Leer en español
Читать на русском
In the U.S., people consume an estimated three billion pizzas a year. That’s a potential of 600,000 tons of corrugated board that could be recovered and reused at least 7 times. WestRock shares results of Grease and Cheese Study
“The number of pizza boxes placed on the market in the U.S. annually is estimated to be 3 billion boxes equating to 600,000 tons of corrugated board,” the study reads. “Pizza boxes represent 1.7% of the 35.9 million tons of corrugated containerboard produced in the U.S. annually.
“If all pizza boxes were recovered for recycling, they would represent approximately 2.6% of the OCC stream or 2.2% of the OCC and mixed paper stream combined.
“Pizza boxes currently found in the recycling stream have an average grease content of approximately 1-2% by weight level.
“Grease is hydrophobic and when pizza boxes approach a 20 wt% concentration of the furnish, grease interference with inter-fiber bonding begins to result in significant paper strength loss (~5%). At pizza box concentrations under 10%, paper strength loss is low.
“The strength loss as a function of greasy fiber and pre-consumer board was almost linear in the 0-20 wt% blend level.
“Cheese, comprised of fats and proteins, is hydrophilic and does not hinder hydrogen inter-fiber bonding of fibers. Cheese tends to solidify and get screened out during the pulping process.
“Therefore, there is no significant technical reason to prohibit post-consumer pizza boxes from the recycle stream.”
The cardboard in old corrugated containers, including pizza boxes, can be recycled up to seven times before the quality of the fiber is degraded. Introducing boxes made with new (virgin) fiber into the recycle stream helps replenish these degraded fibers and sustain the cycle.
The WestRock‘s findings, which concluded that typical amounts of residual grease and cheese don’t impact the quality of the recycled fiber, were validated by The American Forest & Paper Association (AF&PA).
gofro.expert
