Plastic Strapping (PP/PET): What It Is and How It Works

Plastic Strapping (PP/PET) refers to two common types of polymer-based strapping used to secure goods for handling, storage, and transport: polypropylene (PP) and polyethylene terephthalate (PET). Both are flexible, lightweight bands wound on cores and applied with hand tools or automated machines to hold boxes, palletized loads, coils, and other items together. Although they perform the same basic function—providing lateral and top restraint—their material properties, performance, and typical uses differ in ways that matter to packers, warehouse operators, and transport planners.

Basic components and appearance. A roll of plastic strapping looks like a flat ribbon, usually 9 mm to 32 mm wide for common sizes, with thicknesses varying by strap grade. The strap is wound onto a cardboard or plastic core and comes in coils or centered-wound rolls. Color is often natural or black; black PET is common where UV resistance is important. Straps may be smooth or textured for grip.

PP (Polypropylene) strapping — the basics. PP strapping is the lighter, more economical option. It is semi-elastic and has good elongation, which lets it absorb shock and settle around loads. Typical strengths range from about 150 to 600 pounds of break strength for common retail and pallet applications. PP is commonly used for lighter cartons, unitizing boxes on pallets, and bundling small items. It is often sealed with metal clips, plastic buckles, or heat/ultrasonic welds when used with compatible tools.

PET (Polyester) strapping — the professional grade. PET (sometimes called polyester strapping) behaves more like steel strap in many ways: it has higher tensile strength, low elongation, and excellent recovery after tensioning. PET can replace steel strapping for many medium- and heavy-duty applications because it resists loosening, won’t rust, and is safer to handle. PET straps commonly achieve break strengths from 500 to several thousand pounds, depending on width and thickness. They are often heat-welded or friction-welded by machine and used for export pallets, heavy cartons, and products requiring long-term load stability.

How plastic strapping is applied. Application involves three basic actions: tensioning, sealing, and cutting. Manual tools allow a worker to wrap strap around the load, use a tensioner to tighten it to the desired force, and then crimp a metal seal or apply a welded seal. Battery-powered tensioning and sealing tools automate those steps for higher productivity. In medium to high-volume operations, semi-automatic and automatic strapping machines feed, tension, seal, and cut straps around conveyorized loads.

Sealing and joint types. Plastic strapping can be joined with several methods: crimped metal seals (common with PP), friction or heat welds (common with PET), and plastic buckles for temporary ties. Heat or friction welding joins the strap ends by melting and bonding the polymer, creating a clean, low-profile joint suited to automated systems. Metal seals are quick and inexpensive but require a sealer tool and leave a small metal component on the strap.

Choosing between PP and PET. When deciding which to use, consider load weight, transport conditions, long-term storage, and cost. Use PP for light-to-medium loads, quickly handled shipments, or where cost is the primary concern. Choose PET for heavier loads, long-term storage needs, export shipments that must survive rough handling, and situations where rust or safety from sharp steel edges is a concern. PET is also preferred when space is tight and higher tension is needed without strap elongation.

Practical examples. In a retail distribution center, PP strapping might be used to bundle shirt boxes into display packs for short-distance truck delivery. In contrast, a manufacturer shipping heavy machinery parts overseas would often choose PET strapping to secure wooden crates because the PET maintains tension over long transit times and won’t corrode like steel.

Advantages and limitations. Plastic strapping is lighter and safer to handle than steel, reduces damage to products, and is compatible with automated equipment. PET in particular offers high strength and low elongation comparable to steel. However, PP straps are less strong and can stretch under load, while PET, though strong, costs more and may require weld-capable equipment for optimal sealing. Extreme heat can affect polymer straps differently; consult supplier data sheets for temperature limits and chemical compatibility.

Safety and storage tips. Store rolls in a cool, dry place away from direct sunlight to prevent UV degradation. Use appropriate personal protective equipment (gloves, eye protection) during tensioning and cutting. Train staff on proper tension settings and safe handling to avoid strap snapback injuries. Also inspect straps for damage, cuts, or brittleness before use.

Final note for beginners. Plastic Strapping (PP/PET) is a versatile and essential packaging tool. Start by matching strap type to your load profile—light-duty PP for simple bundling, PET for higher strength and long-term stability—and invest in the right tools for the volume you handle. With the right selection and practice, plastic strapping will protect products, improve load integrity, and make warehouse operations safer and more efficient.