Sustainability is defined as meeting the needs of today without compromising the ability for the next generation to meet theirs. Today, many manufacturers have begun practicing green initiatives such as environmental management systems (EMS) and complying with ISO 14000 standards.
According to a survey by the American Production and Inventory Control Society (APICS),1 67% of respondents reported that they practice policies that are conducive to sustainability, and 60% of respondents said they practice policies that reassess natural capital, raw materials, and ecological processes. The study also states, “Sustainability is increasingly a domain of innovation that is reducing cost by reducing demands on resources while increasing reuse of existing assets.”
As a whole, manufacturers need to focus on reducing the consumption of non-renewable resources, while still remaining aware of reducing environmental impact by reviewing packaging and container usage. For example, one study2 indicated switching to reusable packaging required 39% less energy; produced 95% less total solid waste; and generated 29% less total greenhouse gas emissions than single use containers.
Over time, reusable containers will signi-ficantly lower the cost of packaging. Photo: Mills Industries
There are unique specifications required for packaging to be cleanroom-suitable. Corrugated paper packaging is problematic since it emits fibers and paper dust contaminants. Also, the porous surface of corrugated paper is unable to be cleaned adequately for cleanrooms. It also supports mold growth and contains sulfur, which is corrosive.
Rigid plastic packaging and containers are more expensive than corrugated paper; however, they can be cleaned to meet cleanroom requirements. They are generally non-porous and non-shedding, which helps control particle contamination. Rigid plastic containers include those made by a molding process such as vacuum forming and injection molding. Other rigid containers, which include plastic corrugated, are made by an extrusion and die cutting process.
Rigid plastic containers have optional additives which will reduce static discharges. The additives are generally grouped into three categories: conductive, static dissipative, and antistatic. Which type to use in various situations has been a subject of much debate over the last 30 years. Conductive and antistatic are the most common additives. Below are general definitions.
Conductive (surface resistivity 104 to 105 ohms): Conductive additives are created by compounding special carbon black material into plastic resin that permanently changes surface resistivity to prevent static build up. These additives are more expensive that antistatic additives, but they provide a “Faraday cage” and electromagnetic shielding protection. Containers with Faraday cage protection shield contents by conducting static charges away from the contents.
Static dissipative (surface resistibility 106 to 108 ohms): These additives are achieved using proprietary resin additives, though they may not be as readily available as conductive or antistatic material.
Antistatic (surface resistivity 109 to 1012 ohms): Antistatic additives cost less than conductive or static dissipative; however, they may not be permanent depending on the humidity of the room.
When analyzing resource use, it can often be tricky to define which alternative is the most environmentally sound. To measure or compare environmental impacts, a quantitative tool called life cycle assessment (LCA) is used. The primary objective of an LCA is to judge the environmental impacts of a product. LCAs are conducted under ISO 14000 standards. The assessment follows the acquisition of the raw materials to produce the product, to the disposal at the end of its use. A commissioned LCA3 measured the environmental impact outcomes in six categories. The results revealed that the corrugated plastic containers yielded the least amount of environmental impact out of the three alternatives.
There are simple principles that help review packaging selection and lessen environmental impact—reduce, reuse, and recycle.
Reduce weight and thickness
The most important idea of this concept is to reduce the use of a resource if it is not needed. Reduction of weight and wall thickness of packages to what is structurally adequate is an example of this principle. General reduction of weight can reduce environmental impact by 20%, according to Packaging for Sustainability4 by Karli Verghese. It is important to optimize package design for its specific use rather than to simply minimize it. For example, in many cases the use of alternate light yet rigid material such as corrugated plastic instead of molded plastic designs will provide lightweight structural integrity. A corrugated plastic tote 18.5 by 12.20 by 13.38 in. weighs 75% less than a molded plastic tote of the same size while providing the same performance in most circumstances.
