Recyclability aspects of packaging design

Recyclability aspects of packaging design by Susan E. Selke, Ph.D. and Christopher C. Lai, Ph.D. Drs. Selke and Lai are assistant professors with the School of Packaging at Michigan State University, East Lansing, Michigan. The statistics and stories are beginning to sound all too familiar - 135 million tons of municipal solid waste in the United States each year, one-third of states without landfill capacity by 1990, the garbage barge that journeyed for thousands of miles. These grim numbers are forcing municipal, county and state officials throughout the country to deal with the solid waste crisis. Because packaging accounts for about one-third of all municipal solid waste by weight and because packaging is often perceived as unnecessary and wasteful, proposals to regulate or ban packaging of certain types are becoming more common. Plastics are increasingly a target because they are viewed as nonrecyclable, while glass, metal and paper materials are perceived as recyclable. Packaging design and excess packaging The best design for a package is one that makes the packaging, distribution and sale of the product the most profitable. This does not necessarily translate into a package that places the least burden on the disposal system. Because of this, and because packaging functions are misunderstood, there is a common perception that there is a large amount of excess packaging which, if eliminated, would reduce our solid waste problem substantially. Unfortunately, the issue is not this simple. The major functions of packaging are protection, communication and convenience. A packaging engineer s job is not simply to insure that a package performs its functions while it is used, but also to consider what happens to the package after it is used. Proper design has become an important issue in today s package development. Protection. Packaging should protect the product from its environment and protect the environment from the package. Protection includes such aspects as lids that keep carbon dioxide in soft drink containers, child-resistant caps, or polystyrene foam for fragile products. Some charges of overpackaging come from perceptions that the protection for the product is excessive. Manufacturers assess the severity of the product s environment and then package the material to survive conditions somewhere between the best and the worst situations. In doing so, manufacturers try to maximize profits by minimizing expenses, both those due to packaging and those due to package failure (product damage, loss of consumer good will, transportation costs for returned goods, etc.). The feasibility and probability of recycling must be considered when designing recyclable packaging materials. For a costly product such as a television set, the product would be packaged to survive close to the worst conditions. A box containing a television set, then, might include what seems to be an inordinate amount of polystyrene. For a less costly product, the package would not need to be as protective, hence there would appear to be less overpackaging. What appears to be overpackaging is in fact necessary for the efficient functioning of our distribution system. The alternative would be to increase not only the 36 Resource Recycling July 1988

costs of consumer goods significantly, but also increase the burden on the waste disposal system from the disposal of goods improperly packaged. To be sure, there are some cases where the proper balance has not been struck between the distribution system and the amount and type of packaging. In these circumstances, however, any excess packaging will be eliminated in order to cut costs and maximize profits. Communication. The communication function of packaging is served by information on product and manufacturer identification, quantity of contents, warnings, and the buy-me features of retail packages. The communication aspects of a package are more vulnerable to charges of excess packaging. It is easy to look at packages and say we do not need the bright colors, fancy pictures, etc. However, these aspects of packaging seldom add to disposal volumes. More vulnerable to the charge of excess packaging are products packaged to increase their visibility through increased size. A package that does not communicate effectively to the consumer is not likely to survive in the marketplace. Therefore, decisions that increase the amount of packaging and its cost but increase sales are economically sound. Regulatory action or voluntary cooperation by industry is needed to prevent the increased burden on disposal capacities that result from this type of overpackaging. Convenience. Convenience includes dispensing features, such as flip-top caps, packages in a variety of sizes, and singleserving foods. The convenience of packaging is the area where excess packaging is most likely to be found. It is certainly true that much more packaging is used to contain 10 frozen microwave roast beef dinners than to package a beef roast, a sack of potatoes and some green beans. However, if we banned such packaging and products, there would be a loud outcry from consumers. As a society, we demand convenience products, and we demonstrate this demand by our willingness to pay for them with higher prices. In fact, trend analysis indicates that consumers want more and more such products. Moving away from The growing use of multilayer