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HDPE & Industrial Plastics

Learn about HDPE / PE100 and find the best industrial plastic pipe product for your job

All you need to know about High-density polyethylene & industrial plastics

Read our useful information, based on critical properties such as strength, melting point and other thermal qualities. Along with resistance to abrasion, corrosion, chemicals, solvents, acids, bases, fatigue, crushing and UV radiation. Plus identify adaptability based on your specific application, such as translucent piping, colour pigments and performance improvement additives. Once you’ve identified a plastic, browse our product range >>>

ABOUT HIGH-DENSITY POLYETHYLENE / HDPE / PE100 / PE / PEHD / BLACK POLY

High-density polyethylene (HDPE, PE100) or Polyethylene High Density (PEHD), also known as Black Poly or Blackpoly in the industry is a polyethylene thermoplastic made from petroleum. Known for its large strength to density ratio, it is commonly used in the production of plastic bottles, corrosion-resistant piping, geomembranes, and plastic lumber and is commonly recycled. The density of HDPE (0.93 to 0.97g/cm3) is only marginally higher than that of low-density polyethylene, with low polymer branching, giving it stronger intermolecular forces and tensile strength. The difference in strength exceeds the difference in density, giving HDPE a higher specific strength. It is also harder and more opaque and can withstand somewhat higher temperatures 120°C (248°F) for short periods, 110°C (230°F) continuously. High-density polyethylene, unlike polypropylene, cannot withstand normally required autoclaving conditions.

GENERAL PROPERTIES

Terms frequently used to describe this material when used for engineering applications are high density (HDPE), medium density (MDPE) and most recently high performance (HPPE) polyethylene. Others PE types, such as low density (LDPE) and linear low density (LLDPE) are sometimes used for irrigation pipelines. The Type 50 PE of AS1159 that was in common use until 1994, is an HDPE with a long-term design stress of 5.0 MPa. AS/NZS4130 and AS/NZS allow for three specific classifications by material strengths and sub classifications by performance at elevated temperatures. PE100 material’s minimum required strength is 10 MPa. Our bends are manufactured to AS/NZS 4130 from polyethylene’s complying with AS/NZS 4131. Please see our easy to follow quick reference Table of Properties.

MRS (50 year) 10 MPa
Flexural Yield Strength 32 MPa
Circumferential Flexural Modulus (3 minute) 950 MPa
Circumferential Flexural Creep Modulus (50 year) 260 MPa
Density 955 kg/m3
Tensile Yield Stress (50mm/min) 25 MPa
Tensile Yield Strain (50mm/min) 10%
Tensile Modulus 900 MPa
Poisson’s Ratio 0.40
Thermal Expansion Coefficient 0.18 mm/m K
Thermal Conductivity 0.38 W/m K

 

COMPOSITION

The compounds used in some pipes and fittings are pre-compounded resins, either black or coloured with pigment, complying with AS/NZS 4131. The following additives, if used, are added to the PE polymer base resin during the compounding process by the raw material manufacturer. Anti-oxidants are used to inhibit oxidation of the polymer at the compounding stage and during subsequent processing. The oxidation induction test is an indicator of the efficacy of this additive and the residual amount after processing. Carbon black is used in all black pipe at a concentration of 2.25 ± 0.25% by mass as an ultra violet radiation absorber. In natural and coloured PE materials, chemical ultra violet absorbers are used in lieu of carbon black.

THERMAL QUALITIES

The co-efficient of thermal linear expansion of polyethylene varies with temperature but at ambient lies in the range 1.2 to 2.4 x 10-4 per degree C. In broad terms, this is about twenty times that of steel, and therefore unrestrained pipe will expand or contract much more than the steel structure that may be supporting it. Should the pipe be fully restrained, the strain due to thermal change will generate stress in the material. However due to the relatively low tensile deformation modulus (E) of PE and assuming a typical ambient temperature fluctuation of less than 40°C it can be assumed that the safe allowable stress will not be exceeded. Over the longer term, stress relaxation will increase the ability of PE to accommodate high thermal strains. The conductivity of polyethylene varies with temperature almost linearly and is typically 0.47 W/m.K at 0°C to 0.37 W/m.K at 70°C. The specific heat of polyethylene varies with temperature from 1800 Joules/kg.K at 0°C to 2200 J/kg.K at 60°C. At temperatures above 25°C it is necessary to rerate polyethylene pipe systems. The table below provides guidance as to the maximum operating pressure of PE100 pipes. Below is a detailed table on Maximum Allowable Head (m) – PE100:

