PET, PP, Composite or Woven: Choosing Strapping Materials

Introduction

Most packaging failures don’t come from weak strapping—they come from wrong strapping. PP stretches and loosens on heavy loads. PET cracks on irregular cargo. Composite costs more than the application needs. Woven is overkill for boxed goods. Each material has a sweet spot where it outperforms the others, and choosing wrong wastes money on over-spec or risks cargo damage from under-spec. This guide breaks down polypropylene, polyester, composite, and woven strapping by strength, environment, cost, and application fit so you can match material to load requirements without guessing.

Understanding the Four Main Materials

• Polypropylene (PP) is the lightest, cheapest, and most flexible strapping material. It works well for bundling cartons, light pallets, and non-critical loads where some stretching is acceptable. PP elongates 15-25% before breaking, which means it gives under tension and can loosen during transport.
• Polyester (PET) delivers higher strength with minimal elongation—typically 2-5% stretch before failure. It holds tension better than PP and resists UV degradation, making it the go-to choice for medium to heavy pallets and export loads. PET costs 30-40% more than PP but compensates with better performance on loads over 400kg.
• Composite strapping embeds high-tenacity polyester fibers in a rigid polymer coating. It mimics steel’s strength while staying lighter and safer to handle. Composite absorbs shock through controlled elongation and recovery, keeping tension stable through dynamic loads. Breaking strengths run from 1100kg to 2500kg depending on width.
• Woven strapping uses cross-woven polyester fibers that deliver bi-directional strength and split resistance. If a sharp edge cuts partway through woven strap, the cross-weave prevents the damage from propagating along the full length. It’s the most durable option for irregular, heavy-duty loads but costs 50-80% more than standard PET.

Strength and Load Capacity

PP typically ranges from 250kg to 600kg breaking strength in common widths (12-16mm). It works for cartons, bundled boxes, and pallets under 300kg where the load won’t shift much during handling.

PET delivers 400kg to 1200kg breaking strength in similar widths, with embossed PET reaching 1500kg in 19mm configurations. This range covers most industrial pallets, machinery crates, and containerized goods.

Composite and woven strapping start where PET tops out—1100kg to 2500kg in 13-32mm widths. These materials replace steel strapping in applications like steel coils, construction materials, and heavy machinery where loads exceed 1000kg.

System Strength vs Linear Strength

Linear strength measures the strap alone. System strength measures strap plus buckle or seal together. A PET strap rated for 1200kg with a seal that maxes out at 900kg gives you 900kg system strength—the seal becomes the weak link. Always spec the complete system, not just strap ratings.

Environmental Resistance

PP degrades fast in sunlight—it loses 50% of strength after 3-6 months of UV exposure. Indoor packaging or quick-turn shipments work fine, but outdoor storage or export containers need better UV resistance.

PET maintains 80-90% of strength after 12 months outdoors thanks to UV stabilizers in the polymer. It handles temperature swings from -20°C to +60°C without becoming brittle or losing tensile capacity.

Composite and woven strapping resist moisture, salt, and temperature extremes better than flat PET because the protective coating shields internal fibers from environmental attack. These materials work in marine environments, extreme climates, and long-term outdoor storage where standard PET would degrade.

Cost and Value Analysis

PP costs the least per meter—typically ₹2-4 for standard widths. But creep and UV sensitivity mean you might need more straps per load or face damage claims from loosened cargo. Total cost includes retensioning, extra material, and potential losses.

PET runs ₹5-8 per meter and eliminates most PP problems. The 30-40% price premium pays off in fewer straps per pallet, better tension retention, and lower damage rates on medium to heavy loads.

Composite and woven strapping cost ₹12-20 per meter but replace steel strapping that runs similar prices while delivering faster handling, safer operation, and eliminated rust damage. The comparison isn’t composite versus PET—it’s composite versus steel, where composite wins on total cost.

Hidden Costs Matter More Than Material Price

Operator injuries from steel recoil, rust stains on finished goods, and slower application times add costs that don’t show up on purchase orders. A material that costs 20% more but cuts application time by 30% and eliminates damage claims delivers better value.

