Characterization of Recycled Fiber Material Made from Liquid Containerboard (LCB) and/or Old Corrugated Containers (OCC) – Evaluation of its Use by a Handsheet Study

Packaging materials for packaging liquid goods may contain over 75% virgin bleached fiber material that can be used to offset and or upgrade existing board products.

This laboratory handsheet study investigated the use of recycled old corrugated container and liquid container board which is currently not utilized from the recycling stream for paper board production.

Both fiber materials were repulped for 30 minutes at a pH of 10, a temperature of 150°F (65.6°C), and 1% Oxone addition based on fiber content under laboratory conditions. Handsheets were produced from unrefined and refined fiber materials with a freeness level of 400 ml.

Handsheets containing fiber material from liquid containerboard packaging showed an up to 3-fold higher mechanical paper properties if refined for burst, tensile, short compression strength, tensile energy adsorption and elongation. Tear Index values and 0-Span values were comparable, whereas porosity decreased with refining the old corrugated container and liquid container board fiber material.

Handsheets optical properties, L*, a*, b*, whiteness, and brightness, increased gradually from a dark brown color to a lighter brown color based on increasing LCB fiber content. Refined old corrugated container and liquid container board fibers resulted in a slightly darker color value, due to the virgin bleached softwood fibers used to manufacture the liquid container board paper product.

Opacity measured of this study showed a 100% value for all manufactured handsheets.

It can be concluded that utilizing fiber material from recycled liquid containerboard packaging at an addition level of up to 25% can enhance board paper products mechanical and optical requirements. Additional benefits might foster increased sustainability, biodegradability, and eco-efficiency of the paper board product.

However, more research is needed to assess the optimum liquid container board fiber addition for board products including processing and manufacturing conditions, including analyses of economic benefits regarding improvement of mechanical and optical properties of the resulting board product.