Reducing Environmental Impacts of Stretch Film
Evaluating the Alternatives
Billions of pounds of stretch film are consumed annually, wrapping tens of billions of loads based on the original Lantech concept for stretch wrapping. Therefore, Lantech plays a large part in understanding both the positive and negative impact stretch film is having on the environment.
Pressure on the environmental impacts of stretch film has reached a tipping point due to recent legislation focused on establishing a closed recycle loop for Post-Consumer Recycled (PCR) stretch film. Numerous film alternatives have reactively entered the market. Brand owners, resin suppliers, and film companies are facing difficult and complex decisions ahead.
We initiated an investigation into every current stretch wrap alternative. The evaluation compares performance, weight, cost, and estimated environmental impact across representative samples.
If you are interested in learning about this project, we invite you to download the White Paper and watch the video that outlines our findings and conclusions.
Conclusions
- Adding PCR to stretch film is currently NOT a sustainable solution
- Best current environmental choice: 100% virgin stretch film
- Stretch film should be recycled into other “downcycle” plastic products
- Further SOURCE REDUCTION may be achieved with improvements in:
- Wrapper Technology
- Film
- Machine maintenance
FAQ
Post Consumer Recycled (PCR) stretch film is collected after it has been removed from loads at the ultimate destination. It then must be sorted, cleaned of labels, adhesive, ink and foreign matter before being pelletized into resin for blending with virgin resin to produce PCR stretch film. It is distinguished from PIR (Post Industrial Recycled) stretch film which can be scrap or returned goods collected at the film producer.
The gels, and non-compatible materials in PCR dramatically impact the ability to prestretch the film without excessive film breaks. Reducing prestretch to avoid film breaks generally has been shown to double the film weight to achieve the required containment force.
“PCR stretch films from many sources were tested and found to have similar optimization settings. Sample of 30% PCR 80 Gauge as supplied by Sigma Stretch Films USA was selected as a representative.
Ultra-grade premium stretch films were selected to provide “best case” 100% virgin film. Samples from Malpack, Berry, Sigma, and Paragon were tested and found to have similar performance and optimization settings. Sample of Axis 60 gauge provided by Malpack, Canada was selected as representative”
Optimizing normally requires experimenting with materials, and all machine settings to find the prestretch, tension, that provides the required containment force at the lowest film weight…..without film breaks. This is sometimes a tedious and time-consuming process which may have to be repeated if the film quality, load profiles, or machine performance varies. When comparing wrapping materials, it is critical to compare their performance only after each has been optimized.
Using Lantech Film Auditor, 1000’ film samples were run at the equivalent of 35 RPM at progressively lower prestretch until no holes were observed. Result was 150% for PCR and 275% for Virgin.
Using Lantech Film Auditor, 1000’ film samples were run at the equivalent of 35 RPM at progressively lower prestretch until no holes were observed. Result was 150% for PCR and 275% for Virgin.
The containment was measured with the ASTM listed CFT-6 tool on the stretchable materials including the Hexcel, PCR stretch film and the Virgin resin stretch film. The unstretchable Mondi was tensioned with a measured 40 lbs of force on the paper as it was wrapping.
The C02 generated in production of a material is an accepted metric for “carbon footprint” and its relative environmental impact. We have adopted the CO2 content from production of PCR and virgin resin from Mondi’s well researched “Advantage Life Cycle Assessment” (2021)
Load wrapped with 30% PCR required 270 Grams to meet the required containment force (left flask). 70% of that 270 is shown on the bottom of the left flask and is 189 Grams. That is more than the 133 grams (right flask) required to meet the same required containment force
