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Injection Molding Plastic Materials RJC Use

ABS (Acrylonitrile Butadiene Styrene)

ABS Injection Molding plastics provide a balanced combination of mechanical toughness, wide temperature range, good dimensional stability, chemical resistance, electrical insulating properties, and ease of fabrication. ABS plastic is available in a wide range of grades, including medium and high-impact, heat-resistant, plateable fire-retardant, and low and high gloss varieties.

Applications: Computer housings, small appliances, automotive interior trim and medical components

Tensile Strength Flexural Modulus Impact Strength Max Temp. Chemical Resistance
5000-7500 psi 270,000-380,000 psi 3.0-7.5 ft-lb/in notched izod 140°-200° F Poor to Fair

Advantages

  • Good impact resistance with toughness and rigidity
  • Metal coatings have excellent adhesion to ABS
  • Excellent processability and appearance

Disadvantages

  • Poor solvent resistance
  • Low dielectric strength (not a good insulator)
  • Low continuous service temperature (melts easily)

ABS + PC (ABS + Polycarbonate Alloy)

PC + ABS Injection Molding plastics offer improved strengths over ABS at a lower cost than Polycarbonate. Exceptional low-temperature Impact Strength. The Injection Molding Plastic material can be modified by adding glass fiber, mineral fillers and flame retardant. 

Applications: Automotive exterior and interior components, medical hardware, electrical housings, computers, monitors, business equipment housings and enclosures

Tensile Strength Flexural Modulus Impact Strength Max Temp. Chemical Resistance
6400-9150 psi 300,000-400,000 psi 8-12 ft-lb/in notched izod 140°-210° F Poor to Fair

Advantages

  • Good impact resistance with toughness and rigidity
  • Metal coatings have excellent adhesion to ABS
  • Excellent indoor UV light color stability
  • Excellent processability and appearance

Disadvantages

  • Poor solvent resistance
  • Low dielectric strength (not a good insulator)
  • Low continuous service temp. (melts easily)

Acetal (POM) (Polyoxymethylene)

Acetal Injection Molding Plastic is semi-crystalline. They offer excellent inherent lubricity, fatigue resistance, and chemical resistance. Acetals suffer from outgassing problems at elevated temperatures and are brittle at low temperatures. Glass-filled and added lubrication grades are available; flame retardant grades are not.

Applications: Mechanical Automotive, Business Machines and Household Appliance, Components, i.e., Slides, Gears, Cams, Bushings, Door Handles and Seat Belt Parts.

Tensile Strength Flexural Modulus Impact Strength Max Temp. Chemical Resistance
6000-22,000 psi 120,000-170,000 psi .8-2 ft-lb/in notched izod 180°-300° F Excellent

Advantages

  • High tensile strength with rigidity and toughness
  • Good impact and solvent resistance
  • Glossy molded surface
  • Low static and dynamic coefficients of friction (slippery)
  • Many grades have FDA and NSF approvals on food and water contact
  • Replace die-cast metal components

Disadvantages

  • Difficult to bond bond
  • Poor resistance to acid and bases
  • Subject to UV degradation

Acrylic (PMMA) (Polymethyl methacrylate)

Acrylic PMMA is a tough, highly transparent Injection Molding Plastic material with excellent resistance to ultraviolet radiation and weathering. It can be colored, molded, cut, drilled, and formed. Acrylic is an economical alternative to polycarbonate (PC) when extreme strength is not necessary. It is often preferred because of its moderate properties, easy handling and processing, and low cost, but behaves in a brittle manner when loaded, especially under an impact force.

Applications: Automotive Transparent Items such as Head/Tail Lenses and Trim, Household Light Fixtures and Decorative Items, Safety Equipment and Shields.

Tensile Strength Flexural Modulus Impact Strength Max Temp. Chemical Resistance
2800-10,9000 psi 221,000-534,000 psi .22-1.1 ft-lb/in notched izod 183°-217° F Excellent

Advantages

  • Excellent optical clarity
  • Excellent weatherability and resistance to sunlight
  • Rigid with good impact resistance
  • Good light transmission

Disadvantages

  • Poor solvent resistance
  • Subject to stress cracking
  • Slightly absorbs moistures
  •  Continuous service temp. (melts easily)
  • Nylon 6-PA (Polyamide)

    Nylons are semi-crystalline Injection Molding Plastics 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 their properties 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. Applications: Automotive components, Bearings, Electronic Connectors, Gears, Consumer Products and Industrial products.

