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Thermoplastic Material Selection Guide

Disclaimer:

The information presented below is of a general nature and shall not be relied upon other than for

preliminary material identification purposes only.

ABS (Acrylanitrile Butadiene Styrene)

ABS is an amorphous polymer with good Impact Strength and excellent appearance. It is easy to process and

is widely used for computer housings, small appliances, automotive interior trim, and medical components. Itis available in flame retardant grades, and medical grades. ABS has poor chemical resistance.

Tensile Strength5000-7500 psi

Flexural Modulus270,000-380,000 psi

Impact Strength

3.0-7.5 ft-lb/in notched izod

Maximum Temp.200 F short duration, 140 F long term

Chemical Resistancepoor to fair

Cost$$$

Brand NamesCycolac (GE) Lustran (Monsanto)

ABS-Polycarbonate Alloy

These alloys offer improved strengths over ABS at a lower cost than Polycarbonate. Exceptional lowtemperature Impact Strength. Flame retardant grades are available. Due to the world shortage ofpolycarbonate production capacity, lead times for these materials are long, and availability is limited.

Tensile Strength6400-9150 psi

Flexural Modulus

c Injection Molding Engineering Materials http://www.actech-inc.com/en

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300,000-400,000 psi

Impact Strength8-12 ft-lb/in notched izod

Maximum Temp.210 F short duration, 140 F long term

Chemical Resistancepoor to fair

Cost$$$$

Brand Names

Cycoloy(GE), Pulse(Dow)

Acetal (POM)

Acetal polymers are semi-crystalline. They offer excellent inherent lubricity, fatigue resistance, and chemical

resistance. Acetals suffer from outgassing problems at elevated temperatures, and are brittle at lowtemperatures. Glass filled, and added lubrication grades are available, flame retardant grades are not.

Tensile Strength6000-22,000 psi

Flexural Modulus120,000-170,000 psi 1,200,000 psi with carbon fiber

Impact Strength

.8-2 ft-lb/in notched izod, 15 lb/in for impact modified grades

Maximum Temp.300 F short duration with filled grades, 180 F long term

Chemical Resistanceexcellent

Cost$$$

Brand NamesDuracon (Celanese), Delrin (Dupont)

PMMA, Acrylic

Acrylics are amorphous polymers with excellent clarity. They are widely used in optical applications. Acrylics


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also have excellent weather ability and do very well in outdoor applications.

Tensile Strength6000-11,000 psi

Flexural Modulus200,000-600,000 psi

Impact Strength.2-.4 ft-lb/in notched izod, 2.5 lb/in for impact modified grades

Maximum Temp.220 F short duration , 170 F long term

Chemical Resistance

excellent

Cost$$

Brand NamesPerspex (ICI), Plexiglas (AtoHass)

Nylon 6

Nylons are semi-crystalline polymers with a good range of properties. Nylons are widely used because they

have a good cost to performance ratio. Lower numbered nylons, 6 ,6-6, 4-6, absorb moisture and change theirproperties as a result. Nylons have been compounded with reinforcements, fillers and additives to produce a

very wide variety of properties. Nylon 6 has the lowest modulus of all nylon grades.

Tensile Strength6,000-24,000 psi up to 36,000 psi with long glass or carbon

Flexural Modulus

390,000-1,100,000 psi 2,000,000 with long glass fiber or carbon

Impact Strength2-8 ft-lb/in notched izod

Maximum Temp.~300 F short duration 200 F long term

Chemical ResistanceGood to Excellent

Cost$$$

Brand Nameslots


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Nylon 6-6

Nylons are semi-crystalline polymers with a good range of properties. Nylons are widely used because theyhave a good cost to performance ratio. Lower numbered nylons, 6 ,6-6, 4-6, absorb moisture and change their

properties as a result. Nylons have been compounded with reinforcements, fillers and additives to produce avery wide variety of properties. Nylon 6-6 offers better properties than nylon 6 without being as costly asnylon 4-6. It has the best abrasion resistance of all nylons. Verton, long glass fiber filled materials, by LNP,

are excellent metal replacement materials.

Tensile Strength8,000-24,000 psi up to 36,000 psi with long glass or carbon

Flexural Modulus430,000-1,100,000 psi 2,000,000 with long glass fiber or carbon

Impact Strength

2-8 ft-lb/in notched izod


Chemical Resistance

Good to Excellent

Cost$$$

Brand Names

Celanese Nylon (), Verton (LNP), Zytel (Dupont)

Nylon 11

Nylons are semi-crystalline polymers with a good range of properties. Nylons are widely used because they

have a good cost to performance ratio. Higher numbered nylons, 11,12, do not absorb moisture to the extentthat lower numbered nylons do, as a result their properties are more stable over a wide range of conditions.However , they are more expensive. These Nylons have been compounded with reinforcements, fillers and

additives to produce a very wide variety of properties. Nylon 11 offers better Impact Strength anddimensional stability than lower numbered nylons. It is also more flexible.

