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TOP 10 Plastic Injection Molding Material Selection Guide

TOP 10 Plastic Injection Molding Material Selection Guide

Plastic Injection Molding Material Selection Guide

      Ten Engineering Thermoplastics—Performance × Cost × Application in One Chart

 

        Injection molding products live or die by the material you choose. Resin selection sets the ceiling for product positioning, unit cost, processing strategy, and long-term reliability. Based on the real-world needs of automotive, medical, consumer electronics, and food-contact industries, this guide distills ten industrial-grade thermoplastics into an executive-level reference. Each resin is presented in three parts—Key Value → Core Properties → Typical Use Case—so R&D and purchasing teams can communicate with zero ambiguity.

 

I. Five Axes for Resin Decisions

 

AxisCore QuestionCritical DataCommon Pitfall
1. MechanicalHow much tension, compression, torsion, shear?Tensile strength, flexural modulus, Izod impactFocusing on tensile strength and ignoring impact
2. ThermalPeak long-term / short-term temperature?HDT, melt point, TgChecking melt point but not HDT
3. ChemicalAcids, alkalis, oils, alcohols?Chemical compatibility chartsOverlooking detergents / sunscreen attack
4. Optical / UVOutdoor UV, light transmission?Transmittance, ΔYI yellowingIgnoring outdoor yellowing life
5. CostTCO, not raw price onlyRaw resin × cycle time × toolingCheap resin that drags out cycle time

 

II. Snapshot of Ten Mainstream Thermoplastics

 

01｜ABS – Acrylonitrile-Butadiene-Styrene

ABS塑膠樹酯汽車空調

Appearance-grade first choice / plating-friendly

  • Value proposition: High toughness and excellent dimensional stability—perfect for high-gloss or plated finishes.

  • Core metrics: Impact ≈ 220 J/m | Continuous service ≈ 90 °C.

  • Typical uses: Automotive A/C panels, appliance fascias, game-console housings.

  • Mass production of ABS Material Products

 

02｜PA (Nylon 6/6,6/12)

PA尼龍汽車進氣支管

Structural strength / GF-ready

  • Value proposition: High tensile and wear resistance; 30 % glass-fiber grades rival aluminum.

  • Core metrics: Tensile 6 000–24 000 psi | Continuous service 177 °C.

  • Typical uses: Power-tool gearboxes, intake manifolds, sports-equipment fasteners.

  • Mass production of PA Nylon Materail Products

 

 

03｜HDPE – High-Density Polyethylene

HDPE寶特瓶蓋

Food-contact safe / high toughness, low cost

  • Value proposition: Chemically inert with excellent impact resistance; FDA/EU compliant.

  • Core metrics: Density 0.95 g/cm³ | Continuous service 120 °C.

  • Typical uses: Detergent bottles, refuse bins, agricultural pipes.

  • Mass production of HDPE Material Products

04｜LDPE – Low-Density Polyethylene

LDPE塑膠樹酯

Ultra-flexible / high clarity

  • Value proposition: Low melt point and extreme ductility—ideal for film and extrusion jacketing.

  • Core metrics: Elongation > 500 % | Max service 90 °C.

  • Typical uses: Cling film, soft-grip over-jackets, playground slide skins.

  • Mass production of LDPE Material Products

05｜PC – Polycarbonate

PC塑膠樹酯車燈

Optical-grade clarity / extreme impact strength

  • Value proposition: ≥ 89 % light transmission; up to 250 × the impact strength of glass.

  • Core metrics: Vicat 135 °C | Izod impact > 18 ft-lb/in.

  • Typical uses: Riot shields, headlamp lenses, helmet shells, 5 G radomes.

  • Mass production of PC Material Products

06｜POM – Polyoxymethylene (Acetal)

POM塑膠樹酯齒輪組

High precision / self-lubricating drive parts

  • Value proposition: Low friction coefficient (~ 0.2); gear efficiency 8–10 % higher than PA.

  • Core metrics: Shrinkage ≈ 2 % | Continuous service 180 °C.

  • Typical uses: Timing gears, slide rails, precision lock components.

  • Mass production of POM Material Products

07｜PMMA – Polymethyl Methacrylate (Acrylic)

PMMA塑膠樹酯 汽車尾燈

Weatherable clarity / cosmetic optics

  • Value proposition: UV yellowing resistance > 5 years; 92 % light transmission.

  • Core metrics: Pencil hardness 3H | Heat resistance 130 °C.

  • Typical uses: Vehicle tail-lamps, display windows, pool railings, premium packaging windows.