Temperature
(
C)
Minimum Life
(Years)
Design Factor
PN4
PN6.3
PN8
PN10
PN12.5
PN16
PN20
PN25
SDR41
SDR26
SDR21
SDR17
SDR13.6
SDR11
SDR9
SDR7.4
20
100
1.0
40
64
80
100
127
160
200
250
25
100
1.1
36
58
73
91
115
145
182
227
30
100
1.1
36
58
73
91
115
145
182
227
35
50
1.2
33
53
67
83
106
133
167
208
40
50
1.2
33
53
67
83
106
133
167
208
45
35
1.3
31
49
62
77
99
123
154
192
50
22
1.4
29
46
57
71
91
114
143
179
55
15
1.4
29
46
57
71
91
114
143
179
60
7
1.5
27
43
53
67
85
107
133
167
80
1
2.0
20
32
40
50
63
80
100
125

NOTE: The values tabled are for pipe manufactured to AS/NZS 4130 and fittings made from compounds complying with AS 4131. The minimum life periods may be considered to be the minimum potential service lives and represent the maximum extrapolated periods permitted by the ISO9080 extrapolation rules given the available test data. Maximum allowable operating pressure is indicated in metres head (1m = 9.81kPa).

CHEMICAL RESISTANCE

Polyethylene is in chemical terms a non-polar high molecular weight paraffin of the hydrocarbon family. Hence it is very resistant to (non-oxidising) strong acids, strong bases and salts. It is mildly affected by aliphatic solvents although aromatic and chlorinated solvents will cause some swelling. Polyethylene is attacked by strongly oxidising substances such as halogens and concentrated inorganic acids such as nitric, sulphuric (including oleum), perchloric etc.

RURAL & IMPERIAL LINES

Redline poly is made to AS 2698.2 dimensions and has a maximum operating pressure of 900 kPa. Greenline, 800 kPa poly pipe is for rural applications. Both Greenline and Redline pipes use rural compression range of fittings. Sizes range from 3/4 inch to 2 inch.

 

 

OTHER PLASTICS

POLYPROPYLENE / POLYPROPENE / PP

Polypropylene or Polypropene (PP), is a thermoplastic polymer used in a wide variety of applications including industrial processes, manufacturing, medical equipment, packaging and labeling, textiles (e.g., ropes, thermal underwear and carpets), stationery, plastic parts and reusable containers of various types, laboratory equipment, automotive components, and polymer banknotes and is commonly recycled. It is rugged, with good resistance to fatigue and highly resistant to many chemical solvents, bases and acids. PP is reasonably economical and is often opaque or coloured using pigments and can be made translucent when uncoloured. Perfectly isotactic PP has a melting point of 171°C (340°F). Commercial isotactic PP ranges from 160 to 166°C (320 to 331°F), depending on atactic material and crystallinity. Syndiotactic PP with a crystallinity of 30% has a melting point of 130°C (266°F).

ULTRA-HIGH-MOLECULAR-WEIGHT POLYETHYLENE / UHMWPE / UHMW / HMPE / HPPE

Ultra High Molecular Weight Polyethylene (UHMWPE, UHMW) also known as High Modulus Polyethylene (HMPE) or High Performance polyethylene (HPPE), is a subset of the thermoplastic polyethylene. It has extremely long polymer chains, resulting in a very tough material, with the highest impact strength of any thermoplastic presently made. UHMWPE is odorless, tasteless, nontoxic and resistant to UV radiation and micro-organisms. Highly resistant to corrosive chemicals and aromatic solvents (except oxidising acids) as it does not contain susceptible chemical agent groups (such as aggressive esters, amides or hydroxylic). It is self-lubricating, with extremely low moisture and water absorption, combined with very high water resistance (making bonding with other polymers difficult). UHMWPE has notably high abrasion resistance, in some forms being 15 times more resistant than carbon steel. Its coefficient of friction is significantly lower, comparable to that of polytetrafluoroethylene (PTFE, Teflon), yet with better abrasion resistance. Its melting point is around 130 to 136°C (266 to 277°F), and it is not advisable to use UHMWPE fibers at temperatures exceeding 80 to 100°C (176 to 212°F) for long periods of time. It becomes brittle at temperatures below −150°C (−240°F). Under tensile load, UHMWPE will deform continually as long as the stress is present—an effect called creep.

