Upload
nguyenhuong
View
275
Download
7
Embed Size (px)
Citation preview
CHAPTER 1: INTRODUCTION TO POLYVINYL CHLORIDE
Polyvinyl chloride (PVC) was first manufactured in Germany in 1931 as a robust and lightweight new plastic. This breakthrough material was brought about to substitute for metals, glass, wood, natural fibers, papers and fabrics. Over 30 million tons of PVC is used around the globe today, both in industrialized and developing countries, due to its cost efficiency, durability, self-extinguishing properties, processability, and resources saving features.
Owing to its safe, healthy, convenient and aesthetical advantages, PVC products support daily life in a wide variety of fields including urban infrastructures, electronic products, and consumer goods.
For example, PVC can be found in public lifelines such as water supply, sewage pipes, or power lines. It is also used in building materials such as sidings, furniture, spouts, window profiles, flooring, decking boards, and roofing sheets. Agricultural and industrial applications include green house sheets, semi-conductor cleansing facilities, exhaust ducts, and parts for automobile and home electrical appliances. Consumer products include food wraps, synthetic leather and stationery. As you can see, PVC, or polyvinyl chloride/vinyl chloride resin, is a raw material used in a vast range of applications.
General information on PVC is provided here in Chapter 1, followed by introductions on four aspects of PVC; production, characteristics, safety and applications.
Thermosetting resin
Fig.1-1 Synthetic resin and their raw materials
Source: "Dictionary of plastics in use", Industrial Research Center of Japan, Inc. Production Goods Work Station (1993)
Thermoplastic resin
Raw material (monomers)Vinyl chloride monomer (Vinyl chloride: VCM)
Ethylene
Propylene
Styrene monomer
Acrylonitrile/Butadiene/Styrene
Bisphenol A/Carbonyl chloride
Hexamethylenediamine/Adipic acid
Methyl methacrylic acid
Ethylene/Terephthalic acid
Phenol/Formaldehyde
Melamine/Formalin
Caprolactam/Hexamethylenediamine
Trienediisocyanate/Propylene glycol
Bisphenol A/Epichlorohydrin
Dimethylsiloxane
Maleic anhydride/Styrene monomer
Synthetic resin (polymers)Polyvinyl chloride (PVC)
Polyethylene (PE)
Polypropylene (PP)
Polystyrene (PS)
Acrylonitrile-Butadiene-Styrene Resin (ABS)
Polycarbonate (PC)
Polyamide resin (PA:Nylon)
Methacrylic resin (PMMA)
Polyethylene terephthalate (PET)
Phenol resin
Melamine resin
Polyamide resin (PA : Nylon)
Polyurethane (PU : Urethane resin)
Epoxy resin
Silicone resin (SI)
Unsaturated polyester resin (FRP)
2
CHAPTER 1 : INTRODUCTION TO POLYVINYL CHLORIDE
■ A thermoplastic resinPlastics are also called synthetic resins and are
broadly classified into two categories; thermosetting resins and thermoplastic resins(Fig.1-1). The thermosetting resins include phenol resin and melamine resin, which are thermally hardened and never soften again. Thermoplastic resins include PVC, polyethylene(PE), polystyrene(PS) and polypropylene(PP), which can be softened again by heating.
Usually, thermoplastics are supplied in the form of pelletized material (compounds) with additives (anti-oxidants, etc.) already blended in it. However, PVC is supplied in powder form and long term storage is possible since the material is resistant to oxidizing and degradation. Various additives and pigments are added to PVC during the processing stage, and then molded and fabricated into PVC products.
PVC is better known as bineel (vinyl) in Japan. This is due to the fact that PVC products, in the form of films or sheets, were widely used among the public after World War II, and these products were simply called bineel. When these PVC products that are soft to the touch first landed Japan, where only rigid thermosetting resins had been known, they left a very strong impression among the population. This is how bineel mistakenly became a synonym for all soft films including polyethylene films.
■ A safe synthetic resin made fromvinyl chloride monomers (VCM)
Most synthetic resins are made up from single molecule units, called monomers. Through a chemical
reaction known as polymerization, these single molecules are branched into long chains to form polymers (which are also called macromolecules). PVC is also a type of polymer made from VCM through polymerization (Fig.1-1).
Some monomers exist in the form of unstable gaseous chemical substances, and some of these may cause health hazards when in direct contact with humans. In these cases they are manufactured and processed under strict control for safety. On the other hand, polymers, which are manufactured from monomers through polymerization, are solid and chemically stable substances, therefore do not affect human health. VCM, which is the raw material for PVC, is a high-pressure gas that can pose risks on human health such as carcinogenicity, but PVC does not have such carcinogenicity.
As you can see, plastics possess completely different chemical properties before and after polymerization. Since names of these substances sound unfamiliar, misunderstandings tend to occur regarding their attributes and safety. Also due to the fact that the Japanese terms Enbi polymer (PVC) and Enbi monomer (VCM) are both frequently called Enbi, there has been further confusion in Japan.
One example of such confusion is an erroneous report made in Japan on February 2003, which ran "Carcinogenic Enbi (PVC) emissions into the air and soil" - this of course, is a serious misunderstanding.
■ Resource saving and fire resistantproperties
Only 40% of PVC's composition is petroleum-
1. What is PVC?
2. Production of PVC
3
derived. PVC is less dependent on petroleum, which is a natural resource that may one day be depleted. Therefore PVC can be regarded as a natural resource saving plastic, in contrast to plastics such as PE, PP and PS, which are totally dependent on petroleum.
Also, PVC contains components derived from industrial grade salt. Thus, PVC is a fire resistant plastic with properties of chlorine containing substances. When PVC is set on fire, the flames go out as the fire source is removed due to its self-extinguishing properties.
■ One of four major plastics with the longest historyPlastics production in Japan for 2007 was
approximately 15 million tons, out of which 70% is represented by PE, PP, PVC and PS (Fig.1-2). PVC is a general purpose plastic with the longest history in industrial production both domestic and abroad.
Due to its low price, excellent durability and processability, PVC became widely used since around 1948 in commonplace consumer applications, such as air inflated toys including floats and beach balls, films and sheets such as raincoats, bags, containers, or synthetic leather in the form of shoes, hand bags and furniture surfaces. Around that time, PVC began to be used for electrical wire covering. Today, PVC is widely used within civil engineering and construction materials that require durability. Examples include drinking water and sewage pipes, optical fiber protective pipes, wallcovering, flooring, window profiles (PVC saches), and furniture.
