Cellulosic and paper tapes are used in various industries and applications for a host of different reasons. Whether they’re used in painting to create enhanced aesthetics or in construction to provide structural stability, there’s no shortage of uses for these versatile nonwovens.
These tapes require the right chemistry to do their job and deliver strength and reliability without breaking. Masking tapes are particularly complex, as they require a number of different layers and additives to achieve the right characteristics for their applications.
As a long-time supplier to the industry, BASF strives to develop innovative and effective polymers that allow these tapes to perform at their best. John Norton, Technical Specialist for Nonwovens and Composites, describes the role that these tapes play in our world — and the chemistry that goes into them.
The nonwovens family
Cellulosic and paper tapes are a type of nonwoven materials, which are engineered fabrics composed of fibres bound together by chemical, mechanical, heat or solvent treatment.
Their unique composition provides reliable strength and flexibility to a wide variety of applications, with extensive subcategories under the nonwoven family that offer specialized attributes and capabilities.
“There are a lot of different technologies that can be used when creating these materials,” says Norton. “There are nonwovens made from glass to nonwovens made with natural fibers like jute and kenaf fibers, and everything in between.”
Other common areas nonwovens are used in include abrasives, ceiling and wall tiles, insulation materials, coatings, roofing materials and tapes.
“BASF creates the emulsion polymers or binders that glue the fibers together, and they provide strength, structure and other desired performance characteristics,” says Norton.
A sticky situation
Cellulosic and masking tapes make up one of the largest market segments of the nonwovens category. Commonly used in construction, painting and general-purpose applications, these tapes are designed for strength, flexibility and ease-of-use.
Masking tapes are particularly complex. They are composed of a saturated paper and multiple coatings, which include a pressure sensitive adhesive (PSA), primer, barrier, and release coatings.
“Masking tapes are very complicated because they require multiple coatings,” says Norton. “On the backside there’s a pressure sensitive adhesive (PSA), as well as a coating between the PSA and the saturated paper that helps with adhesion. On the other side, you may have a barrier coat to prevent solvents from penetrating through the tape. Finally, the very last coating on the top is called a release coating. These coatings are very, very thin, but they’re also highly effective.”
Although tensile strength is a key attribute of an effective tape, achieving the right balance of strength and elongation is important to allow the tape to perform as needed per end use. This is where BASF’s strong background in chemistry provides an advantage.
“You have to have the right balance of tensile strength and tear strength,” explains Norton. “You don't want a tear strength that’s too low because you don’t want it to rip when you peel it off the roll of tape, but you can't make tear strength so high that you can't just tear it off when you need to.”
Binder basics
Considering this balancing act of attributes, BASF chemists work continuously to develop polymers that improve tear and tensile strength, elongation, flexibility, film forming and enhanced barrier properties.
The performance characteristics and capabilities of cellulosic tapes are often determined by the choice of polymer binders used to create them. Binders may provide strength and resistance to exterior chemicals and forces, including solvents, UV rays and temperature variations.
“The masking tape backing is usually made of crepe paper, which doesn't have a tremendous amount of strength or the barrier properties that a tape would need, so they're saturated with either styrene-butadiene polymers or styrene-acrylic polymers,” says Norton. “These polymers provide strength and allow you to control tensile strength and tear strength, and they also give toughness to the tape.”
BUTOFAN® NS 209 carboxylated styrene-butadiene binder is an industry staple that provides a good balance of tensile strength and elongation with excellent barrier properties, and BUTOFAN 4000 is a next-generation polymer that provides excellent thermal dimensional stability, making it ideal for applications where high temperatures.
As with most construction materials, cost-performance ratio is a large factor in choosing the right solution. As a mainstay in the industry, BASF is capable of delivering high-performance solutions at competitive prices.
“One of the main things that our customers look for is cost-performance balance,” says Norton. “We are very competitive price-wise, and we provide high quality polymers for these markets so customers can get exactly what they want from their tapes and nonwovens.”
For more information on BASF’s polymers, binders and additives for tapes, Click Here.