The demands for improving extrusion blow molded containers are rapidly increasing. A recently published forecast by Mastio & Company, a consulting firm in St. Joseph, MO, estimates 6.2% growth per year in plastic containers for blow molded food and beverage. Comparable or even slightly higher expansion is predicted for segments of consumer packaging that include pharmaceutical, health care, and cosmetics. The demand for EVOH is growing at a rate of at least 10% a year with 70% of that growth being in food packaging. 2003 year-end statistical summaries from the Society of the Plastics Industry indicate that of all plastics-related equipment categories: “Blow Molding showed the most promise, realizing increases in units shipped and dollar value of shipments of 19.4 percent and 10.5 percent respectively.”

Growth of that magnitude is fueled by diverse dynamics. Consumers demand that products must be convenient to use. Retailers want great shelf appeal and containers that are easy to stock and handle. Manufacturers want lower costs combined with improved performance in the filling line and shipping chain. Product formulators want longer shelf life from containers, frequently requiring barrier properties for moisture, gas, oxygen, chemicals and other elements. Converters want faster production rates, designs that lend themselves to higher speed production and more repeatable, high quality capabilities. This trend is especially strong in food, diary and beverage packaging. “Recently we have seen more interest in multi-serving packages versus the smaller single serve containers,” says Jeff Newman, VP of Wilmington Machinery.

Solving such packaging challenges may seem overwhelming. To meet diverse and many times conflicting specifications, companies are exploring multi-layer and barrier alternatives. In that regard, working together with material suppliers and machinery manufacturers often leads to the best and fastest solutions. For instance, Wilmington Machinery, barrier specialist in high speed blow molding machinery, has identified numerous multi-layer options to help its customers solve packaging problems such as improving shelf appeal, reducing costs, and creating better barrier protections.

Barrier protection for longer shelf life and improved product formulations is easily achieved by today’s improved materials using multi-layer configurations. Some packaging can be improved by adding a layer of the new highly effective moisture barrier material to the inside. A thin layer of flavor barrier material can be added and matched to a specific product need. A chemical solvent barrier can be achieved easily by adding a thin layer of specialized material. Oxygen barriers to extend shelf life and protect products are routinely accomplished through multi-layering methods as evident by the recent success of the plastic coffee canister in North America.

The blow molding industry is moving toward multi-layer and barrier applications. “Coextrusion blowmolded, barrier, single serve containers can be produced at a lower cost than comparable containers made using coinjection, barrier, stretch blowmolding,” says Bob Miller of Business Development Associates, a packaging consulting firm. “In addition the growing trend of using full body shrink labels eliminates any issues previously associated with gloss or clarity requirements of the container; thus, potentially favoring extrusion blowmolded polyolefin containers over PET.” Product designers, material suppliers and machinery manufacturers are now integral in the conversion process for testing, material evaluations and package performance. To meet the demand for new product development, Wilmington has equipped its laboratory with two multilayer machines for packaging and industrial applications. Additional process engineering, design engineers and a new field service manager support the overall turnkey efforts. “The focus at Wilmington Machinery is delivering the finished part. That means providing complete blow molding production lines that meet customers’ expectations, regardless of how demanding,” says Newman, a 20-year veteran of high output blow molding systems. “Innovations in multi-layer blow molding systems and materials have opened the door for cost effective conversion and package improvement opportunities that were not possible 5 years ago.”