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Downhole Plastics, Composites, and Ceramics

Plastics, usually high performance types, are commonly used in logging tools as electrical insulators and as structural elements (supports for detectors and the like).  In addition to simple plastics, composite materials have been used in downhole tools, such as fiber reinforced phenolic resins (Garolite, Micarta, etc.) and fiberglass reinforced plastic (FRP).  Some manufacturers have used machinable ceramics, but such use has been limited by cost.

The following list is incomplete, and reflects our experience with various polymers, composites, and ceramics.  This effort is organized into three main groups consistent with the page title above, and within each group materials are listed alphabetically using the name we prefer here at AnaLog Services, Inc. (a purely subjective determination).  The date shown in brackets is that of commercialization or first mass production if known.  Properties are for rod stock.  Temperatures in brackets are from a second source, less conservative than our primary source.  Prices are rounded to the nearest dollar for comparison purposes only, and are per foot of rod stock except where otherwise noted (based on October, 2005 quotes).  If we have omitted something or if you know cheaper sources that allow relatively small orders, please contact us.

PLASTICS

Most common plastics are unsuitable for use in downhole logging tools because of the elevated temperatures encountered in even moderately deep wells.  Any plastic material with a maximum usable temperature rating of less than 200F should not be considered, and such plastics have been omitted from this list.  Boedeker Plastics, Inc. has a great Sortable Materials Properties Table complete with links to datasheets covering most common plastics (thanks to Scott Baer).

CPVC (chlorinated polyvinyl chloride a/k/a hot and cold water pipe plastic)  Amorphous Thermoplastic  [PVC 1938]
Color:  Gray, Cream, Others     Machining:  Easy
Maximum Temperature:  200F  (217F Melting Point)     Dielectric (Insulator) Strength:  Outstanding - 1,250 V/mil
Tensile Strength:  Good - 8,200 psi     Flexural Strength:  Good - 15,000 psi
Impact Resistance (Izod Notch):  Good - 1.6 ft-lb/in
Cost:  1" - $4, 2" - $17

Delrin or ACL or POM (acetal or polyoxymethylene; Celcon, Ultraform)  Semi-Crystalline Thermoplastic  [1958]
Color:  Opaque White, Others     Machining:  Easy     Special Features:  Low Friction; Creep and Fatigue Resistant
Maximum Temperature:  180F, 185F Glass Filled  (347F Melting Point)
Dielectric (Insulator) Strength:  Good - 450 V/mil
Tensile Strength:  Excellent - 11,000 psi     Flexural Strength:  Good - 13,000 psi
Impact Resistance (Izod Notch):  Good - 1.0 ft-lb/in
Cost:  1" - $4, 2" - $14
Note:  Delrin is at the low end of the temperature range usable in logging tools, but several manufacturers have gotten away with using it.  It has qualities that recommend it even with its marginal temperature rating.

Halar or ECTFE (ethylene-chlorotrifluoroethylene; Flametec)  Semi-Crystalline Thermoplastic Copolymer
Color:  Translucent to Opaque Off-White, Others     Machining:  Easy     Special Features:  Low Friction
Maximum Temperature:  302F  (464F Melting Point)     Dielectric (Insulator) Strength:  Excellent - 500 V/mil
Tensile Strength:  Good - 7,000+ psi     Flexural Strength:  Good?
Impact Resistance (Izod Notch):  Excellent
Cost:  1" - $52, 2" - $
Note:  ECTFE is the toughest of all the fluoropolymers, exhibiting nylon-like durability.  It has extremely low permeability to liquids, gases, and vapors, and is highly resistant to most chemicals.

