Paper

• Watch out for "erasable paper" by Xerox-- a way to make prints whose images last only a day, so that the paper can be used again and again. The technology, which is still in a preliminary state, blurs the line between paper documents and digital displays and could ultimately lead to a significant reduction in paper use. While potential users have shown interest in transient documents, there is still much to be done if the technology is to be commercialized.

• Wisconsin's paper industry has seen many changes over the past 150 years. In fact, Wisconsin is America's #1 papermaking state.

• The vast majority of paper manufactured ends up in people's homes and businesses, where 90% is discarded within a year. The U.S. EPA cites municipal landfills as the single largest source of methane emissions to the atmosphere, and has identified the decomposition of paper as among the most significant sources of landfill methane.

• Between 2.2 and 4.4 tons of wood are cut and transported for every ton of virgin pulp, versus 1.4 tons of waste paper for a ton of recycled pulp. However, recycled paper only had about 10% of the printing and writing paper market and even those papers contained mostly virgin materials. Most paper companies own many mills. One or two might be making recycled, but the rest are all making virgin paper. Even many of the recycling mills are making a lot of virgin paper.

Contents 1 How Paper Started 2 Recycled Paper Production 3 Tests 4 What's Needed? 5 Concerns over Paper 5.1 Curl 5.2 Stickies 5.3 Duplexing 5.4 Dusting 6 Links to other Paper Wiki 7 References

[edit] How Paper Started

It all started during the year AD 105 when paper was invented. For centuries, people tried to discover better surfaces on which to record their thoughts. Almost everything imaginable was tried. Wood, stone, ceramics, cloth, bark, metal, silk, bamboo, and tree leaves were all used as a writing surface at one time or another. The invention of paper was reported to the Chinese Emperor by Ts’ai Lun, an official of the Imperial Court. He took the inner bark of a mulberry tree and bamboo fibers, mixed them with water, and pounded them with a wooden tool. He then poured this mixture onto a flat piece of coarsely woven cloth and let the water drain through, leaving only the fibers on the cloth. Once dry, Ts'ai Lun discovered that he had created a quality writing surface that was relatively easy to make and lightweight. However, archaeologists reported that the actual invention of paper begun 200 years ago. Ancient paper pieces from the Xuanquanzhi ruins of Dunhuang in China's northwest Gansu province apparently were made during the period of Emperor Wu who reigned between 140 BC and 86 BC.

[edit] Recycled Paper Production

Recycled paper production produces less pollution, uses more benign chemicals, and requires less bleaching than virgin paper production. The only area in which recycled paper creates more disposal materials is in the greater amount of sludge. The problem materials that fall into recycled paper sludge would otherwise have been scattered throughout landfills or concentrated in incinerator emissions or ash. Recycling mill sludge becomes an environmentally preferable way of handling potentially toxic materials such as inks and additives (coatings and fillers) than landfill deposition. The sludge of many recycling mills tests non-toxic. Sludge that tests hazardous can be disposed of by an environmentally controlled method. Recyclers are increasingly finding ways to reclaim and reutilize some components of recycled paper sludge.

Producing recycled paper uses much less total energy than producing virgin paper. Depending on the grade, producing recycled paper may use more or less purchased energy (a subset of total energy), in the form of fossil fuels and purchased electricity. Virgin freesheet grades require slightly less purchased energy to produce than recycled ones, because some of their energy needs are met by burning wood-derived process waste. Virgin groundwood papers, by contrast, require more purchased energy to produce than do recycled groundwood papers. Even when recycled paper production uses more fossil fuel than its virgin counterpart, on a lifecycle basis the recycled system generates fewer greenhouse gas emissions.

Recycled paper production requires postconsumer materials which are finished products that have served their intended end use and would otherwise end up in a landfill or incinerator. As "postconsumer" paper is more diverse, with characteristics such as copier toner and a wide variety of adhesives that are not found in preconsumer scraps, it is much harder to recycle than preconsumer materials. Preconsumer component include trim and scrap from manufacturing processes (e.g., the conversion of paper rolls into envelopes) and overissue publications.

Paper that is collected for recycling is sorted according to the type of mill that will use it. Most recovered office paper can be sent to a deinking mill, which separates the ink, coatings and other extra materials from the paper fibers. The fibers are then sent to a paper machine to be made into new paper. The deinking process is described here:[1]

1. Old papers are mixed with water and broken up using a pulper agitator.
2. The pulp is pushed through a screen to remove solid impurities such as staples and glue.
3. Fine soapy bubbles are added to the pulp to bring ink particles to the surface.
4. Impurities are separated from the pulp are removed.
5. Ink particles are removed by rubbing fibres together.
6. The pulp is bleached using hydrogen peroxide.
7. Fine soapy bubbles are added again to the pulp to bring up to the surface the remaining ink.
8. The pulp is centrifuged to separate impurities.
9. Bleached again to increase whiteness and removal of remaining coloring.
10. The pulp is pushed through a screen residual sticky particles.
11. The pulp is thickened by dewatering, sheeting, cutting and baling.
12. Now, the pulp is ready for conversion into recycled paper.

