Glass, Plastic or Can?

As a former packaging manager of a large beverage company, when it came to beverages I always wondered which was more environmentally friendly. Much like the old "Paper or Plastic" argument at the grocery store, which is better or is anything actually better for the environment? This is not an easy question to answer. Since looking into this issue, I have decided to break it up into several posts.

The Sustainable Packaging Coalition defines four life cycle phases of key importance to determining how earth-friendly a package is: sourcing, manufacture, use and end-of-life.

I am going to try to avoid statistics as much as possible. While some statistics are probably OK, in the format of a blog, at a minimum they will put you to sleep and at worst, they are tools used by people trying to prove a point. As someone once said, there are three kinds of lies; lies, damned lies and statistics!

Raw Sourcing:

Glass (Bottles)

Glass is made up primarily of SiO2 or silicon dioxide. Also known as silica most commonly found in nature as sand or quartz. Silica is the most abundant mineral in the Earth's crustand the second most abundant element. Silica occurs commonly in nature as sandstone, silica sand or quartzite. It is the starting material for the production of silicate glasses and ceramics. It can exist in an amorphous form (vitreous silica) or in a variety of crystalline forms. Often it will occur as a non-crystalline oxidation product on the surface of silicon or silicon compounds.

The production of glass dates to the Egypt, Mesopotamia & Roman empires. (Fifteenth century) Modern glass making dates back to the late 19th century; That is, glass made by machine. Simplified: glass is made up primarily of Sand (Silicone Oxide SiO2), Soda Ash, Limestone, Feldspar and minor ingredients: (Fining agents, decolorizers & colorizers) Glass is remarkable for its strength and being chemically inert. These ingredients are mixed together (Also known as fusion casting) in a large furnace that runs at about 2800°F.  Typical glass factory diagram. 

Aluminum (Cans)

The chief source of aluminum is bauxite ore is mined and refined into aluminum. Bauxite is combined with caustic soda, lime, and steam to produce a sodium aluminate liquor. Impurities are filtered or settled out of the liquor and alumina hydrate is precipitated out of the mixture. The alumina hydrate is calcined to remove moisture and drive off the bonded water.

The resulting alumina is ready for smelting into aluminum. Alumina is electrolytically reduced into molted aluminum. Aluminum's melting point is approximately 1221°F. This reaction occurs in Hall-Heroult reduction cells (called pots) where the bound oxygen in the alumina reacts with carbon electrodes to form carbon-dioxide gas and aluminum. Each ton of aluminum requires 0.4-.05 tons of carbon anodes. The resulting aluminum is formed into slab ingots that are up to 26 inches thick, 20 feet long, and weigh up to 20 tons each.

The aluminum is then rolled into sheets through the process of forming. The slab is heated in a furnace and rolled between powered rollers until the plate is approximately 1 inch thick. The plates are further reduced in finishing mills where they are hot rolled to a thickness of 0.25 - 0.4 inch. These sheets are rolled into large coils and graded for quality.

Aluminum is too reactive chemically to occur in nature as the free metal. Instead it is found combined in over 270 different minerals. Aluminum is also an abundant metal and the third most abundant after Silicone Oxide and makes up about 8% of the Earth's solid surface. Refined aluminum is remarkable for its ability to resist corrosion. 

Polyethylene terephthalate (PET) 

PET is a thermoplastic polymer resin of the polyester family. Wikipedia. The raw materials are petrochemicals: crude oil, natural gas and ethylene glycol. PET is hydroscopic, meaning that it naturally absorbs water and it must have this moisture removed as much as possible before molding or extruding. Once molded, PET has a high resistance to moisture and is very strong.

Crude oil is a naturally occurring flammable liquid found in rock formations consisting on a complex mixture of hydrocarbons plus other organic compounds. Therefore, PET is an organic compound. PET was invented by DuPont chemists in the 40's during a search to make new textiles. The PET soda bottle was patented in 1973 and a two-piece 2 liter bottle was first used by Coca Cola in 1975. 

PET raw materials are either extruded or injection molded and chopped into pellets. PET has a melting point of approximately 480°F.  The raw pellets are packed in large pallet sized boxes.

So who wins raws sourcing? Since glass and aluminum are minerals and must be mined using equipment and refined in furnaces using extremely high temperatures, I have to vote for PET here. Sure, PET is refined directly from petroleum byproducts, however the energy costs used in the formation do not begin to add up to the amount of energy used to keep the mining equipment and furnaces running 24 hours a day, seven days a week. Energy that comes from Petrochemicals.

Scorecard: Glass = 0, Aluminum = 0, PET = 1

Up next: manufacturing

Glass, Plastic or Can? Which package is most "Sustainable"

It's been a busy July with a bunch of press approvals so I haven't been blogging as much as I should be. I have been thinking about this subject for a long time and talking to a bunch of container companies lately. In the next couple of weeks I will attempt to qualify which container is the most "Earth Friendly" from manufacturing through consumer disposal & recycling. I am going to limit myself to comparing containers that hold 12oz of beverage: a glass beer bottle, a common aluminum soda can and a PET bottle. The decoration, secondary and tertiary packaging will be considered to as well as the cap.

The bigger problem in this country is the real lack of recycling, the packaging material is just not getting where it needs to go to be recycled and there is no infrastructure to handle the waste stream. Not sure yet if I would support a national recycling law or support new deposit requirements.

If you are involved with this issue, please feel free to send me some information or make a comment. Thanks - Barry

On Press Again

I was at a paperboard company last week, on press to approve a box re-run for a client. It was especially critical because the first run had been rejected due to gross color variation. Why was it rejected? Because someone at the printing company miss-handled the WIP and shipped set-up material to the client. (This printer uses "set-up" material to get their die-cutter in registration.) When the item went into production, the packaging looked terrible and the entire job was returned to the printer for credit. 

While the job itself was not especially challenging, there were some things working against us from the start. There was a warm red and two special blacks used on these three items. The warm red on the proof was a build using 100% process M & Y.

1. The tone of the warm red was off giving the proof a blue cast.

2. The special blacks were not well-defined by the client. The way they were separated was not the way I would have done it, but it was already on-press.

3. Two of the items were running on different presses at the same time. 

4. The paperboard stock on press was not from the same mill as the proof. In this case the surface texture was way different. 

I decided that as a strategy we would get one up and running first on the older press and then match the second item to it on the newer, better press. I had to determine that we were not going to run a "special" magenta. Running special colors in the process stations can create as many problems as it solves. This practice is not that uncommon such as swapping out cyan for pro-blue, but when playing in the reds this can throw off the whole balance of the job. Plus; there were some process elements on this job that would be affected.

It took seven pulls to get it acceptable once we determined that the red wasn't going to get any better and the mottling wasn't going away on the black due to stock. On the other press, we got the color into the OK zone on the second pull. The third item was a quick changeover with a reset of the ink densities. 

If you are a printer, make sure you have a system set up that prevents shipping sub-quality material to your customer. When I was at CCL Label many years ago, one of our new CS agents sent labels they literally took out of a dumpster to the buyer at Clairol. The next day we almost lost that account. If you can't avoid setting up on the actual job, then quarantine it or have a quality agent approve the material. This stuff might seem like 101 to you, but the folks on the line may not have their head in the game.

On the artwork side, I am not 100% clear that the design firm, the client and the printer were in alignment as to how these jobs were going to print. Having this alignment would be beneficial to everyone in order to manage expectations. 

Fortunately, our client was happy with the job and hopefully the printer will remember this experence on future runs. . .    Have you ever had similar issues?