DUSSELDORF, GERMANY - While metallocene catalyst technologies promise to improve product performance, resin processors say, ``Show me.'' ``I've seen far more paperwork about metallocene resins than I've seen actual resins,'' said Kevin Chandler, packaging development manager for Four Square, a division of Mars U.K. Ltd. of Basingstoke, England.
Chandler and David W. Brooks, materials development team leader for Car-naud-Metalbox plc of Wan-tage, England, spoke March 6 in Dusseldorf at the Inter-national Congress on Metal-locene Polymers - Metallo-cenes '96. Their companies are two of the largest suppliers of packaging materials in Europe, and they represented processors at the conference.
Brooks said CMB has gone wanting for resins based on metallocene catalyst technology. When asked where CMB expects to make packaging available with metallocene resins, Brooks said, ``Nowhere.''
``I would like to see these materials; there are none available,'' Brooks said.
Brooks concentrated on rigid packaging, noting that markets
for bottles in Europe consume more than 4.8 billion pounds of resins a year, and are dominated by high density polyethylene for household, toiletry and cosmetic products.
Markets for other rigid containers in Europe consume more than 5.5 billion pounds of resins, while the 20 billion closures made each year consume 572 million pounds.
Brooks said that the prospects for resins made with metallocene technology - including PE, poly-propylene and polystyrene - appear good in Europe, but such resins will have to compete with existing resins in price, availability and recyclability.
Polyolefins, such as PE and PP, and polyesters, such as PET, ``are the favored polymers for the long term,'' he said, noting that this favoritism may benefit producers of metallocene polyolefin resins.
``The challenge for plastics packaging is `zero' contamination of the product due to migration of monomers or additives from the package,'' Brooks said.
``Metallocene polymers will possess much-improved organo-leptics, lower extractables and volatiles, which enhance its prospects for packaging foods and beverages in bottles,'' Brooks said, basing his comment on information provided by Exxon Chemical Co.
Chandler's company produces more than 1 billion single-serving drink packages a year. He noted that his firm's customers rarely know what plastic product they are holding.
``Their prime concerns are about ease and safety of use, cost and, `What do I do with what's left?' '' Chandler said.
He said that translates into his company seeking a single material that can combine all the properties it needs to supply its teas, coffees and other drinks to consumers.
Chandler said Four Square has made significant processing advances.
By linking its thermoforming lines to its sheet extrusion lines, the firm has taken advantage of residual heat from the extrusion process, and cut processing costs 40 percent.
Four Square uses a metalized PET film to package its coffee products, and an oriented PP for premeasured soft drinks.
``I'd be happy to use a metallocene resin if one was available and if it would meet our requirements,'' Chandler said. ``But I would like to have objective measures for testing the resins.
``Where a demonstrable im-provement can be shown in the process, a price premium on the resin could be accepted. If the required performance levels for the finished product can be achieved with less material - down gauging - then there is yet more scope for sharing the benefits,'' Chandler said.
``So many current applications call for blends or modified base materials. These applications are common to a great many end users, and hence offer the commercial viability that goes with large-scale production.''