Polyvinyl chloride (PVC) is the biggest characteristic of flame retardant, so is widely used in fire protection applications.But the polyvinyl chloride (PVC) in the process of combustion will release hydrogen chloride and other toxic gases, such as dioxin.
Polyvinyl chloride (PVC) combustion can be divided into two steps.In 240 ºC to 340 ºC before burning decomposition of hydrogen chloride gas and alkadiene contain a double bond, and then in 400-470 ºC carbon burning.
PVC formability:
1. Amorphous materials, hygroscopicity, liquidity is poor, in order to improve the liquidity, prevent bubbles and appropriate drying in advance.
2. Easy to decompose, especially at high temperature in contact with the steel and copper are more likely to break down decomposition temperature (200 degrees c).Molding temperature range is small, must be strictly controlled temperature for the material.
3. Use of screw injection machine and direct the nozzle aperture should be larger, in case of blind Angle hysteresis material.
4. Mould gating system should be thick, the appropriate gate section, mould should be cooling, mould temperature 30 to 60 degrees, the material temperature 160-190.UPVC profile:
UPVC is also called the hard PVC, it is made by the polymerization of vinyl chloride monomer and amorphous thermoplastic resin with certain additives (such as stabilizer, lubricant, filler, etc.).
In addition, using additives used with other resin blend modification method, has the obvious practical value.These have CPVC resin, PE, ABS, EVA, MBS, etc.UPVC high melt viscosity, liquidity is poor, even increase injection pressure and melt temperature, the change of liquidity are slim.
In addition, the forming temperature and the thermal decomposition temperature of the resin is very close, capable of forming temperature range is very narrow, is a kind of difficult to molding material.
Features introduced:
1, light weight, convenient transportation and handling:
PVC pipe material is very light, handling, construction is convenient, the artificial can be saved.
2, good chemical resistance
PVC pipe with excellent acid, alkali resistance, corrosion resistance, is quite suitable for the chemical industry to use.
3, small fluid resistance
PVC pipe wall smooth, fluid resistance small, its roughness coefficient of only 0.009, is lower than other pipes, under the same flow rate, pipe diameter can be narrowed.
4, large mechanical strength
Outside of the PVC pipe resistance to water pressure strength, compressive strength, good resistance to impact strength, etc., are suitable for all kinds of conditions of the piping engineering.
5, good electrical insulation
PVC tube full of excellent electrical insulation, is suitable for wire, cable ducts, piping and building on the wire.
6, do not affect water quality
PVC pipe by dissolution test confirmed that does not affect the water quality, the best tube for the tap water piping.
7, construction simple
PVC pipe joint construction of easy quickly, so the project construction cost is low
Applicable occasions:
1)Water supply engineering
2)Electrical engineering
3)Construction engineering
4)Ground water engineering
5)Telephone engineering b
6)Well drlling engineering
7)Salt water engineering
8)Gas supply engineering
9)Chenmical factory
10)Paper mill
11)Acidifying∽Fermenting plant
12)Electroplating groend
13)Agricultual plant
14)Mining plant
15)Supply
16)Free way engineering
17)Golf course engineering
18)Fishery use for plastic raft
Suitable temperature: is not more than 40 degrees (cold water pipe)
Usage: water supply pipe (not drink);Rain pipes etc.
Similar contrast:
UPVC pipe and PE pipe are thermoplastic plastic tube, they share a common feature of side, but in the loft.Heat resistant requirements.Anti-aging and other technical features also have difference.Now the UPVC pipe and PE pipe technical characteristic analysis is as follows:
UPVC compared with PE pipe performance:
The types of pipe Faults UPVC corrosion resistance is strong, easy to connect, and cheap, hard.Does not apply to hot water, joint adhesion high technical requirements, curing time is longer than the other.HDPE is qualitative light, good fatigue strength, good temperature resistance, good toughness and flexible Welding need power;Mechanical connection fittings price is more expensive.