    Tensile Strength Flexural Modulus Impact Strength Max Temp. Chemical Resistance
    6,000-24,000 psi 390,000-1,100,000 psi 2-8 ft-lb/in notched izod 200°-350° F Good to Excellent

    Advantages

    • Temperature capability 600°-700° for short term
    • Excellent chemical resistance
    • High resistance to abrasion
    • Tough and withstands repeated impact

    Disadvantages

    • Absorbs moisture (can affect the electrical and mechanical properties)
    • Requires UV stability
    • Attacked by strong acids/bases
    • High notch sensitivity

Nylon 6/6-PA (Polyamide)

Nylons are semi-crystalline Injection Molding Plastics 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 their properties as a result. Nylons have been compounded with reinforcements, fillers and additives to produce a very wide variety of properties. Nylon 6-6 offers better properties than nylon 6 without being as costly as nylon 4-6. It has the best abrasion resistance of all nylons. Verton, long glass fiber filled materials, by LNP, are excellent metal replacement materials. Applications: Automotive components, electronic connectors, gears, consumer products and industrial products.

Tensile Strength Flexural Modulus Impact Strength Max Temp. Chemical Resistance
8,000-24,000 psi 430,000-1,100,000 psi 2-8 ft-lb/in notched izod 220°-350° F Good to Excellent

Advantages

  • Temperature capability 600°-700° for short term
  • Excellent chemical resistance
  • High resistance to abrasion
  • Tough and withstands repeated impact

Disadvantages

  • Absorbs moisture (can affect the electrical and mechanical properties)
  • Requires UV stability
  • Attacked by strong acids/bases
  • High notch sensitivity

PBT Polyester (Polybutylene Terepthalate)

PBT polyesters are semi-crystalline. They are versatile Injection Molding Plastic materials with a good range of properties. They have excellent electrical properties and are abrasion resistant. PBT has been extensively compounded giving a very wide 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.

Applications: Industrial equipment applications, business equipment, automotive housings-under the hood, power tool casings.

Tensile Strength Flexural Modulus Impact Strength Max Temp. Chemical Resistance
6,000-13,000 psi 300,000-1,200,000 psi 1 ft-lb/in notched izod 250°-420° F Fair to Good

Advantages

  • Good flow
  • Tough
  • Hydrollysis Resistant
  • High impact
  • Easily Processed

Disadvantages

  • Low Max. Use temperature
  • Lower Stiffness than similar PET
  • Lower Strength than similar PET
  • Attacked by Strong Bases

PC (Polycarbonate)

Polycarbonate is an amorphous Injection Molding Plastic material with excellent impact strength, clarity, and optical properties. It is very widely used and a wide variety of compounds are available. Polycarbonate has excellent mechanical properties, and can be molded to tight tolerances. It is attacked by solvents and petrochemicals, and its weatherability is only adequate. Applications: Automotive Headlights, Business Machines, Consumer Products, Telecommunications, Medical Products and Mechanical Goods.

Tensile Strength Flexural Modulus Impact Strength Max Temp. Chemical Resistance
9000-23,000 psi 340,000-1,400,000 psi 2-18 ft-lb/in notched izod 150°-300° F Poor to Fair

Advantages

  • High impact resistance
  • Clarity
  • Good flammability performance
  • Dimensional stability
  • Chemical resistance (PC blends)

Disadvantages

  • Only fair solvent resistance
  • Subject to stress cracking
  • Degrades if not processed correctly
  • High processing temperature
  •  Yellowing after long term exposure to UV light

PEI (Polyetherimid)

PEI is an amorphous, high temperature Injection Molding Plastic material with relatively low cost compared to other high temperature materials. It has excellent elongation and Impact Strength, and can be molded to tight tolerances. Its chemical resistance is not as good as crystalline materials but is excellent for an amorphous material. PEI behaves similar to polycarbonate, but can perform at higher temperatures. Applications: Commercial aircraft interiors, healthcare products, cooking utensils, fiber optics, electrical and electronic applications.

Tensile Strength Flexural Modulus Impact Strength Max Temp. Chemical Resistance
14,000-28,000 psi 480,000-1,300,000 psi 2 ft-lb/in notched izod 375°-420° F Fair to Good

Advantages

  • High heat resistance
  • Exceptional strength and impact modulus
  • High dielectric strength
  • Broad chemical resistance
  • Biocompatible
  • Excellent machinability and finishing characteristic
  • Outstanding processability on conventional molding equipment
  • Flame resistance with low smoke evolution

Disadvantages

  • Translucent and opaque-clear is not available
  • High cost
  • Notch sensitive
  • High processing temps required
  • PE (Polyethylene)

    Polyethylene is a widely used, inexpensive, Injection Molding thermoplastic. It has good inherent lubricity, and is easy to process. Polyethylene has good to excellent chemical resistance. It is also soft and cannot be used in temperatures much above 150. As a family, they are light in weight and possess toughness, chemical resistance, impermeability as well as excellent electrical insulating properties. Applications: Consumer products, houseware items, electronic wire/cable insulators and medical products

    Tensile Strength Flexural Modulus Impact Strength Max Temp. Chemical Resistance
    1900-4500 psi 40,000-105,000 psi 2-No break ft-lb/in notched izod 130°-150° F Good to Excellent

    Advantages

    • Low Cost
    • Impact resistance from -40° to 194° F
    • Moisture resistance
    • Food grades available

    Disadvantages

    • Poor weather resistance
    • High thermal expansion
    • Subject to stress cracking
    • Difficult to bond
    • Flammable
    • Poor temperature capability

LDPE (Low Density Polyethylene)

Polyethylene is a widely used, inexpensive, Injection Molding thermoplastic. It has good inherent lubricity, and is easy to process. Polyethylene has good to excellent chemical resistance. It is also soft and cannot be used in temperatures much above 150. As a family, they are light in weight and possess toughness, chemical resistance, impermeability as well as excellent electrical insulating properties. Low density polyethylene is the softest and most flexible version of this material. It has high elongation giving it excellent impact strength. This is offset by its permanent deformation upon impact. Applications: Consumer products, houseware items, electronic wire/cable insulators and medical products.

