Kimberly-Clark Corp. makes things that consumers use to clean up around the house, including paper towels, tissues and diapers.
Its products are in households all over the world, but the company also wants to expand its offerings beyond its normal lines of paper-based products — so it has created flexible, absorbent products using thermoplastics.
The new technology, which uses extruded polystyrene foam sheets, is not in commercial production yet, but the Irving, Texas-based firm is looking at potential uses and is open to licensing its technology to other companies.
``This is a new class of material and a new product space,'' Jeffrey Krueger, research scientist in materials development for Kimberly-Clark, said during the Society of Plastics Engineers' Antec conference May 6 in Milwaukee.
Kimberly-Clark began looking at thermoplastics as a way to help it create a new class of higher-end items that will provide it with a new product niche and revenue stream. It wanted something that would hang on to liquid more than paper, but still be flexible and inexpensive to produce.
The firm looked at both polyolefin and polystyrene before settling on PS for its potential to absorb more than olefins, Krueger said.
The next issue became finding a way to take a stiff extruded sheet and making it flexible, as well as boosting its absorbent properties.
Working on a pilot line, the company landed on two techniques used in tandem, using a blend of surfactant additives along with additional blowing agents in the production line.
``Then something else that developed is, because the sheet was no longer firm and stiff, we needed to [reconfigure] the standard polystyrene sheet foam extruder to handle something soft and pliable,'' Krueger said.
Once the new flexible sheets come out of the extrusion line, they still need additional treatment to pierce the outer layer, creating a way for liquid to get to the absorbent inner core, Krueger said. Kimberly-Clark has created a variety of ways to break that barrier, including pin points placed on the sheet in a decorative pattern or scuffing the surface to create ``suede'' appearance.
The firm also discovered that the thermoplastic makes a good print surface for decorating the sheets, he said.
Although the PS sheets are not in full production yet, they are ready for commercial launch on the right product. The company has a few ideas for using the PS sheets, Krueger said, from foam paint brushes to an absorbent mat that pet owners can place beneath dog and cat water dishes to protect their floors from spills.
``It's going to be something for higher-value-added products,'' he said.