■ Contributes to energy saving and reduces CO2 emissions
Production of PVC requires little energy due to
the manufacturing process of its raw material, VCM. According to the results of survey by the Plastic Waste Management Institute, PVC requires only about 70% of energy required for production of other plastics. This means less CO2 emissions occur from production processes, thus contributing to the prevention of global warming.
Furthermore, as PVC products have the required strength, durability, and low thermal conductivity, its heat-insulating efficiency is three times as high as that of metal such as aluminum when used as window profiles and siding boards. Therefore consumption of fossil fuels such as petroleum can be cut back, which contributes to further reduction of CO2 emissions.
(1) Linkage of PVC related industries
■ Upstream of the PVC industry (the basic petrochemical industry, the soda industry)※ Ethylene and chlorine are raw materials for PVC.
Therefore, industries positioned upstream of the PVC industry are the basic petrochemical industry, which supplies ethylene, and the soda industry, which supplies chlorine.
※ By thermal cracking of naphtha, the basic petrochemical industry manufactures ethylene and propylene, etc. Naphtha is mainly supplied from the petroleum refinery industry, which uses imported crude oil as raw material.
※ The soda industry produces caustic soda, chlorine
and hydrogen via electrolysis using industrial grade salt as main raw material.
■ The PVC industryThe PVC industry produces an intermediate raw
material called ethylene dichloride (EDC) using ethylene and chlorine, the former of which is supplied by the basic petrochemical industry and the latter being supplied by the soda industry. EDC is then thermally cracked to produce VCM. Finally, VCM is polymerized to produce PVC (Fig.1-3).
Naphtha :Crude oil is heated for refining at the refinery to obtain heavy oil, light oil, kerosene, gasoline, naphtha fractions, and LP gas. Naphtha is transferred to petrochemical plants, where ethylene, propylene, butylene etc. are obtained by thermal cracking.
22.1%30.0%
70.0%
21.1%12.0%
14.8%
100%
Fig.1-2 Production ratio of four major plastics (2007)
PE (total of HDPE and LDPE)
Total plastics 14.61
million tons
Other
PVC
PP
PS (including ABS and AS)
Total of fourmajor plastics
Source: "Yearbook of Chemical Industries Statistics 2007", METI
4
CHAPTER 1 : INTRODUCTION TO POLYVINYL CHLORIDE
■ Downstream of the PVC industry (the PVC converter industry)
PVC is supplied downstream to the PVC converter industries, where various additives including stabilizers and plasticizers are blended, of which are then converted by extrusion molding and calendering. Resulting products are further fabricated into construction and civil work materials, agricultural and industrial materials, parts for the assembly industry,
and consumer products. The PVC industry and the PVC converter industry
are closely associated with each other, and in some cases, both are called the PVC industries collectively. According to a rough calculation of the industrial statistics for 1998, the number of businesses is 4,600; the number of employees is 72,000, and the shipped value amounts to ¥1.5 trillion, or 15% of the total shipment value of all plastics.
(2) Production process of raw material for PVC (VCM)
VCM is a high pressure gas with a molecular weight of 62.5 and boiling point of - 13.9℃ , therefore it is manufactured under strict quality and safety control.
There are two ways to manufacture VCM; the direct chlorination method and oxychlorination method. Under the direct chlorination method, ethylene (obtained from thermal cracking of naphtha) and chlorine (obtained from electrolysis of salt) reacts within a catalyst-containing reactor to form the intermediate material EDC. EDC is then thermally
cracked to yield VCM at a few hundred ℃ (① in Fig.1-4).
When the hydrogen chloride obtained as by-product from the above method reacts with ethylene in the presence of catalyst and air (or oxygen), EDC is obtained again. This is called the oxychlorination process (② in Fig.1-4). When EDC from the oxychlorination process is dehydrated and then thermally cracked (likewise with the EDC from the direct chlorination process), VCM is obtained.
These two methods are combined thus at the major VCM plants in Japan. Fig.1-5 is a flow chart of VCM manufacturing processes shown in Fig.1-4.
EDC PVC
Fig.1-4 VCM production method
②Oxychlorination
①Direct chlorination
Ethylene
Air (Oxygen)
Ethylene Chlorine
EDC
Hydrogen chloride Thermal cracking
Thermal cracking
Polymerization VCM
Source: Prepared from material by the Japan Petroleum Institute (JPI)
Fig.1-3 Linkage of PVC related industries
Naphtha NaphthaPetroleum
Petroleum refiningindustry
Sea water
Rock saltSalt industry
(Installation, Assembly, Consumption)
End user industry, Consumer
●Upstream
Basic petrochemical industry
EthyleneEthylene
(Electrolysis)
PVC industryIndustrialgrade salt
Industrialgrade salt
Caustic sodaChlorine
Soda industry
EDC VCM PVC PVCindustries
Chlorine
(Processing Fabrication)
PVCPVC productsPVC converter industry
●Downstream
5
(3) PVC production processes
Generally, the suspension polymerization process is adopted to manufacture PVC. First, the raw material VCM is pressurized and liquefied, and then fed into the polymerization reactor, which contains water and suspending agent in advance. Through high-speed agitation within the reactor, micro particles of VCM are obtained. Next, the initiator for polymerization is fed into the reactor, and PVC is produced by reaction under a few atmospheric pressures at 40 - 60℃. PVC obtained through suspension polymerization is
suspended in water as micro particles of 50~200 µm diameter (in slurry form). Therefore, slurry discharged from the polymerization reactor is dehydrated, dried and the particle size matched by screening to yield PVC in the form of white powder. The unreacted VCM is entirely recovered through the stripping process, and after refining, recycled as raw material for reuse in this process (Fig.1-6). Emulsion polymerization process and bulk polymerization process are also adopted.
Recovered VCM storage tank
RecoveredVCM
storage tank
VCM tank
Volumeter CatalystPolymerization reactor
Additives
Gasholder
Crude VCMstorage tank
VCM purification column
Vacuumpump
Compressor Purified water Stripping
Tank
Centrifuge
Slurry tank
Fluidized-bed dryer
Screen
PVC storage tank
PVC
Source: Prepared from material by the JPI
Fig.1-6 PVC polymerization process flow diagram
Fig.1-5 Process flow diagram for VCM
Chlorine
Ethylene
chlorination reactor Air
(oxygen)
Ethylene
Oxychlorinationreactor
Direct Caustic sodaQuench column
Caustic soda washing column
Decanter
Dehydrating column
Low boiling point fraction collection column
High boiling point fraction collection column
Recovery column
Cracking furnace
Quenchcolumn
Hydrochloric acid removalcolumn
Monomer recovery column
Caustic soda washing columnVCM
Source: Prepared from material by the JPI
6
CHAPTER 1 : INTRODUCTION TO POLYVINYL CHLORIDE
(4) PVC as petrochemical product
■ A petrochemical product manufactured from ethylene
PVC is a petrochemical product, since its intermediate raw material, EDC, is manufactured from ethylene (Fig.1-7). 13% of all ethylene demand during 2001 was used for production of EDC (ethylene requirement breakdown). Almost all of EDC is used for PVC production in Japan, although a small portion is used for manufacturing of ethylenediamine, organic solvents and various pharmaceutical products.
