Chlorine Free Paper Issues

 

LISTENING STUDY Question 47:
Are there differences in quality or performance for tree free papers?

In general the agricultural fibers are usually about the same length as deciduous wood fibers, but shorter than coniferous wood fibers. Kenaf grown in tropical area will have fiber length of 7 mm or longer. Agricultural fibers will produce a wide variety of papers such as currency paper and calligraphy paper that require long and thin fibers. - James S. Han, Research Chemist, USDA Forest Service Forest Products Laboratory

Yes, there are significant differences. - Living Tree Paper Company

Yes, these differences are dictated by each fiber type. Hemp, for example, has much different characteristics than rice straw. - Jeff Lindenthal, President, Green Field Paper Company

Yes. Quality and performance are factors of the raw material and the manufacturing process. Good and poor qualities of paper can be produced from either wood or agriculturally based papers. - Tom Rymsza, President, Vision Paper

Kenaf and hemp core pulps and rice and wheat straw pulps appear to have the lowest strength characteristics - below that of hardwood pulps and far below that of softwood pulps. - Environmental Defense Fund Paper Task Force, White Paper 13, "Non-Wood Fiber Sources"

It depends on the appropriate selection of agri-fibers, pulp technology, and papermaking technology.
      See for example, my presentations, "Agri-Pulp Newsprint" and "Experience in the Technical and Market Development of Agri-Pulp Printing Papers in North America." - Al Wong, Founder, Arbokem

Yes, there are wide variations in quality. - Jeanne Trombly, Fiber Futures

There are no quality or performance differences between kenaf and wood. - Tom Rymsza, President, Vision Paper

Yes, there are substantial differences in the quality and performance of paper made from agricultural fibers versus wood fibers. Differences are dependent on the type of agricultural fiber used, the relative amount of each fiber used, the grade of the paper being made, and the application of the paper by the consumer. Consumers have historically chosen wood based paper products because of their high quality and relatively low cost. - International Paper

The market and performance will bring this out, but theoretically any agricultural fiber can be made into wood type products.
      Re-Vision paper works better in appearance and machinery. But in real markets, cotton based toilet papers are inherently better. Trying to pound-for-pound replace newsprint with [tree free] newsprint or copy paper isn't an advantageous path. We should be making funky filters for Italian cars and other specialty products. - Peter A. Nelson, President, AgroTech Communications, Inc.

Experiences with a product are highly varied. The quality and performance potential is probably dependent on the experience of those trying to use the products.
      Another consideration is that nonwood paper producers often are not coming from multi-generational experience. While a copy paper mill had years to perfect the processes to produce precisely what the consumer wants, new mills have to start from scratch with an extended trial-and-error process. Therefore, if the papers don't initially perform as well, it may be due to lack of expertise rather than fundamental flaws.
      An overlying concept with these papers is that before we get into the economics and other challenges, we really need to prove that nonwood papers provide a better environmental profile and outcome. Having not shown that, investment is hard to come by. We're hoping that the Listening Study will point to the best opportunities. From there, there can be many opportunities, whether they are public, private, or partnership-based. Ideally we can lay out the science in a sensible way to find small gaps and decide if it makes sense to continue promoting tree-free papers. At this point, no one in particular wants to assume that trees are bad, nor should we make such assumptions. It is not clear that agricultural fiber is necessarily better than an equivalent acre of trees. It may not be a "one or another" thing. Trees might be ideal for certain products and places whereas agricultural fibers might be better in other mixes. - Russell Clark, Environmentally Preferable Purchasing Program, US EPA

Clearly there are very significant differences between nonwood fibers that might be used to make paper. But of the nonwood papers that have actually been brought to market in the U.S., including some using agricultural residues and others using on-purpose crop fibers, we have heard of no problems from paper purchasers. By the time they get that far, the producers seem to have worked out enough technical problems that the papers themselves are high quality. - Susan Kinsella, Conservatree

