Elasticity & Recovery
Stretch and Deformation Recovery Solutions for Hot Melt Adhesive Films and Webs. Precise material selection for elastic fabrics, seamless garments, sportswear, and flexible composite products.
Elasticity and recovery are core mechanical properties of hot melt adhesive composites, directly determining the stretch compatibility of the composite material, wearing comfort, dynamic deformation stability, and long-term resistance to relaxation. Womet’s full range of hot melt adhesives is divided into four grades: high-elastic high-recovery, medium-elastic adaptive, low-elastic cushioning, and rigid non-elastic.
Core Definitions & Industry Standards
Understanding the key mechanical parameters and traceable testing methods that define our material grades.
1 Professional Definitions
Elasticity refers to the ability of a material to deform under external force. Recovery refers to the ability to spontaneously return to its original dimensions after the force is removed.
- Elongation at break: Maximum stretch ratio before breaking.
- Instantaneous recovery rate: Proportion of deformation recovering immediately.
- Residual deformation rate: Permanent deformation after release.
- Stress at given elongation: Force required at a specific stretch ratio.
- Fatigue recovery stability: Recovery decay after repeated cycles.
Industry-Standard Testing Methods
| Test Item | Reference Standards | Description |
|---|---|---|
| Tensile & Break Properties | GB/T 1040.3 / ASTM D882 / ISO 527-3 | Constant-speed tensile test on universal testing machine for film/web samples. |
| Elastic Recovery Rate | GB/T 3923.1 / ASTM D4964 | Stretch to fixed length, hold, release; measure recovery after 30s rest. |
| Repeated Stretch Fatigue | GB/T 13525 / ISO 7784 | 1000 cycles of fixed-stretch loading; inspect recovery decay, delamination. |
| Low-Temperature Recovery | ASTM D1045 / GB/T 1682 | Condition at low temperature, verify material does not harden. |
Polymer Recovery Mechanism
Essential Material Principles determined by polymer chain structure, crystallinity, soft/hard segment ratio, and crosslinking density.
High-Elastic (TPU/TPE)
Soft-segment rich amorphous elastic system. Entropy-driven chain retraction provides fast recovery and extremely low residual deformation. "Non-stiff stretching and non-loose recovery".
TPU: Soft segment energy storage, hard segment reset. TPE: Fast reset of hard segment domains.
Medium-Elastic (EVA/PO)
Semi-crystalline system. Amorphous regions extend, crystalline regions orient. Some recovery ability but significant plastic deformation, tending to loosen after repeated stretching.
Rigid Non-Elastic (PA/PES)
Highly crystalline, highly regular structures. Stretching causes rigid deformation with almost no elastic recovery. "Crisp shaping, no stretch, no recovery".
Relationship Between Elasticity and Crystallinity
Elastic recovery rate has a negative exponential relationship with crystallinity: for every 10% increase in crystallinity, instantaneous recovery decreases by 15–20%.
Vomet Control: TPU (10–25%), TPE (<5%), PA/PES (>60%). Physically crosslinked systems show ≤5% recovery decline after 1000 cycles, while semi-crystalline systems decline 20–30%.
Complete Product Line – Elasticity & Recovery Performance Overview Table
The full range of adhesive films, webs, and functional films is summarized below, with quantified elongation, recovery rate, residual deformation, elasticity grade, and mechanical characteristics, enabling precise matching to elastic/stretch or rigid/shaping applications.