Four major applications, i.e., low-density polyethylene (LDPE), high-density polyethylene (HDPE), EDC and styrene monomer (SM) comprise about 70% of all ethylene consumption (almost all styrene is used for PS).
■ PVC industry and petrochemical complexes The petroleum refining industry and the basic
232,153 thousand kl 7,739
3,8903,603 3,142 2,162
2,097
1,135
698754
3,533
1,749
125
547
727
230
58,403 thousand kl (25%)
23,024 thousand kl (10%)
22,630 thousand kl (10%)
43,058 thousand kl (19%)
53,946 thousand kl (23%)
966
537
261
734587
367
6,286
7,337
4,487
295
3,087
281
235
1,6551,024
16
961
270
520
743
12,888
295
418
1,254
Fig.1-8 Production flow of typical petrochemical complex (focus on ethylene derivatives 2007)
Crude oil
Gasoline
Naphtha
Kerosene
Light oil
Heavy oil
Chlorine
Caustic soda
Industrial grade salt
Ethylene
Ethylene oxide
Ethyl benzene
Acetaldehyde
EDC
Organic solvents
Propylene
Butadiene
Aromatics
Others
Unit: 1,000 tons/year
Ethylene glycol
Styrene monomer
Butanol
Ethyl acetate
Acetic acid Vinyl acetate
VCM PVC
Phenol
Octanol
Propylene oxide
Acrylonitrile
Benzene, Toluene, Xylene
Ethylenediamine PP
Phenolic resin
Phthalates*
*(for Plastcizers)
Acrylic fiber
Urethane foam
High purity terephthalic acid
Synthetic rubber
Polycarbonate
Polyester fiber
LDPE
HDPE
PET
PS
Acrylonitrile-Styrene
ABS
MBS
SBR
Polyvinyl acetate
Sources: Present Status of Petrochemical Industry: 2008 by the Japan Petrochemical Industry Association, Yearbook of Chemical Industries Statistics 2007 by the METI Guidebook for the Soda Industry by the JSIANOTE: 1. Imported naphtha of 26,873 thousand kl is not shown here. Total naphtha supply of 49,503 thousand kl is a sum of 22,630 thousand kl of domestic naphtha and imported naphtha. 2. Derivatives having two or more raw materials are shown against the major raw material. 3. Figures does not represent yields from each material substances.
LDPE
HDPE
1.95
1.25 EDC (PVC,
Ethylenediamine, others) 0.98
SM 0.85
Ethyl acetate 0.75
Others (Acetaldehyde, etc.)
1.58
Source: Prepared from chemical industry statistics by the Japan Petrochemical Industry Association, materials by the METI
Fig.1-7 Breakdown of ethylene applications (2001) (ethylene requirement)
Ethylenedemand
7.38(100%)
(13%)
(17%)
(27%) (21%)
(10%)
(12%)
Unit : Million tons
7
petrochemical industry in Japan are located at coastal areas, where there is easy access to imported natural resources such as crude oil, in the same way as energy industries such as the thermal power generation industry. They form petrochemical complexes, where refineries, ethylene centers and the petrochemical plants are connected by pipelines. Likewise, the soda industry is located together with petrochemical complexes in many cases, since it is preferable for large-sized soda plants to be at the coastal areas for easier access to imported salt and consumption of
caustic soda's by-product, chlorine.VCM plants, which use ethylene and chlorine as
major raw materials, and PVC plants, are generally located in the petrochemical complex due to this background. Fig.1-8 focuses on the flow of ethylene which is one of five types of products that are yielded by cracking of naphtha, and downstream on to the production of petrochemical products such as general-purpose plastics. Figures show the production volume in 2007.
(5) PVC as a chlorine product
■ Ratio of VCM within the totalchlorine demands
Ethylene and chlorine are the majorraw materials for VCM. Therefore, VCM is affected by the supply-demand situations of both ethylene and chlorine, respectively. As already mentioned, in Japan the share of VCM amount to 13% of all ethylene use (ethylene requirement). In contrast, VCM amounts to 40% of all chlorine use. Therefore, the demand-supply situation of chlorine has more impact on VCM than that of ethylene (Fig.1-9).
■ The balance between chlorine and caustic sodaChlorine is a by-product of caustic soda production,
generated at a ratio of 0.88:1. As applications for chlorine and caustic soda are totally different, one striking a balance between supply and demand does not necessarily mean the other would also. In fact, until 1970, the demand for chlorine was weaker than that of caustic soda, therefore, caustic
soda production was adjusted to meet the chlorine demand, and the resulting shortage of caustic soda was supplemented by imports. Afterwards, chlorine became short of supply since demand for PVC grew year by year (Fig.1-10). In order to make up for the chlorine shortage, EDC, which is comparatively easy to transport, was imported.
Fig.1-9 VCM share in total chlorine demand (fiscal 2006)
VCM 40%
Food 1% Solvent 2%
Chloromethane 5%
Source: Japan Soda Industry Association (JSIA)
Propylene oxide 5%
TDI/MDI (raw materialfor urethane) 8%
Others 39%
Chlorine demand Domestic chlorine supply Chlorine import ( )
'82 '83 '84 '85 '86 '87 '88 '89 '90 91 '92 '93 '94 '95 '96 '97 '98 '99 '00 01 '02
2,781
2,391
390
3,025
2,530
495
3,163
2,681
482
3,253
2,666
587
3,292
2,715
577
3,502
2,901
601
3,763
3,119
644
3.921
3,271
650
4,043
3,445
598
3,967
3,407
560
3,914
3,361
553
3,737
3,269
468
3,943
3,367
576
4,188
3,544
644
4,328
3,598
730
4,423
3,861
562
4,203
3,684
519
4,419
3,903
516
4,285
3,883
402
4,042
3,689
353
4,074
3,806
268
'03 '04 05 '06
4,048
3,822
224
4,092
3,936
156
4,096
3,894
202
4,121
3,898
223
2,000
0
3,000
4,000
5,000
fiscal year
1,000 tons
Chlorine demand
Chlorine import
Domestic chlorine supply
NOTE: 1. The chlorine demand represents the "net demand" derived by subtracting the recovered chlorine from the gross domestic chlorine demand. 2. The chlorine import is derived from all imported chlorine products in terms of chlorine requirement.