Nylon 6/6 or PA (polyamide)  Semi-Crystalline Thermoplastic Polycondensate  [1935]
Nylon is named after New York and London.  On "N" day in 1940, 780,000 pairs of "Nylons" were sold in a single day.
Color:  Translucent to Opaque Off-White, Black, Others     Machining:  Easy     Special Features:  Low Friction
Maximum Temperature:  White 185F [225F]  (490F Melting Point)
Dielectric (Insulator) Strength:  Good - 400 V/mil
Tensile Strength:  Excellent - 11,500 psi     Flexural Strength:  Good - 15,000 psi
Impact Resistance (Izod Notch):  Fair - 0.6 ft-lb/in
Cost:  1" - $3, 2" - $11
Note:  Cast Nylon 6 will go to 200F [230F and intermittently to 330F]; it is an excellent electrical insulator, but has poor impact resistance, and is more expensive than Nylon 6/6.  Oil-impregnated cast Nylon will go to 230F, and is also an excellent electrical insulator, but with good impact resistance; it is comparable in cost to Cast Nylon 6.

PBI (polybenzimidazole; Celazole)
Color:  Black     Machining:  Difficult     Special Features:  Low Friction
Maximum Temperature:  650F  (800F Melting Point)     Dielectric (Insulator) Strength:  Excellent - 550 V/mil
Tensile Strength:  Outstanding - 23,000 psi     Flexural Strength:  Outstanding - 32,000 psi
Impact Resistance (Izod Notch):  Poor - 0.5 ft-lb/in
Cost:  1" - $492, 2" - $1,020!
Note:  Highest performing engineering plastic currently available, and priced to reflect it.

PEEKTM (polyetheretherketone; Arotone, Doctalex, Kadel, Ketron, Mindel, PEEKTM, Santolite, Staber, Zyex)
Semi-Crystalline Thermoplastic Polycondensate  [1962]
Color:  Opaque Tan, Brown, Black     Machining:  Difficult     Special Features:  Low Friction; Gamma Ray Resistant
Maximum Temperature:  464F, 480F Glass Filled  (644F Melting Point)
Dielectric (Insulator) Strength:  Good - 480 V/mil
Tensile Strength:  Excellent - 16,000 psi     Flexural Strength:  Excellent - 25,000 psi
Impact Resistance (Izod Notch):  Good - 1.0 ft-lb/in
Cost:  1" - $73, 2" - $274
Note:  Victrex® is the exclusive manufacturer of PEEKTM polymer; see their informative website www.victrex.com.

PET or PET-P (polyethylene terephthalate polyester; Ensitep, Ertalyte)  Semi-Crystalline Thermoplastic  [1942]
Part of the
polyester plastic family.  The PETF film version is commonly known as Mylar (a DuPont trademark).
Color:  Opaque White     Machining:  Easy     Special Features:  Dimensionally Stable; Low Friction
Maximum Temperature:  230F  (490F Melting Point)     Dielectric (Insulator) Strength:  Fair - 400 [385] V/mil
Tensile Strength:  Excellent - 11,500 [12,400] psi     Flexural Strength:  Good - 15,000 [18,000] psi
Impact Resistance (Izod Notch):  Fair - 0.7 [Poor - 0.5] ft-lb/in
Cost:  1" - $4, 2" - $16

PPO (Modified) (polyphenylene oxide-styrene alloy; Ashley, Noryl)  Thermoplastic Polycondensate  [1965]
Color:  Black     Machining:  Easy     Special Features:  Low Friction
Maximum Temperature:  240F  (310F Melting Point)     Dielectric (Insulator) Strength:  Excellent - 500 V/mil
Tensile Strength:  Good - 9,600 psi     Flexural Strength:  Good - 13,500 psi
Impact Resistance (Izod Notch):  Excellent - 5.0 ft-lb/in
Cost:  1" - $7, 2" - $28

Polycarbonate or PC (Hyzod, Lexan, Makrolon, Tuffak)  Amorphous Thermoplastic Polycondensate  [1958]
Color:  Colorless Transparent, Others     Machining:  Easy     Special Features:  Dimensionally Stable
Maximum Temperature:  240F [270F]  (310F Melting Point)     Dielectric (Insulator) Strength:  Fair - 390
Tensile Strength:  Good - 9,500 psi     Flexural Strength:  Good - 15,000 psi
Impact Resistance (Izod Notch):  Outstanding - 13 ft-lb/in
Cost:  1" - $7, 2" - $29
Note:  Glass-filled black polycarbonate will go to 266F, and it is a better electrical insulator.  But is over twice as expensive, and exhibits only a fraction of the impact resistance of plain polycarbonate (Izod Notch 2 ft-lb/in).

