eSUN PLA+ Mechanical Properties: Strength Data

eSUN PLA+ mechanical properties deliver impressive tensile strength and impact resistance that make it ideal for functional 3D printed parts beyond decorative models. With a 63 MPa tensile strength and 9 kJ/m² IZOD impact rating, PLA+ bridges the gap between standard PLA’s ease of use and engineering-grade material performance.

PLA+ vs Standard PLA Mechanical Performance

Understanding PLA+ Strength Data for 3D Printing Applications

When evaluating eSUN PLA+ mechanical properties for a project, its strength data directly informs which applications it can reliably handle. The 63 MPa tensile strength and high impact resistance make it suitable for components like tool handles, drone frames, and functional prototypes that endure repeated stress. This performance moves it decisively beyond standard PLA, which is often limited to visual models or light-duty use. For engineers and hobbyists comparing filaments, this data is crucial for predicting a part’s durability and selecting the right material to prevent mechanical failure, ensuring prints are fit for their intended purpose from the start.

How eSUN Improved Toughness and Impact Resistance

eSUN modified standard PLA with additives and processing techniques that significantly improve toughness and layer adherence. The key improvement is the 9 kJ/m² IZOD impact strength rating, which represents a major step up from standard PLA’s brittleness. This makes PLA+ “hard to break” according to eSUN’s material profile—a critical difference when printing functional parts that experience real-world stress.

The material achieves this toughness improvement while maintaining good strength-to-rigidity balance. The 63 MPa tensile strength provides structural load capacity, while the 1973 MPa flexural modulus ensures parts don’t deform under bending forces. This combination prevents the common PLA failure mode where parts snap suddenly under impact rather than bend and absorb energy.

When to Choose PLA+ Over Standard PLA

Choose PLA+ when printing parts that will experience mechanical stress, impacts, or vibration. Standard PLA excels for display models, decorative items, and prototypes that won’t be handled roughly. PLA+ is your choice for mechanical components, tool handles, snap-fit assemblies, and any part that needs to survive real use.

PLA+ also prints faster (40-100 mm/s recommended speed range) and produces smoother surface finishes than standard PLA, reducing post-processing time. For designers who value both aesthetics and durability in a single material, PLA+ offers the best of both worlds.

Tensile Strength Specifications and Applications

63 MPa Tensile Strength Breakdown

eSUN PLA+ achieves 63 MPa tensile strength under GB/T 1040 testing standards. This measures the maximum pulling force the material can withstand before breaking, expressed in megapascals (force per square millimeter of cross-sectional area). To put this in perspective, 63 MPa is substantially higher than standard PLA (typically 50-55 MPa) but lower than true engineering plastics like ABS (40 MPa) or Nylon (70-80 MPa).

The testing methodology uses a standardized dumbbell-shaped specimen pulled at controlled speed until failure. eSUN reports this value based on actual injection molding test specimens matching FDM print geometry, giving you realistic expectations for your printed parts rather than theoretical material data.

Parts That Benefit from High Tensile Strength

Parts under direct tension—like cables, connectors, mounting brackets, and structural supports—directly benefit from 63 MPa tensile strength. A 5mm diameter PLA+ cable can handle approximately 1,233 Newtons of pulling force before failure (calculated from cross-sectional area × material strength). This makes PLA+ suitable for:

• Mechanical assemblies: Linkages, joints, and moving components that transmit forces
• Tool handles: Gripping surfaces for hand tools and powered equipment
• Snap-fit connectors: Interlocking parts that hold under tension but flex without permanent deformation
• Cable organizers and clips: Parts holding weight or resisting pull forces
• Structural brackets: Load-bearing supports for shelving or mounting hardware

20% Elongation at Break Implications

eSUN PLA+ stretches 20% of its original length before snapping under tensile load. This 20% elongation at break is significantly higher than standard PLA (3-5%), indicating the material absorbs energy through controlled deformation rather than fracturing immediately. This property distinguishes PLA+ as a “tough” material suitable for parts that encounter shock loads.

The elongation characteristic means PLA+ parts can survive temporary overload conditions. A snap-fit clip might flex 15% without breaking, absorbing the shock of installation and removal. This flexibility makes parts forgiving during assembly and less prone to catastrophic failure from accidental impacts.