Source: JSIA
Fig.1-10 Transition of the balance between chlorine and caustic soda
8
CHAPTER 1 : INTRODUCTION TO POLYVINYL CHLORIDE
■ Dependency of VCM production on imported EDCEspecially during the mid 1980s, imports of EDC
increased year by year in order to make up for the grave shortage in chlorine due to the growth of domestic demand for VCM and also the increased export of VCM to China. The import of EDC marked an all time high of 842 thousand tons in 1996. As a result, the dependency of VCM production on imported EDC (i.e., the ratio of VCM manufactured with imported EDC) reached 34% (Fig.1-11).
After 1997 when VCM production hit its peak, the dependency of VCM on imported EDC started to decline. The decline resulted from the price hike of imported EDC partially due to growth in worldwide VCM demand; domestic VCM manufacturers had boosted production based on domestic chlorine.
After 2000, the import of EDC decreased to less than 500 thousand tons per year along with the
decline of PVC production. This was partially due to the general economic recession in Japan and reduced domestic demands (secondary converters had moved abroad). In 2004, the import of EDC further declined to 200 thousand tons, shifting the dependency ratio on imported EDC to below 10%. The price increase of imported EDC and domestic chlorine was partially responsible for the deficit of the Japanese PVC Industry after the latter half of 1990s. Thus, the balance between chlorine and caustic soda as well as the supply-demand situation of VCM both domestic and abroad are the dominant factors for the amount of EDC imported as raw material and the domestic shipment/export amount of VCM.
Crystalline :Molecules are aligned in a regular grid pattern when the substance is in solid form and stable. PVC has a dominant amorphous molecular structure, with only 5~10% of crystalline components.
Polarity : Tendency within parts of the molecule to be slightly charged positively and negatively. Parts within the molecule that are charged are called polar parts, as opposed to nonpolar parts where there is very little electrical charge.
0
500
1,000
1,500
2,000
2,500
3,000
Imported EDC
PVC production
VCM production
VCM production (EDC requirement)*
EDC dependency ratio (%)**
(1,000 tons)
1994
586
2,111
2,318
1,942
30
1995
723
2,274
2,586
2,167
33
1996
842
2,511
2,921
2,448
34
1997
696
2,626
3,124
2,618
27
1998
570
2,457
2,995
2,510
23
1999
553
2,461
3,124
2,618
21
2000
417
2,410
3,032
2,541
16
2001
383
2,195
2,895
2,426
16
2002
295
2,225
2,970
2,489
12
2003
256
2,164
2,948
2,470
10
2004
185
2,153
2,977
2,495
7
2005
153
2,151
3,038
2,546
6
2006
318
2,146
3,228
2,705
12
2007
223
2,162
3,142
2,633
8
15
20
25
0
5
10
30
35
40(%)
1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007
1,000 tons Imported EDC EDC dependency ratio VCM production (EDC requirement)
x 100VCM production (EDC requirement)
** EDC Dependency Ratio =
* VCM production (EDC requirement) = VCM production x 0.838Imported EDC
Source; Yearbook of Chemical Industries Statistics, METI Trade Statistics of Japan, Ministry of Finance
Fig.1-11 Transition of EDC import and dependency ratio on imports
3. Characteristics of PVC
9
PVC, PE, PP and PS are called general-purpose plastics. The features of the plastic are determined by the chemical composition and type of molecular structure (molecular formation: crystalline /amorphous structure)(Fig.1-12).
PVC has a unique amorphous structure with polar chlorine atoms in the molecular structure. Having chlorine atoms and the amorphous molecular structure are inseparably related. Although plastics seem very similar in the daily use context, PVC has completely different features in terms of performance and functions as compared with olefin plastics which have only carbon and hydrogen atoms in their molecular structures.
(1) Chemical stability
Chemical stability is a common feature among substances, containing halogens such as chlorine and fluorine. This applies to PVC resins also, which furthermore possess fire retarding properties, durability, and oil/chemical resistance.
■ Fire retarding propertiesPVC has an inherently superior fire
retarding property due to its chlorine atom components, and do not require addition of fire retardants to its products. For example, the ignition temperature of PVC is as high as 455℃ , and is a material with less risk for fire incidents since it is not ignited easily (Fig.1-13).
Furthermore, the heat radiation in burning is considerably low with PVC, when compared with those for PE and PP, and is hard to spread fire to nearby materials even while burning (Fig.1-14). Therefore, PVC is the most suitable plastic to be used in products requiring fire retarding properties such as housing materials.
■ DurabilityUnder normal conditions of use, the factor
most strongly influencing the durability of a material is resistance to oxidation within the air. PVC, having the molecular structure where chlorine atom is bound to every other carbon chains, is very resistant to oxidative reactions, and maintains its performance
500℃
400℃
300℃
200℃
Vinylidene chloride Low flammability Fluoroplastic
PS Hard to ignite
Cellulose acetate
PVC Nylon
PU
PE
Nylon
PVC
PE PU
Methacrylicresin
Pine wood Pine wood Cotton Paper Paper Wool High flammability Easy to ignite
Fig.1-13 Flash ignition and ignition temperatures of mateials
Source: "Technical Information: Five Properties of Polyvinyl Chloride" by the technical committee of the Vinyl Institute, 1988 (PVC and Polymer, Vol.29, No.9, 6-11: No.10, 10-16, 1989)
Vinylidenechloride
Material 91
250
315
746
859
1216
1325
1335
Maximum heat release(kW/m2)
Fig.1-14 Maximum heat release by various materials
PVC
Fire resistant ABS
Fire resistant PS
ABS
PS
Polyester
PE
PP
Source: PVC and polymer Vol.29 (1989)
H
C
H
H
C
H
C
H
H
C
H
C
H H
H
C
H
C
H CH3
H
C
Molecular form Amorphous part
Crystalline part
carbon, hydrogen, chrorine carbon, hydrogen
CrystallineThe crystalline part is fixed, the amorphous part is flexible.
Amorphous
Molecular chains are fixed.
PVC PS PE PP
Chemical composition
Fig.1-12 Molecular structures of general purpose plastics
10
CHAPTER 1 : INTRODUCTION TO POLYVINYL CHLORIDE
almost semi-permanently. In contrast, other general purpose plastics with structures made up only of carbon and hydrogen are susceptible to deterioration by oxidation in extended use conditions.
