Sustainability Through Multiwall Packaging

An Overview

Few human activities, including paper packaging, leave the environment untouched; despite their net benefits. Yet the main pathways to minimize the impact of human activities on the environment are evident: First and foremost, use renewable resources to provide for future needs and new uses; use no more than necessary; process natural resources with as little environmental burden as possible; reuse or recycle the products whenever possible. Relegate as little of the product into the waste stream as possible by finding other uses, recycling the product's components, or extracting renewable energy or compost from it. And finally, manage the waste streams to minimize the impact of the waste itself upon the environment.

Successfully achieving continuously better sustainable outcomes in our society requires achieving those goals in a manner that is economically sustainable, as well. To endure, economic methods must be employed to produce sustainable outcomes. Research focused on extending the range of sustainable choices must be part of any integrated approach.

Maximize Use of Renewable Resources

In the flexible packaging arena, multiwall packaging uniquely relies on paper, a renewable resource for almost all of its construction. The paper supplied to the US producers of multiwall packaging comes overwhelmingly from a renewable resource base, supplied sustainably from woodlands managed under the principles and practices of the Sustainable Forestry Initiative (SFI), the Forest Stewardship Council (FSC), the PEFC or similar programs.

Other materials such as coatings, starches, adhesives, films and inks used in the construction of multiwall sacks, while a significantly smaller portion of the finished product, may also be entirely or largely based upon renewable resources. Examples include corn- or potato- based starches and soy-based water soluble inks. Today, while most films are not made from renewable materials, research is underway to develop alternatives made from renewable materials that meet performance requirements economically. And work is also underway to develop renewable fiber-based barrier materials that provide adequate grease resistance while being repulpable in today's commercial paper recycling operations.

Users of paper multiwall sacks may want to communicate to their consumers about the renewability of their packaging. To facilitate this, PSSMA has developed a Renewable Resource logo which may be printed on sacks made of renewable resources. For an image of this label and to learn about the criteria for using it on packaging, please visit our Renewable Resources Logo page. PSSMA invites paper multiwall sack users to talk with their suppliers concerning details of using the logo on their packaging.

Use No More Material Than Necessary

Because it conforms so closely to the volume of material being packaged, multiwall packaging meets this measure of sustainability by design. No overpackaging is needed, as multiwall packaging meets both transport and go-to-market needs.

In addition though, driven primarily by advances in papermaking technology over time, the amount of fiber needed to package the same volume of product has decreased substantially. This improvement has occurred in both the thickness, or basis weight (weight/unit area), of the paper used and in the number of plies needed to achieve necessary performance features. Illustrative of the trade-offs between packaging material alternatives, it is this very strength characteristic of virgin sack kraft paper that enables the use of less fiber that also renders impracticable the inclusion of substantial amounts of less long and strong recycled fibers for multiwall sack paper construction.

Process Raw Materials with Minimum Environmental Burden

The environmental burden associated with construction of multiwall sacks is almost always much less than that associated with producing the materials from which the sacks are constructed. Because this is generally the case with converting operations relative to primary raw material extraction and processing operations, most of the current efforts to quantify sustainability factors for packaging are concentrated on primary manufacturing operations.

Almost all of the paper used in the production of multiwall packaging in the US today comes from mills that are committed to the Workplace Safety of the American Forest & Paper Association (AF&PA), the national trade association of the US forest products industry.

Renewable Energy & Co-generation

The forest products industry leads all other industries in the use of renewable energy, with 66% of the total energy used by AF&PA member mills generated from renewable biofuels. According to the US Department of Energy, pulp and paper mills produced 62% of the biomass-based fuel generated by the US industrial sector in 2012. Also, the forest products industry which supplies the kraft and other papers used in multiwall sack construction is a leader in the production and use of more efficient co-generated electricity. Not only does cogeneration at pulp and paper mills take advantage of renewable energy sources, it squeezes out energy remaining in the exhaust steam for manufacturing and heating processes, rather than wasting it to cooling towers as happens with conventional electricity production. AF&PA members have committed to one of the most extensive collections of quantifiable sustainability goals for a major US manufacturing industry. These goals and annual reporting of progress towards achieving them can be found at

Greenhouse Gases

Carbon-neutral renewable energy generated by our members is equivalent to 200 million barrels of oil annually, and its use avoids fossil fuel-based GHG emissions. At pulp and paper mills, the emission rate expressed in tons of carbon dioxide (C02) equivalents per ton of production has been reduced by 55.8 percent between 1972 and 2012. A recent study by the National Council for Air and Stream Improvement (NCASI) shows that the GHG reduction benefits of using biomass residuals for energy by the forest products industry are equivalent to about 218 million tons of carbon dioxide. This is comparable to removing about 40 million cars from the road.

PSSMA has developed a user friendly carbon footprint calculation tool that allows its members to calculate the carbon footprint of various designs of paper shipping sacks throughout the entire production, end use and disposal processes. Contact a PSSMA member to learn more about how that tool can help reduce the carbon footprint of your paper shipping sacks.

The Bottom Line

Many factors contribute toward improved sustainability of multiwall packaging. Chief among them is the use of a renewable resource base, coupled with advances that allow multiwall converters to use less input materials to achieve equivalent packaging performance. Using paper and other materials that have been manufactured with minimum environmental burdens also help producers of multiwall packaging to make more sustainable products.

Finally, by relying upon paper as the primary bag construction material, customers and consumers can depend upon multiwall packaging to provide flexible packaging solutions where greenhouse gas emissions are largely offset by carbon sequestered in sustainably managed forests and forest products.

For more information 

Paper Shipping Sack Manufacturers' Association 
5050 Blue Church Road 
Coopersburg, PA 18036 
Phone: 610-282-6845 
Fax: 610-282-1577