What is Composite Strap & Woven Lashing?

Packaging and cargo security are critical in transportation. Two materials making significant impacts are composite straps and woven lashing. Their unique properties and diverse applications have made them popular in various industries. This article will provide an in-depth look into these materials and their advantages in shipping and storage.

Brief Overview

Composite Strap

Composite strapping is constructed from vertical strands of polyester fibres with a clear polypropylene coating. This design is available in multiple widths and tensile strengths. The polypropylene layer enhances the strap’s abrasion resistance and permits a modest elongation during transit, ensuring cargo remains secure.

They are known for their high tensile strength, UV resistance, and ability to retain tension, making them suitable for various packaging needs. Unlike poly-woven straps, the composite strap is notably stiffer due to its polypropylene coating. Combined with galvanized wire buckles, this rigidity simplifies feeding the strap underneath pallets.

Key Benefits and Advantages:

• Durability: Polyester fibres give the strap high tensile strength, ensuring it remains intact under pressure.
• Abrasion Resistance: The polypropylene coating enhances resistance to wear and tear.
• Flexibility with Rigidity: Unlike some other straps, composite straps are stiff due to their polypropylene coating, making them easier to thread under pallets, yet they allow a modest elongation during transit.
• Lightweight: Makes it user-friendly and reduces shipping weight.

Common Applications:

• Securing heavy goods during transportation.
• Stabilizing cargo in maritime shipping.
• Bundling goods in warehouses for space optimization.

Woven Lashing

Woven lashing belts are crafted from high-tensile polyester yarns. These belts boast low elongation (under 10%), making them exceptionally tearing-resistant while exhibiting minimal moisture absorption. Unlike some other belts, woven strapping belts remain splice-free, offering flexibility and universal application. Specifically, woven lashing is designed as a one-time-use cargo securing strap with remarkable tensile strength, making it the ideal choice for anchoring heavy machinery within shipping containers or securing flat-rack cargo.

They can be used with all load buckles that undergo treatments to protect them from corrosion, seawater, and other environmental hazards. These buckles are designed for effortless threading and to provide unparalleled load performance. Among the variants, galvanized wire buckles are optimized for composite strapping, whereas phosphate wire buckles pair best with polyester woven strapping.

Key Benefits and Advantages:

• High Tensile Strength: Using polyester yarns ensures the lashing can withstand substantial loads.
• Low Elongation: With elongation below 10%, it remains taut and effective even under stress.
• Moisture Resistant: Its material composition absorbs very little moisture, preventing weakening due to damp conditions.
• Universal Application: Its flexibility and strength make it suitable for various uses.

Common Applications:

• Anchoring heavy machinery within shipping containers.
• Securing flat-rack cargo.
• Bundling large items for over-the-road transport.

Manufacturing Processes

Composite Strap

For the manufacture of composite straps, the primary raw materials, polyester fibres and polypropylene, play a crucial role. These materials are usually procured from specialized suppliers committed to providing the highest grade and purity, ensuring the final strap’s strength and durability.

The manufacturing process begins with the polyester fibres being straightened and aligned to travel vertically. Once aligned, these fibres are encapsulated with polypropylene in specialized machinery. This combination is then subjected to a weaving or binding process, meticulously ensuring the fibres are tightly held within the polypropylene coating, forming the composite strap.

Quality is paramount in this production process. Every batch produced undergoes rigorous testing protocols, evaluating factors like tensile strength, elongation properties, and abrasion resistance. Regular audits of the manufacturing process ensure unwavering adherence to international industry standards. Furthermore, the final composite strap often carries certifications from recognized global entities, ensuring users of its quality and safety in diverse applications.

Woven Lashing

The essence of woven lashing lies in the high-tensile polyester yarns. These yarns are typically sourced from trusted suppliers, given the pivotal role they play in determining the strength and resilience of the lashing. The production process starts with these polyester yarns being methodically threaded into weaving looms.

The yarns are interwoven through intricate techniques, creating a dense, strong matrix that bestows woven lashing its distinctive strength and flexibility. This specific woven design ensures that weight and tension are uniformly distributed, further amplifying its capability to bear substantial loads.

Like composite straps, quality control is stringent for woven lashing. Once manufactured, the lashing undergoes tests evaluating its tensile strength, flexibility, and resistance to moisture. Adherence to domestic and global standards is maintained religiously throughout manufacturing. To attest to the reliability and excellence of the lashing, it often comes endorsed with certifications from authoritative bodies worldwide.