Tensile Strength Flexural Modulus Impact Strength Max Temp. Chemical Resistance
1,200-4,000 psi 35,000-48,000 psi No break ft-lb/in notched izod 130°-150° F Good to Excellent

Advantages

  • Low cost
  • Impact resistance from -40° to 194° F
  • Moisture resistance
  • Food grades available

Disadvantages

  • Poor weather resistance
  • High thermal expansion
  • Higher cost
  • Subject to stress cracking
  • Difficult to bond
  • Flammable
  • Poor temperature capability
  • PP (Polypropylene)

    Polypropylene is a widely used, semi-crystalline Injection Molding Plastic 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 Injection Molding Plastic material with excellent chemical resistance. It has no known solvent at 73 F. Polypropylene is difficult to mold to extremely close tolerances. Applications: Packaging, industrial components for fluid processing, household goods, automotive and electrical hardware.

    Tensile Strength Flexural Modulus Impact Strength Max Temp. Chemical Resistance
    4,500-18,500 psi 210,000 -1,500,000 psi 1.4-5.5 ft-lb/in notched izod 150°-300° F Excellent

    Advantages

    • Excellent moisture resistance
    • Food grades available
    • Mold–in hinge possible
    • Good impact strength

    Disadvantages

    • Degraded by UV
    • Flammable (retarded grades available)
    • Attacked by chlorinated solvents

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  • PPS (Polyphenylene Sulfide)

    PPS is a high temperature semi-crystalline Injection Molding Plastic material. It has good mechanical properties and excellent chemical resistance at elevated temperatures. PPS has been compounded extensively and many different types of 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 or glass/mineral filled grades. PPS is very sensitive to molding conditions and must be processed properly to achieve its maximum potential. Applications: Hydraulic components, bearings, cams, valves and electronic parts

    Tensile Strength Flexural Modulus Impact Strength Max Temp. Chemical Resistance
    14,000-28,000 psi 550,000 -2,900,000 psi .5-6 ft-lb/in notched izod 450°-500° F Good to Excellent

    Advantages

    • Capable of extended usage at 450° F
    • Good radiation resistance
    • Good solvent and chemical resistance
    • Excellent dimensional stability
    • Flame retardant
    • Low water absorption

    Disadvantages

    • Difficult to process (high melt temps)
    • High cost
    • Fillers required to obtain good impact strength
    • Attacked by chlorinated hydrocarbons

TPE (Thermoplastic Elastomer)

Thermoplastic elastomers (TPE) are a combination of polymers (usually a plastic and a rubber) which consist of both thermoplastic and elastomeric properties resulting in a product that is extremely easy to use in manufacturing a variety of products. TPE Injection Molding Plastic require little or no compounding and no need to add reinforcing agents, stabilizers or cure systems. Applications: Automotive Fluid Delivery Systems, Household appliances, Sporting goods, Electrical and Medical components.

Tensile Strength Flexural Modulus Impact Strength Max Temp. Chemical Resistance
1,000-7,000 psi 5,000-800,000 psi 2.5-No Break ft-lb/in notched izod 200°-300° F Fair to Good

Advantages

  • Low compression and tension set
  • Easily processed
  • Fatigue resistance
  • Good tear strength

Disadvantages

  • Flammable but flame retardant grades available
  • Extensive heat aging causes severe change in mechanical properties
  • High cost

TPU (Thermoplastic Polyurethane Elastomer)

Injection Molding Thermoplastic polyurethane elastomers exhibit excellent abrasion and wear resistance and high tensile and tear strengths. TPUs are tough, durable, easy to clean and well-suited to applications that demand the elasticity of rubber combined with high stability. In addition, the inherent translucency of these products makes it easy to color and that is an added benefit in many applications. Applications: Automotive and Aerospace Applications, Medical and Optical purposes, Electrical Wire and Cable Coverings.

Tensile Strength Flexural Modulus Impact Strength Max Temp. Chemical Resistance
6960-12,000 psi 260,000-340,000 psi .80-10.1 ft-lb/in notched izod 160°-250° F Fair to Good

Advantages

  • Chemical Resistant
  • Low temp. flexibility
  • Abrasion and wear resistant
  • Easily Processed

Disadvantages

  • Shorter shelf life
  • Lower Stiffness than similar PET
  • Drying required pre-processing
  • Narrow hardness range