Flexural Strength and Rigidity Analysis

74 MPa Flexural Strength Standard

eSUN PLA+ demonstrates 74 MPa flexural strength under GB/T 9341 testing conditions. Flexural strength measures how much bending force a material can withstand before permanent deformation or failure occurs. The 74 MPa rating is tested using a three-point bending setup where a specimen is supported at two ends and force is applied at the center until it breaks or bends beyond specified limits.

For practical printing applications, this means a 4mm thick horizontal cantilever beam can support approximately 12 kg of distributed weight before permanent deformation. Flexural strength directly impacts parts like:

• Shelving brackets and support arms
• Door hinges and moving flaps
• Spring-like features and flexible tabs
• Beam-type structural members

1973 MPa Flexural Modulus Performance

The 1973 MPa flexural modulus indicates PLA+ is a relatively rigid material that resists bending deflection. Modulus measures stiffness—how much force is required to bend the material a given amount. A higher modulus means less deflection under load. PLA+ at 1973 MPa sits between flexible filaments (like TPU at 400-500 MPa) and ultra-rigid materials (like carbon fiber composites at 4000+ MPa).

This rigidity is ideal for parts that must maintain dimensional accuracy under load. A 20mm diameter rod won’t sag significantly when supporting shelf items, and mechanical linkages won’t develop play or wobble from flexing. The material provides enough stiffness for precision mechanical work without becoming brittle.

Comparing Rigidity to Other Filaments

PLA+ offers superior rigidity to flexible materials but maintains better impact tolerance than ultra-rigid options. Standard PLA typically measures 2700-2800 MPa in flexural modulus, making PLA+ slightly more flexible (which improves toughness). ABS filament averages 1800-2100 MPa, placing PLA+ in the same performance range. Nylon 12 is significantly more flexible at 800-1200 MPa, while carbon fiber reinforced composites exceed 4000 MPa.

For most functional part applications, PLA+ provides the optimal balance—rigid enough to prevent deflection but flexible enough to absorb impact without shattering.

Impact Resistance: 9 kJ/m² IZOD Standard

What IZOD Impact Testing Measures

The IZOD impact strength test (GB/T 1043) measures how much energy a material absorbs before fracturing under a sudden blow. eSUN PLA+ rates 9 kJ/m² in this standardized test, where a pendulum hammer swings against a notched specimen. The energy absorbed before the specimen breaks is calculated and reported in kilojoules per square meter of notch area.

The 9 kJ/m² rating means PLA+ can absorb significant impact energy. To contextualize: standard PLA typically rates 2-3 kJ/m², making PLA+ three to four times more impact-resistant. This dramatic difference is why PLA+ is marketed as “hard to break” and suitable for parts experiencing mechanical shock.

Real-World Impact Resistance Applications

Impact resistance becomes critical in several practical scenarios:

• Dropped parts: A protective case or housing survives being dropped on hard surfaces
• Assembly impacts: Press-fit components withstand the shock of being assembled without cracking
• Vibration environments: Parts experiencing continuous vibration don’t develop fatigue cracks
• Tool use: Handles struck against work surfaces maintain integrity
• Mechanical games and toys: Moving parts endure repeated impacts during use

Why High Toughness Matters for Functional Parts

Toughness—the combination of strength and elongation—is what separates materials that fail catastrophically from materials that deform and survive. A brittle material with high tensile strength might snap suddenly under impact. A tough material absorbs energy through controlled deformation. eSUN PLA+ with 20% elongation at break and 9 kJ/m² impact strength behaves like a tough material, absorbing impact energy rather than transferring it directly to fracture.

For functional parts in real use, this matters enormously. Your part won’t shatter when accidentally dropped. It won’t crack at snap-fit assembly points during installation. It won’t develop sudden cracks from vibration that eventually lead to catastrophic failure. This reliability makes PLA+ suitable for parts people depend on.