packaging makes separation of some types of plastics impossible. convenience products (and hence, overpackaging) would require changes in lifestyle that few consumers seem willing to make. Internalizing disposal costs Packaging design decisions are based on profitability. However, the cost of disposal is not usually included in these decisions, primarily because disposal costs are external to the process. The cost of disposal is borne by someone else, not the manufacturer. If a way were found to internalize disposal costs into manufacturing, then producers would incorporate disposal considerations into the design process, just as they do with processing, labor and material costs. Taxes on certain categories of packaging have been proposed as a way to accomplish this objective. AB 2020, the California beverage container redemption law, also has this effect. But most existing and proposed legislation looks only at packaging, usually beverage packaging, thereby targeting only a small fraction of the municipal solid waste stream. A study conducted by Franklin Associates Ltd., Characterization of Municipa/ Solid Waste in the United States, 1960 to 2000, indicates that although durable and nondurable goods have increased as a percentage of the waste stream, packaging has in fact declined. Thus, attempts to internalize disposal costs should include durable and nondurable goods as well. Recyclability of packaging materials Recyclability denotes the degree to which materials are potentially recyclable, which may bear no relation to recycling rates. A recycling system that is economically viable and technically feasible must be in place for materials to be recovered and recycled. Metals. In general, metals are highly recyclable. Packaging metals are primarily aluminum and steel, with some tin used as a coating for steel on tinplate cans and steel drums. Aluminum, mostly from beverage cans, is the success story of package recycling. For the last several years, around 50 percent of all aluminum carbonated beverage cans produced in the U.S. have been collected and recycled. Most aluminum cans are recovered in states with deposit systems or in states where aluminum companies and others have sponsored buyback operations. Because recycling aluminum saves about 95 percent of the energy required to produce aluminum from ore, scrap aluminum has a relatively high value. Most aluminum in packaging is in the form of cans - 1,475,000 tons in 1984; Continued on page 66. Resource Recycling July 1987

managed to come close to breaking even with revenues from the sale of recyclables. Problems Both staff and board members indicate difficulty over the years in balancing the business of recycling with the strong environmental and recycling values inherent in the community. For example, ACRC does not accept tin cans or plastics since a cost-effective market does not exist for these materials. Many Arcata residents, however, feel these materials should be recycled at a loss. The center has also had to deal with the ebb and flow of outside funding. Special purchases are made when outside funding is available, but both staff and special activities, such as multi-material drop-off sites in rural communities, are cut when outside funding is low. Plans and prospects ACRC enjoys widespread support in Arcata, a community which displays strong environmental values. A 1984 survey indicated that 75 percent of Arcata residents knew about ACRC. And 60 percent of Arcata residents used ACRC at least once a month. Given this strong community support, ACRC will no doubt continue to maintain the current recycling level over the long term. Revenues from recyclables will likely continue to provide bread and butter to the operation. Given fluctuating markets and the need for new or stronger activities, outside funding will still be needed to guarantee breaking even. Prospects for county and perhaps city funding look promising since recycling is accepted as a viable solid waste management strategy as well as an environmental effort. ACRC staff and board representatives indicate five new or expanded activities which may have impact on the center in the near-term. ACRC will serve as a redemption center for California s beverage container redemption program. Results of the neighborhood pilot program may lead to expanded neighborhood efforts, contingent on funding. ACRC plans to make site and exterior building improvements in 1987. Humboldt County has authorized a $17,000 countywide solid waste public education program in 1987. ACRC hopes to raise money to study the feasibility of starting a local end-use market for recyclable material. The center hopes that a local end user will eliminate the expense of transporting recyclables long distances. A local end user could also produce jobs, income and locally owned enterprise in Arcata. Plastics industry (continued from page 31) its high performance engineering polymers, in which the polymers have at least three lives, and which does away with current, more common types of plastics. The first life for the GE materials would be in packaging, a short life cycle application. Used GE packaging materials would then be reformulated into compounds for automotive applications, an intermediate life cycle use. Finally, used plastic automotive parts would be recycled into products used in construction, a relatively long life cycle application. GE is prepared to handle the entire