Side-by-side comparison found that on average, virgin paper production requires substantially more water and yields wastewater that has significantly higher levels of major water pollutants than does recycled paper production.

The fibers in fine paper can be recycled up to a dozen times before becoming too short for papermaking. Generally speaking, recycled fibers have reduced bonding potential compared to their virgin counterparts, which tends to reduce strength and requires compensation in the manufacturing process. In some circumstances, however, recycled fibers may also impart desired qualities to the paper sheet, such as smoothness and dimensional stability.

There are many recycled-content papers that perform as well as virgin paper and some that perform better than their virgin counterparts. The age, capabilities and operation of papermaking equipment have a greater impact on the properties of the finished paper than its recycled or virgin content. Papermakers adjust for the differing properties of recycled fiber in numerous ways in the manufacturing process.

The kinds of recycled paper now available are:

• letterhead, stationery and envelopes
• business cards
• brochure papers
• high quality copy paper
• offset
• text and cover
• book printing papers
• opaques
• all grades of coated papers
• bristols, index, translucent, tag and board, drawing, and specialty papers.

[edit] Tests

In 1998, the U.S. Conference of Mayors conducted a study with leading equipment manufacturers and the Government Printing Office. Over two million sheets were tested for paper feeding, reliability, image quality, toner fixability, smoothness, curl, and other aspects. Results proved that recycled papers with 30% postconsumer content performed just as well as virgin papers and recycled papers with lower postconsumer content.

Ongoing testing is reported by Buyers Laboratory, Inc., an independent office products testing laboratory, which has for many years used recycled as well as virgin paper in all its tests of different brands of copiers. It reports "no noticeable difference in the runnability of recycled paper versus virgin paper.

Commercial printers and copier machine manufacturers today agree that recycled paper is suitable for all their machines. They only require good quality paper, whether recycled or virgin. You just have to choose the right grade for the job.

[edit] What's Needed?

• Buyers, specifiers and advocates to keep up and increase the demand for recycled paper with high postconsumer content, so that mills will continue to invest to produce the paper. Paper distributors, printers and retailers need to see demand for recycled paper if they are to continue stocking it. Manufacturers need to hear demand to continue making it. That's why it's crucial to always specify recycled paper with postconsumer content. Moreover, requiring postconsumer content develops markets for community recycling collection systems by creating incentives for paper mills to buy their postconsumer scrap paper. This, in turn, encourages research and development and mill investments in recycling technology, further strengthening market capacity.

• Major national magazines to lead a switch to recycled paper.

• Corporations to make recycled paper the paper of choice for all corporate uses.

• Advocates to remain vigilant in national and international venues, insisting on meaningful postconsumer definitions and content requirements. In particular, the World Trade Organization has targeted recycled content specifications as a "restraint of trade." Advocates must not allow paper companies or trade associations to dictate what kind of paper they are "allowed" to buy.

• The Federal Trade Commission (US-FTC) to require the term "recycled," described in its environmental labeling guidelines, to indicate postconsumer content, even if it is zero. The FTC environmental labeling guidelines require only "recovered materials" for papers labeled as "recycled." There is no postconsumer content required. If the label does not indicate postconsumer content, you should assume there is none until investigating further.

• Federal, state and local governments to favor increased postconsumer content levels over the minimums specified by the White House Executive Order and the U.S. Environmental Protection Agency (EPA). Currently, EPA publishes a range of achievable postconsumer contents for many papers, although most paper companies aim for the minimums. The Executive Order, incorporated into the EPA guidelines, only states a minimum postconsumer content. Governments use many purchasing strategies to favor specific goals, such as inclusion of small and minority businesses, preferences for veterans, and awards to local businesses. Many helped developed the markets for recycled paper through application of price preferences for specific minimum contents. Similar strategies can be employed now to reward paper manufacturers that produce environmental papers with more than the minimum recycled or other ecological specifications.

• Pulp and paper companies to continue investing in deinking technology and incorporating postconsumer content into their papers.

• Office products companies such as Hewlett-Packard, Xerox, IBM, and others that offer "private label" papers under their corporate name to require that those papers include postconsumer content.

• Technology companies to continue improving deinking systems so that they can take wider ranges of wastepaper, and to produce recyclable glues for labels and notes.

• Mass-mailers and their providers, including the U.S. Postal Service, direct mailers, magazine publishers, billing entities, and others, to insist on the development of recyclable adhesives, and then commit to using only recyclable products.

• Wastepaper dealers to mine the deeper and harder-to-get-at veins of postconsumer wastepaper, particularly from smaller companies and decentralized offices.

• Distributors to become far better educated about and committed to promoting recycled papers, and to stocking it so that buyers can easily get it.

• Office supply stores and retailers to supply recycled content alternatives for all products feasible, at prices as cost-competitive as possible, and to revamp their purchasing policies which often unnecessarily limit recycled content options and increase their prices.