Density and Weight Considerations

1.23 g/cm³ Density for Lightweight Designs

eSUN PLA+ has a density of 1.23 g/cm³ (measured per GB/T 1033 standards), making it one of the lightest structural filaments available. For comparison, standard PLA is approximately 1.25 g/cm³, ABS is 1.04 g/cm³, and aluminum is 2.7 g/cm³. This low density is ideal for applications where weight is critical:

• Drone components and aerial carriers
• Wearable items like COSPLAY armor and prosthetics
• Lightweight mechanical systems and robotics
• Aerospace prototypes and models
• Portable tools and handles

A solid PLA+ cube 10cm on each side weighs only 1.23 kg, while the same aluminum cube would weigh 2.7 kg. This weight savings compounds dramatically with larger parts and complex assemblies.

Weight vs Strength Trade-offs

eSUN PLA+ doesn’t sacrifice strength for low weight. The 63 MPa tensile strength and 74 MPa flexural strength are maintained despite the low density. The material achieves this through optimized polymer structure rather than density compensation.

To minimize weight further in your designs, use the recommended 20% infill percentage during printing rather than solid infill. A part with 20% infill and 4-perimeter shell (eSUN’s standard recommendation) weighs about 1/5 of a fully solid part while retaining most mechanical strength. A cube with 20% infill weighs only 0.25 kg instead of 1.23 kg, dramatically reducing weight in portable applications while maintaining adequate structural integrity.

Optimizing Print Settings for Strength

Infill Percentage Impact on Mechanical Properties (20% standard)

eSUN specifies 20% infill percentage as the standard for mechanical property testing. This infill level provides the optimal balance between structural strength and material efficiency. The mechanical property values in the datasheet—63 MPa tensile strength, 74 MPa flexural strength, and 9 kJ/m² impact resistance—are achieved with 20% infill density.

Changing infill percentage directly affects part strength:

For parts experiencing light loads or primarily used to demonstrate form and fit, 10-15% infill saves material and print time. For functional parts under anticipated stress, maintain the 20% standard. For critical components like mechanical supports or parts with potential for hard impact, increase to 30-50% infill.

Shell Configuration for Maximum Strength (4 perimeters)

eSUN recommends 4 outline/perimeter shells and 4 top/bottom layers as the standard print configuration. These 4-perimeter shells create a robust outer wall that:

• Provides most tensile strength (outer material handles pulling forces)
• Protects internal infill from environmental exposure
• Creates smooth visible surfaces
• Maintains dimensional tolerance

The 4-layer configuration means approximately 1.6mm of solid material surrounds your part (assuming 0.4mm nozzle). This thickness is sufficient for most functional applications. Increasing to 5-6 shells adds marginal strength (maybe 5-10%) but increases print time and material significantly. Reducing below 4 shells compromises mechanical properties and surface quality.

For maximum strength in high-stress areas, you can locally increase infill density or shell count in your slicing software. Create reinforced zones in areas you know will experience load—around screw holes, snap-fit points, or structural supports.

Real-World Applications and Testing

Functional Parts and Prototyping Success Stories

eSUN PLA+ is approved for “prototyping,” “mechanical parts,” and “functional” applications in its official datasheet. This approval is based on actual mechanical testing showing the material reliably meets published strength specifications. Common successful applications include:

• Mechanical prototypes: Testing design concepts before manufacturing in final materials
• Jigs and fixtures: Production tools that hold or position components during assembly
• Snap-together assemblies: Interlocking parts that create modular systems
• Moving components: Gears, cams, linkages, and mechanical joints
• Replacement parts: Low-volume production of wear items like clips, brackets, and handles
• Test articles: Parts for durability and stress testing before committed manufacturing

The key success factor is matching the material’s actual properties (63 MPa tensile, 74 MPa flexural, 9 kJ/m² impact) to your part’s real-world loading. A simple bracket holding light weight succeeds easily. A high-stress mechanical joint experiences failure if not designed with adequate safety margins based on PLA+ specifications.

COSPLAY and Mechanical Component Uses

eSUN specifically lists COSPLAY as an approved application. The material’s combination of properties makes it ideal for costume and armor work:

• Low density (1.23 g/cm³): Wearable armor pieces weigh dramatically less than metal or resin alternatives
• High impact resistance: Armor withstands contact impacts during wear and movement
• Good toughness: Pieces won’t crack from bending as the wearer moves
• Smooth surface: Requires minimal sanding before painting
• FDA approved: Safe for direct skin contact in extended wear

For mechanical components, the material’s 20% elongation at break and 9 kJ/m² impact strength prevent the sudden failures that plague standard PLA in moving part applications. Gear teeth won’t shear off; bearing surfaces won’t chip; moving joints won’t crack at stress concentration points.

