If you're doing a lot of walking in new shoes at a trade show, blisters can be a painful curse. However, in the world of packaging, blisters are a blessing.

Consumer goods manufacturers use blister packaging for batteries, calculators, hardware, light bulbs, memory storage devices, pens, scissors, spark plugs, toothbrushes and many other products. Pharmaceutical and cosmetic manufacturers are also major consumers of the user-friendly packaging format.

Blister packs are a cost-effective type of primary packaging that allows a product to be clearly seen, but not touched, as it hangs on a retail shelf. Retailers typically display numerous blisters near checkout lanes, hoping to boost impulse sales while consumers wait in line. Blisters are also popular in retailing because the hanging format minimizes the use of precious floor space.

Blister packs are one of the most popular types of consumer packaging. A blister is a thermoformed cavity in plastic that is then sealed to an insert card with a product in between.

"Blister is our industry term for a clear, formed plastic, bubble that closely contours a product," says Mark Anselmo, vice president of FormTex Plastics Corp. (Houston). "The plastic blister is usually heat-sealed to printed paper card or foil stock. A perfectly fitted blister will display and sell a product much better than a loosely fitted blister package."

Blister packaging is more popular than ever. In fact, the Packaging Machinery Manufacturers Institute (Arlington, VA) reports that demand for blister packaging machinery increased 24 percent last year. It is the second most popular type of packaging equipment, ranking only slightly behind converting machinery. Equipment in this category primarily includes forming and sealing machinery.

Manufacturers are scrambling to address consumer convenience issues by placing more and more products in blisters. Indeed, demand for blisters and other types of high-visibility packaging is growing 5.1 percent annually, according to a recent study conducted by the Freedonia Group Inc. (Cleveland). By 2008, blister packs will represent a $1.7 billion market. And, it will jump to $2.1 billion by 2013.

Growth will result from increased consumer spending and a growing demand for greater product security, says Esther Palevsky, a Freedonia Group analyst. More and more retailers want packaging that deters theft and pilferage, but also allows consumers to easily view the contents of the package.

Market Trends

Large retailers, new pharmaceutical regulations and environmental concerns are spurring demand for blister packaging. The widespread popularity of big-box retailers, such as Costco Wholesale Corp. (Issaquah, WA), Home Depot Inc. (Atlanta), Staples Inc. (Framingham, MA), Target Corp. (Minneapolis) and Wal-Mart Stores Inc. (Bentonville, AR), has been fueling the growth of high-visibility packaging.

"This is because of the self-service nature of these stores and the need for security, especially with smaller items or higher-cost items," says Palevsky. "The use of blister pack displays also helps keep smaller items, such as hardware and office supplies, more organized. This format gives manufacturers good billboard space for providing product information or instructions."

For instance, packaging plays a key role in marketing at Stanley Tools (New Britain, CT). The blister card on its Fat Max Xtreme tape measure features a raised, curved area to accentuate the name of the product and its unique feature-13 feet of blade standout-which results in a 3D effect. The blister also has raised borders that help support the heavy tool and its paper backing. Because the actual product is showcased in the front of the package, it stands out and helps sell itself.

"While blister packaging demand is growing for retail items, this does not necessarily translate to favorable domestic demand for this type of packaging," warns Palevsky. "Since so many [consumer goods] are produced offshore, they are likely to be packaged wherever they are produced. As a result, the outlook for U.S. demand for blister packaging is not as healthy."

However, the pharmaceutical market represents a bright spot for blister packs. "In pharmaceutical applications, growth is driven by efforts to improve patient compliance and reduce institutional errors in drug dispensing," says Palevsky. "Improved child resistance, tamper evidence and security needs are also factors, as are regulations that took effect [earlier this year] mandating that all drugs dispensed in hospitals and nursing homes must be packaged in a unit dose format with a bar code."

Putting medication into blister packs isn't a new idea. Most short-term medications are distributed that way. However, most long-term medications are packaged in small plastic bottles. Blisters are a user-friendly, safe and attractive alternative that is starting to become more popular.

"Blisters sealed in cards to create ‘wallets' and other package types add space for additional information about the product and provide an attractive FDA-compliant format," says Richard Bahr, president and CEO of MGS Machine Corp. (Maple Grove, MN). "Blister packs place a premium on safety and assistance for the consumer to receive their medication on a timely basis."

"Blister packaging formats are becoming more innovative than just a simple carded blister," adds Bahr. He says Dosepak by MeadWestvaco Corp. (Stamford, CT) is an example of an innovative format for a carded blister.

The package prevents children from accessing the medication, yet it's also easy to use for older adults, who often have limited dexterity. "Part of the compliance is the two-part sleeve and card that forms a slide out display card that locks into the sleeve," Bahr points out.

To help patients adhere to appropriate instructions, the package incorporates an easy-to-read, three-step dosing process on the inside of the package. The Dosepak also provides more copy area than a standard bottle label and allows for a larger font size for ease of reading.

Studies have shown that consumers comply with medication requirements far better when pharmaceuticals and medical devices, such as inhalers and nasal sprays, are packaged in a blister card format. For instance, researchers at Ohio State University (Columbus) recently discovered that patients taking lisinopril, a medication used to treat chronic high-blood pressure, were more likely to have their prescriptions refilled on time if the medication came in a blister package rather than as loose tablets in a bottle.