According to measurements on underground PVC pipes by the Japan PVC Pipe & Fittings Association, a pipe used underground for 35 years showed no deterioration, and its strength remained the same as with new pipes (Fig.1-15).
A report from Germany, where rigid PVC pipes were used from the early days, states that a PVC pipe used for over 50 years displayed the same strength as with new pipes.
Almost no deterioration was observed upon recovery of three kinds of automobile exterior accessories (flexible PVC products using plasticizers) from end-of-life cars after 13 years of use and upon comparison of physical properties with new products (Fig.1-16). The shortened time for thermal decomposition (loss of durability) is due to the heat history in the re-converting process, and can be recovered to that of the original products by adding
stabilizers. Recovered products can in fact be molded back into the same products through re-converting, regardless of whether they are pipes or automobile parts. The physical properties of these re-converted products are almost the same as with products made from virgin resin, and there is also no problem upon actual use.
As described above, PVC has an outstanding durability and is a suitable material for long service life products, and has an excellent recycleability.
Taking advantage of this characteristic, PVC is used in exhaust gas ducts, sheets used in construction, bottles, tubes and hoses.
■ Oil/Chemical ResistancePVC is resistant to acid, alkali and almost all
inorganic chemicals. Although PVC swells or dissolves in aromatic hydrocarbons, ketones, and cyclic ethers, PVC is hard to dissolve in other organic solvents.
A B C
2000
1500
1000
500
0A B C
25
20
15
10
5
0A B C
120
100
80
60
40
20
0A B C
2
0
-2
-4
-6
-8
-10
13 years later
A B C
400
300
200
100
0A B C
250
200
150
100
50
0A B C
400
300
200
100
0A B C
120
100
80
60
40
20
0
Fig.1-16 Change of physical properties of recovered automobile exterior accessories
Degree of polymerization Original
Plasticizer content (%) Hardness (at 23℃) Brittle temperature (℃)
Sample Sample Sample Sample
SampleSampleSampleSample
Tensile strength (kg/cm2) 100% Modulus (kg/cm2) Elongation (%) Thermal decomposition time (mins)
Source: "PVC and environmental issues" by Tetsuya Makino, Seikei Kakou (a journal of the Japan Society of Polymer Processing), Vol.10, No.1 (1998)
(M
Pa)
100 20 30 40 50
58
60
64
66
62
50
52
56
54
Tens
ile s
treng
th Number of years in use
Fig.1-15 Aging of strength in rigid PVC pipe
Source: Japan PVC Pipe & Fittings Association
11
(2) Mechanical stability
PVC is a chemically stable material, which shows little change in the molecular structure, and also exhibits little change in the mechanical strength. However, high-polymer material is a viscoelastic body and deformed by continuous application of exterior force, even if the applied force is well below its yield point. This is called creep deformation. Although PVC is a viscoelastic body, its creep deformation is very little compared with other plastics due to little molecular motion at ordinary temperature, in contrast to PE and PP, which have greater molecular motion in their amorphous sections. Through a joint research with the Kyoto Institute of Technology, it was found out that the service lives of rigid PVC pipes were over 50 years. Specifically, internal pressure creep tests revealed that rigid PVC pipes retain about three times the designed circumferential stress even after 50
years of service. This is proof that PVC can maintain its mechanical strength for an extended period of time (Fig.1-17).
Viscoelastic body :Refers to material having both viscosity and elasticity. Distortion occurs as soon as external force is applied and thereby absorbing the force (elasticity), but when the force is continuously applied, deformation occurs to a certain extent (viscosity).
Yield point :When external force is applied to a material, elastic deformation (strain) takes place up to the yield point, and the strain disappears as soon as the external force is removed. When the external stress is greater than the yield point, plastic deformation (permanent set) takes place and the material would not recover its original shape even after removal of exterior force.
(3) Processability and moldability
The processability of a thermoplastic material depends largely on its melt viscosity. PVC is not meant for injection molding of large sized products, since its melt viscosity is comparatively high. On the other hand, the viscoelastic behavior of molten PVC is less dependent on temperature and is stable. Therefore PVC is suitable for complex shaped extrusion profiling (e.g., housing materials), as well as calendering of wide films and sheets (e.g., agricultural films and PVC leather). The exterior surfaces of molded PVC products are excellent, and displays superior embossing performance - enabling a wide variety of surface treatments with textures ranging from enamel gloss to the completely delustered suede. Since PVC is an amorphous plastic with no phase transition, molded PVC products have high dimensional accuracy. PVC also exhibits excellent secondary processability in bending fabrication, welding, high-frequency bonding, and vacuum forming, as well as on-site workability.
Paste resin processing such as slush molding, screen-printing and coating is a convenient processing technique that is feasible only with PVC. These processing methods are used in flooring, wall covering, automobile sealants and undercoating.
Interior decoration films
10010 1000 10000 100000 1000000
10
25
100
50
Fig.1-17 Circumferential stress by internal pressure and breaking time of rigid PVC pipes
Circ
umfe
rent
ial s
tress
(MPa
)
Elapsed time (hrs) 50 years
Source: Japan PVC Pipe & Fittings Association
4. Safety of PVC
12
CHAPTER 1 : INTRODUCTION TO POLYVINYL CHLORIDE
(4) Others (versatility in designingthrough compounding)
PVC has polar groups (chlorine), and is amorphous, therefore mixes well with various other substances. The required physical properties of end products (e.g., flexibility, elasticity, impact resistance, anti-fouling, anti-bacteria, anti-mist, fire retarding) can be freely designed through formulation with plasticizers and various additives, modifiers, and coloring agents. PVC is the only general purpose plastic that allows free, wide and seamless adjustment of the required physical properties of products such as flexibility, elasticity, and impact resistance, by adding plasticizers, additives, and modifiers.
Since the physical properties of end products are adjustable through compounding, it requires only a few types of resin to cover all the applications of high-polymer materials (fiber, rigid and flexible plastic, rubber, paint, and adhesive). This controllability is also extremely beneficial recycling-wise.
The polar groups in PVC contribute to ease in coloring, printing and adhesion, therefore PVC products do not require pretreatment, which enables a wide variety of designs. PVC is used in various scenes taking full advantage
of its superior printability, adhesion properties and weatherability. Patterns such as wood grain, marble, and metallic tones are possible. Familiar examples include wall coverings and floorings, housing materials, furniture, home electric appliances, or signboards and ads on airplanes, bullet trains, buses and trams.