Polyetherimide or PEI (Tempalux, Ultem)  Amorphous Thermoplastic
Color:  Light to Dark Amber, Opaque Tan Glass Filled     Machining:  Difficult?     Special Features:  Low Friction
Maximum Temperature:  340F  (426F Melting Point)     Dielectric (Insulator) Strength:  Excellent - 830 V/mil
Tensile Strength:  Excellent - 16,500 psi     Flexural Strength:  Excellent - 20,000 psi
Impact Resistance (Izod Notch):  Poor - 0.5 ft-lb/in
Cost:  1" - $20, 2" - $75

Polyimide or PI (Aurum, Duratron, Envex, Kapton, Kinel, Matrimid, Meldin, NEW-TPI, Vespel, VTEC)
Thermoplastic / Thermoset Polycondensate  [1955]
Color:  Yellow-Tan, Brown     Machining:  Easy     Special Features:  Low Friction
Maximum Temperature:  550F  (Does Not Melt)     Dielectric (Insulator) Strength:  Excellent - 560 V/mil
Tensile Strength:  Excellent - 12,500 psi     Flexural Strength:  Good - 16,000 psi
Impact Resistance (Izod Notch):  Fair - 0.8 ft-lb/in
Cost:  1" - $493, 2" - $1,735!
Note:  The new player in town is VTEC; it is being called "the plastic ceramic" by some users.  Aurum, Duratron, and Envex are no longer in production.

Polypropylene or PP  Crystalline Thermoplastic  [1955]
Color:  White     Machining:  Very Easy     Special Features:  Lightweight
Maximum Temperature:  210F  (320F Melting Point)     Dielectric (Insulator) Strength:  Excellent - 500-660 V/ml
Tensile Strength:  Fair - 4,800 psi     Flexural Strength:  Fair - 7,000 psi
Impact Resistance (Izod Notch):  Good - 1.9 ft-lb/in
Cost:  1" - $2, 2" - $9
Note:  The homopolymer values are given above; the co-polymer exhibits slightly inferior maximum temperature and dielectric characteristics, but has much better impact resistance (Izod Notch 7.5 ft-lb/in).  One of my favorite uncles and a great scientist, Max Levine, was instrumental in the commercialization of polypropylene fiber (Herculon).

Polysulfone or PSU (Udel, Ultrason)  Amorphous Thermoplastic Polycondensate  [1965]
Color:  Liight Amber     Machining:  Easy    Special Features:  Dimensionally Stable; Low Friction, Radiation Resistant
Maximum Temperature:  285F [300F]  (371F Melting Point)     Dielectric (Insulator) Strength: Good - 425 V/mil
Tensile Strength:  Excellent - 10,200 psi     Flexural Strength:  Good - 15,400 psi
Impact Resistance (Izod Notch):  Good - 1.3 ft-lb/in
Cost:  1" - $12, 2" - $41

Ryton or PPS (polyphenylene sulfide; Fortron, Techtron)  Semi-Crystalline Thermoplastic Polycondensate  [1973]
Color:  Tan, Brown     Machining:  Easy     Special Features:  Dimensionally Stable; Low Friction; Chemical Resistant
Maximum Temperature:  425F, 450F 40% Glass Filled, Intermittent to 500F  (545 Melting Point)
Dielectric (Insulator) Strength:  Excellent - 541 V/mil, Fair - 385 V/mil 40% Glass Filled
Tensile Strength:  Excellent - 13,500psi, 13,000 psi GF     Flexural Strength: Excellent - 21,000 psi, 23,000 psi GF
Impact Resistance (Izod Notch):  Fair - 0.6 ft-lb/in, Good - 1.0 ft-lb/in 40% Glass Filled
Cost:  1" - $86, 2" - $
Note:  Ryton was originally developed specifically for downhole oilfield applications.