Application Techniques

Use of Composite Straps

Preparation involves ensuring the strap is free from knots or twists before use. During the application phase, it’s essential to maintain uniform tension throughout the strap to guarantee stability; tools such as tensioners can be beneficial in attaining the correct tension level. The securing step requires appropriately placing compatible buckles or seals to prevent slippage. Using two straps for added security might be prudent for heavier loads.

Initial Setup:

• Begin by wrapping the strapping around the crate or box.
• Insert the strapping end upwards through the centre of the buckle and then around its open leg, forming a loop.
• Ensure that when looking at the buckle, it faces to the right, resembling the letter “C”. The strap on top should have a shorter end.

Applying Tension:

• Pull the top strap tight around the buckle’s leg. Then, pull both top ends of the strapping in opposite directions. For additional tension, use manual tensioners.
• Position the tensioner on the bottom strap, roughly 30 cm from the buckle.
• Raise the tensioner’s gripper foot and place the bottom strap underneath it. The top strap should pass through the cutter housing and windlass of the tensioner.
• Begin tensioning. Once the buckle presses down on the strap, squeeze the tensioner’s handle to cut the strap and then remove the tensioner.

Verifying Buckle Quality:

• Proper tensioning should result in the buckle’s legs closing down on the strap. If the buckle deforms or its legs move upward instead of downward, it may be made of inferior soft wire steel, indicating lesser quality.

Lashing Techniques with Woven Straps

For preparation with woven straps, ensure the strap is straight and devoid of knots. The next step, looping and anchoring, involves forming a loop at one strap end and securing it to a fixed point, establishing a robust foundation for lashing.

During tensioning, draw the strap over the item, ensuring it’s flat and not twisted, and apply uniform tension by using strapping tensioning tools. Finally, for securing, once the appropriate tension is achieved, fasten the strap using suitable buckles or seals, ensuring a firm grip without damaging the strap.

Setting up the Buckle:

• Hold the buckle with the left hand.
• Feed the woven lashing upwards through the centre of the buckle, moving it away and around it.
• Bring it upwards through the top small opening of the buckle and then downwards through the buckle centre.

Lashing Feed:

• Take the bottom lashing (the part attached to the coil) and feed it upwards through the buckle centre towards you.
• Fold the lashing around the buckle, then guide it upwards through its small bottom opening and downwards through its centre.
• Pull the lashing tight by hand.

Using the Manual Tensioner:

• Approach from the right and place the tensioner onto the bottom lashing.
• Press the tensioner’s handle to release its gripper foot. Slide the bottom lashing beneath this foot and continue to thread it through the tensioner’s knife assembly and winger.
• To tension the lashing, move the tensioner’s handle up and down. Once you achieve the desired tension, press down on the handle to cut the lashing.
• Lastly, remove the tensioner by sliding it away to the right.

Safety Precautions and Best Practices

Regardless of the type of strap used, certain safety precautions should be standard practice:

• Regular Inspection: Before use, always inspect straps for signs of wear, tear, or damage. Compromised straps can fail during application or transport.
• Avoid Over-tensioning: While it’s important to secure items firmly, over-tensioning can damage the strap or the items being secured.
• Wear Protective Gear: During tensioning, gloves and safety glasses can protect against unexpected snaps or recoil, especially with steel or heavy-duty straps.
• Stay Updated: Periodically review and stay updated with industry best practices and safety standards for strapping and lashing techniques.

Comparison with Other Packaging Solutions

Traditional Steel and Plastic Straps: Steel straps have long been used in the packaging industry due to their strength. They are especially prevalent in heavy-duty applications. However, they come with the drawback of being susceptible to corrosion. Plastic straps, lighter in weight, are suitable for less demanding tasks but can stretch more and offer less strength than steel.

Advantages of Composite and Woven: Composite straps, combining polyester fibres with polypropylene, balance strength and flexibility. They aren’t prone to rust like steel, making them suitable for damp environments. Woven lashing, made from polyester yarns, offers high strength with reduced stretching. Both options have the added benefit of being resistant to moisture absorption, which can extend their usable life.

Cost-Benefit Analysis: While composite and woven lashing solutions might have a slightly higher upfront cost than some traditional plastic straps, their durability and versatility can lead to long-term savings. Compared to steel, the lightweight nature of these straps can also contribute to decreased shipping costs. These modern solutions can prove cost-effective over time when factoring in the reduced maintenance and replacement costs due to their longer lifespan and resilience to environmental factors.

Conclusion

Composite straps and woven lashing offer a dependable and efficient solution for securing goods. Their durability and resistance to various environmental factors emphasise their utility. Humi Pak offers an extensive selection of load-securing solutions designed to safeguard goods against damage during transit. Contact us for a no-obligation consultation with our packaging engineers to learn more.