(1) Production safety
VCM, which is the intermediate raw material for PVC, has a boiling point of - 13.9℃ and a flash point of - 78℃ . Caution is required upon handling since it is a dangerous substance in gaseous form. The PVC industry in Japan handles VCM with utmost care at PVC manufacturing facilities and has safe working environments. No hazard has ever been brought to local communities. Neither has there been any death incidence or sufferers due to improper manufacturing process control throughout the years.
(2) Safety upon use
PVC is a chemically and mechanically stable material with excellent fire retarding properties, and is a safe plastic under normal conditions of use. Fig.1-19 is an excerpt of the Material Safety Data Sheet (MSDS) prepared by PVC manufacturers. The MSDS shows data for the safe use of PVC.
5
4
3
2
1
Fig.1-18 Comparison of physical properties of PVC materials with polyolefin materials
Fire retardance
Oil resistance
Abrasion resistance
Scratch resistance
Adhesion
Gloss
Compression Set
Exterior appearance
Moldability
Tensile strength
PVC materialsPolyolefin materials Improved polyolefin materials
Source: "PVC and environmental issues" by Tetsuya Makino, Seikei Kakou, Vol.10, No.1 (1998)
13
(3) Evaluation of carcinogenicity
In 1974, cancer incidents were reported among workers who had been employed by the PVC industry in the U.S., and VCM were reported to be responsible. As a result of an epidemiological survey, a very rare type of cancer (angiosarcoma) was identified in workers who had been exposed to high concentrations of VCM for an extended period of time.
Following this report, improvements of work environments were accelerated through closed system EDC/VCM manufacturing processes and automated cleaning of PVC polymerization reactors, in the U.S. and across of the world.
In Japan, a new guideline was introduced in 1975 where the geometrical average was to be within 2ppm in the general work environments and within 5ppm inside the polymerization reactor. Subsequently, better process control technologies were introduced such as enhanced polymerization rates and recovery of unreacted VCM from the reactor. The PVC industry also worked on the reduction plan for hazardous air pollutants in cooperation with administrations (see Chapter 3).
There were once cancer incidents among workers who cleaned polymerization reactors for extended
H
C
H n
H
C
Fig.1-19 Material Safety Data Sheet (MSDS)
References1) "Plastic Data Handbook" Edited by Kimimasa Itoh. Kogyo Chosakai Publishing Co., Ltd. (1980) P.1162) Same as above. P.110
Disclaimer The contents herein are based on documents, information and data available at the time of press. However, no guarantee is extended as to the physical/chemical characteristics and dangerousness. Cautions are meant for normal conditions of handling. Appropriate safety measures must be taken for each special conditions of handling.
PVC(White powder)
PVC materialfor molding (Colored pellets)
Product designationDistinction of single/mixed materialChemical nameChemical formulaStructural formula
Classification # in official gazetteCAS No. Classification of hazardousness Title of classification Danger HazardousnessFirst aid If in contact with eye
If in contact with skin If swallowedMeasures in case of fire Extinguish method Extinguishing Agent Others
Measures upon leakageCautions upon handling Handling Storage
(CH2CHCl)n
Polyvinyl chlorideSingle materialPolyvinyl chloride (PVC)
6-66 (Japanese Chemical Substances Control Law) 9002-86-2
Not applicable to classification standards None None
Do not rub, rinse with water for 15 minsand consult a physicianRinse with waterConsult a physician
Extinguisher must use air breathing apparatus Water, dry chemical, foam Irritant gas is emitted when burnt. Major component of gas: HCl, CO and CO2. Collect the diffused in empty containers
Do not expose to fire. Do not diffuse Avoid exposure to direct sunlight, and store at a well ventilated, cool and dark place
Explosion preventive measures Concentration control Permissible Concentration Measures for facilities
Protective gears
Physical/Chemical characteristics External appearance Property Boiling point Vapor pressure Volatility True specific gravity Solubility Info on danger (Stability/Reactivity)
Ignition temperature Flash ignition temperature
Combustibility
Oxidative property Dust explosiveness Stability/ReactivityInfo on hazardousness
Cautions upon disposal
Cautions upon transportation
Applicable laws and regulations
Not applicable None (Japan Society for Occupational Health)Desirable to install local ventilators with dust filters where diffusion tends to occur
White powder
Not applicableNot applicableNot applicable 1.4 (20℃)Not soluble in water
391℃ 1) 454℃ 2)
Stable in room temperatureStable in terms of dust explosiveness Stable under normal handling conditions
None specifically
Use the following protective gears when necessary ●Respirators (dust masks in operation, and air breathing apparatus mask in case of fire)●Protective spectacles
(dustproof spectacles)●Protective gloves●Protective clothes
(not required generally)
Self-extinguishing resin with oxygen index of approx. 45
Avoid damage to containers and collapse of cargo
Unclear, but no case known to show hazardousness
Incinerate by incinerators with exhaustgas treatment facilities, or landfill as non-dangerous waste
14
CHAPTER 1 : INTRODUCTION TO POLYVINYL CHLORIDE
periods of time, but after the carcinogenic effects of VCM surfaced, improvements were made immediately for the safety and hygiene in the work environment, and methods to use VCM safely was established within a short period of time.
For reference, the International Agency for Research on Cancer (IARC), which is a branch of the World Health Organization (WHO), classified VCM as substance belonging to Group 1 (Carcinogenic to humans) in June, 2001 (Fig.1-20). On the other hand, PVC was classified as Group 3 (Not-classifiable as to its carcinogenicity to humans), along with tea and caffeine. (WHO is continuing its quantitative risk assessment on carcinogenicity).
(4) Residual monomers in PVC
Trace amounts of unreacted VCM are found in PVC, but their concentrations are not a problem upon processing and use of PVC products. Food packaging and medical appliances require stringent safety measures; therefore the following specifications have been established.
① Specifications for food packaging■ Standards in the Food Sanitation Law
In 1973, a research was conducted in Italy where oral doses of VCM were given to experimental animals, which resulted in manifestation of angiosarcoma. This lead to further investigations on residual VCM in PVC across the world, and the US National Toxicology Program (NTP) was one such example. In Japan, review of the Food Sanitation Law started immediately from a hygienic standpoint. Safety evaluations were made based on residual monomer levels and its relationships
with migration levels. On February, 1977, the Ministry of Health and Welfare set the standard of residual VCM in PVC to be below 1 ppm and announced this through public notification No.17. The notification continues to be effective to date.