| Product Name | Elasticity Grade | Elongation at Break | Instantaneous Recovery Rate | Residual Deformation Rate | Mechanical Characteristics & Advantages | Suitable Applications |
|---|---|---|---|---|---|---|
| TPU Hot Melt Adhesive Film | High-elastic high-recovery | ≥400% | ≥90% | ≤3% | Balanced soft/hard segments, ample elasticity without sagging, uniform stretch without whitening, low recovery decay after repeated stretching, excellent low-temperature recovery retention, combines elasticity and structural strength | Sportswear, elastic underwear, seamless bonding, flexible braces, footwear elastic composites |
| TPE Hot Melt Adhesive Film | Super-elastic high-recovery | ≥450% | ≥95% | ≤2% | Ultra-soft elastic system, very low stretch resistance, zero tightness, extremely fast instantaneous recovery, soft and supple feel, excellent dynamic deformation tracking, no sticking or crease residue | Yoga wear, next-to-skin underwear, baby textiles, premium soft luggage |
| PA Hot Melt Adhesive Film | Rigid non-elastic | ≤50% | ≤30% | ≥15% | High-crystallinity rigid structure, almost no elastic deformation, strong shaping and crispness, does not easily relax under stress, no deformation after washing, excellent support stability | Shirt interlinings, cuffs, waistbands, garment shaping reinforcement, stiff home textile composites |
| PES Hot Melt Adhesive Film | Rigid non-elastic | ≤50% | ≤25% | ≥18% | Dense and stable molecular structure, high rigidity, deformation-resistant, aging-resistant, maintains shape after high-temperature washing, no relaxation or recovery | Outdoor workwear, durable home textiles, industrial fabrics, high-temperature wash shaping products |
| EVA Hot Melt Adhesive Film | Low-elastic cushioning | 50%~150% | 40%~60% | 8%~15% | Slight cushioning elasticity, no high recovery ability, prone to plastic deformation under load, loosens after long-term stretching; suitable only for static, low-frequency deformation | General packaging, static composites, low-frequency consumer products |
| PO/EAA Hot Melt Adhesive Film | Medium-elastic adaptive | 100%~200% | 60%~80% | 5%~10% | Moderate elasticity range, suitable for small-deformation applications; strong adhesion to metal, plastic, and inert substrates; stable elasticity, not prone to delamination | Industrial material bonding, plastic lamination, functional products with small deformation |
| PA Hot Melt Adhesive Web | Rigid non-elastic | ≤40% | ≤25% | ≥20% | Stable grid structure, rigid shaping, breathable but not loose, effectively fixes fabric shape, prevents deformation and shifting | Home textile shaping, garment accessories, breathable reinforcement composites |
| PES Hot Melt Adhesive Web | Rigid non-elastic | ≤40% | ≤20% | ≥22% | Highly stable rigid grid, wash-resistant, aging-resistant, deformation-resistant; long-term use without loosening or shifting | High-end durable breathable shaping fabrics, outdoor functional textiles |
| TPU Hot Melt Adhesive Web | High-elastic high-recovery | ≥350% | ≥85% | ≤4% | High-elastic breathable grid, strong stretch tracking, uniform recovery with no residual deformation; combines breathability, seamlessness, and high elasticity; no whitening under stretch, dots do not detach | Elastic breathable garments, sportswear, seamless next-to-skin home textiles |
| EVA Hot Melt Adhesive Web | Low-elastic cushioning | 40%~120% | 30%~50% | 10%~18% | Basic cushioning elasticity, loose structure, loosens after repeated stretching; only meets basic breathable composite shaping requirements | General civilian breathable products, budget luggage composites |
| PP Hot Melt Adhesive Web | Rigid non-elastic | ≤30% | ≤20% | ≥25% | High rigidity, corrosion-resistant, compact structure, almost no elastic deformation; excellent shaping stability and chemical resistance | Protective fabrics, windproof shaping fabrics, industrial breathable composites |
| TPU/PU Waterproof Dot Film | High-elastic high-recovery | ≥300% | ≥80% | ≤5% | Dot-structured high elasticity; whole structure stretches synchronously, recovery without detachment or dot separation; waterproof function compatible with elastic tracking; no leakage or deformation under stretch | Elastic waterproof garments, outdoor stretch functional fabrics, flexible waterproof composites |
Parameter notes: The above values are typical test results at 23°C and 50% relative humidity. Variations of ±5% may occur due to adhesive layer thickness, lamination process, and substrate matching. Please refer to factory test reports for specific products.
Relationship Between Elasticity and Thickness
For the same material, the thickness (basis weight) of the adhesive film or web significantly affects the elastic feel of the composite. Greater thickness increases the volume fraction of the adhesive layer in the overall composite structure, leading to a more pronounced “locking” effect on the fabric’s original stretch. hrs offers multiple thickness specifications for fine-tuning elastic feel.
Expert Selection Advice
Choose the thinnest thickness that provides reliable bonding to maximize stretch retention and reduce cost. For products requiring high support (e.g., braces), a thicker gauge may be appropriate.
