One can trace the origins of synthetic papers to around 1970, when Union Carbide introduced a semi-transparent, matte-finish polypropylene-based film called Ucar. The product was the offspring of a relationship between the petrochemical and forestry industries. David Hoag, national converting sales manager for Arjobex, Charlotte, NC, explains, "Since water and trees are essential to the manufacturing of paper, they felt there weren't many that they considered to be good pulp- and paper-making sites left in the world. Furthermore, in those years oil prices were very inexpensive, which prompted a couple of petrochemical companies and a couple of paper making companies to embark on the making of a synthetic paper. The aim was to create a synthetic paper that would be an alternative to cellulose fiber, but have some of the same features from a printability point of view, and maybe even have some enhanced benefits as an alternative to paper products." As a result, Union Carbide and Mead Paper Company got together to develop Ucar.

Victor Balest, sales director for Polylith synthetic papers, Granwell Products, West Caldwell, NJ, continues the history: "A major limitation in this material (Ucar) was that it was not opaque or white. It may also have been too expensive relative to wood pulp papers. Around 1972, Union Carbide sold the manufacturing rights to Oji Yuka Paper Co. in Japan. Oji added TiO2, titanium dioxide, and the new material had better opacity and whiteness. Because trees are not as plentiful in Japan as they are in other parts of the world, the Japanese recognized the value of a synthetic paper. The relative and cost differentials between synthetics and pulp papers were not as pronounced in the Orient. Later, less expensive mineral fillers either augmented or replaced the more expensive TiO2. Oji called their product Yupo. Limited distribution rights were agreed to with Kimberley-Clark Corp. in the United States, and with some value-added features, Kimdura was born."

Kimdura — or as it is known today, Yupo — was the first known synthetic paper on the market.

The early days
Around the same time, Union Carbide was also working on a manufacturing process over in England. A few years later, the UK division was sold to BP Chemicals. Hoag says, "BP then got involved with a French company called Arjo Marie — a French paper making company, and that's how Arjobex came about.

Luggage tag application from Dupont Tyvek.

Polyart, a registered product of Arjobex, was born in 1975 as a legacy of the Mead and Union Carbide venture. Arjobex sold Polyart as an alternative to paper where paper could not hold up in an application. That's how Kimdura marketed itself as well.

Hoag says, "Kimdura came to the US in 1973. Polyart didn't come to the States till about 1983. Then, along the way, you had people like Teslin from PPG Industries come in as well."

Teslin is a registered product of PPG Industries, Pittsburgh, PA, and is among the leading synthetic papers available in the market. According to PPG Industries, before the advent of the Teslin sheet, it was difficult to perform high-quality printing on a synthetic sheet. Teslin sheet is polyolefin-based; 60 percent of its weight is non-abrasive filler, and 65 percent of its volume is air. It is porous, and therefore highly absorbent, allowing inks to set almost instantly. Inks penetrate the surface and anchor themselves in the sheet's structure, yielding superb print definition and pigment holdout. Adhesives and coatings also bond well.

Polylith, a more recent competitor, is a registered tradename of Granwell Products. According to Balest, "Kimdura had a big head start on us, but we have rapidly closed the gap, and today Polylith is fast becoming one of the leading synthetic papers worldwide. Many converters and end users are interested to replace PVC or polystyrene or other more costly synthetics, as well as replacing paper itself."

Raul Pintor, marketing manager for Trespaphan America, Greensboro, NC, points out that Trespaphan technology is quite different of the common synthetic papers. "It is not a coated film," he says. "It is just pure coextruded, white opaque polypropylene with outstanding de-stacking properties when cut and stack is required, obtaining cost opportunities comparing coated synthetic papers. Also Trespaphan synthetic papers have a glossier appearance, with a matte side for better handling."

"Narrow web converters require slit rolls and often smaller quantities, and the distributor/converter is especially suited to deliver this service," says Balest. "Like all maturing industries and markets, these distributors will have to develop strong relationships with their customers in the years ahead, because there will be cases where large volume users will want to buy direct from the factories."

Definitions and characteristics
"The problem today," says Hoag, "is that a lot of the packaging companies saw that synthetic paper manufacturers were creating a nice little niche market, and they wanted a piece of it as well. All of a sudden you had others coming in and wanting to be a part of the market. They started to put a coating down on their product and called themselves synthetic too. Unfortunately, over time synthetic paper has become much more generalized. Initially it was meant to be an alternative to paper, which is why it's called synthetic paper. But, over time it has come to mean anything that's not vinyl."