■ Voluntary Standard by Japan Hygienic PVC Association (JHP Standard):
In 1970, prior to the abovementioned public notification, Japan Hygienic PVC Association (JHPA), which consists of PVC manufacturers and PVC product manufacturers, had worked out voluntary standards based on the Food Sanitation Law in the form of positive list (JHP standard: recommendable substances for use/guideline upon manufacturing of food packaging) ahead of the Responsible Care concept (see footnote of page 38).
JHPA had decided to work out this voluntary standard when the result of the animal experiment in Italy was reported. By the time the public notification No.17 was announced by the Ministry of Health and
■ Positive list ・A list presenting the designations of chemical substances which can be used as raw materials, their quality, quantity, application and elution limit, etc. ・Polymer (resin), additives, plasticizers, stabilizers, antioxidants, UV absorbers, surfactants, lubricants, colorants and fillers foaming agents, and others■ Material test ・Substances not to be used intentionally or to be included in the product and their test methods are stipulated ・Cadmium, lead, dibutyltin compounds, cresol, phosphates, VCM■ Elution test ・Non-volatile residues, heavy metals, and consumption of KMnO4
The JHP standard by JHPA consists of:1) Positive list (list of recommended raw materials to be used), and2) Material test and leach test methods for PVC food packaging based on the Food Sanitation Law. The level of residual VCM is stipulated to be below 1ppm.
Fig.1-21 JHP standard
Source: Prepared based on "Voluntary standards for food sanitation etc. of PVC products, (JHP standard: version 12)" March, 1993, JHPA
Group 1
Group 2A
Group 2B
Group 3
Group 4
Classification
Carcinogenic tohumans
Probably carcinogenic to humans
Possibly carcinogenic to humansNot classifiable as to its carcinogenicity in humans
Probably not carcinogenic to humans
Agents Asbestos, VCM, 2,3,7,8- TCDD, Formaldehyde, Cadmium,Benzene,Benzopyrene, Acrylamide, Ultraviolet radiation Lead & lead compounds (inorganic)Acetaldehyde, Styrene, Lead compounds (organic)Caffeine, Chlorinated drinking-water, DEHP, PVCCaprolactam(raw material for nylon)
MixturesAlcoholic beverages, Tobacco smoke, Soot
Diesel engine exhaust
Coffee, Gasoline, Pickled vegetables (Asian traditional)
Tea (black tea, green tea)
105
66
248
515
1
Fig.1-20 Evaluations of carcinogenicity by the IARC
Source: IARC website
SubstancesNumber
As of Mar. 2008
5. JIS and PVC Applications
15
Welfare in February 1977, reduction of residual VCM had already been achieved.
The voluntary JHP standard is a comprehensive voluntary standard that integrates official regulations, and following the revision of the Food Sanitation Law, the 1ppm limit of residual VCM was immediately adopted (Fig.1-21).
② Standards for medical equipmentAnother example of measures against residual VCM
is the case in medical PVC products including blood
bags, liquid/blood transfusion sets, artificial heart lung apparatus and artificial kidneys. PVC has been used safely for more than 40 years both at home and abroad, in accordance with the Pharmacopoeia of Japan, voluntary standards established by the Japan Medical Devices Manufacturers Association (Fig.1-22), and GMP (Good Manufacturing Practice). PVC resins in compliance with standards shown in Fig.1-22 are used for medical products. The level of residual VCM is set below 1ppm in this application field as well.
(1) The Japanese Industrial Standard (JIS) for PVC
PVC is controlled under the following test methods and shipped in uniform quality. PVC compound is a form of PVC product but it is marketed as an intermediate material to be molded into PVC products. Therefore test methods for compounds are also shown.
(2) JIS for PVC products
PVC has a wide variety of applications, and more than 200 JIS items are relevant. PVC products contribute to society under support by these vast number of standards.
Fig.1-22 Standards for medical apparatus
Test method for transfusion bags (Pharmacopoeia of Japan )
Designation of medical products
Transparency/External appearance
PVC compound I ・ II for medical apparatus (voluntary standards by the Japan Medical Devices Manufacturers Association)
Plasticized PVC transfusion bags
No abnormality by visual inspection Same as with left
Same as with left
Same as with left
Same as with left
VCMbelow 1μg (1 ppm) (others: omitted)
(others: omitted)
△PH, KMnO4 reducing substance, UV absorption spectrum
Acute toxicity tests, Intracutaneous reaction
Tests on eluates
Biological tests
Blood set, Disposable set for artificial heart/lung equipment, Blood tube for hemodialysis, Blood catheter, Transfusion set,Blood transfusion set, Others
Source: Prepared based on the document by the Japan Medical Devices Manufacturers Association
Material tests
Plastics-PVC homopolymer and copolymer: designations, specification, specimen, properties* PVC: Method to measure impurities*Method of viscosity measurement with rotational viscometer*Method to measure apparent density*Method to measure viscosity of diluted solution (reduced viscosity of PVC/K value)*PVC homopolymer and copolymer (method to measure residual VCM)*PVC paste resin (method to measure apparent viscosity)*PVC homopolymer and copolymer (method to measure volatile component/ moisture content)*Method to prepare PVC paste (dissolving method)*Plasticized (flexible) PVC compoundMaterials for molding and extrusion of un-plasticized PVC (PVC-U) (Rigid PVC compound)Plastic: Materials for molding and extrusion of plasticized PVC (PVC-P)
K 6720- 1~2K 6737K 7117-2 K 7365 K 7367-2 K 7380 K 7381 K 7382 K 7383 K 6723 K 6740 K 7366
JIS
* Changeover to a new JIS standard will take place in October 2004 in line with the international standardization towards ISO. 13 other new JIS standards will be introduced.
16
CHAPTER 1 : INTRODUCTION TO POLYVINYL CHLORIDE
PVC has superior features in one, and is used in various fields ranging from the lifeline (water supply, sewage, electric cable, etc.), basic industries (housing), consumer products, and front line electronics, to medical apparatus and products. The application of PVC is divided, in general, based on the hardness
of products, e.g., rigid, flexible, electric cables and others. The most prominent feature of PVC product is applications requiring long service lives. Fig.1-23 shows the applications in the vertical direction and the service life in the horizontal direction, with some photographs of applicable products.
