welding and flange thread connection is mainly used for water supply pipes, hot and cold water pipes, gas pipes, underground high pipes.

GRP tube

Excellent corrosion resistance, light weight, high strength, good design performance. Connection method: ferrule connection, flange connection, petrochemical pipeline and large diameter water supply and drainage pipeline

How to identify PP pipe?

1. “Touch”: Whether the texture is fine and the particles are even. Nowadays, PPR pipes on the market mainly have white, gray and green colors. Under normal circumstances, recycled plastics can't be white, so consumers tend to think that white is the best. In fact, this view is one-sided. As the technology is updated, color is not the standard for distinguishing PP-R tubes. The quality of the tube is not able to solve the problem. Touching it, the coarse particles are likely to be mixed with other impurities.

2. "Smell": There is no smell. The main material of the PP-R pipe is polypropylene. The good pipe has no odor, and the poor one has a strange smell. It is very likely to be blended with polyethylene instead of polypropylene.

3. "Pinch": PP-R tube has a considerable hardness, and can be squeezed into a deformed tube, certainly not a PP-R tube.

4. "Pound": A good PP-R tube, "rebound" is good, too easy to smash naturally is not a good PP-R tube. However, the hardness is not equal to the elasticity. If the PP-R tube is not broken, the consumer should have doubts. Because some unscrupulous manufacturers increase the hardness of the pipe by adding too much impurities such as calcium carbonate, such a pipe is prone to brittle cracking for a long time.

5. "burning": Ignite and burn, it is very intuitive and very useful. The PP-R tube, which is mixed with recycled plastic and other impurities, will emit black smoke and have a pungent smell. After burning, the good material will not emit black smoke or odor. After burning, the molten liquid will still be clean.

How to identify PVC?

The conventional PVC identification methods are generally classified into the following three categories, namely:

1. Identification of combustion method:

Softening or melting temperature range: 75~90 °C;

Combustion: difficult to soften;

Burning flame state: there is smoke on the yellow and green; after the fire: off from the fire; smell: irritating sour.

This method is the easiest and straightforward and is generally preferred.

2, solvent treatment identification:

Solvent: tetrahydrofuran, cyclohexanone, ketone, dimethylformamide;

Non-solvent: methanol, acetone, heptane.

By adding suspected PVC plastic to the above solvent, observe the dissolution of the plastic to determine whether it is PVC. After the solvent is heated, the dissolution effect will be more pronounced.

3. Proportion method:

The specific gravity of PVC is 1.35~1.45, which is generally around 1.38.

Polyvinyl chloride and other plastics can be distinguished by differences in specific gravity or by specific gravity.

However, because PVC can add plasticizers, modifiers and fillers, the PVC becomes very different in specific gravity, and the difference between soft and hard is great. At the same time, many properties of PVC plastics are changed due to the addition of some components, resulting in The commonly used identification method is not effective, and even the phenomenon changes, and it is impossible to make an accurate judgment. For example, in terms of density, plasticized polyvinyl chloride (about 40% plasticizer) is 1.19~1.35; while PVC hard products are increased to 1.38~1.50. In the case of highly filled PVC products, the density sometimes exceeds 2.

4. Determine by determining whether the material contains chlorine.

In addition, it can also be determined by measuring whether or not chlorine is contained in the material, but since vinyl chloride copolymer, neoprene, polyvinylidene chloride, chlorinated polyvinyl chloride, etc. all contain a relatively high proportion of chlorine, color development by pyridine is also required. Reaction to identify. Note that before the test, the sample must be extracted with diethyl ether to remove the plasticizer. Test method: The sample taken with diethylbenzene is dissolved in tetrahydrofuran, the insoluble component is filtered off, and methanol is added to precipitate it. Dry below the degree. A small amount of dried sample was reacted with 1 ml of pyridine. After a few minutes, 2 to 5% sodium hydroxide in methanol (1 g of sodium hydroxide dissolved in 20 ml of methanol) was added, and the color was observed immediately, 5 min. And observe again after 1h. Different chlorine-containing plastics can be identified based on color.

In daily life, the more contact you need to distinguish between PVC and PE plastic film (bag), simple method:

Touch method

It feels lubricated by hand, and the surface is coated with a layer of wax (chemically called waxy), which is a non-toxic polyethylene film bag, while the polyvinyl chloride film is somewhat sticky to the touch.

2. Jitter method

The hand is shaken, the sound is brittle, and the quality is easy to float is a polyethylene film bag. The low-pitched sound is a polyvinyl chloride film bag.

3. Combustion method

It is flammable in case of fire, the flame is yellow, there is paraffin-like oil dripping when burning, and there is a gas when the candle burns. It is a non-toxic polyethylene film bag. If it is not easy to burn, it will be extinguished when it leaves the fire. The flame is green and it is a PVC film bag.

4. Immersion method

After immersing the plastic bag in water and pressing it into the water, the polyethylene that can float out of the water surface is polyvinyl chloride (the density of polyethylene is less than water, and the density of polyvinyl chloride is greater than water; respectively, at room temperature is about 0.92 g/cm3 and 1.4 g/cm3).

It is also possible to take a copper wire and burn it red in a fire. Then, the copper wire is brought into contact with the test plastic film to cause a chemical change, and the copper wire with the plastic component is put back into the flame. At this time, it is necessary to observe carefully. If there is a colorful and dazzling green flame, it means that the plastic material contains chlorine and belongs to the polyvinyl chloride material.