Groundwood Comes Out of Closet
Once viewed with disdain, paper now offers valuable eco and economic advantages.
By Trish Wales -- Graphic Arts Online, August 1, 2008
Historically, uncoated groundwood paper was viewed with disdain—yellow unstable papers relegated to low-end applications or newspapers. Technology advancements, an economic slowdown, escalating fuel costs and increased focus on sustainability have changed that opinion.
Xerox led the charge into groundwood last summer when it introduced High Yield Business Paper. This year, AbitibiBowater upped the ante with its Ecopaque rolls for longer press runs. These groundwood grades challenge uncoated freesheet papers in multiple market segments by offering some interesting new choices.
The same trees are used in making groundwood and freesheet papers. The processing of the trees into pulp is what separates groundwood from freesheet papers. In the groundwood process, the whole tree including the natural lignin is ground into small pieces. About 90% of the tree is converted to paper, compared to 45% of the tree in the freesheet process. Half the number of trees are cut down to produce a groundwood versus a freesheet.
Lignin, a substance with positive and negative properties, is the major difference. It is removed in the freesheet pulping process, while groundwood processing retains it. Lignin is an opaque substance with limited photo stability. Newspapers yellow with time because of lignin.
Freesheet papers also lack some degree of photo stability. The optical brighteners added to most uncoated freesheets are the culprits. Both uncoated mechanical and uncoated freesheet products turn yellow with time, although by different mechanisms and to different degrees.
The economic angle
The opacity of a groundwood sheet is about equal to the opacity of a 10% to 20% heavier freesheet. Interpretation: You can substitute a lighter basis weight paper, maintain critical quality parameters and take the press yield and postal savings to the bank.
A book weighs less and a catalog costs less to mail. Mailing 1,000 five-sheet sets of a document using High Yield Business Paper would save $80 in mailing costs over a comparable uncoated freesheet.
Steve Simpson, VP and GM of Xerox's paper and supplies unit, reports that “High Yield Paper is now a major part of our sustainability strategy. High Yield has solidly surpassed our revenue and volume expectations each month—and continues to climb.”
Abitibi/Bowater further advanced the efficient use of the tree by bringing an enhanced web product to market. Ecopaque arrives with a 90 Brightness and a 120 Whiteness. This paper, in development over several years, signals the emergence of uncoated groundwood as a candidate for short-life collateral, catalogs and forms. Groundwood paper can be clean and crisp not just yellow and dingy. And note that today's web presses easily print the product.
Most paper products are short-lived and arguably over-engineered. Uncoated groundwood papers use fewer trees, are more economical if appropriate basis weight substitutions are made, and are now visually pleasing, as well as printable in today's digital devices and web presses.
ONLINE: Paper channel at graphicartsonline.com/paper
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