multi-life program, as long as the only plastic products in use are GE types of engineering polymers. Huebner stated that current commodity plastics have no part in a materials strategy, because they cannot be recycled efficiently and economically. Similarly, thermoset plastics have no part in a materials strategy. Since they cannot be recycled, they are simply obsolete. Conclusions Plastics recycling is no longer the poor stepchild it was only a few short years ago. There is a great deal of public, industrial and academic attention being paid to the problems and their solutions. The most important advance is the realization that plastics can be recycled, are being recycled, and that there are many people anxious to be in the plastics recycling business. There are not nearly enough people yet, but the numbers are growing steadily. Aluminum recycling (continued from page 41) annual metal supply comes from reclaimed aluminum. Ambitious goals To work toward an 80 percent aluminum can recycling rate by 2000, Reynolds plans not only to add more recycling centers to its collection network, but also to increase its use of reverse vending machines, making it easier for people to recycle at supermarkets, drug and convenience stores, and on shopping center parking lots. Automotive scrap will account for an increasing amount of recoverable aluminum as newer, aluminum-rich cars reach scrap yards. To tap this source of aluminum, Reynolds will expand its efforts to target the recovery of recyclable aluminum components in automobiles; aluminum from appliances and municipal refuse will be targeted as well. RR Information for the article was provided by Reynolds Metals Company. Packaging design (continued from page 37) another 245,000 tons of aluminum were used in foil form in flexible or rigid containers ( 1985 Packaging Encyclopedia). Very little aluminum foil is recycled. About 60 percent of foil is used in rigid or semi-rigid containers and could be fairly easily recycled; the 40 percent of foil in flexible packaging is often in a multilayer structure and has very limited recyclability. Although the magnetic nature of steel makes it easy to separate from other materials, steel recovery rates are not as high as aluminum. Recycled steel does not have the huge energy savings associated with aluminum recycling, and steel costs less than aluminum. Therefore, the incentives to recover steel cans are not as great as for aluminum. 66 Resource Recycling July 1988

In 1984, recovery of steel from packaging wastes was estimated at 0.5 percent of gross discards (Franklin Associates). The largest use of steel in packaging is cans (especially food cans) - 4,200,000 tons in 1984; another 604,000 tons were used in drums, 595,000 tons in strapping, and 65,000 tons in gas cylinders. Processing tinplate steel cans for tin recovery also takes place. Tin prices have increased a great deal over the last 20 years, providing an economic incentive for tin recovery. However, the trend in the last few years is toward replacing tinplate with tin-free steel. Thus, tin recovery is becoming less important. Glass. In 1984, about 12,799,000 tons of glass packaging were discarded (Franklin Associates) and about 8 percent of that amount was recovered for recycling. A significant amount of recovered glass containers comes from states with deposit systems, followed by states with glass bottle buy-back programs. A very important factor in determining if glass packaging is recycled is the proximity of a glassmaking facility; the high weight-to-value ratio makes transporting cullet (scrap containers) over long distances uneconomical. Some plants will not accept all colors of scrap glass containers, depending on the color of glass container manufactured. Paper and paperboard. Paper and paperboard packaging production totaled 30 million tons in 1984 (7985 Packaging Encyclopedia). Corrugated and solid fiber containers accounted for 18,760,000 tons of this figure. Overall recovery of paper was nearly 13 million tons, or 21 percent of gross discards (Franklin Associates). Paper recycling is limited by the chemical and physical properties of the materials - repeated reprocessing damages and shortens the fibers. Contamination from food residues, bacteria, coatings or inks affects the paper recycling process negatively, because contaminants cannot be burned off as they can in metal or glass recycling processes. Plastics. Plastics packaging consumption in 1986 amounted to 5,726,000 tons - 2.9 million tons went into bottles and other containers, 2 million tons were used in film, and the remainder was used in coatings and closures. Nearly all this packaging was thermoplastics, with low density polyethylene (LDPE) accounting for 33.4 percent, high density polyethylene (HDPE) 30.8 percent, polystyrene (PS) 10.6 percent, polypropylene (PP) 9.2 percent, polyethylene terephthalate (PET) 6.6 percent, and polyvinyl chloride (PVC) 5.1 percent (Modern Plastics, January 1987). Plastics, like paper, are inherently less recyclable than metal and glass due to their chemical and physical properties, and contamination. The polymer molecules that make up plastics are damaged in reprocessing, particularly by exposure to heat. Concerns about the absorption of contaminants into the molecular structure of the plastics prevent the use of recycled plastic as food containers. Plastics recycling is also severely limited by the different chemical characteristics of plastics. For example, thermoplastics melt when heated, and thermosets do not. Even within the category of thermoplastics, resins of different chemical characteristics are generally incompatible. When melted together, a recycled product with very poor properties is produced. To obtain scrap plastics of one resin type, the products must be separated be-