Teflon or PTFE (polytetrafluoroethylene)  Semi-Crystalline Thermoplastic  [1950]
Color:  Opaque White     Machining:  Easy     Special Features:  Very Low Friction
Maximum Temperature:  500F  (600F Melting Point)     Dielectric (Insulator) Strength:  Fair - 285 V/mil
Tensile Strength: Poor - 3,900 psi     Flexural Strength:  No Break, 1,950 psi Glass Filled
Impact Resistance (Izod Notch):  Good - 3.5 ft-lb/in
Cost:  1" - $10-17, 2" - $40-61
Note:  Teflon is used in many downhole tools, but it is fairly soft and is noted for susceptibility to creep (deformation).  Glass filled or mica filled (Fluorosint) Teflon exhibits improved structural properties.  The mechanical grade Teflon is reprocessed material; while it is somewhat less expensive, it is rated as a poor electrical insulator (presumably because of impurities).  Other fluoropolymers are available, such as PFA, ETFE (Tefzel), FEP, PVDF (Kynar, Hylar), (P)CTFE (Kel-F), etc.; they are all more expensive than Teflon, but several offer better creep performance.
See our pages on Teflon Insulated Wire and Teflon Tubing.

Torlon or PAI (polyamide-imide)  Amorphous Thermoplastic
Color:  Greenish-Tan, Brown, Black     Machining:  Easy    Special Features:  Dimensionally Stable; Low Friction
Maximum Temperature:  500F  (527F Melting Point)     Dielectric (Insulator) Strength:  Excellent - 580 V/mil
Tensile Strength:  Excellent - 18,000 psi     Flexural Strength:  Excellent - 24,000 psi
Impact Resistance (Izod Notch):  Good - 2.0 ft-lb/in
Cost:  1" - $107, 2" - $431
Note:  Highest performing melt-processable engineering plastic currently available, and priced to reflect it.

COMPOSITES

Composites consist of thermoset resin impregnated layers of substrate, or base material.  Industrial composites are divided into two major classes according to the pressure applied during the curing process - under 100 psi are referred to as low pressure laminates, and over 100 psi, high pressure laminates.  The base (reinforcement material) may be paper, cotton cloth, fiberglass, or a host of other synthetic fibers.  The resin may be phenolic (phenol-formaldehyde) [1909], melamine (melamine formaldehyde) [1938], polyester [1942], silicone [1943], epoxy [1946], or others.  Most composites weigh about half as much as aluminum.  Phenolic resin, dating back to 1909, is the earliest mass produced synthesized plastic polymer.  It is a noble predecessor to our modern plastics (Bakelite and Formica, a paper laminate, are familiar phenolic resin based products), yet phenolic composites remain useful in logging tools to this day.  Micarta was the Westinghouse trade name for their early phenolic composites, now part of Norplex; Garolite is the McMaster-Carr equivalent (both lines now include other resins).  Atlas Fibre is a large manufacturer of composites; see their Material Specifications table.

Fiberglass or FRP (fiberglass reinforced plastic)
Color:  Green, Tan, Red, Others     Machining:  Easy (Nasty and Quickly Wears Conventional Tooling)
Maximum Temperature:  140-400F (Resin / Construction Dependent)  (Does Not Melt)
Dielectric (Insulator) Strength:  Poor to Excellent (Resin / Construction Dependent)
Tensile Strength:  Generally Excellent     Flexural Strength:  Generally Excellent
Impact Resistance (Izod Notch):  Generally Excellent
Cost:  Varies Widely
Note:  NEMA GP03 is a glass fiber reinforced polyester resin laminate capable of up to 400F operation, but unfortunately it is not easily made into rod stock.  Some of the Garolite / Micarta composites are actually FRPs; see Garolite G-10 and G-11 below.

