Plastic is a common material with polymer synthetic resin as its main component. They are plastic and fluid under certain temperatures and pressures, can be molded into specific shapes, and can maintain their shape under certain conditions. Most plastics can be injection molded, so injection molding materials are often referred to as those plastics that can be used in injection molding production.
Product designers need to rely on material properties to ensure design feasibility and performance. Injection molding engineers need to precisely regulate process parameters based on the thermal behavior of the material to optimize production. Mold designers need to design the mold structure with the material fluidity and shrinkage. Quality control personnel need to trace the root cause of the problem through material defect analysis.
If you are a beginner in injection molding, we recommend that you first click on “What is Injection Molding” to gain a comprehensive basic understanding of the process.
Injection molding materials are usually divided into the following 5 categories according to the scientific classification system:
Future innovation directions include modified plastics that can be more customized for different performance needs. All injection molding materials are classified based on characteristics like durability, heat resistance, flexibility, and eco-friendly options.
This knowledge base covers most commonly used plastics (including some modified plastics). You will be able to get a basic understanding of each plastic's properties, applications, as well as its key advantages and disadvantages.
Gears, bearings, automotive parts, textiles
High strength, wear resistant, good fatigue resistance
Excellent mechanical properties and wear resistance
Hygroscopic and can absorb moisture
Automotive parts, electrical components, industrial parts
High strength, heat resistant, good chemical resistance
Higher melting point and rigidity than PA6
Stronger hygroscopicity, poor dimensional stability
Oil pipelines, soft hoses, precision parts
Low water absorption, oil resistance, flexibility
Good low temperature resistance and stable size
High cost, insufficient hardness
Electronic accessories, medical parts, thin-wall products
Ultra-low water absorption, high toughness
Best dimensional stability among nylon materials
Expensive, poor high temperature resistance
Gears, slider parts, fasteners
High hardness, wear resistance, self-lubricating
High surface hardness, not easy to deform
Poor weather resistance, easy to age
Transparent parts, safety protection, electronic shells
High transparency, impact resistance, heat resistance
Super strong impact resistance, non-toxic
Poor scratch resistance, sensitive to hydrolysis
Home appliances, electronic housings, daily necessities
Balanced performance, easy coloring, easy processing
Good comprehensive performance, low price
Poor heat resistance, easy to yellow
Light guide plates, display screens, optical parts
High light transmittance, weather resistance
Crystal clear, excellent outdoor stability
Low hardness, easy to scratch and crack
Beverage bottles, packaging, fiber products
High strength, transparent, gas barrier
Light weight, environmental protection, recyclable
Poor high temperature resistance
Daily packaging, containers, auto interior parts
Light weight, corrosion resistance, high temperature resistance
Low cost, high heat resistance, good toughness
Poor low temperature resistance, easy to brittle
Plastic bags, pipes, chemical containers
Excellent chemical resistance, low temperature resistance
Soft and tough, acid and alkali resistant
Low heat resistance, difficult to bond
Disposable tableware, packaging, toys
High transparency, light weight, low price
Good rigidity, easy to process and shape
Very brittle, poor impact resistance
Pipe fittings, profiles, daily plastic products
Wear resistance, flame retardant, low cost
Flame retardant, good chemical stability
Poor high temperature resistance, easy aging
Aerospace, medical equipment, precision machinery
Ultra-high temperature resistance, high strength
Comprehensive top performance, corrosion resistance
Extremely expensive, high processing difficulty
Aerospace components, high temperature insulation parts
Super high temperature resistance, radiation resistance
Extreme environment resistance, stable performance
High price, difficult molding
Electronic flame retardant parts, auto high temp parts
Flame retardant, high temperature resistant, corrosion resistant
Excellent flame retardant and chemical resistance
Brittle, poor toughness
Soft rubber parts, non-slip accessories, daily soft glue
Soft elastic, environmental protection, recyclable
Rubber feeling, good anti-slip performance
Poor high temperature resistance, easy to stain
Shoe materials, waterproof parts, wear-resistant parts
High wear resistance, oil resistance, high elasticity
Wear-resistant, tear-resistant, high transparency
Easy to yellow, poor hydrolysis resistance
Disposable tableware, degradable packaging, 3D printing
Fully biodegradable, plant-based raw materials
Environmental protection, non-toxic, clear texture
Poor heat resistance, brittle and fragile
Degradable plastic film, shopping bags, flexible packaging
Tough, fully degraded, good processing
Good toughness, solves PLA brittleness problem
High cost, low hardness
Anti-corrosion parts, high temperature sealing, non-stick coating
Anti-corrosion, high temperature resistance, self-lubricating
King of corrosion resistance, ultra-low friction
Difficult injection molding, poor rigidity
Chemical equipment, lithium battery parts, waterproof film
Aging resistance, corrosion resistance, high strength
Strong weather resistance and film forming property
Expensive, strict processing requirements
Notebook shells, automotive interior, large household appliances
Balanced toughness and rigidity, easy processing
Overcome PC stress cracking and ABS heat resistance defects
Slightly poor weather resistance
Structural parts, auto parts, high rigidity products
Glass fiber reinforced, high rigidity
Low cost and high strength after modification
Poor surface appearance, easy warping
Foam materials, shockproof accessories, daily soft products
Light, soft, shock absorption
Good cushioning performance, non-toxic
Poor high temperature resistance, easy aging
Outdoor products, solar shells, outdoor profiles
Ultra-strong weather resistance, anti-aging
No yellowing for long-term outdoor use
Higher price than ordinary ABS
For most established products like water bottles or electronic device casings, material choices usually follow industry norms. For example, PP plastic works well for containers because it resists chemicals. ABS plastic, on the other hand, is good for consumer electronics casings. It balances strength and looks nicely. These material picks have stood the test of time, backed by decades of manufacturing experience.