Tool Compatibility and Application Speed

PP uses friction weld sealers or heat sealers for joint closure. Manual tools work fine for low volumes; automatic machines handle high-speed packaging lines. PP’s flexibility makes it easy to tension and seal quickly.

PET requires serrated seals and stronger tensioners because the material is stiffer and needs more force to reach target tension. Battery or pneumatic tools make sense above 100 loads per day to maintain consistent tension and reduce operator fatigue.

Composite and woven strapping use wire buckles that create high-strength joints without heat or crimping. Manual tensioners work for low volumes; heavy-duty loads need pneumatic systems that deliver 500kg+ of tensioning force.

Safety and Handling

PP is the safest to handle—soft, light, and forgiving if you make mistakes during application. No sharp edges, minimal recoil when cut, and easy disposal.

PET has stiffer edges that can cut if handled carelessly, but it’s still safer than steel. Coil weights run 15-25kg for standard sizes, manageable for most operators.

Composite and woven strapping eliminate steel’s biggest hazards: dangerous recoil when cut, sharp edges that slice hands or damage cargo, and heavy coils that cause back injuries. A composite strap rated for 1500kg weighs 40-50% less than equivalent steel, cutting handling fatigue significantly.

Disposal and Recycling

PP and PET are both recyclable, but PP contamination in PET streams creates problems for recyclers. Keep them separate. Composite and woven materials use polyester cores, making them recyclable as PET with proper processing.

Frequently Asked Questions

Q: Can I use PP for heavy loads if I add more straps?
A: Not reliably. PP’s high elongation means it stretches and loses tension during transport regardless of how many straps you apply. Adding more PP straps to a heavy load increases material cost without solving the creep problem. Switch to PET or composite for loads over 400kg.

Q: When does composite make sense over standard PET?
A: When your loads exceed 1000kg, experience high shock or vibration during transport, or require steel-replacement strength with safer handling. Composite also wins when cargo has sharp edges that would damage flat PET—the rigid coating resists abrasion better.

Q: Is woven strapping worth the premium over composite?
A: Only for the most demanding applications: extremely heavy loads (2000kg+), irregular cargo with sharp protrusions, or situations where partial damage to the strap can’t compromise the full system. Most industrial operations get better value from composite, reserving woven for edge cases.

Q: What’s the real difference between smooth and embossed PET?
A: Embossed PET has a textured surface that grips better in serrated seals, achieving higher joint efficiency and system strength. Smooth PET looks cleaner but can slip at the seal under maximum load. For critical applications, embossed PET delivers 10-15% better joint performance.

Q: Can one strapping material handle all my packaging needs?
A: Unlikely. Most operations benefit from stocking 2-3 materials: PP for light cartons, PET for standard pallets, and composite for heavy-duty loads. Trying to use one material everywhere means over-speccing some applications and under-speccing others.

Q: How do I calculate the right breaking strength for my load?
A: Multiply total load weight by 1.5 to account for dynamic forces during transport. Divide by the number of straps you’ll apply to get per-strap load. Select material with system breaking strength that exceeds this number. Example: 800kg load ÷ 4 straps × 1.5 safety factor = 300kg minimum per strap.

Conclusion

Match PP to light loads under 300kg with quick turnover. Use PET for medium to heavy pallets needing tension retention and UV resistance. Choose composite or woven for heavy-duty applications over 1000kg or when replacing steel. Spec complete systems—strap plus seals plus tools—not just strap ratings.

Review your current strapping inventory against actual load requirements and identify mismatches costing you money.

Amass-Strap manufactures PP, PET, composite, and woven strapping systems engineered for specific load and environmental requirements. We provide application-specific recommendations based on your cargo weight, handling conditions, and packaging workflow—not one-size-fits-all product lists. Our technical team helps you calculate system strength, match compatible seals and tools, and optimize material selection for the best total cost.

Visit amass-strap.com to see our complete range of strapping materials with detailed specifications and application guides, or contact us to discuss your packaging needs and get material recommendations matched to your exact load types and volumes.