Garolite / Micarta NEMA G-10 (fiberglass reinforced epoxy resin, FR4 for flame retardant version)
Color:  Opaque Green or Brown-Green     Machining:  Easy (Nasty and Quickly Wears Conventional Tooling)
Maximum Temperature:  284F  (Does not melt, but will darken and eventually char at higher temperatures.)
Dielectric (Insulator) Strength:  Excellent - 800 V/mil
Tensile Strength:  Outstanding - 45,000 / 38,000 psi     Flexural Strength:  Outstanding - 75,000 / 65,000 psi
Impact Resistance (Izod Notch):  Excellent - 14 / 12 ft-lb/in
Cost:  1" - $15, 2" - $56

Garolite / Micarta NEMA G-11 (fiberglass reinforced epoxy resin, FR5 for flame retardant version)
Color:  Opaque Green     Machining:  Easy (Nasty and Quickly Wears Conventional Tooling)
Maximum Temperature:  350F  (Does not melt, but will darken and eventually char at higher temperatures.)
Dielectric (Insulator) Strength:  Excellent - 900 V/mil
Tensile Strength:  Outstanding - 43,000 / 37,000 psi     Flexural Strength:  Outstanding - 80,000 / 70,000 psi
Impact Resistance (Izod Notch):  Excellent - 12 / 9 ft-lb/in
Cost:  1" - $26, 2" - $103

Garolite / Micarta NEMA XX (paper reinforced phenolic resin)
Color:  Opaque Tan or Copper     Machining:  Easy
Maximum Temperature:  284F  (Does not melt, but will darken and eventually char at higher temperatures.)
Dielectric (Insulator) Strength:  Excellent - 750 V/mil
Tensile Strength:  Excellent - 15,000 / 12,000 psi     Flexural Strength:  Good - 16,000 / 13,200 psi
Impact Resistance (Izod Notch):  Fair - 0.65 / 0.6 ft-lb/in
Cost:  1" - $8, 2" - $33

Garolite / Micarta NEMA CE (cotton canvas reinforced phenolic resin)
Color:  Opaque Tan to Brown     Machining:  Easy
Maximum Temperature:  239F [257F]  (Does not melt, but will darken and eventually char at higher temperatures.)
Dielectric (Insulator) Strength:  Excellent - 550 V/mil
Tensile Strength:  Excellent - 11,000 / 9,000 psi     Flexural Strength:  Good - 17,500 / 15,000 psi
Impact Resistance (Izod Notch):  Good - 1.7 / 1.5 ft-lb/in
Cost:  1" - $10, 2" - $34
Note:  Machined parts are tougher than Garolite LE due to the heavier reinforcement fabric, but does not machine as nicely.

Garolite / Micarta NEMA LE (cotton linen reinforced phenolic resin)
Color:  Opaque Tan to Brown     Machining:  Easy
Maximum Temperature:  250F [285F]  (Does not melt, but will darken and eventually char at higher temperatures.)
Dielectric (Insulator) Strength:  Excellent - 625 V/mil
Tensile Strength:  Excellent - 13,000 / 9,000 psi     Flexural Strength:  Excellent - 22,000 / 16,000 psi
Impact Resistance (Izod Notch):  Good - 1.35 / 1.1 ft-lb/in
Cost:  1" - $12, 2" - $45
Note:  Machines cleaner than Garolite CE due to the finer reinforcement fabric.

CERAMICS

There are a number of machinable ceramics that have been used in downhole logging tools.  Some of the glass-mica ceramics can even be machined with conventional tooling, but most types require carbide tooling, with the toughest requiring diamond tooling.  There are a few types of castable ceramics that can serve as electrical insulators, but some types are conductive.  What all ceramics have in common is high cost.


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03-30-02
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