They look like paper, and many of them feel like paper. They perform as films do, because most of them are film products. Since their introduction more than 30 years ago, synthetic papers have earned a lasting place in the catalogue of versatile substrates employed in the printing and packaging fields. Because of their appearance, durability, and resistance to tearing and outdoor elements, they are the material of choice in a wide range of applications, and continue to grow in popularity.
The history of synthetic paper is convoluted, and involves companies on both sides of the globe. The earliest incarnation, called Ucar, resulted from joint efforts by Union Carbide and Mead Paper Company. Manufacturing rights then went to Oji Yuka Paper Co. in Japan, which added titanium oxide to the product and named it Yupo. Kimberly-Clark received distribution rights back in the Western Hemisphere, re-tweaked the product, and called it Kimdura. Over the past several years, Yupo has acquired all of Kimberly-Clark's synthetic paper businesses.
When Union Carbide was working on its synthetic paper formulas in the 1970s, it sold its UK division to BP Chemicals, which teamed up with Arjo Marie, a French company. That alliance led to the formation of Arjobex, which produces Polyart, a family of synthetic papers for the packaging and label (and other) markets. Polyart was introduced to the United States in about 1983, about 10 years after the arrival of Kimdura.
Valeron, an ITW company, also is a major player in the field, as are the products manufactured by Nanya Plastics in Taiwan.
Most synthetic papers are biaxially oriented polypropylene (BOPP) films that are produced in a couple of different ways and coated with proprietary formulas. Then there is DuPont Tyvek, a household word today, in many senses a synthetic paper but different from the others. Tyvek is a large family of tough, durable products of high density polyethylene fibers, formed by spinning continuous strands of very fine interconnected fibers, then bonding them together with heat and pressure. It's white, chemically inert, and contains no binders. Though there are many variations, Tyvek comes in two basic types: 10 and 14. The fibers in 10 are dense and the surface is smooth, highly opaque and white; it is this type that is used by packaging people. Type 14's fibers are not as densely bonded, and the resulting substrate has higher mobility and a fabric-like drape.
Brands and hybrids
"Synthetic paper is a fancy name for plastic film with a coating on it, typically," says Steve Nimz, president of Protect-All Print Media, Darien, WI, USA. Nimz should know. His company markets many brands of the material, including Valeron, Yupo, and others. "There are so many different types out there today because there has been quite an increase in the size of the market. We carry five or six different brand names, and all serve different purposes."
Protect-All takes synthetic papers a step further by creating its own versions from existing brands, marketing them under the Printmaster and Packmaster names. "We take some brands and laminate them together to make hybrids," says Nimz. "For example, Valeron is extra tear resistant, but it lacks some other properties, so we'll laminate an Appleton direct thermal synthetic to give it strength and direct thermal capabilities.
"We also take our coatings here and do niche applications, such as for dot matrix or impact printing, a technology that has declined in the US but still is big in Southeast Asia and Australia, for the steel industry. Or we will put a synthetic between two layers of conventional paper, making a sandwich. It's common for price tickets, where the customer needs a durable tag for high value items, but doesn't want it to look different from other items in the store."
Synthetic substrates differ in appearance somewhat, more so in performance. "They differ relative to the manufacturing technique," says David Hoag, national converting sales manager for Arjobex, Charlotte, NC, USA. "Polyart is a BOPP, like most others, but what differentiates it is the way we orient...