UNPLASTICISED POLYVINYL CHLORIDE / uPVC / RPVC / RIGID PVC

Unplasticised Polyvinyl Chloride (uPVC) or Rigid PVC (sometimes abbreviated as RPVC), is a phthalate and BPA free and rigid product of Polyvinyl chloride (PVC). It has strong resistance against chemicals, sunlight, and oxidation from water it is extensively used in the building and construction industry as a low-maintenance material for pipe and in profile applications such as doors and windows. The material comes in a range of colours and finishes, including a photo-effect wood finish, and is used as a substitute for painted wood, mostly for window frames and sills when installing double glazing in new buildings, or to replace older single-glazed windows. Other uses include fascia, and siding or weatherboarding. This material has almost entirely replaced the use of cast iron for plumbing and drainage, being used for waste pipes, drainpipes, gutters and downspouts. uPVC is also used for bottles, other non-food packaging, and cards (such as bank or membership cards).

CHLORINATED POLYVINYL CHLORIDE / CPVC

Chlorinated Polyvinyl Chloride (CPVC), is a thermoplastic produced by chlorination of polyvinyl chloride (PVC) resin. Uses include hot and cold water pipe, and industrial liquid handling. CPVC can withstand corrosive water at temperatures greater than PVC, typically 40 to 50°C (104 to 122°F) or higher, contributing to its popularity as a material for water piping systems in residential as well as commercial construction. The principal mechanical difference between CPVC and PVC is that CPVC is significantly more ductile, allowing greater flexure and crush resistance. Additionally, the mechanical strength of CPVC makes it a viable candidate to replace many types of metal pipe in conditions where metal’s susceptibility to corrosion limits its use. CPVC is similar to PVC in resistance to fire. It is typically very difficult to ignite and tends to self-extinguish when not in a directly applied flame. Due to its chlorine content, the incineration of CPVC, either in a fire or in an industrial disposal process, can result in the creation of chlorinated dioxins.

ACRYLONITRILE BUTADIENE STYRENE / ABS

Acrylonitrile Butadiene Styrene (ABS) is a light weight thermoplastic polymer. Used in manufacturing, especially injection molded and extruded products, such as drain-waste-vent (DWV) pipe systems, automotive trim components and bumper bars, medical devices, electrical and electronic assemblies enclosures, protective headwear, whitewater canoes, furniture buffer edging and joinery panels, luggage and protective carrying cases, small kitchen and household appliances, consumer goods, toys and musical instruments. ABS is resistant to aqueous acids, alkalis, concentrated hydrochloric and phosphoric acids, alcohols and animal, vegetable and mineral oils; swollen by glacial acetic acid, carbon tetrachloride and aromatic hydrocarbons; attacked by concentrated sulfuric and nitric acids; and soluble in esters, ketones, ethylene dichloride and acetone. ABS is a terpolymer making it stronger than pure polystyrene, styrene provides a shiny, impervious surface; polybutadiene, a rubbery substance, provides resilience. It is uniquely amorphous and therefore has no true melting point, for the majority of applications can be used between −20 and 80°C (−4 and 176°F). Its mechanical properties vary with temperature and can be influenced by processing conditions—molding at a high temperature improves gloss and heat resistance whereas low temperatures creates high impact resistance and strength. Fibers (usually glass) and other additives can be mixed in the resin pellets to make the final product strong and raise the operating range to as high as 80°C (176°F), (glass transition temperature is approximately 105°C (221°F)). Additionally, coloured pigments can be added to the translucent ivory to white raw material. It’s aging characteristics are largely determined by polybutadiene content and antioxidants in the composition. Other factors include exposure to ultraviolet radiation, for which additives are available to protect against.

POLYVINYLIDENE FLUORIDE / PVDF

Polyvinylidene Fluoride or Polyvinylidene Difluoride (PVDF), is a highly non-reactive and pure thermoplastic fluoropolymer. PVDF is a specialty plastic material in the fluoropolymer family; generally used in applications requiring the highest purity, strength, and resistance to solvents, acids, bases and heat and low smoke generation during a fire event. It is available as piping products, sheet, tubing, films, plate and an insulator for premium wire. A relatively low melting point of around 177°C (351°F) and low density (1.78g/cm3), makes it easily injected, molded or welded and commonly used in the chemical, semiconductor, medical and defense industries, as well as in lithium ion batteries. Used increasingly as a crosslinked closed cell foam in aviation and aerospace applications. A fine powder grade, KYNAR 500 PVDF or HYLAR 5000 PVDF, is also used as the principal ingredient of high-end paints for metals. These paints have extremely good gloss and colour retention, and are in use on commercial and residential metal roofing.

BUY : ARCBEND™ TECHNOLOGY : SWEEP BENDS

Australian producers of quality, made-to-order long radius sweep bends in all pressure ratings, various diameters and angles of 90, 60, 45 and 30 degrees. Our sweep bends are specially engineered and designed to retain their shape and improve flow characteristics, thereby reducing wear and maintenance.