Tensile Strength8,000-17,000 psi

Flexural Modulus170,000-1,200,000 psi

Impact Strength


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2-No Break ft-lb/in notched izod


Chemical ResistanceGood to Excellent

Cost$$$$$

Brand NamesRilsan(Elf AtoChem)

PBT Polyester (Polybutylene Terepthalate)

PBT polyesters are semi-crystalline. They are versatile materials with a good range of properties. They haveexcellent electrical properties and are abrasion resistant. PBT has been extensively compounded giving a verywide range of properties. PBT performs much like Nylon but can handle higher temperatures and does not

absorb moisture. PBT has excellent impact strength but is very notch sensitive.

PBT is very anisotropic in shrinkage, so it is difficult to mold to extremely tight tolerances.

Tensile Strength

6,000-13,000 psi

Flexural Modulus300,000-1,200,000 psi

Impact Strength

1 ft-lb/in notched izod . 30+ ft-lb/in un-notched

Maximum Temp.420 F short duration 250 F long term

Chemical ResistanceFair to Good

Cost

$$$

Brand NamesCelanex (Hoechst Celanese), Valox (GE)

LCP (Polyester Liquid Crystal Polymer)

LCPs are cool, relatively new materials with interesting properties. They have Tensile Strength and modulus


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close to aluminum.

Because of the highly oriented, rod like nature, of the polymer molecules, LCPs present some interestingdesign challenges. This is because the molecules will only form in straight lines. Additionally, the high

orientation only occurs within about .040 of the surface of the part. Molecular orientation below this skin israndom. As a result all of the strength of the material is in the skin.

Good design data is not available for these materials, so prototyping is a must. prototypes must be molded,

because of the molecular orientation mentioned above.


Flexural Modulus1,300,000-4,600,000 psi with carbon fiber 3.2x10E6 with glass fiber

Impact Strength

1.1-11 ft-lb/in notched izod

Maximum Temp.

500 F short duration 430 F long term

Chemical Resistance

Good to Excellent

Cost$$$$$$$$

Brand NamesVectra (Hoechst Celanese), Xydar (Amoco)

PP, Polypropylene

Polypropylene is a widely used, semi-crystalline material. It has been extensively compounded to provide a

wide range of properties at a wide range of costs. In general, polypropylene is a low temperature material withexcellent chemical resistance. It has no known solvent at 73 F.

Polypropylene is difficult to mold to extremely close tolerances .


Flexural Modulus

210,000 -1,500,000 psi

Impact Strength1.4-5.5 ft-lb/in notched izod

Maximum Temp.

Up to 300 +F short duration 150 F long term


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Chemical ResistanceExcellent

Cost

$ to $$$

PC, Polycarbonate

Polycarbonate is an amorphous material with excellent Impact Strength, clarity, and optical properties. It isvery widely used and a wide variety of compounds are available. Polycarbonate is a victim of its own success

as worldwide production is at capacity, and there are currently long lead times for this material.

Polycarbonate has excellent mechanical properties, and can be molded to tight tolerances. It is attacked bysolvents and petrochemicals, and its weatherability is only adequate.

Tensile Strength

9,000-23,000 psi

Flexural Modulus

340,000-1,400,000 psi

Impact Strength2- 18 ft-lb/in notched izod

Bulletproof un-notched


Chemical ResistancePoor to Fair

Cost$$$$

Brand NamesCaliber (Dow), Lexan (GE)

Polyimide (Thermoplastic) (Aurum)

Polyimides offer excellent properties at high temperatures. A thermoplastic version of this material became

available recently. Both amorphous and crystalline grades are offered. Polyimide materials are attacked byalkali and are very expensive.

Tensile Strength

13,000-36,000 psi

Flexural Modulus


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420,000 -2,800,000 psi


Maximum Temp.580 +F short duration 450 F long term

Chemical ResistanceGood - attacked by alkali

Cost$$$$$$$$$$$$$$$$!!! (expensive stuff)

PPO Modified Polyphenylene Oxide (Noryl)

By itself PPO is an excellent material with wonderful properties, unfortunately it cannot be processed byconventional means. As a result, PPO has been modified by placing it in a styrene matrix to create a readilyprocessable amorphous material with properties superior to ABS. Modified PPO has good Impact Strength,

stiffness, surface appearance, and flame retardency. It has fair to good chemical resistance too, but is moreexpensive compared to ABS.

Tensile Strength

6,000-18,000 psi

Flexural Modulus270,000 -1,400,000 psi




Cost$$$$

Brand NamesNoryl (GE)

PPS Polyphenylene Sulfide

PPS is a high temperature semi-crystalline material. It has good mechanical properties and excellent chemicalresistance at elevated temperatures. PPS has been compounded extensively and many different types of


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properties are available. PTFE filled PPS is one of the best bearing materials available.

Unfilled grades of PPS have poor properties, so components are usually made from glass filled orglass/mineral filled grades.

PPS is very sensitive to molding conditions and must be processed properly to achieve its maximum potential.

Tensile Strength

14,000-28,000 psi

Flexural Modulus550,000 -2,900,000 psi

Impact Strength

.5-6 ft-lb/in notched izod


Chemical Resistance

Good to excellent

Cost$$$$ to $$$$$$$

Polysulfone

Polysulfone is a high temperature amorphous material with relatively low cost. It is transparent and can be

used at temperatures of up to 300 F. Polysulfone has been compounded, with glass and mineral filled gradesavailable.


Flexural Modulus

390,000-1,500,000 psi

Impact Strength.65-7 ft-lb/in notched izod



Cost$$$$$


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