- June 01, 1996, Sacharow, Stanley
"There's nothing in the world as powerful as an idea whose time has come." Dr. Samuel Johnson.
Suppliers of polyethylene terephthalate (PET), which was in tight supply last year, expect resin capacity to increase by more than 50% over the next three years. While this means that PET pricing will most certainly dip in the short term, many of the large PET resin suppliers feel that overall future demand will absorb the increased capacity.
The explosive growth of PET resin in packaging applications is basically due to its strong "replacement value" for glass bottles, aluminum cans, and other flexible films. Its perception as a "green" resin, bolstered by its functional soft drink recycling infrastructure, set the stage for frantic user interest in the material. Now, with the pace of applications rapidly increasing, packaging pundits expect PET resin growth to top 12% per annum over the next five years.
These optimistic projections are rather unusual for a thermoplastic resin that's been around commercially for more than 60 years. Discovered by William Hume Carothers at DuPont (Berzelius in 1847 first reacted glycerol with tartaric acid), PET's first major success in packaging was in 1956. Luchow's, a popular New York restaurant, marketed some of its dishes in frozen boil-in-bag pouches constructed from "Mylar/polyethylene" Coated with a thin layer of reflective aluminum (MET/PET), Mylar film reached outer space as the inflatable Echo I satellite.
Between 1959 and 1970 PET was the major drawable film used in thermoformed cured meat packaging. Replaced by nylon in the 1970s, PET's real leap forward was as the soft drink bottle replacement for glass in the late 70s. Now, with almost total market penetration, sales to that market have flattened out in North America. In Europe PET usage is still on the increase as these containers are rapidly replacing glass and polvinyl chloride in most soft drink and bottled water applications.
The next major market PET is gearing itself up to conquer is the single-serving soft drink bottle, presently in the domain of the 12-oz aluminum can. PET bottles - both round and contoured - are being increasingly seen on the supermarket shelf. Expectations are that by 1999, beverage can shipments will decline, and capacity utilization will fall to less than 80% from a 1994 level of about 93%. With the projected overcapacity of PET and subsequent cost decrease, it seems entirely possible that PET. containers will move strongly into the 12-oz soft drink market.
Film labels that perform on the newly developed contoured PET bottles remain a major challenge to the supplier. Required are shrink film formulations that intimately clasp the walls of the bottle and may be applied at the rapid speeds required for automatic machinery. Such labels are now available and are capable of being applied at speeds in excess of 600/min.
There are other label developments introduced specifically for this emerging market. Included are a variety of sleeve concepts, metallized paper labels, and even labels that change in color due to temperature fluctuations.
Recently introduced on the market is polyethylene naphthalate (PEN) and PET/PEN blends. The first truly commercial hot-fill applications for PET/PEN blends should soon be on the shelf. PET Partners of the Netherlands (located in Etten Leur) is currently on the verge of introducing containers for a variety of applications, including jams, ketchups, pickles, and pharmaceuticals. The containers are reported to contain a wide range of PET/PEN blends and are not slated for any drink applications.
Still controversial, the use of PEN for hot filling has been reported to have several limitations. These include limited shelf life, raw material instability, and processing difficulties. In Packaging Week (March 28, 1996), the U.K.'s leading packaging journal, Tony Holland reports that "little in the way of data sheets was available from PEN suppliers, which adds to excessive development costs." On the bright side, PEN is reported to have superb stretchability, barrier properties, and scratch resistance.
Because of the widespread interest in polyesters, The Packaging Group is sponsoring "International Polyester Week" Oct. 7-10, 1996, and will discuss all the polyesters in a variety of tutorials and seminars. For information call 908/636-0885 or fax 908/390-1402.
Stanley Sacharow has been in the flexible packaging industry for almost 35 years. His company, The Packaging Group, is an organizer of targeted conferences and a consultant to the international packaging/converting industry.