Up, Up, and Away

If you want to highlight an important growth segment that promises to expand the use of film materials, start with pouches. Pouch configurations using laminated film structures are providing consumer product companies (CPCs) with unique opportunities to reduce supply chain costs, while offering consumers distinct packaging, convenience, and ease of use.

As pouch applications continue to grow, new material configurations extend their reach even further. The available material options are beginning to run the gamut from standard offerings to high-tech configurations engineered for specific applications that push the envelope of technical capabilities.

Depending on a package’s functionality and end-use requirements, there can be numerous design elements to consider. “Most pouch designs are custom configurations,” says Dan Kearny, VP of marketing for Bemis (www.bemis.com). “Size, type of side and bottom seals, reclose type (if applicable), and materials used are common variables.”

Some of the configurations are customized from a common material base. Kearny notes that a very common configuration for pouches is a 48-guage oriented polyester (OPET) laminated to a polyethylene (PE) film. From here, the gauge of the PE film can be changed to accommodate different pouch sizes.

Further modifications can be made from this base to meet additional needs. “Sometimes additional stiffness is built into the pouch through the use of stiffer PE resins,” says Kearny. “Additional barriers can be added through the use of a third ply of film such as metallized OPET or OPP [oriented polypropylene], or the substitution of a standard PE sealant with a coextruded sealant that contains barrier resins.”

Sal Pellingra, innovation and marketing director, Ampac Flexibles (www.ampaconline.com), concurs with the assessment of customized designs for pouches. “Pouch applications are almost always custom structures,” he says. There are many factors that make them unique, including shelf life, aesthetics, manufacturing capability, and environmental conditions through distribution and use.

“Product compatibility and shelf life are the primary considerations,” he says. “Material, barrier, and sealing need to remain compatible with, contain, and meet shelf-life targets.”

For aesthetic factors, Pellingra mentions the need to define the graphic requirements such as a clear package, opaque, metallic, or process print. “Two products from different manufacturers could each require a barrier lamination, but one may want the consumer to see the product and one may want to represent the product with process print and high graphics,” he says.

The customer’s manufacturing capability and product functionality dictate other important considerations. If a customer can produce its own pouches, then the material can be supplied as rollstock, says Pellingra. If not, then pre-made pouches would need to be supplied.

Product functionality requirements raise several questions. “Does the pouch require a fitment for pouring? Easy tear capability for opening? Resealability for multiple uses? A handle? How will it stand up? For heavy products versus light products the base or gusset would be configured differently to ensure good shelf display,” notes Pellingra.

Short-run impact

The broad industry trend for shorter production runs, which has already impacted the label market, is also making its presence felt in the flexible packaging/pouch arena. “With the trend towards specialty, short runs for trial, travel, and convenience-size packaging, manufacturers are looking toward the narrow-web flexo market to fill this demand,” says M. -David Parsio, product manager, pouch materials for Multi-Plastics, Inc. (www.multi-plastics.com).

“Typically, gravure printers would customize the laminated construction depending on the filled product characteristics and barrier properties needed,” he continues. “Then, [they would] reverse/subsurface print and bury the inks within the construction to provide protection in wet chemical environments.” Because of this trend, substrate suppliers such as Multi-Plastics are introducing multi-layered laminated structures that can be surface-printed.

Retort and microwave

As pouch configurations continue to expand their reach, market segments that are providing further room for growth include retort and microweavable packaging. However, the opportunities for growth also bring along stringent technical requirements that impact both package and graphic designs. These challenges are related to exposure to high temperatures and pressures, and although the demands are similar for both retort and microwave applications, there are enough disparities to require a different focus in the design and manufacturing of the pouch.

Doug Frost, account development manager for Sonoco (www.sonoco.com), makes a key point that impacts the priorities for design and manufacturing. “For retortable pouches, the product/package has to withstand the retort process in good shape because it still has to go on the store shelf and obviously, has to look good,” he notes. “With microwave pouches, the packaging is discarded by the consumer after being microwaved.”

As an example, he mentions the issue of stress whitening that can occur in retort applications due to the variability in expansion rates of adhesives and film layers. Frost says that Sonoco works closely with its ink and adhesive suppliers to eliminate such problems.

Pellingra also notes that inks, adhesives, and sealants need to be specially formulated to survive retort conditions. “In addition, process conditions and quality-control testing on the printing press for ink adhesion, the laminator for adhesion bond strengths, and the pouch machine for seal strengths are held to very stringent parameters, much more than products going into other more common food applications,” he says.

“For microwave applications the challenges are similar and yet different,” continues Pellingra. “Because of the high temperatures that packaging will see in the microwave, packaging materials must be designed with high temperature resistance and low extractables and odors. Consumers must be assured that only the food is being cooked or reheated and not the packaging.”

Venting is another key requirement for microwave pouches. Angela Adams, segment manager, retort, for Sonoco says, “Microwave pouches need to vent, but without splatter or spillage. Typically, the consumer creates the vent at the time of use, so an easy-open feature is important in microwave package design.”

Kearny notes the potential for newer self-venting pouch designs. “Many packages on the market today require the consumer to cut the package open prior to cooking,” he observes. “Newer packaging technology is enabling self-venting features to be incorporated into most packaging formats. This method is preferred by consumers as it eliminates one more step in the meal preparation process.”

According to Pellingra, venting systems are a very competitive area. “Because of that, not all systems are available to all packagers,” he says. “In addition, some systems are very costly. Opening the technologies or moving to simpler venting methods would benefit both packagers and consumers with lower cost products.”

More room for growth

There seems to be no limit to where pouches will be used. These experts mentioned a variety of growth opportunities: replacing rigid containers, bag-in-box replacement, beverages, and pet foods—just to name a few. For the most part, a large measure of this growth will translate into real opportunities for film and flexible packaging converters. pP