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PVC :

the long term

building materialJoël FumireResearch & Technology SBU Vinyls

São Paulo, 2005

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PVC in building

PVC is one of the most used plastics in building

Why ?

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PVC in building

Building means …

… Strength , see the rigidity modulus !

… weather resistance in all climates

… well adapted to specific use (e.g. pipes)

… Durability from 30 to > 100 years

… competitive cost !

… recyclable

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Comparison E Modulus

0500

100015002000250030003500

HDPE PP-H PP-C PP-Talc20

PVC-U

E Modulus (MPa)

0.000.501.001.502.002.503.003.50

HDPE PP-H PP-C PP-Talc20

PVC-U

Specific modulus (MPa/€/density)

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Rigidity in Sewage

Key property : annular stiffness. Directly related to the E-modulus of the material :

Stiffness : SN = K. E. I / D3

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Good Weathering resistanceUV-resistance :PVC can be formulated easily to be used on a long term basis in very

sunny climates

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PVC adapted for use : drinking water pipes

Key properties :

Pressure resistance No modification of the water

quality Long term durability

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PVC adapted for drinking water pipes

Key property : long term

pressure resistance

Rupture curves

0

10

20

30

40

50

1 10 100 1000 10000 100000 1000000hours

Ten

sio

n (M

Pa)

PVC-U

PE100

P

e

D

s

P = 2. s / (D/e -1)

50 y.

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PVC adapted for drinking water pipes

No modification of water quality :

No significant leaching of substances to the water No taste or smell transferred to water

PVC pipes comply with the requests of drinking water contact in the most severe regulations (CEE, NSF, BGVV, etc…)

Excellent resistance to bacteria growth

PVC is approved for drinking water transportation in the majority of countries

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Other key properties for PVC pipes

Chemical inertia towards many chemicals : Cleaning liquids, acids, No sensitivity towards oxidising substances

Good Fire resistance Among plastics, PVC is one of the most difficult to ignite. It is self-extinguishing

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PVC pressure pipes are in use since more than 60 years

PVC pressure pipes are designed theoretically for 50 years but can last more than 100 years

PVC Window profiles are used since more than 40 years and are still performing well

Durability

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Pressure pipes 60 years old – Dr Nowack study

Study realised in Germany : published in KRV (1995) by Dr. Nowack

PVC pipes were produced and installed in Bitterfeld in 1935-1940 with the technology available at that moment (physical, chemical)

Pipes from 1938 extracted from Bitterfeld

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Pressure pipes 60 years old – Dr Nowack study

Tests on these pipes show that : Burst-pressure curve is still linear with no "knee" Burst-pressure at 60°C is found still > 5 N/mm² after 600 h

Some of the pipes are still operating today at 20°C under 5.0 bar with satisfactory performance

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TNO study on residual lifetime of PVC pipes

Are 50 years old pipes to be replaced ?

Study was realised between 2002 and 2005 by the Dutch institute

TNO Science and Industry (A. Boersma & J. Breen)

Water pipes from the 1950's until today were excavated and extensively tested :

Pipe codeYear of

production /installation

Diameter (mm)

Vitens 59/200 1959 200Nuon 70/500 1970 500Hydron 75/315 1975 315Hydron 84/400 1984 400Brabant 97/160 1997 160Wavin 03/160 2003 160

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TNO study on residual lifetime of PVC pipes

Physico-chemical analysis :

The K values were close to 66 (1 exception at 72)

The level of gelation was between 38% and 80% (the pipes from the 1970's showed the lowest gelation)

Analysis of the transformation of the stabiliser system indicates negligible consumption (at room temperature)

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TNO study on residual lifetime of PVC pipes

Mechanical testing :

Craze initiation is affected by the physical ageing and by fatigue phenomenon

Burst pressures are still at a good level (and still compliant to ISO standard)

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TNO study on residual lifetime of PVC pipes

Main conclusions of this study are : No chemical degradation appears Gelation : seems to be correlated with craze initiation Fatigue could lead to an increased mechanical ageing Production and laying conditions induce additional

stresses in the material

The lifetime can be expected to be 100 years or more for high quality produced and installed pipes.

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Window frames since the 1970's

Window frames are installed since the 1960's

This window was installed in Germany in1972

and is still in operation after more than 30 years of good operation!

Usually PVC frames are not replaced because of damage

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Drinkable water piping

0

20

40

60

80

100

120

140

160

Costs in DM/m

Installation

Material

Competitive price : costs of piping systems (installation and assembling)

DN 100 DN 150 DN 200

PV

C-U P

E

Ste

el

Cas

t Ir

on

PV

C-U

PE

Ste

el Cas

t Ir

on

PV

C-U

PE

Ste

el

Cas

t Ir

on

So

urc

e :

DV

GW

19

98

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Recycling

Today in Europe > 7 000 t/y of PVC is recycled in pipes

For homogeneous rigid PVC, recycling is mainly a collecting process

For composite material (or heavily contaminated PVC) a special separation process has been developped :

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Recycling

PVC material can be extruded several times

The problem is the availability of recycled material since the articles installed in the 1970's are not available for recycling !

Thank you for your attention !