Thickness Specifications & Elasticity Effects
| Film Thickness / Basis Weight Range | Effect on Elasticity | Recommended Applications |
|---|---|---|
| 0.02–0.05mm (16–40 g/m²) |
Almost no effect on fabric’s original stretch; feel retention ≥95% | Ultra-thin lace, chiffon, elastic stockings, transparent elastic garments |
| 0.06–0.10mm (50–80 g/m²) |
Slight increase in overall rigidity; 5–10% loss of elasticity, but improved tear strength | General elastic underwear, sports T-shirts, elastic home textiles |
| 0.11–0.20mm (90–150 g/m²) |
Noticeable structural support; 15–25% loss of elasticity, slightly firmer feel but crisp | Elastic braces, functional sportswear, elastic footwear materials |
| 0.21–0.35mm (160–250 g/m²) |
Significant reduction in fabric stretch margin; >30% loss of elasticity, semi-rigid | Shaping elastic composite products, backpack shoulder straps |
Custom Processing & Tuning
Womet supports custom tuning of elastic feel through formulation modification, thickness matching, and process temperature control.
Material Processing (OEM)
Match adhesive to substrate elasticity coefficient, completely solving mismatched elasticity.
Lamination OEM
Uniform elasticity across entire width, eliminating local unevenness.
Dot Coating OEM
Custom high-elastic dot structure, preserves native stretch, combines waterproof/breathable performance.
Low-Temperature Elastic Retention (-20°C)
TPU/TPE modified series retain ≥80% recovery at -20°C, remaining soft and stretchable without brittle breaks. Standard EVA falls to ≤40% and becomes hard.
Low-Temperature Elastic Retention Data Sheet
For cold winter environments or cold-chain storage/use, Womet’s high-elastic materials are modified for low-temperature performance. The following data details recovery retention across extreme temperature variations.
| Material | Test Temp | Elongation at Break Retention | Instantaneous Recovery Retention | Feel Evaluation |
|---|---|---|---|---|
| TPU High-Elastic Film | -20°C | ≥85% | ≥80% | Slightly firmer, still stretchable and recoverable, no brittle break |
| TPU High-Elastic Film | 0°C | ≥92% | ≥90% | Slightly tighter feel, fast recovery |
| TPU High-Elastic Film | 23°C | 100% | 100% | Soft, ample elasticity |
| TPE Super-Elastic Film | -20°C | ≥90% | ≥88% | Slight stiffening, still soft |
| TPE Super-Elastic Film | 0°C | ≥95% | ≥94% | Soft feel, fast recovery |
| EVA Standard Film | -20°C | ≤60% | ≤40% | Hard and brittle, turns white easily under stretch |
| PA Rigid Film | -20°C | No significant change (already non-elastic) |
– | Maintains crispness, no embrittlement |
Conclusion
Womet’s TPU/TPE high-elastic series, through the addition of cold-resistant plasticizers and optimized soft segment structure, maintain good elasticity even at -20°C. These properties make them highly suitable for winter outdoor sportswear and cold-chain workwear applications.
Need material samples for your cold-weather products?
Engineered for extreme cold-chain and outdoor environments.
Causes of Elasticity Failures & Process Correction
Problems such as composite becoming stiff, loss of elasticity, slow recovery, whitening under stretch, loose deformation, and layer separation after repeated stretching are 90% caused by mismatched process parameters, not material defects.
|
Failure Mode
|
Root Cause
|
Process Correction
|
|---|---|---|
| Composite becomes stiff Elasticity disappears | Temperature too high, hold time too long; excessive thermal crosslinking locks molecular chains, losing elastic deformation ability. | Solution: Reduce lamination temperature, shorten hold time; use low-temperature precision melting to preserve native elastic chain activity. |
| Slow recovery Does not snap back immediately | Insufficient melting, incomplete rheological relaxation; molecular chains not fully extended, weak recovery driving force. | Solution: Fine-tune temperature to standard melting range, ensure complete relaxation to restore entropy-driven recovery. |
| Local whitening under stretch Uneven elasticity | Uneven pressure, large variation in adhesive thickness; stress concentration in thin areas causes overload whitening. | Solution: Calibrate roller pressure and flatness, ensure uniform adhesive thickness across width; synchronized deformation. |
| Loosening & permanent deformation After repeated stretching | Wrong material selection: low-elastic plastic material used instead of high-elastic material; poor fatigue recovery stability. | Solution: Replace with TPU/TPE high-elastic system to improve fatigue stability and reduce residual deformation. |
| Layer separation After stretching elastic fabric | Mismatch between adhesive elastic modulus and fabric elastic modulus; shear stress from out-of-sync deformation. | Solution: Match a high-elastic adhesive with similar modulus so fabric and adhesive stretch and recover synchronously. |
Elastic Fatigue Life &
Repeated Stretch Decay Curve
Comprehensive endurance testing of hrs TPU high-elastic films against conventional alternatives.