(3) Applications of PVC (PVC products)
Fig.1-23 Applications and service life of PVC - 1 Long ShortService life
Long term (some years~50 years) Less than a few years
ducts, tanks, semi-conductor cleansing devices,flanges, other facilities/equipments,
anti static plates
■ Industrial
■ General name plates,construction materials,sign boards,stationeries,agricultural applications
Flat
pla
tes
Rig
id p
rod
ucrs
Film
s/S
hee
ts
■ Construction materials
Co
rru
gat
ed s
hee
t
corrugated sheet
■ Agricultural applications
name plates, construction materials
terrace roofing
displays
displays
separated trays
separated trays
blister packs■ Non food packaging
dimpled sheets
packaging (for eggs, tofu, fruits)caps,
food trays
■ Food packaging
■ Others cooling towers, toys,electronic equipment accessories, stationeries,cards,FDJ
terraces, dormer, carports, blinds, sheds, arcades,
accessories
cards
temporary structures, snow fences
casing,lightweight packaging
clean rooms
Fig.1-23 Applications and service life of PVC - 1 Long ShortService life
Long term (several years~50 years) Less than a few years
ducts, tanks, semi-conductor cleansing devices,flanges, other facilities/equipments,
anti static plates
■ Industrial
■ General name plates,construction materials,sign boards,stationeries,agricultural applications
Flat
pla
tes
Rig
id p
rod
ucts
Film
s/S
hee
ts
■ Construction materials
Co
rru
gat
ed s
hee
ts
corrugated sheet
■ Agricultural applications
name plates, construction materials
terrace roofing
displays
displays
separated trays
separated trays
blister packs■ Non food packaging
dimpled sheets
packaging (for eggs, tofu, fruits)caps,
food trays
■ Food packaging
■ Others cooling towers, toys,electronic equipment accessories, stationeries,cards,FDJ
terraces, dormers, car ports, blinds, sheds, arcades
accessories
cards
temporary structures snow fences
casing,lightweight packaging
clean rooms
17
agricultural water system
Fig.1-23 Applications and service life of PVC - 2 Long ShortService life
Long term (several years~50 years) Less than a few years
Rig
id p
rod
ucts
■ Water supply
■ Agricultural water
■ Sewege
■ Industrial, facility drainage
■ Cable protection
Pip
esFi
ttin
gs
Sp
ou
ts
■ Other applications
power tube
■ Special purposes base pipes for PVC lined steel pipes
adaptor for steel pipes right angle elbow
rainspouts, chicken farm spouts, accessories
plant piping, well drilling, natural gas pipelinesindustrial waterworks, marine structures, componentswater discharge facility buildings, roadworks, railroad sathletic fields, air conditioning, gray waterworkswater draining from retaining walls, highways
electric conduits (telecommunication, signals, indoor wiring, lighting, vehicles)
optical fiberprotection cables
aquacultures, hot springs, coil core
NTT cable protecting tube
power tubes
pipe fittings
paddy field irrigation pipelineirrigation for farmland
waterworksexclusive water works simplified water works
public sewage systemfarm village sewage systemdevelopment of housing premises
Sewage system
waterworks
Y shaped fitting
rainspout
18
CHAPTER 1 : INTRODUCTION TO POLYVINYL CHLORIDE
Fig.1-23 Applications and service life of PVC - 3 Long ShortService life
Long term (several years~50 years) Less than a few years
Rig
id p
rod
ucts
Pro
file
ext
rusi
on
■ Construction materials
window profiles, wire screens, girt, bargeboards, fascias, decks, trim, parting, angles, panels, ribs, knobs, accordion doors, sidings window profiles
siding (exterior of housings) siding (exterior of stations) various construction materials
■ Consumer products
drain boards, bath tub lids, rails, hanger,
pen tray
■ E&E wiring ducts, wire protectors, handle for radio-cassette players, battery separators
speakers
IC carriers
IC carriers
■ Furniture/ Wooden product applications
edges, trims, outside corners, squinches, deck plates
decks, etc. counter table
■ Vehicle applications
vehicle interior
interior of JR sleeper express trains
■ For food packaging
soy sauce, Worcester sauce, vinegar, seaweed
■ For non food applications
cosmetics, shampoo, detergents
Other applications valves, flanges, night soil tanks, rain water sumps, wastewater sumps, in-house sumps, keyboards
sumps valves/flanges
various rigid PVC extrusion molded products
various bottlesBlo
w m
old
ed p
rod
uct
s
penholder
19
Fig.1-23 Applications and service life of PVC - 4 Long ShortService life
Long term (several years~50 years) Less than a few years
non woven fabric
Flex
ible
pro
du
cts
Gen
eral
film
s/S
hee
ts
■ Laminated products
printed plywood, PVC laminated steel platesprinted films for interior finishing,printed sheets for exterior finishing
hot springs (ceiling) theaters (walls) stores (exterior wall)
doors (surface)
pianos (surface)
■ Packaging various covers, fabric wrapping blood bags, IV infusion bags, food wraps, stickers (labels)shrink film
waste fluid storage bags
■ Vehicle applications
instrument panels, consoles, door sheets, ceiling, carpet, trunk room sheets, insulating tapes
■ Consumer products
furniture, accessories
Agricultural films green house gardening, vegetables, fruits, paddy, tobacco
Artificial leather wallcovering, vehicle seats, furniture, baggage,bags, garments, stationeries
wallcovering, sofa
baggage, footwear
stationeries, bags, toys, raincoats, umbrellas, adhesive tapes, adhesive plasters
agricultural PVC films
footwear
20
CHAPTER 1 : INTRODUCTION TO POLYVINYL CHLORIDE
Fig.1-23 Applications and service life of PVC - 5 Long ShortService life
Long term (several years~50 years) Less than a few years
Flex
ible
pro
du
cts
waterstops, industrial hoses/tubes, gaskets (for residences, home electrical appliances, automobiles), machinery/equipment parts,flooring of housings
Extruded profiles medical tubes, garden hoses,tubes for food, skipping ropes
draining hoseshousing material parts
table edges
side molding
artificial heart-lung catheter
various shaped extruded profiles refrigerator door gaskets
Injection-molded products and others
tarpaulins (canvases, tents, sunshades), mattresses, sealing sheets, civil work sheets, roofing sheets, waterproof sheets, insulation sheet
carrier cart bumpers
vacuum cleaners automobile parts
Cable covering electric power cable, machine control cable, construction/housing cable, electric wire for machine/equipment (cords, wires, harnesses),consumer products, telecommunications
high-voltage cables
cables for construction works (low-voltage )
power cords
interfacing cables flat-shaped cablestape/ribbon cables
Ele
ctri
c ca
ble
s an
d o
ther
s
Flooring homogeneous tiles, composite tiles, cushion flooring, long sheet flooring, tile carpet, laminated tile
flooring for stores such as department stores, super markets, and DIY shops
Fiber fishing nets, ropes, insect screens, brushes, wigs
Otherspaints,expanded products (floats, heat insulators, cushion material)
dolls, shoe soles, boots,gloves, industrial tapes