Environmental Issues

"At face value, blister packaging is one of the simplest manufacturing technologies available," says Rick Thomas, CEO of CardPak Inc. (Solon, OH). The paper and plastic are joined together in a blister sealer, which is a hot plate that presses down on tooling that accommodates both the blister and the card. The plate is heated to 425 F. It is pressed against the card by a pneumatic cylinder operating at 90 psi.

"The advantage to blister packaging has always been that the process is very lean," adds Thomas. "Many setups can be accomplished in a shift, due to fast changeover. The heat seal fixtures all have quick disconnect features and can be changed over in 5 minutes; no scrap is necessary."

"That being said, some of the newest package designs being mandated by Costco and Wal-Mart are requiring some very novel systems," says Thomas. "We worked on a line of new packages for Costco that required a 56-station inline heat sealer with upper and lower heat platens employing an inline spot locator for a piece of corrugated micro flute that acts as a ‘stiffener' for stacking in a warehouse club retailing arena. What had been a very straightforward piece of heat seal machinery, essentially unchanged since the 1960s, became a highly sophisticated, engineered application for a whole new line of packages."

Several types of high-visibility packaging are available. For instance, clamshells are closely related to blister packs. However, they are more rigid because they are made from thicker plastic. They also typically feature a hinged lid. Clamshells have traditionally been used to package larger, heavier products.

"For 20 years, the clamshell package has been the standard for marketing at club stores and even in the conventional retail stores for the simple fact that it is a very useful package for theft prevention and package visibility," explains Thomas. "The consumer is immediately attracted to the package because it has high-impulse sales value. The package also reduces shrinkage, because the radio frequency-sealed package has to be opened with scissors or even a razor blade. Most products packaged in clamshells are $10 retail and higher."

Blister packs are generally less expensive than clamshells, since they use less plastic. And, they are a better alternative than traditional folding cartons because of the constant possibility of impulse sales. "Cost is the single largest misconception when we are advising a client to consider blister packaging," notes Thomas. He says a typical 3-inch by 7-inch package usually comes in complete under $0.05 for materials and labor vs. $0.15 to $0.20 for a clamshell.

However, blister packs do have some drawbacks vs. clamshells. "The blister only allows customers to view one side of the product," explains Palevsky. "In some applications, such as cosmetics, blister packs can be perceived as an option for lower quality goods, especially since higher-end products sold in department stores are not packaged this way."

However, clamshells are notoriously difficult to open. In fact, Consumer Reports magazine claims that frustration levels are at an all-time high. The publication recently released its Oyster Awards for hard-to-open packages.

The hard plastic clamshell was the overall winner. A sample product, a cordless phone, took the magazine's staff more than 9 minutes to open. Although some other products, such as a toy doll, took longer to open, the clamshell was singled out because it was impossible to open by hand. The plastic was too thick to open with scissors, so a box cutter was required. In the process, the testers sliced the instruction manual and nearly cut some battery wires.

Some manufacturers are addressing this issue by installing perforations around the perimeter of clamshells that make packages easier to pull apart. Other manufacturers are abandoning traditional clamshells in favor of a new type of hybrid blister pack.

"There has been a measurable shift at the wholesale clubs from clamshell packages to a more environmentally friendly package," says Thomas. "Recent initiatives by Wal-Mart are mandating these changes."

Wal-Mart's environmental goals aim to "be supplied by 100 percent renewable energy; create zero waste; and sell products that sustain our resources and environment."

The retailer is trying to be an environmental steward by reducing the use of petroleum-based PVC plastic. Costco is also scrambling to replace plastic clamshells with paperboard-blister hybrid packages. The new packaging uses printed paperboard and recycled polyester thermoforms.

"Paperboard is a renewable resource, and combined with a recycled blister, the package is less costly, more environmentally friendly and it provides a better package than the petroleum-based clamshells," explains Thomas. He says a double card with a trapped piece of corrugated cardboard used as a stiffener, combined with a blister, gives the stackable strength of the clamshell. The billboard provided by the cards adds to the security and impact of this new packaging format.

"This is one of the most exciting innovations in visual carded packaging in many years," claims Thomas. "The fact that this clamshell package uses a nonrenewable resource has provided a completely new approach.

"The trap blister uses two pieces of renewable paperboard, recycled corrugated cardboard and a recycled blister material produced from recycled soda bottles," adds Thomas. "Plastic usage is reduced up to 80 percent. The billboard usage is maintained with multicolor, offset printing, all at a price up to 50 percent less than the clamshell."

According to Thomas, the hybrid blister package is driving a major shift in several market segments, such as the cosmetics industry. He says it has required a completely different approach in the package converting system, because the package requires heat and seal pressure from the top and bottom.

"Most blister packaging technology for the past 40 years was predominantly one side only," explains Thomas. "The forming technology in the thermoforming process has not changed significantly. The newer plastics, such as a biodegradable PLA and recycled plastics such as RPET, are far more difficult to form than the standard PVC sheet, but these are more anecdotal changes than fundamentally new approaches."