• All of us to seriously practice source reduction and minimize paper consumption, even while valuing, using completely, and recycling the paper we do need.

[edit] Concerns over Paper

Producing a quality paper requires papermakers to establish strict performance specifications and to control the variability of the papermaking process to meet these specifications consistently.

[edit] Curl

Papers will not curl as long as they are designed and engineered for the intended end use of copying. The key to having a stable sheet (acceptable curl) includes:

• Optimum fibre orientation,
• Proper moisture content,
• Optimum fibre length and morphology,
• Sheet structure (fibre distribution),
• Surface sizing.

As post consumer (short fiber) content is increased some strength characteristics are negatively impacted. These include tear, tensile, elongation and stiffness to name a few. However these parameters are far less critical to the performance of copy paper compared to offset (web & sheet) stock. Length of the fibre is one of many parameters, which affect sheet stability. Having long fibre length alone does not ensure problem free copier performance.

Excessively long fibre can be detrimental to curl due to the fact that softwood fibres (long) typically have higher coefficients of moisture expansion. It is more important to strive towards top and bottom sides of the sheet that are similar in structure and composition. This will ensure that the shrinkage of the fibres on the topside of the sheet will be more or less equal to the shrinkage of fibre on the bottom of the sheet, thus minimizing curl during toner fusing.

There are ways of compensating for the shorter fibers, including adding only 20-30% recycled and using more softwood."

There are many types of post consumer fibres utilized in the making of recycled products. Recycled fibre from bleached OCC tends to have longer fibre length than mixed office waste paper. The percent of long vs. short fiber depends on the recycled pulp supplier and their process. Paper makers will make adjustments to their refining to compensate for average fiber length. An important factor is the "drainage" on the paper machine (how the wet papermaking solution forms the paper web). The ability to uniformly control drainage is important for making a consistently high-quality, low-curl paper – recycled OR virgin.

A very delicate balance must be maintained between fiber length mix, amount of filler, fiber processing and drying to produce a low curl high formation sheet.

Curl is mostly related to the hardwood to softwood ratio, the 'cutting' and 'brushing' of the fibers, fiber orientation (on the papermaking machine), moisture content and drying strategy, though higher postconsumer content papers tend to encounter curls due to shorter fibers.

[edit] Stickies

A specific problem unique to recycled paper are the "stickies" (adhesive and plastics) which can build up on the paper-making machines (causing holes and inclusions in the paper, degrading its quality) and on copying/printing equipment (causing spots on the photoreceptor, which in turn causes poor print quality).

[edit] Duplexing

There are several factors important to duplexing, including stiffness, dimensional stability and acceptable opacity. Factors such as ash content, caliper, fiber furnish blend and starch pick-up can affect these.

[edit] Dusting

The acid papermaking process uses talc and clay as fillers while the alkaline based process uses chalk which is calcium carbonate. Calcium carbonate is brighter than talc & clay which promoted paper manufacturers to increase the amount of filler in the paper to produce an economical sheet that permanently stays white and bright. Increased amount results to other advantages such as archival benefits, whiteness, improved fibre bonding, and smoother surface. Since more filler is used in the alkaline process, it is important to make sure the surface of the sheet is sealed. Calcium carbonate is more abrasive on the slitters and knives used in the converting (sheeting) process, making it necessary to change them out more frequently or to do some modification on the sheeting equipment to maintain a clean edge cut. Most converting units are equipped with vacuum systems to further ensure that cut edge debris is removed from the sheet. Manufacturers resolved these issue by making the slitting, cutting and dust removal systems more robust. If the sheet surface is not sealed properly and the sheeting process is not maintained, increased dusting can occur during imaging.

Some issues regarding alkaline v. acid would affect offset printing paper applications, such as 'chalking,' But with office paper applications, alkaline paper allows for brighter and longer lasting paper. The isues of acid- vs. alkaline-based paper production are very complex and really depend on the type of paper being produced. Whether a sheet is manufactured under alkaline or acid conditions, dusting can still be an issue. Today, it would be very expensive to make acid-based uncoated copy paper.

Most paper mills switched to alkaline many years ago, and as they did so, they learned how to reduce surface dust and converting dust (by updating knife maintenance schedules to accommodate the new filler materials in the sheet). Today, there is very little difference in dust in the end product between alkaline and acid office papers.

[edit] Links to other Paper Wiki

Paper tips, Own your paper, Test new paper, Recycling tips, Paper recycling tips, Disposable Paper Products Tips, Buying disposable paper products, Disposable paper products tips, Buying toilet paper, Paper bags, Energy and paper saving tips, Use less wrapping paper, Paper towels, Buy paper products made with clean, safe processes, Preserve the rainforest

[edit] References

• Fact Sheet: Buy Recycled Paper! by Susan Kinsella, 2000.
• Q&A on the Environmental Benefits of Recycled Paper by Environmental Defense and the Alliance for Environmental Innovation.
• The Environmental Paper Listening Study from Conservatree.org
• Cascades.com/Paper