FDA Approval and Safety Considerations

eSUN explicitly states PLA+ is “Approved by FDA, safer to use.” This approval indicates compliance with FDA food contact regulations (21 CFR Part 177) for materials intended to contact food. The significance extends beyond food applications—FDA approval signals the material has undergone safety testing for leaching of harmful compounds under realistic use conditions.

For functional parts in non-food applications, this approval provides confidence regarding material safety. However, remember that FDA food-contact approval applies specifically to food exposure. Use PLA+ freely for:

• Kitchen items and food handling tools
• Drinking containers and lids (not dishwasher safe due to low 53°C heat distortion temperature)
• Food storage enclosures
• Medical equipment components (non-implant)
• Child-safe toys and wearables

Avoid using PLA+ in applications requiring sustained heat above 53°C (the heat distortion temperature), high-temperature industrial environments, or anywhere the material might degrade and leach compounds into a sensitive application.

FAQ

What is the difference between eSUN PLA+ tensile strength and flexural strength?

Tensile strength (63 MPa) measures force applied by pulling—how much the material resists being stretched. Flexural strength (74 MPa) measures force applied by bending—how much the material resists being bent. Both are important for functional parts. Tensile strength matters for parts under direct pulling loads (cables, straps, connectors). Flexural strength matters for parts that experience bending (cantilever brackets, hinges, beams). eSUN PLA+ provides strong performance in both, making it versatile for various mechanical applications.

Is 20% infill enough strength for mechanical parts?

Yes, 20% infill is the eSUN-tested standard that achieves the published mechanical properties. For parts experiencing light to moderate loads—most prototypes, fixtures, brackets, and handles—20% infill provides adequate strength while saving material and reducing print time. For high-stress applications or parts with safety-critical loads, increase infill to 30-50%. Parts requiring absolute maximum strength use 80-100% infill, though this significantly increases weight and material cost. Design your parts conservatively by calculating expected loads and applying 2-3x safety factors to ensure 20% infill is adequate for your specific application.

Can PLA+ parts be used outdoors or in wet environments?

PLA is susceptible to degradation from UV exposure and moisture over extended periods. eSUN’s PLA+ datasheet doesn’t specify outdoor durability specifications. For outdoor use, apply UV-protective coatings or use indoors only. Short-term wet exposure (occasional splashing, brief water immersion) is acceptable. Long-term immersion or high-humidity environments will gradually weaken PLA+ through hydrolysis. If outdoor durability is critical, consider ABS or polyurethane-based filaments instead, which better resist environmental degradation.

What print settings should I use to achieve the 63 MPa tensile strength rating?

Use eSUN’s recommended parameters: 210-230°C extruder temperature, 45-60°C bed temperature, 100% fan speed, 40-100 mm/s printing speed, 4 perimeter shells, 4 top/bottom layers, and 20% infill percentage. The datasheet’s mechanical properties were tested with slightly different parameters (190-230°C extruder, 45°C bed, 40 mm/s speed) for establishing baseline values. Using 40 mm/s speed ensures optimal layer bonding. Higher speeds (80-100 mm/s) improve productivity but may slightly reduce mechanical properties. Lower temperatures or insufficient cooling reduce layer adhesion and effective strength.

How does eSUN PLA+ compare to other tough filaments like TPU or Nylon?

eSUN PLA+ (63 MPa tensile, 20% elongation, 9 kJ/m² impact) offers better stiffness and strength than TPU (typical 15-20 MPa tensile, 500%+ elongation) but less flexibility. Compared to Nylon (70-80 MPa tensile, 30-50% elongation, 10-15 kJ/m² impact), PLA+ is slightly weaker but prints more easily with fewer heating requirements and less warping. PLA+ is ideal for functional parts needing good strength-to-stiffness balance with easier printing. Choose TPU for flexible components that must bend dramatically. Choose Nylon if ultimate strength and impact resistance justify the more difficult printing process and material cost.