Teufelberger Brain Box

Knowledge that sticks. Simply explained. In the Brain Box, you'll find compact explanations, fascinating insights, and practical how-tos about materials, processes, and technical terms.

Illustration of a human head with thought bubbles and question marks on a blue background – symbolizing curiosity and questions.
Schematic representation of a manufacturing process: from raw material dosing stations through extrusion screw, moulding tool, and water bath to stretching and winding units.

Good to Know

From raw material to strap – how strapping is made

The extrusion process is the heart of strapping band production. Here, plastic is transformed under heat and pressure into a continuous strap.

Extrusion is the first and most crucial step in manufacturing plastic strapping bands. The raw material (either granules or flakes) – made of polypropylene (PP) or polyethylene terephthalate (PET) – is melted in an extruder and pressed through a shaping die. The result: a continuous band that is then cooled, stretched, and wound onto coils.
The quality of the extrusion process significantly affects the band’s properties – from strength and elongation to surface texture.

  • Raw material: Plastic material as granules or flakes  (PP or PET)

  • Melting: In the extruder at high temperatures

  • Shaping: Through dies

  • Cooling: In water baths

  • Winding: Onto spools for further processing

Term Explanation

Expert Know-How to go. Expressions and terms that are good to know when handling with strapping.

Breaking strength (or breaking load) refers to the maximum tensile force a new strapping band can endure before it breaks. It’s a key parameter for packaging and transport safety. Depending on the material, width, thickness, and structure, the breaking strength can vary significantly.

Why is this important?

Only when the breaking strength matches the application can safe strapping be ensured – whether for light boxes or heavy pallets.

  • Definition: Maximum force (in N or kg) before the band breaks

  • Depends on: Material, band dimensions, and structure

The connection that holds everything together.
Strapping bands aren’t tied – they’re welded, usually using friction or heat welding. The resulting weld is the joint between the two band ends. Its strength – known as weld joint  strength – is crucial for the overall stability of the strapping.

Why is this important?
A weak weld joint can cause the strapping to fail – potentially leading to significant damage.

  • Weld joint: Connection between band ends

  • Weld joint strength: Load capacity of this connection

  • Influencing factors: Temperature, pressure, welding time, band quality

Shock Reserve is the strap's ability to absorb sudden forces—like a jolt during loading or a bump on the road—without snapping. This extra buffer ensures your goods stay secure, even when the unexpected happens.

  • Prevents load shifting during sudden impacts

  • Increased transport reliability

  • Lower damange rates and claims

Retained tension refers to the amount of tension left in the strapping after a given period of time.

Why does it matter?

  • Absorbs shock during transit: Plastic strapping elongates under tension, allowing it to stretch and absorb impacts without snapping.

  • Maintains load integrity: Proper retained tension ensures the strap continues to hold the load securely, even after settling or shifting.

  • Prevents over-elongation: Too much stretch can reduce recovery ability, weakening the strap’s hold.

  • Supports sustainability: Efficient strapping reduces waste and improves transport safety — a win for both performance and the planet.

Two horizontal green strips: the top one with a textured surface, the bottom one smooth and solid-colored.

Good to Know

Smooth vs. Embossed Strap

Structure with function – what the surface does.

PET strapping come with either a smooth or embossed surface, while PP straps are only available with an embossed surface. These differences are not just visual – they affect friction, processing, and strength. The type of strapping machine used is also a key factor.

 

Why is this important?
The choice of band surface affects how well the band runs through machines, how securely it holds, and how it behaves during strapping.

Glass bowl filled with water containing floating and submerged strips of colored strapping – in red, yellow, blue, black, and white.

Good to Know

PP or PET – How to tell the Difference?

A simple trick with powerful insight.

PP and PET are the two main materials used for strapping – but how can you tell them apart? The so-called sink/float test provides a quick answer: just place a piece of band in water and observe.

Why is this important?
Distinguishing the material is essential for proper disposal and material sorting.

  • PP (Polypropylene): Lower density → floats in water

  • PET (Polyethylene terephthalate): Higher density → sinks in water