  • Mass production of PMMA Material Products

08｜TPU – Thermoplastic Polyurethane

TPU手機殼

High elasticity & wear resistance / soft-touch over-mold

  • Value proposition: Shore A 60-75 tunable; tear strength > 100 kN/m.

  • Core metrics: No cracking at −40 °C | Excellent oil and grease resistance.

  • Typical uses: Drop-proof phone cases, smart-band straps, athletic shoe soles.

09｜TPE / TPR – Thermoplastic Elastomer

TPE塑膠樹酯

Overmolding companion / fully recyclable

  • Value proposition: Rubber feel with thermoplastic processing; bonds well to PP and ABS.

  • Core metrics: Elongation > 500 % | Continuous service 170 °C.

  • Typical uses: Tool grips, cable boots, child-safe toys.

  • Analysis of Overmolding Products

10｜PP – Polypropylene

PP塑膠樹酯保鮮盒

Design flexibility / best cost–performance

  • Value proposition: Only 85 % the weight of ABS; survives 200 000 hinge cycles without failure.

  • Core metrics: Density 0.90 g/cm³ | Chemical resistance rated “excellent.”

  • Typical uses: Food containers, living-hinge lids, interior fasteners, medical tubes.

  • Mass production of PP Material Products

 

III. Thermoplastic Property Matrix (Representative Un-filled Grades)

 

ll values shown are representative data for general-purpose, unfilled grades. Actual properties vary by formulation, additives and glass-fibre content; always confirm with the supplier’s technical data sheet (TDS) before final selection.

 

#ResinDensity (g/cm³)Melt Point (°C)HDT @ 0.45 MPa (°C)Tensile (MPa)Flex Modulus (MPa)Izod (J/m, N)Shrink (%)
1ABS1.04210-25088-10040-452 000-2 400180-2200.4-0.7
2PA61.13215-22575-9560-802 700-3 00070-1001.0-1.5
3HDPE0.95125-13575-8526-33900-1 20050-701.5-4.0
4LDPE0.92110-11545-608-11200-300NB†1.5-4.0
5PC1.20260-310125-14060-702 100-2 400600-8500.5-0.7
6POM1.41165-175100-12060-752 800-3 20090-1101.5-2.0
7PMMA1.18180-20095-10560-702 400-3 30015-250.2-0.8
8TPU (Polyester)1.18— ‡45-9030-5025-70700-9001.0-2.0
9TPE / TPR0.90-1.25— ‡60-1202-155-25200->1 0001.0-2.5
10PP (Homo)0.90160-17095-10532-401 300-1 60025-601.5-2.5

 

    • Melt temperature = DSC peak or MFR test range.
      † HDT (Heat-Deflection Temperature) indicates heat resistance; choose 20–40 % glass-fibre grades for higher stiffness.
      ‡ NB = No Break in notched-Izod impact testing.
      § Elastomers have no true melt point; use the processing window (170–210 °C) or glass-transition range (-40 to -20 °C) for design purposes.

 

Quick-Match Index

 

Product NeedRecommended ResinWhy
Clear + high impactPC≥ 88 % Tt + Izod > 600 J/m
Self-lubricated gearsPOMμ≈0.2 + high hardness
Living hinge / food contactPPTough, chemical-resistant, low cost
Outdoor glossy partsPMMA (+ UV)UV stable, hard surface
Soft-touch over-moldTPE / TPUExcellent PP/ABS bond

 

IV. Three-Step Resin Selection Workflow

 

    1. Define KPI – Quantify strength, clarity, flame rating, etc

    2. Assess Service Environment – Continuous temp, chemicals, UV, wear.

    3. Calculate TCO – Raw price × cycle time × tooling = Total Cost of Ownership.

TIP：

    • High clarity + impact → PC

    • Ultra-low friction + precision → POM

    • Living hinge + acid/alkali + lowest cost → PP

 

Conclusion

Understanding the performance limits of injection-molding resins unlocks the trinity of function, manufacturing efficiency, and cost competitiveness. For flow analysis, DFMA optimization, or cost benchmarking, contact our technical team—let material advantages become your brand’s market differentiator.

 

🔗 Further Reading

 

  1. Comprehensive Guide to Overmolding

  2. High-Efficiency Precision Injection Molding

  3. Podcast: “What Is a Plastic Molding Machine?”

  4. Thermoset Plastics: Properties & Applications

  5. Insert-Molding Design Handbook

  6. PMMA vs. PC—Creating the Ideal “Window” for Your Product

 

 

 

 

 2025-07-31