Hemp received a favorable initial rating in the USDA study. Hemp and Kenaf are not related, but they do have similar characteristics. Unfortunately, it is illegal to grow hemp in the US, and the yields per acre indicate a high cost of raw material which is not competitive with wood fiber. Additionally the strong bast fibers are dramatically different than wood fibers, and they require additional processing to prepare a pulp suitable for commercial type papers.
      Agricultural residue is a broad term, but in the context of pulp and paper, it usually means corn stalks and various hays, primarily wheat straw and rice straw (but could include other straws from grains). Since pulp and paper making requires homogenous material to produce consistent results the mixing of different types of agricultural residue is not indicated.
      Additionally corn stalks and straws contain a high level of silica, which has significantly negative implications for chemical recovery and environmental compliance at a pulp mill. While novel processes have been proposed to alleviate the silica problem, none are commercially proven or in current operation.
      Corn stalks are the most abundant agricultural residue material available, and there has been some historic use as a raw material in pulping, albeit, limited. Corn stalks produce a low pulp yield. For every one ton of pulp, you get two tons of waste material which contains a high amount of silica. The short weak fibers will probably be detrimental to recycling.
      Straws are another abundantly available raw material, and they have a more extensive history of use in the industry, with the last straw pulp mill in the US ceasing operations in 1960. Wheat or Rice Straws contain short, weak fibers, a high level of silica and, like corn, will not recycle well.
      Flax and cotton are mature on-purpose crops that have historic use in pulp and paper, especially specialty grades. They both yield long fibers, (much longer than wood fibers) and both carry a very high raw material cost when compared to wood.
      Both bamboo and arundo donax were considered in the USDA study, and both plants have received recent attention in the nonwoods sector. Both plants are perennials (grasses- multi-years to harvest) and not conducive to farming that is based upon annual row crops. They both have a physical structure that is suitable for chipping, which produces a wood-like raw material for the pulp mill in-feed. Both plants produce high yields per acre, and a pulp similar to hardwood pulps.
      Bamboo pulp is produced in Asia, and it should be noted that bamboo forests provide the sole food source for the Panda Bear, which is an endangered species.
      Arundo Donax grows in the wild in California and can be propagated elsewhere. It is sometimes call "giant reed" and it is used to made reeds for wood-wind instruments. It is considered a highly invasive toxic pest in California, where efforts exist to eradicate it.
      Bagasse (sugar cane) fiber is a by-product of sugar production. It is a hardwood-like fiber that has historically and currently been used for common paper products in areas where a sugar cane industry exists. After the sugar is extracted, burning the leftover bagasse fibers for energy value or pulping for paper are two uses for this process residue, and both uses are common. Bagasse has a lower silica content than corn stalks or straws. - Tom Rymsza, President, Vision Paper

Kenaf is one of the best alternatives because it is a "New Crop" and that is really good for sustainable agriculture. The Search for New Fiber Crops program selected it as the most viable plant to replace trees in paper making. That search program also identified crotalaria and roselle as high potential.
      Kenaf was chosen because its outer bast fiber was similar to softwoods, and its inner core is similar to hardwoods. The whole kenaf stalk can be used to make high quality paper. Kenaf has a low lignin content, so the chemistry needed to convert it to pulp is less than that used for trees. Kenaf produces a pulping yield of 50% or more, using less energy, making it an efficient raw material. It does not contain silica, so it is suitable for existing well known and well proven chemical systems, and can be processed without producing additional environmental liability. Kenaf's raw material cost is competitive to wood fiber, and it is a very environmentally sound crop, requiring lower chemical use than most other crops.
      It is a fast growing plant, growing from seed, planted in the spring, to a height of 12-18 feet tall in about 5 months. In studies in cooperation with the University of Tennessee using no-till agriculture, we have demonstrated that it can be economically grown using lower chemical inputs than other crops in that region, particularly cotton.
      It produces about six tons of fiber in this time period, and that is two or three times the fiber produced by trees in a forest in a twelve month period. That high level of fiber production means it is absorbing CO2 and sequestering the carbon faster than a forest. - Tom Rymsza, President, Vision Paper

 


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