Consequently, the definition of synthetic paper has evolved, and includes variations.
Hoag says synthetic paper is film. "What they did was figure out a way to make film print out like a paper product. For example, Arjobex took clay coating and put it on film to give it paper like surface for printing purposes. Kimdura did it a bit differently, but the expectations were the same: To create a product that had paper-like qualities, but was more durable and able to handle applications that a paper wouldn't. It is a product that doesn't need to be laminated to create durability and weatherability," he says.

Dave Kee, marketing manager, Dupont Tyvek, Wilmington, DE, defines synthetic paper as a non-cellulosic sheet material resembling paper and used in a similar fashion. He says "Most synthetic papers are made from thermoplastic materials such as polyolefins, nylon, polystyrene, etc., by direct film or foil extrusion or by bonding filaments thereof. Tyvek is a nonwoven material by manufacturing terms, and by this definition classifies as a synthetic paper when used for graphic applications."
 

Applications of synthetic papers from Avery Dennison

Paul Mitcham, national marketing manager, Yupo Corporation America, Chesapeake, VA, defines synthetic paper this way: "Synthetic paper is category of paper that is made without any wood fibers and is especially formulated to be receptive to commercial printing inks. It differs from plastic film in certain ways, because of the printing characteristics, and it differs from traditional paper because of the lack of wood fibers." Yupo America is a division of Oji-Yuka Synthetic Paper Co., Tokyo.

Rich Witmer, marketing communications manager at Valéron Strength Films, Houston, says, "We define synthetic paper as a paper-like film that lies somewhere between traditional plastic films and high-value paper. Synthetic paper is generally accepted to be not of organic nature or wood-based, but oil/resin based in its manufacture."

"Synthetic paper is a film," says Ben Reif, director of sales and marketing, Wausau Coated Products, Wausau, WI. "It could be a number of things, a polypropylene, or polyethylene based — with some sort of a coating — usually a clay coating on it, that makes the product easy to print. By easy to print I mean you can use standard inks, and you don't need a top coat or corona treatment."

Russell Lauricella, vice president of sales, Hop Industries Corporation, Garfield, NJ, says, "The term synthetic paper has evolved now to the point where manufacturers and distributors are using it for any type of plastic film that will accept offset printing other than your generic PVC films, or polystyrenes. The product is evolving to include oriented polypropylene films that people are now referring to as synthetic paper, that really aren't synthetic papers — they are basically just film. Manufacturers apply some clay coatings to these materials and all of a sudden it becomes labeled as a synthetic paper. I think that term is more geared to appeal to the printer, to give the product the connotation as a printer friendly material."

Robert Weber, sales manager, Multi-Plastics, Lewis Center, OH, says "With the strength and durability of plastic and the appearance and printability of paper, synthetic paper is very versatile." Customers would opt for synthetic paper for its durability, tear resistance, strength and weatherability properties.

Synthetics vs. paper vs. film
"Synthetic papers use a plastic resin backbone rather than the pulped wood fibers used in traditional paper," says John Giblin, marketing director of Granwell Products. "Both types of papers similarly use mineral fillers and optical brighteners to gain opacity, brightness and smoothness. The printability characteristics for synthetic papers and wood pulp papers are comparably developed by the use of calendering rolls and imparting surface printability enhancements."

For printers, synthetic paper is comparable in use to conventional papers. "Depending on the press configuration, the printer may only need to use higher solids inks to successfully print on synthetics," says Giblin. "This is important to the printer since it gives direct access to higher value-added products and market categories. Synthetic paper has many of the technical product performance properties of plastic films but also has the printability and surface characteristics of paper. With a good synthetic paper grade it's hard to tell it's not paper by feel or print quality. It's only when you try to tear it or soak it with water that the difference shows itself.

Synthetic card stock from Valéron Strength Films.

"Due to the tremendous yield differences, it's better to compare the economics on an MSI basis rather than per pound. In this respect a pound of synthetic paper goes a lot further than a pound of wood fiber paper. The big savings comes with not having to treat synthetic paper, as many conventional wood fiber papers are treated, to withstand anticipated field conditions such as water, grease, dirt, UV resistance, etc."

Synthetic papers work just fine on all types of printing presses — flexo, letterpress, litho, screen and gravure — and they handle fine screens and graphics well. Steve Nimz, president of Protect-All Media, Darien, WI, adds, "We get quite a few calls for synthetics that can be printed by multiple technologies, typically flexo and laser, flexo and thermal transfer, and flexo and direct thermal. There is also interest in synthetic media for Xeikon and Indigo digital presses, but so far most of the production volume has been small."