But your product might not be one of those common items. Or maybe it's an innovation based on an established product. In those cases, you'll need to choose materials. There are several factors you'll have to weigh:
Material cost per kg plus processing expenses and tooling impact.
Mechanical, thermal, and electrical material properties required for product operation.
Resistance to chemicals, UV, moisture, or extreme temperature conditions.
Injection molding process compatibility including flow behavior and cooling rates.
Surface finish quality, color stability, and optical clarity characteristics.
Certifications for food-grade, medical, or flame-retardant plastics.
How to cut through the complexity? Start by answering several critical questions every designer asks:
To answer this question, you need to first clarify the cost structure of injection molding production and address the question of how material selection affects each cost element.
| Cost Component | Percentage Range | Details |
|---|---|---|
| Raw Material Costs | 40-60% | Includes base resin prices (subject to crude oil fluctuations) and costs of modifying additives. |
| Processing Costs | 20-35% | Includes equipment energy consumption, molding cycle time, and scrap losses. |
| Mold Costs | 15-25% | Includes initial investment, maintenance costs, and life cycle expenses. |
| Post-Processing Costs | 5-20% | Includes surface treatments, assembly difficulty, and testing fees. |
| Cost Type | Material Impact Mechanism | Optimization Strategy |
|---|---|---|
| Raw Material Cost | Significant price gaps between specialty and commodity resins. | Avoid overspecification, fit-for-purpose selection |
| Processing Cost | Flowability affects cycle time and output efficiency. | High-flow material for thin-wall structure |
| Mold Cost | Reinforced materials accelerate mold wear. | Hardened mold steel or surface coating |
| Post-Processing Cost | Surface performance determines secondary processes. | Integrated material to reduce processes |
Once costs are confirmed as feasible, designers will likely turn their attention to a product's visual appeal. Choosing the right injection molding material means considering how well it can achieve the desired look. This usually ties to the surface treatments applied after injection molding.
| Processing Technology | Applicable Materials | Effect Characteristics | Cost Coefficient | Design Case Examples |
|---|---|---|---|---|
| In-Mold Decoration (IMD) | ABS, PC, PMMA | 3D graphics/text embedding, seamless touch control | ★★★☆ | Automotive center console panel |
| Painting | General plastics | High gloss/matte finish, gradient colors | ★★☆ | Appliance housing |
| NCVM Vacuum Plating | PC, PC/ABS | Metallic texture + signal transparency | ★★★☆ | Mobile phone antenna cover |
| Electroplating/Vacuum Plating | Electroplating-grade ABS | Mirror chrome/gold effect | ★★★★ | Bathroom faucet trim |
| Hydrographics/Heat Transfer | Complex curvature parts | Wood grain/marble imitation, seamless coverage | ★★☆ | Helmet, outdoor equipment |
| Laser Engraving | Glass fiber reinforced plastics | Permanent marking, micro precision carving | ★☆☆ | Medical device labeling |
| Texture Etching | PP, ABS, TPE | Leather grain, anti-slip texture, matte effect | ★☆☆ | Tool handle, daily consumer goods |
We sincerely hope that you can have a deeper understanding of injection molding materials, as this will be greatly beneficial for your product design. In fact, many of our clients have varying degrees of understanding of plastic materials, and a small portion of them even specify particular material suppliers for us to purchase from. We highly encourage you to do this. At the same time, we can also provide various purchase verifications and material testing certifications.
HDPE, LDPE and LLDPE.
Both Homopolymer and Copolymer types.
GPPS and HIPS.
Clarity and resistance to UV light.
Rigid and flexible grades available.
Balanced toughness and rigidity.
Impact resistance and high transparency.
Nylon grades including PA6, PA66, PA11, PA12.
High stiffness, wear resistance and lubricity.
High heat resistance and electrical insulation.
Excellent strength and dimensional stability.
Soft elastic, eco-friendly and recyclable.
High elasticity, wear resistance and oil resistance.
Ultra-high temperature resistant and flame retardant.
Top performance for medical & aerospace applications.