New Tool: ProSource
Check out our packaging and processing solutions finder, ProSource.

Flexible bag becomes all wet

Bag serves as a self-contained, disposable dehumidifier. Calcium chloride in a top portion absorbs moisture, that drains into the bag's lower portion. Filling machinery saves labor costs for DampRid.

Dehumidifier bags are overwrapped in film and sold in a colorful carton that?s merchandised at retail in a paperboard display
Dehumidifier bags are overwrapped in film and sold in a colorful carton that?s merchandised at retail in a paperboard display

When DampRid, Inc. introduced its Hanging Dehumidifier(TM) last year, the Orlando, FL, firm hoped the flexibly packaged product would "put the company on the map." Actually, DampRid feels fortunate to still be on the map, considering Hurricane Floyd caused the company to evacuate its premises for three days as a precautionary measure in September. Fortunately, Floyd's wrath didn't alter the company's plans to move into a new 76ꯠ sq' facility, more than twice the size of its previous plant.

According to Eric Claiborne, DampRid's vice president and general manager, "the product's success is one of the main reasons why we're moving into a new building." The product wouldn't work, however, without its functional bag.

The flexible bag is converted by Laminated Films & Packaging (Portsmouth, NH). Measuring about 14" from top to bottom and 9" across, the 3-mil bag structure includes 48-ga metallized polyester adhesive-laminated to linear low-density polyethylene supplied in rollstock from AlliedSignal Specialty Films (Morristown, NJ). Laminated Films uses that structure to create the back portion of the bag, as well as the bottom half of the bag's front. The top half of the bag's front is made of Tyvek® from DuPont (Wilmington, DE).

Laminated Films heat-seals the bottom and two vertical bag sides. The converter also heat-seals what it calls "a broken seal" across the 9" width dimension. This effectively creates upper and lower parts of the bag.

DampRid fills calcium chloride (and scented fragrance crystals) into the upper portion of the bag before inserting a plastic handle and heat-sealing the top. Consumers then hang the bag on a rod in a clothes or linen closet or shower where the calcium chloride absorbs moisture. As the calcium chloride breaks down, the moisture drains by gravity through the small openings in the broken seal area into the unfilled bottom part of the bag.

Depending on the humidity level in the area where the bag is placed, the Hanging Dehumidifier can last as long as six weeks before the consumer disposes of it. The product is meant to prevent damage to clothing and prevent mildew, stains and odors from forming on carpeting, walls and furniture. The Hanging Dehumidifier is designed for use in high humidity environments as an inexpensive alternative to electric dehumidifiers.

Structure serves

DampRid relies on Laminated Films to select its materials. "The product has a need for certain materials and they filled them for us," explains Claiborne. "There was considerable thought put into the structure and the rate of moisture absorption. We learned not to add Tyvek to both sides of the bag because it would then absorb too fast."

According to Jim Landers, president of Laminated Films, "We selected the polyester and LLDPE from AlliedSignal to make the bags for DampRid. This film is for a pretty heavy product. We conducted drop testing and this material passed those tests. It also gave DampRid the cosmetic appearance it wanted."

The Tyvek, a spun-bonded olefin material made from high-density PE fibers, combines the properties of paper, film and cloth. It allows moisture from the environment to enter the bag and be absorbed by the calcium chloride. At the same time, the permeable material allows the scent to diffuse from the bag.

On to filling

DampRid receives bags from Laminated Films. The converter prints the Tyvek flexographically in five colors. DampRid's red and yellow logo and product name stand out prominently in the dark blue background color.

DampRid's Claiborne explains, "We place the flat bags on a wicketed magazine on a machine that we made here at our own machine shop. Suction cups pick up a bag and place it under a filler."

Supplied by Spee-Dee Packaging Machinery (Sturtevant, WI), the auger filler was added in January '98. It fills 16 oz of calcium chloride into the top portion of the bag.

Laminated Films' Landers points out that the minute breaks in the horizontal cross seal and the tension formed in the bag during the fill prevent the calcium chloride from falling through to the bottom portion of the bag.

Mechanical fingers carry the bag from the auger filler to the next station where a Spee-Dee volumetric filler adds 1 oz of fragrance pellets. Afterward, a mechanical inserter places an injection-molded HDPE hanger tab to the top edge of the bag, between the film and Tyvek material. Heat-seal bars then seal the top of the bag. Filling is done at speeds of about 30 bags/min.

The mechanical fingers release the sealed bag onto a conveyor that carries it through the DampRid machine that tri-folds the bag, much like a microwave popcorn bag. The bag is conveyed through a Rennco (Homer, MI) wrapper that heat-seals the bag inside Cryovac (Duncan, SC) D9555 film. "If you don't have an outer overwrap to seal the product, it will begin to absorb humidity inside the carton," says Claiborne.

Finally, an Econocorp (Randolph, MA) Spartan cartoner automatically places one overwrapped Hanging Dehumidifer bag into a folding carton from Tropical Paper Box (Miami, FL). The 20-pt clay-coated newsback board is offset-printed in four colors by Tropical. Cartons are glued shut with hot melt.

Counting its benefits

"We added the Econocorp cartoner last summer," says Claiborne. "Before that, we were cartoning manually on three daily shifts. By adding the Spartan, we're saving about $62ꯠ a year and the cartons look like they were done automatically. The seal looks good and it's a fast process."

Claiborne has also been satisfied with the two Spee-Dee fillers, which he says the company learned about through reading trade magazines.

DampRid runs six packaging lines, one of which is dedicated to the Hanging Dehumidifier. "This is the newest product," says Claiborne. "We sell it in six-pack cartons to mass retail outlets, grocery stores and home and hardware centers. They sell individual packs to consumers." Retail prices range between $3 and $4.

"The product is doing well on the market, and we've been running this line on two shifts, five days a week," says Claiborne. "Depending on how well it continues to do in the future, we may add a second line for the product because we may add different fragrances for the Hanging Dehumidifier."

Discover Our Content Hub
Access Packaging World's free educational content library!
Read More
Discover Our Content Hub
Rethinking Packaging Robotics to Prioritize Flexibility
In this ebook, you’ll learn how to guard against the traps that CPGs sometimes inadvertently set for themselves when implementing robotics that lead to automation “brittleness.”
Read More
Rethinking Packaging Robotics to Prioritize Flexibility