The Power of Numbers
Will five-layer blown film technology be ‘the new three-layer’?
ExxonMobil made quite the splash at K 2013, particularly for a company that did not exhibit. But the Houston-based chemicals giant made sure that its suite of high-performance polyolefins were in the hoppers of numerous machine builders that were running lines at the fair.
The materials giant’s message to blown film processors at K 2013 was similar to its theme at the show three years ago: You can improve performance, get into new markets and increase the sustainability of your operation—a key for brand owners—by making the jump from three-layer to five-layer blown film technology for non-barrier applications. Over that time frame, ExxonMobil says it has advanced the technology considerably and has several customers finalizing formulations for commercial applications.
Collation film figures to be one such application. At K 2013, Windmoeller & Hoelscher ran 40-micron thick, five-layer collation film for carbonated beverages using Exxon’s Exceed and Enable metallocene-based PEs. Rates exceed 2,200 lb/hr.
The standard thickness for collation film had been 50 microns, so processors that avail themselves of five-layer machinery and cutting-edge resin technologies can offer brand owners a film with better properties that’s also 20% thinner. “Sustainability will be a key driver to the conversion of three-layer systems to five,” Dirk Van der Sanden, ExxonMobil’s global processing and converting advisor for polyolefins, told Plastics Technology at W&H’s booth at K.
He added: “What we’re offering North American film processors is more than just resin…it’s a business proposition. Designing exclusive film formulations tailored to the latest in machinery technology is like having computer software updated to take advantage of the latest hardware,” Van der Sanden added.
“The performance opportunities for five-layer films are huge,” Van der Sanden stated. Such structures can deliver a balance of optical and performance properties that are difficult to attain with three-layer systems. Five-layer systems also provide processors with more control over the thickness of the layers to meet application requirements. Higher throughputs, for example, can be achieved by running higher-melt-strength materials in the layers.
Five-layer technology is also more flexible than their three-layer cousins, ExxonMobil officials noted. For one thing, you can run a three-layer product on a five-layer line if necessary.
ExxonMobil’s message was both logical and compelling, and it will be interesting to see how it will resonate with blown-film processors in North America, who by and large tend to embrace new concepts gradually. The shift from monolayer to three-layer structures took a lot longer than most observers expected; fact is, there is still a lot of single-layer capacity out there. Then again, most film-extrusion experts will tell you that the learning curve from single- to three-layer is quite steep, much more so than the jump from three-layer to five.
Of course, an argument can also be made that North American processors are more progressive than most think. Look at the cast stretch film market. Once dominated by single- and three-layer systems, it made the leap to five-layer technology fewer than 20 years ago, when Gloucester sold two lines to Chaparral Films in Mauriceville, Tex. (now part of ITW). Now, stretch film processors are working on “nano” structures consisting of dozens of layers.