fore or after chipping. In practice, separation after chipping quickly becomes uneconomical if there are a large number of resin types. Separation before chipping is successful, but depends on people or machines recognizing the different types of resins. Some containers, such as PET soft drink bottles or HDPE milk bottles, are easily identifiable. However, the growing use of multilayer packaging makes separation of some types of plastics impossible. A plastic ketchup container, for instance, contains both polypropylene and ethylene vinyl alcohol, along with adhesive agents, and cannot be separated into pure component streams. Approximately 20 percent of PET soft drink bottles are currently recycled (Robert S. Weis, Plastics Recycling Foundation s Efforts in Plastics Recycling, Proceedings, Recycled Plastic: Applications and Development, School of Packaging, Michigan State University, 1987). Some recycling of HDPE milk botties and HDPE base cups from PET bottles does occur, but this amounts to less than 1 percent of the HDPE currently used in packaging. PET recycling is more successful because of the excellent physical properties of PET and because deposit legislation has resulted in accumulations of PET bottles. Recycled PET is able to compete with commodity resins such as HDPE and with relatively high cost virgin PET. Products made from mixed or commingled scrap plastics are being man- ufactured with some success. These products can often tolerate the inclusion of some nonplastic components as well, such as aluminum chips from closures and paper fragments from labels. The relatively poor mechanical properties of the products are sufficient for their end uses. The products are usually wood or concrete substitutes, such as flooring, benches, fencing and retaining walls. Other materials. Some packaging materials are composed of combinations of basic materials, usually plastics with paper or metal or both. Just as combining two or more kinds of plastic causes difficulties in recycling, combining paper and/or metal with plastics also makes recycling difficult and sometimes impossible.

The metal portion of the package might be recovered by burning off the plastic and paper, but the amount of metal present is generally so small that this is not economical even if it is technically feasible. Trying to separate either the paper or plastic for recycling is generally not feasible either. The best hope for recycling such materials may be as a component in mixed (commingled) plastic recycling systems, where they may serve as a filler without significant deterioration of the overall properties of the blend. Design for recycling When designing packages for future recycling, the technological feasibility of recycling the package material and the probability of recycling the package must be considered. For example, no packaging material is currently being recycled at the highest feasible rate nationwide. Recycling of aluminum beverage cans comes closest, with rates over 90 percent in some states with deposit laws; many communities in other states have virtually no recycling. Recycling of aluminum packaging other than beverage cans is virtually nonexistent. After aluminum beverage cans, glass container recycling comes next in overall percentage. Steel can recycling is negligible in most localities. For the most part, recycling of paper packaging is limited to recovering old corrugated containers from commercial establishments. Most plastics recycling takes the form of recovering PET containers in states with deposit systems. Thus, our conclusion must be that designing packages with recycling in mind is not enough. The packaging industry must join with legislators and the general public to support expanded recycling, both of packaging materials and other consumer and industrial items. There is no category of packaging materials that is inherently unrecyclable, though some materials are more easily recyclable than others. With this in mind, we propose four general rules for designing packaging for recycling. Use reusable packaging to avoid waste generation. Use only one material for the package, if possible. All-steel or all-aluminum cans would be preferable to bi-metallic cans. Choose materials that are compatible or easily separable when two or more materials must be used. Use recycled materials in package production as much as possible. Consider blends of recycled and virgin materials as well as 100 percent recycled material. Most packaging materials are potentially recyclable to some degree, but package design can make recycling more or less difficult and economical. Although package disposal is generally considered an external cost to the manufacture of the package, package design should incorporate ease of disposal with the traditional package functions of protection, communication and convenience. But designing packages for ease of recycling will not by itself lead to actual recycling. Support for the development of recycling systems is also required from industry, legislative bodies and the general public. RR