Manufacturing products out of recycled material is another method of reduction, as it eliminates the need to use untouched virgin resources and will reduce environmental impact. Recycled content is divided into two categories:post-consumer (generated by the general public) and post-industrial (generated by companies internally from industrial processes). Many industrial container manufacturers limit their recycled content to internally created post-industrial to control the quality of the material. Manufacturers also limit the amount of recycled content. The overuse of recycled content may degrade the physical properties and then may not perform as needed.
Design to reuse
Reusable containers work the best in a “closed loop” system where a durable tote can provide a high number of reuses. A closed loop system will work best if totes can be controlled and economically returned. Ideally, containers should be engineered for reuse with the following criteria in mind: designed for durability and part protection; designed to take ergonomic considerations in mind for manual handling; designed to be collapsible or nest-able for storage; and sized to maximize part density lot size while making the best use of truck cube, warehouse space, racks, carts, conveyors, etc.
Recycle and buy back programs
Recycling captures losses from the manufacturing value stream, which provides more value. A recent article in Plastics News stated that 934 million pounds of post-consumer rigid plastics (not including bottles) was recycled in the U.S. and Canada in 2011. This amount was up 13% from the previous year and the number of recycling facilities that accept rigid plastics is up 40%. Most rigid plastic containers are made from thermoplastics with oil or natural gas being its primary feedstock. The advantage with thermoplastics is that they can be ground down, re-melted, and processed as recycled content into plastic articles. Most common thermoplastics used in rigid plastic containers for various industries are: high density polyethylene (HDPE); polyvinyl chloride (PVC, vinyl); plypropylene (PP); polystyrene (PS); and high impact polystyrene (HIPS); and others including but not limited to acrylonitrile butadiene styrene (ABS).
Many manufacturers of rigid plastic containers offer take back or buy back programs. These programs offer a price per pound set by manufacturers; oftentimes there are also freight costs to consider.
The price of recycling depends on the quantity of scrap material produced. Companies that buy plastics are generally looking for a truckload quantity of baled plastic or granulated (ground down) and sorted according to resin type. They will pay a market price per pound, otherwise the regional material recovery facility or municipal recycling facility should be contacted. The demand is generally is higher for high density polyethylene (HDPE PP). Ideally, packaging should be designed for disassembly and recycling. Here are a few key things that can make the recycling process easier:
• Indicate recycle symbol with resin code on packaging
• Design containers to be made from homogenous material
• Design for collapsibility or to be disassembled
Sustainability is profitable
In general, reusable packaging costs five times as much as expendable packaging; however, according to Eric Fredrickson,2 president of Thor Consulting in Boston, it lasts 100 times longer. Gradually, reusable containers will significantly lower the cost of packaging. A study found that without new technological advances, simply moving to the green supply chain could reduce costs up to 20%.5 Several companies have transitioned to returnable containers and have saved money by doing so. For example, General Motors saved $12 million in waste disposal costs by switching to reusable containers.6 Pitney Bowes spent $100,000 annually on corrugated paper boxes, only getting five uses per container. Since they have switched to reusable collapsible corrugated plastic totes, the company has been able to utilize the boxes for 200 to 300 round trips.7 Texas Instruments saved $20 million in real costs by getting suppliers to return their packaging over a three-year span.
Many companies are searching for methods to lessen their environmental impact in all steps of production. Add in the necessity of cleanroom compatibility, and the challenge to be greener becomes a bit more difficult. However, at least in the field of packaging, all functional needs and environmentally-friendly wants can be achieved by looking into alternative packaging.
1. APICS 2012 Sustainability Challenges and Practices, p. 2-3
3. 2011 LCA Commissioned by Mills Industries (available by contacting Mills Industries)
4. Packaging for Sustainability—Karli Verghese. p. 51
5. Green Supply Chains: An Action Manifesto—Stuart Emmet & Vivek Sood, Preface xiii, p 5
6. Lean and Green—Pamela J. Gordon. p 6, 124
7. Packaging World, August 2000 www.packworld.com
Michael Mills is president of Mills Industries, a third generation family owned and operated company.
Justin Mills is a member of the marketing team and assists with technical writing as well as marketing functions.
This article appeared in the May 2013 issue of Controlled Environments.