Nimz says synthetic papers do not swell or absorb moisture like conventional papers. "Conversely, it also does not absorb ink in the same fashion as paper. Therefore, not only is the drying process different, but also usually more expensive ink formulations are typically required for synthetics."

Ken Machlica of Avery Dennison points out that synthetic papers don't really have an inherent shelf life as long as they are stored in proper conditions. "The surface of uncoated, or bare, films must be corona treated to have the surface tension to allow the ink to adhere," says Machlica, product manager at Fasson Roll North America, Painesville, OH. "Shelf life, depending upon the type of film and the treatment process, can be anywhere from 30 days to a year. Synthetic paper manufacturers have developed coatings to put on top of their films to lock in the surface tension, and there's no longer an issue regarding shelf life."

Lori Davis, executive vice-president and co-owner of Contract Converting, Greenville, WI agrees: "Aging does not seem to affect synthetic papers, and they offer good resistance to yellowing. They also provide a very long shelf life. Synthetic papers provide better print quality, more snap, more gloss, more graphic impact. Plus they offer improved durability and toughness."

Although Balest agrees that synthetic papers are superior to pulp papers, he maintains that they are still more costly than most papers. According to Mickey Mishne, president of Polymer Consulting, the price of synthetics has dropped from four times the price of paper to three, but says it will never equal the price of paper. "Especially never in the USA, because paper is very cheap. Outside the US and Canada, synthetic paper and cellulosic paper are the same price as paper is — much more expensive outside the USA and Canada."

Current economic conditions, however, are driving prices of synthetics down and leading them to try to sell directly to printers, cutting out the paper merchants.

Markets and Trends
The consensus seems to be that synthetic papers are used whenever paper cannot fulfill an application. Hoag says, "It has basically became a problem solver."

The tag and label industry is the largest growth segment for the synthetic market. These include wraparound labels, in-mold labels, tags, and a multitude of pressure sensitive products. Other markets include rough duty maps and manuals, POP display materials, store banners, posters, phone/medical cards, menus, covers, ID cards, tamper evidence, outdoor applications, the forest industry and numerous commercial printing applications.
 

Synthetic papers are safe for use on food products.

To illustrate that plastic films as well as conventional papers are also being replaced by synthetic paper, Giblin says, "We've developed a non-PVC synthetic paper that is used as a direct replacement for PVC film in pressure sensitive labels at improved economics. In almost all the markets we supply, increased durability of some sort is needed. It may be scuff, UV, water/moisture, folding, grease, dirt resistance that is needed. A medical association was offset printing their tri-fold brochures on clay coated paper that was subsequently laminated between plastic film to prevent wear and tear. They now print on Polylith synthetic paper and have reduced their costs by 30 percent."

Synthetics have made their way into more non-traditional markets as well. Mitcham says, "Since the paper market is very mature, a lot of designers are out there looking for something different to show their clients, and many times synthetic paper is that choice, because it looks different, feels different, characteristics are very different, and it has some environmental edge to it — since it's tree free."

Frank Bobick, senior sales representative at Ritrama Inc., Minneapolis, MN, says polyester synthetics are being used in the health and beauty market. "The customer was looking for embossable film material. The end user had requested a label that looked like a heavy weight cotton paper, but they wanted it to be waterproof. We used polyester synthetic paper as a portion of this construction, first because it has a matte appearance to it, and they wanted a muted look for it to stimulate a paper look, and second because they can use their full emboss coverage on the entire label surface to give it the appearance of paper. The pattern they emboss into this construction and the look of the polyester construction has simulated for them what they were looking for."

Security has become a larger market for synthetics, especially since September 11. Says Witmer, "RFID tags using Valéron Strength Film as the strength layer are in use in retail environments. These tags protect high-value items by making the tag more resistant to tearing and also protect the integrity of the RFID inlay."

"Airlines are now expected to match checked baggage with the passenger manifest before leaving the gate," notes Nimz. "Baggage tags must be strong enough to withstand the rigors of handling, they must be capable of accurately storing passenger information via printed bar codes and/or RFID and they must remain human and machine readable. Conventional paper is not durable enough for this application. In fact, the majority of the synthetic papers are not up to the task either. In this example, when a baggage tag is removed, either intentionally or unintentionally, more is lost than just the passenger's name and destination. Security of the airport and the airplane can be compromised by unidentifiable baggage."

According to Witmer, "We are seeing a lot of new topcoatings to broaden the range of synthetics. For example Valéron can now be coated with an inkjet-receptive coating for large format digital printing. Coatings also exist for Xeikon printing, and specialty laminations allow Valéron film to be laser printable.

