Polypropylene (PP) belongs to the Polypropylene is a thermoplastic
from the polyolefin group. PP is a semi-rigid, translucent polymer
with good toughness and weather resistance properties. It has low
water absorption and is easily moulded as low cost. Polypropylene
is a largely non-polar, partially crystalline thermoplastic with a
crystallinity of 60 to 70%. PP has a density of 0.90 to 0.91 g/cm3
which is amongst the lowest densities for all plastics. PP has a
non-swelling and insoluble surface; and is characterized by its
outstanding chemical resistance, high thermal resistance and good
fatigue strength. |
| Its superior qualities and cost efficiency makes it a popular
material of choice over Polyethylene (PE) and Polyvinyl Chloride
(PVC) in industrial uses and also commercial uses.Due to its
excellent thermal stability, PP can be used successfully even at
1000C. |
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It shows superior impact strength as compared with PVC. PP is
normally available in grey color and its high rigidity makes
visually pleasing pipe layouts possible and the lower coefficient
expansion makes installation easier. |
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It is generally available in three forms for use in pipelines PP-
Homopolymer (PP-H), PP-copolymer (PP-C) and PP Random Copolymer
(PP-R). Other options in PP include fire retardant grades &
electro-conductive grades. PP can also be UV stabilized by use of a
stabilizer and can be produced in black color. |
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Various types of commercially available PP includes the following: |
PP- Homopolymer (PP-H) : | | | | PP - Homopolymer is produced by a continuous chain of polypropylene
units which results in a high stiffness material. Mostly popular in
grey colors only. Advanced homopolymer types like beta nucleated
PP, are widely used to make piping systems. |
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PP- Block copolymer (PP- B) : | | | | PP- Block copolymer (PP - B) Produced by adding 4-15% ethylene to
the polypropylene gives much improved impact strength and
considerably lowers the brittle point such that it is well below
normal service temperatures i.e. -15 to -20oC. Material is
available in natural & grey colors. |
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PP Random Copolymer (PP-R) : | | | | Random copolymer PP typically contains between 1 and 7 wt.-% of
ethylene molecules and 99 to 93 wt.-% propylene molecules. The
ethylene molecules are inserted randomly between the propylene
molecules in the polymer chain. Random copolymer polypropylene is a
clear, semi-crystalline polymer which exhibits high stiffness,
better impact strength and good electrical insulation properties. |
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PP Fire retardant (PPFR) : | | | | PP is enhanced by additives to limit its oxygen index. Available in
V0, V1 & V2 classifications. |
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PP Electro-conductive (PP- Cond) : | | | | Also another type enhanced PP, developed especially for use
application may require earthing of the piping system. | Top |
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