Most paper is recyclable
Most materials made of paper fibres are recyclable. Indeed, according to laboratory testing, (virgin) paper fibres can be recycled as many as nine times. With each recycling, however, the fibres become progressively weaker until eventually they wear out and must be replaced with a fresh infusion of longer and stronger virgin fibres. This traditional life cycle flow of paper materials is outlined in the chart below.
The Paper Recycling Flow Chart
The blending of virgin fibre with used paper is necessary to keep the whole paper recycling loop going since the fibres become shorter and weaker the more times they are recycled. The European multiwall bag industry, for example, produces a mostly recycled content product but needs an annual quota of virgin fibre from Canada and other countries to maintain the necessary strength properties of the bags it produces.
The flow chart to the left shows what’s called the traditional paper recycling loop. Used paper and board recovered from industrial, commercial and institutional sources is shipped back to the recycling mills again and again until the paper fibres wear out. The dotted loop (recovering paper materials from the home) ties into the larger loop and helps keep the whole recycling loop going. Laboratory tests indicate paper fibre can be recycled up to nine times before becoming too short or weak to make paper.While each recycling mill is different, and is built to handle the particular types of recovered paper it requires to make a new paper product, the paper recycling process itself is generally the same for all mills. The recovered paper is dropped into a pulper, which acts like a big washing machine. Non-paper materials such as plastic, glass and metals are removed through a series of cleaning and screening processes. The paper fibres are then pumped onto a fast-moving screen to form paper or board. The rest of the process involves removing the moisture out of the paper or board so that it can be wound onto big rolls or cut into sheets for further conversion into paper products.
Length and strength
It is the length and strength of the paper fibres that generally determines where they get used next, rather than the particular product they may have been part of in the first place. For example, the virgin fibres of Canadian produced multi-wall sacks are widely sought after by recyclers because of the strength properties they offer to other paper products.
It is highly unlikely that a virgin multi-wall bag will be recycled back into a new multi-wall bag. Partly this is because of geography (virgin mills tend to be in remote rural areas while recycling mills are predominantly in urban locations). What usually happens is that the strong fibres in bags are given a new life as part of a mix of (predominantly recycled fibres) in a new corrugated box or other paper product. This is why specific recycling rates for kraft paper bags are hard to nail down, and why they are frequently lumped in with corrugated box recovery numbers, because that is where they often end up.
Mixing and matching
This mixing and matching of stronger and weaker paper fibres to provide the appropriate performance standards for new bags also helps explain the growing trend of using old corrugated boxes (OCC) as the primary feedstock for new multi-wall, grocery, retail, and composting bags, rather than virgin fibres. Paper makers will mix and match to meet the specific performance requirements of the package.
Some 96% of Canadians have access to the recycling of kraft paper bags through curbside, depot, or retail take-back programs. This achievement allows bag producers to make unqualified use of the recyclable logo or word on their bags since the federal environmental labelling guidelines specify 50% access as a minimum threshold in the marketplace in which the bag is sold 1.
Actual recycling rates
As noted above, actual recycling rates are very hard to tie down because kraft bags are not a large product line compared to others such as corrugated boxes and boxboard, and because very few of the surveys that have been undertaken to date specify “paper bags” as a separate item. They tend to get lumped in with the collection of old corrugated boxes.
One of the few surveys to include paper bags from both the industrial and residential sectors was completed by Statistics Canada in 1996. It estimated a “sent for recycling” rate for a combined “paper bag” category of just 4 per cent. That’s almost 20 years ago, and certainly residential paper collection (including bags) has grown immensely since then.
The only specific and recent residential paper bag data comes from Quebec where “kraft paper shopping bags” and “kraft paper packaging” are both given a 30% recovery rate. Their plastic counterpart is given a 7% recycling rate2.
But recycling practitioners and the receiving paper mills know that in practice paper bags are bundled in with mixed paper and old corrugated bales for recycling. This is why kraft paper bags that end up in the residential waste stream are frequently given the same recovery rate as corrugated. Paper bags bundled with corrugated have an almost 10 times higher recovery rate in Ontario’s Blue Box program than plastic bags (85% compared to 9%), and are almost five times less expensive to recycle3.
Some householders still use paper bags to put out various recyclables at the curb for pick-up, although most Canadians now use blue boxes or carts. And of course, multi-wall paper bags are widely used to contain food scraps and leaf and yard waste. Instead of being recycled, these bags are composted along with their contents, a favoured option because paper compostable bags don’t require expensive de-bagging machinery and extra municipal labour costs.
Relevant PPEC Factsheets
1Recyclable, PPEC Factsheet refers to Environmental claims: A guide for industry and advertisers, developed by the Canadian Standards Association (CSA) and the Competition Bureau. See Section 10.7 of these guidelines for claims of recyclability http://www.competitionbureau.gc.ca/eic/site/cb-bc.nsf/eng/02701.html.
2 Éco Entreprises Québec, Waste Characterisation, 2010.
3 Stewardship Ontario, Ontario Blue Box Generation and Recovery Data, Table 1, 2012. Paper bags bundled with corrugated had a recovery rate of 85%; plastic bags bundled with plastic film (a recovery rate of 9%). The net cost of recycling plastic film (which includes plastic bags) was $1,861.57 a tonne (Gross and Net Costs Data, Table 2), over five times the net cost of recycling paper bags bundled with corrugated.