Davis says, "Because there are many product options, tag and label printing technologies, and makes of thermal or laser imaging, it is critical to test products prior to production. Tag and label manufacturers need to know that 'one synthetic does not fit all'. Some are designed specially for laser or thermal printers. Others are better suited for flexo or offset printing. Some offer added UV resistance and durability. Some are superior for diecutting or folding. Others offer superior characteristic for adhesive hold-out."

Challenges
One big problem with synthetic paper, according to Reif of Wausau Products, is lack of laser printability. "I think that if it could be laser printed, and if it was guaranteed to laser print, you would see the market explode." Reif explains that synthetic paper can't be laser printed because polyethylene melts in a laser printer. There is an exception, however, and that is Teslin.

"That product is silica-based; it's highly absorbent, which makes it extremely easy to print, whether it's flexo, offset or laser printed." When it melts it turns into a powder, and would not contaminate or ruin the chromium drum inside the printer. But Teslin is thick. Reif says, "The thinnest they make it is about 7 mils in caliber. When you put it together with an adhesive and a liner, it makes it impossible to feed through most laser printers, because it's too thick. It's also too expensive."

Nimz says there is a solution to almost anything. "At Protect-All, we have the ability to combine the best properties of several different synthetics, from different manufacturers, into composite structures to achieve whole new categories of synthetics. For example, Valéron Film is widely recognized as a very strong, tear-resistant product, but because it is made from high density polyethylene it will not survive the hot fusion temperatures of laser printing. By laminating thin gauge thermally stable synthetics from another manufacturer to both sides of the Valéron we end up with a very strong, durable synthetic that is now also laser printable. This is only one example; there are many other potential synergies by combining products from different manufacturers into synthetic hybrids."

A bigger problem, Nimz believes, is the lack of familiarity of synthetics by press operators. He says, "While virtually everyone has printed on conventional paper at one time or another, the same is not true for synthetics. Synthetic paper is new print media for many pressrooms in the United States."

Converters should pay heed to tooling life and die wear when using synthetics, Nimz adds. "This is due to the variety of whiteners, opacifiers, additives and coatings that are used. Most of these additives are abrasive in nature."

Future
Lauricella of Hop Industries says, "Everyone is looking into printing on plastics in order to keep their competitive edge," says Lauricella of Hop Industries. "In the commercial offset printing environment we definitely see growth, but the real growth for this product is in the flexographic industry — for all sorts of labels, the wrap-arounds, the inserts. The more yield-friendly synthetics will put up real competition against polystyrenes. Styrene has been used because of its low specific gravity, basically one of the cheapest plastics on the market for inserts and labels. Now we have substrates out there that are coming in at 15 percent lower than styrene."

On the other hand, Mitcham foresees more exposure of synthetics to non-traditional markets. "As marketing becomes more effective, and people become more aware of synthetics, its reach will grow. Ten years ago the commercial printing market for synthetics was very small. Today it has grown considerably."

As part of this growth, Bobick from Ritrama sees synthetic paper "becoming much more widely marketed into the point-of-sale area, as a replacement for vinyl because it's a lot less expensive, and because a lot of point-of-sale interior decals don't require any outdoor durability. The only issue you run into is that there is a certain comfort level with vinyl."

Hoag feels that synthetics are an environmentally friendly alternative to vinyl especially in Europe, since vinyls are looked down upon somewhat there. As for the US, he says, "The future for synthetics is very bright. As people in the States become more sensitive to the environmental issues associated with vinyl, synthetics will replace vinyl." Hoag also believes that although it has been hard for synthetics to penetrate the digital printing market, he sees this as the next area of opportunity.

Balest says, "Adhesive laminated label stock for shelf labeling is an important new market. Removal and replacement of shelf marketing stickers is facilitated with films as opposed to pressure sensitive paper shelf labels. There is very strong competition for narrow web printers from traditional sheetfed litho printers, and from rotogravure printers, the former in the area of cut and stack, full wrap bottle labeling as well as with in-mold labeling, and the latter in in-mold labeling."

Mishne sees pouch packaging as a major emerging market. "An emerging trend, not yet commercialized, is fast-food packaging based on biodegradable synthetic paper, and synthetic papers replacing paper for cash register tapes to improve bag recyclability."

Davis anticipates much greater use of synthetic tag and label materials in laser printing, "as more customers are custom-imprinting tags off their computers with laser printers." She says, "Currently, laser compatible synthetics are the most costly of the synthetic paper spectrum, but as demand increases, cost will decrease and make it readily available."