Testing Methodology
A precision universal testing machine was utilized to evaluate our TPU high-elastic film (0.10mm thickness). The material was subjected to rigorous cycles of 100% fixed stretch to accurately measure residual deformation, recovery rate, and appearance retention under extreme mechanical stress.
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Tested at 500, 1000, and 2000 cycle intervals
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0.10mm standardized film thickness
TPU High-Elastic Film Performance Data
Measured over 2000 continuous stretch cycles
| Stretch Cycles | Instantaneous Recovery | Residual Deformation | Appearance Changes | Bond Strength |
|---|---|---|---|---|
| 0 (Initial) | 92% | 2.8% | No abnormality | 100% |
| 500 | 90% | 3.2% | No whitening, no delamination | 97% |
| 1000 | 88% | 3.8% | Slight gloss change, no whitening | 94% |
| 2000 | 85% | 4.5% | No visible damage, still elastic | 90% |
Conventional EVA Film
Tested under identical conditions (0.10mm thickness) after only 500 cycles:
- Recovery rate plummeted to 52%
- Residual deformation reached 12%
- Obvious whitening and delamination observed
- Bond strength retention dropped to 65%
hrs TPU High-Elastic Film
Demonstrates exceptional fatigue resistance. Our TPU film retains >85% recovery even after 2000 rigorous cycles, maintaining residual deformation strictly within 5%.
Application Verdict
Fully meets and exceeds the strict durability requirements of sportswear, medical braces, and other high-intensity applications where long-term elasticity and structural integrity are non-negotiable.
Need the Complete Technical Data Sheet?
Get access to our full laboratory test reports, including stress-strain curves, environmental resistance data, and detailed specifications for all hrs hot-melt adhesive films.
Application Case Studies
Standard mass-production parameters and real-world solutions across diverse scenarios.
Ultra-Soft Seamless Lamination
Solution: TPE super-elastic film (110°C, 0.2MPa, 12s).
Fabric stretches smoothly without resistance, no crease after bending. Recovery decay ≤3% after 1000 cycles.
Elastic Support Lamination
Solution: TPU high-elastic film (115°C, 0.25MPa, 15s).
Balances high elongation and structural strength. Fast recovery with moderate support, stable recovery shaping.
Business Shirt Collar
Solution: PA rigid non-elastic film (135°C, 0.3MPa, 20s).
Uniform crispness, extremely low residual deformation. Remains flat and shaped after 50 washes.
Elastic Waterproof Fabric
Solution: High-elastic TPU/PU dot film (110°C, light pressure).
Elasticity retention ≥95%; no dot detachment or leakage under stretch; combines waterproof with elastic feel.
Breathable Elastic Bedding
Solution: TPU high-elastic web (112°C, slow nip).
Overall breathable, stretch recovery uniform and smooth, no hard grid points.
Sports Bra Zero-Feel
Solution: 0.02mm TPE micron film (108°C, 0.18MPa, 10s).
Elasticity retention 98.3%. Zero tightness. Invisible elastic bonding layer.
FQAS
Expert answers to common material selection and process questions.
What material is preferred for high-elastic garments?
Why can’t high-elastic film be used for shaping products?
The fabric is elastic, why does it become stiff after lamination?
How can we quickly evaluate elastic compatibility during development?
Does washing and drying affect elasticity?
Need a Custom Elastic Solution?
Leverage our factory-direct polyurethane formulation platform. We can customize TPU/TPE adhesive films enabling linear adjustment from "extremely soft" to "strong support".
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