It is well understood that paper fibers cannot be recycled indefinitely. The US EPA indicates that papers can be recycled an estimated 4-7 times and the Technical Association of the Pulp and Paper Industry (TAPPI) cites 5-7 times. The range of reuse depends on both the type of fiber and the subsequent treatment of that fiber. Longer stronger fibers, like softwood kraft fibers used in paper bags, will generally survive longer than a shorter weaker fiber - such as a mechanically pulped hardwood used in newsprint and some magazine grades.
How many times “does” a paper fiber get recycled?
Keeping fiber available for re-use is based on two key metrics - the recovery rate (collection) of different paper products and the subsequent yield in processing.
There is ample data to show that different paper products are recovered at different rates. Corrugated containers lead the charge at over 90% while the rate for printing and writing grades is just about 55%.
When it comes to processing yield, again there are vast differences by product category. Paperboard manufacturers cite yields of 95% or better. According to Ron Fox of paperboard manufacturer, Graphic Packaging International, “When we reuse the fiber, we’re basically just filtering out the non-fibrous, extraneous materials like plastics and metal. We keep all the fiber and additives. So when we’re making containerboard or boxboard, at the lowest our yield is about 90%. Generally we yield about 97% 98%.” The key to the higher yield is to keep the processing to a minimum. Says, Fox, “We don’t deink it, we don’t bleach it, we don’t do anything to degrade that fiber”. (Cited on p. 16 in “Rethinking Recycling”)
At the other end of the spectrum, products such as our coated fine papers require a much cleaner, purer fiber. Cleaning, filtering and processing recovered fiber to meet the tough standards of graphic paper applications requires additional energy and chemicals to raise its quality and separate the fiber from materials such as adhesives, clay and ink. Deinking facilities that produce fibers for use in graphic paper routinely report lower yields – around 70% - with some sources reporting yields as low as 52%.
When we combine the effects of recovery rates and yields, we find that a significant portion of fiber never sees a second use. For example, if we start with 100 tons of office paper fiber and only 55% is collected and then 30% is lost in deinking, less than 40% of the fiber actually ends up recycled after just a single round of recovery and processing.
(100 x 0.55 x 0.7 = 38.5)
So what can we do to keep more fiber in the system?
Step 1. Collect more
As a society we should strive for the highest collection possible. This is one of the reasons we are so passionate about using “please recycle” logos on printed materials.
Step 2. Waste less fiber
We need to face the facts. Clearly paperboard manufacturing is a better use of recycled fiber than premium printing and writing grades. It is important that procurement policies and decisions allow fiber to get put to its best use where it will have higher yield and less environmental impact.
If you want the deep, deep dive on what happens to fibers in recycling, check out this peer reviewed paper by a group of professors at NC State. In their summary they say “…recycling of paper involves many compromises…” and “it can be quite complicated to determine the most appropriate, and even the most ethical way to deal with recycling of paper.”