Table of Contents
INTRODUCTION
When it comes to securing pallets for transport and storage, stretch film is a indispensable tool in warehouses, distribution centres, and manufacturing facilities across the UK. However, many businesses don’t fully understand the critical importance of achieving the ‘rigid state’ when applying stretch film. This optimal condition is the sweet spot between too tight and too slack – and getting it right can mean the difference between safe, secure loads and costly pallet failures.
UNDERSTANDING THE RIGID STATE
The rigid state occurs when stretch film is stretched to its optimal point – just before it reaches its breaking point. At this level of stretch, the film becomes rigid and provides maximum load stability throughout the entire journey. This isn’t simply about applying more film or stretching it as tight as possible; it’s about finding that precise balance where the film performs at its absolute best.
When stretch film reaches its rigid state, it transforms from a flexible plastic wrap into a strong, cohesive barrier that works as one unified piece rather than individual revolutions around the pallet. This transformation is crucial for maintaining load integrity during transport, handling, and storage.
THE DANGERS OF OVER STRETCHING
Applying stretch film too tightly might seem like the logical approach – after all, tighter must mean more secure, right? Unfortunately, this common misconception can lead to significant problems.
When stretch film is over-stretched, it becomes vulnerable to tearing and breaking, particularly at stress points or when the load encounters sharp edges or corners. The film loses its elasticity and ability to absorb shock, making it brittle and prone to failure. This can result in catastrophic pallet collapse, potentially causing:
- Product damage and loss
- Workplace accidents and injuries
- Delays in delivery schedules
- Increased labour costs for restacking
- Potential fines from clients
- Damage to company reputation
Over-stretched film also tends to create uneven tension across the load, leading to weak spots that can compromise the entire wrapping job. The film may snap during application, wasting material and requiring operators to start the wrapping process again.
THE PROBLEMS WITH UNDER STRETCHING
On the opposite end of the spectrum, under-stretched or slack stretch film presents its own set of challenges. When film isn’t properly stretched to reach its rigid state, it continues to stretch during transport, becoming increasingly baggy and loose as the journey progresses.
This ongoing stretching creates an unstable load that can shift, topple, or collapse entirely. Under-stretched film fails to provide adequate load containment, allowing products to move within the wrap and potentially fall from the pallet. The consequences include:
- Load instability during transport
- Product shifting and damage
- Increased risk of pallet collapse
- Poor protection against dust, dirt, and moisture
- Wasted film material due to ineffective application
- Higher overall packaging costs
Under-stretched film also fails to create the necessary cling and cohesion between layers, resulting in a wrap job that looks secure but lacks the structural integrity needed for safe transport.
ACHIEVING THE PERFECT BALANCE
Finding the rigid state requires understanding both the film’s properties and the specific requirements of your load. This optimal stretch point varies depending on several factors:
Film Type and Quality: High-performance films, such as those utilising nanotechnology, can achieve superior rigidity with less material compared to traditional commodity films. These advanced films often provide better puncture resistance and tensile strength when properly stretched.
Load Characteristics: The weight, dimensions, and stability of your products influence the stretch requirements. Heavier loads may require different stretching techniques compared to lighter, more fragile items.
Application Method: Whether you’re using hand-applied or machine-applied stretch film affects how easily you can achieve the rigid state. Machine application typically provides more consistent results and better control over stretch levels.
Environmental Conditions: Temperature and humidity can affect film performance, requiring adjustments to achieve optimal rigidity.
Proper Application Techniques
Achieving the rigid state isn’t just about stretch level – it’s also about proper application technique. Key considerations include:
Pallet Foundation: Ensuring the film extends to at least 33% of the pallet height and maintains continuous coverage up the load is crucial for stability. Many pallet failures occur due to insufficient locking to the pallet base.
Overlap Pattern: Adequate overlap between revolutions allows the film to work as one cohesive unit rather than separate layers. Proper overlap ensures the stretched film can maintain its rigid state throughout the load.
Wrap Pattern: The pattern of film application affects load stability. Block-stacked pallets require different wrapping strategies compared to loads with interlocking patterns.
The Benefits of Getting It Right
When stretch film is properly applied to achieve the rigid state, the benefits are substantial:
- Enhanced Load Stability: Products remain secure throughout transport, reducing damage and loss
- Cost Efficiency: Less film waste and reduced product damage lead to lower overall costs
- Improved Safety: Stable loads reduce workplace accidents and road safety incidents
- Better Protection: Rigid film provides superior barrier properties against environmental factors
- Increased Productivity: Efficient wrapping processes reduce labour time and improve throughput
Modern packaging operations can achieve up to 65% cost reductions whilst maintaining superior load stability by optimising their stretch film application to achieve the rigid state consistently.
The old saying that you can achieve more with less is certainly true when it comes to our Shield nano films. It’s all about applying the film correctly, not in the amount you use.
AARON ENTWISTLE
LOAD STABILITY SPECIALIST
CONCLUSION
The rigid state represents the optimal performance point for stretch film – where maximum stability meets efficient material usage. Understanding this concept and implementing proper application techniques can transform your packaging operations, reducing costs whilst improving load security.
Remember, it’s not about using more film or applying it tighter; it’s about applying it correctly to achieve that crucial rigid state where your stretch film performs at its absolute best.
Key takeaways
- The rigid state is the optimal stretch point – just before the film reaches its breaking point, where it provides maximum stability
- Over-stretching causes brittleness – leading to tears, breaks, and potential pallet collapse during transport
- Under-stretching creates instability – resulting in loose, baggy film that continues stretching during transit
- Proper technique is essential – including adequate pallet foundation coverage (33% minimum) and correct overlap patterns
- Quality matters – high-performance films can achieve better rigidity with less material compared to commodity films
- Cost savings are significant – proper application can reduce packaging costs by up to 65% whilst improving load stability
- Safety is paramount – achieving the rigid state reduces workplace accidents and prevents dangerous load failures on roads
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