New Commercially Compostable Paper Products from Cortec® Corporation: Laboratory Compost Disintegration Studies

August 19, 2021

Introduction

Cortec®, a USDA BioPreferred® Program Pioneer,* is a leading provider of environmentally responsible solutions in the fields of packaging and metal preservation. All Cortec® paper products are made with FSC® certified recycled fibers. Several of these papers, including CorShield® VpCI®-146, are also USDA Certified Biobased Products, which emphasize a focus on sustainable materials sourcing. At the other end of the circular spectrum, barrier papers such as EcoShield® VpCI®-144 and EcoShield® Barrier Paper are repulpable and recyclable (tested according to the FBA Voluntary Standard for Repulping and Recycling and the EU Recyclability Assessment System Aticelca 501:2019) to promote a reusable end of life disposal option. The latest innovations in the circular economy of paper packaging products from Cortec® are biodegradable Vapor phase Corrosion Inhibiting (VpCI®) paper and barrier paper that have recently passed compostable disintegration testing according to the ASTM D6868 standard for commercial composting.

CorShield® VpCI®-146 Paper (Recyclable, Biodegradable, Compostable) with Eco-BioTechnology is a performance-proven premium corrosion inhibiting paper. It relies on Cortec’s patented biodegradable and compostable Vapor phase Corrosion Inhibiting Technology. The barrier paper, currently in R&D, utilizes biobased and biodegradable barrier materials to provide an excellent barrier to water. It also resists oil and grease.

Experimental Procedure

Thermophilic aerobic composting was conducted as follows (according to ISO 20200). Compost Medium: Purchased garden variety compost; mixed with yard and food waste.

* For more information about the BioPreferred® Program, go to http://www.biopreferred.gov.
† Most of these products are intended to be composted in a commercial composting facility operated in accordance with best management practices.
Check locally to see if such a facility exists in your community and if they will accept your specific product.

Testing Conditions: Temperature was 58 ± 2 °C (136 ± 36 °F) (in calibrated ovens #1 and #2); RH was 50-55% (in compost medium).

Assembly: In a container, a piece of testing paper was placed on top of the compost medium. The paper was covered with a thin layer of compost at the beginning of the composting. This top layer of compost was carefully brushed away when the paper started to show disintegration. The container was covered by foil to preserve moisture.

Twice a week, the composting container was examined. The container weight was monitored, and lost moisture was replenished by spraying DI water. Progress in the paper disintegration was photographed weekly. The testing was terminated after 12 weeks.

Composting Results Summary

Paper Tested  Weeks Needed to Meet the Compostable Disintegration
Criteria (Residues <10% Original Film Mass, ASTM D6868
CorShield® VpCI®-146 10 weeks
Biodegradable Barrier Paper 10 weeks

Progress in Film Disintegration

Notes: The paper disintegrated after a 10-week composting period. Composting two more weeks after Week 10 did not show a change in compost appearance, confirming the time needed for disintegration is 10 weeks. No visible paper fragments were observable at Week 12.

Notes: The paper disintegrated after a 10-week composting period. Composting two more weeks after Week 10 did not show much change in compost appearance, confirming the time needed for disintegration is 10 weeks.

Conclusions

ASTM D6868 indicates that a paper meets the compost disintegration criteria if it leaves less than 10% of the original mass after 12 weeks of composting. CorShield® VpCI®-146 and the biodegradable barrier paper in R&D both disintegrated after 10 weeks, faster than the requirement specified by ASTM D6868. They both passed the disintegration testing.

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