Questões

A Brief and Simplified Description of Papermaking

The paper we use today is created from individual wood fibers that are first suspended in water and then pressed and dried into sheets. The process of converting the wood to a suspension of wood fibers in water is known as pulp making, while the manufacture of the dried and pressed sheets of paper is formally termed papermaking. The process of making paper has undergone a steady evolution, and larger and more sophisticated equipment and better technology continue to improve it.

The Wood yard and Wood rooms

The process at Androscogging began with receiving wood in the form of chips or of logs 4 or 8 feet in length. From 6 AM to 10 PM a steady stream of trucks and railroad cars were weighted and unloaded. About 40 percent were suplied by independents who were paid by weight their logs. The mill also received wood chips from lumber mills in the area. The chips and logs were stored in mammoth piles with separate piles for wood of different species (such as pine, spruce, hemlock).

When needed, logs were floated in flumes......(1).....the wood yard.....(2).....one of the mill’s three wood rooms. There, bark was rubbed......(3)........in long, ribbed debarking drums by tumbling the logs against one another. The logs then fell into a chipper;......(4)......seconds a large log was reduced to a pile of chips approximately 1 inch by 1 inch by 1/4 inch.

The chips were stored in silos. There were separate silos for softwoods (spruce, fir, hemlock, and pine) and hardwoods (maple, oak, beech, and birch). This separate and temporary storage of chips permitted the controlled mixing of chips into the precise recipe for the grade of paper being produced.

The wood chips were then sorted through large, flat vibrating screens. Oversized chips were rechipped, and ones that were too small were collected for burning in the power house. (The mill provided approximately 20 percent of all its own steam and electricity needs from burning waste. An additional 50 percent of total electricity needs was produced by harnessing the river for hydroelectric power.)

Once drawn from the silo into the digesters, there was no stopping the flow of chips into paper. 

Pulpmaking

The pulp made at Androscoggin was of two types: Kraft pulp (produced chemically) and ground wood pulp (produced mechanically). Kraft pulp was far more important to the high quality white papers produced at Androscoggin, accounting for 80 percent of all the pulp used. Kraft pulp makes strong paper. (Kraft is German for strength. A German invented the Kraft pulp process in 1884.) A paper’s strength generally comes from the overlap and binding of long fibers of softwood; only chemically was it initially possible to separate long wood fibers for suspension in water. Hardwood fibers are generally smaller and thinner and help smooth the paper and make it less porous.

The ground wood pulping process was simpler and less expensive than the Kraft process. It took high quality spruce and fir logs and pressed them continuously against a revolving stone that broke apart the wood’s fibers. The fibers, however, were smaller than those produced by the Kraft process and, although used to make newsprint, were useful at Androscoggin in providing “fill” for the coated publication gloss papers of machines 2 and 3, as will be described later.

^(A)The chemical Kraft process worked by dissolving the lignin that bonds wood fibers together. ^(B) It did this in a tall pressure cooker, called a digester, by “cooking” the chips in a solution of caustic soda (NaOH) and sodium sulfide (Na²S), which was termed the “white liquor.” ^(C)The two digesters at Androscoggin were continuous digesters; chips and liquor went into the top, were cooked together as they slowly settled down to the bottom, and were drawn off the bottom after about three hours. ^(D) By this time, the white liquor had changed chemically to “black liquor’’; the digested chips were then separated from this black liquor. ^(E)

In what was known as the “cold blow” process, the hot, pressurized chips were gradually cooled and depressurized. A “cold liquor’’ (170°F) was introduced to the bottom of the digester and served both to cool and to transport the digested chips to a diffusion washer that washed and depressurized the chips. Because so much of the lignin bonding the fibers together had been removed, the wood fiber in the chips literally fell apart at this stage.

The black liquor from the digester entered a separate four-step recovery process. Over 95 percent of the black liquor could be reconstituted as white liquor, thereby saving on chemical costs and significantly lowering pollution. The four-step process involved (1) washing the black liquor from the cooked fiber to produce weak black liquor, (2) evaporating the weak black liquor to a thicker consistency, (3) combustion of this heavy black liquor with sodium sulfate (Na₂SO₄ ), and redissolving the smelt, yielding a “green liquor” (sodium carbonate + sodium sulfide), and (4) adding lime, which reacted with the green liquor to produce white liquor. The last step was known as causticization.

Meanwhile, the wood-fiber pulp was purged of impurities like bark and dirt by mechanical screening and by spinning the mixture in centrifugal cleaners. The pulp was then concentrated by removing water from it so that it could be stored and bleached more economically.

By this time, depending on the type of pulp being made, it had been between 3 1/2 and 5 hours since the chips had entered the pulp mill. 

All the Kraft pulp was then bleached. Bleaching took between 5 and 6 hours. It consisted of a three-step process in which (1) a mix of chlorine (Cl₂ ) and chlorine dioxide (CIO₂ ) was introduced to the pulp and the pulp was washed; (2) a patented mix of sodium hydroxide (NaOH), liquid oxygen, and hydrogen peroxide (H₂ O₂ ) was then added to the pulp and the pulp was again washed; and (3) chlorine dioxide (ClO₂ ) was introduced and the pulp washed a final time. The result was like fluffy cream of wheat. By this time the pulp was nearly ready to be made into paper.

From the bleachery, the stock of pulp was held for a short time in storage (a maximum of 16 hours) and then proceeded through a series of blending operations that permitted a string of additives (for example, filler clay, resins, brighteners, alum, dyes) to be mixed into the pulp according to the recipe for the paper grade being produced. Here, too, “broke” (paper wastes from the mill itself) was recycled into the pulp. The pulp was then once again cleaned and blended into an even consistency before moving to the papermaking machine itself.

It made a difference whether the broke was of coated or uncoated paper, and whether it was white or colored. White, uncoated paper could be recycled immediately. Colored, uncoated paper had to be rebleached. Coated papers, because of the clays in them, could not be reclaimed.

TEXT

    A library tradition is being refashioned to emphasize early literacy and better prepare young children for school, and drawing many new fans in the process.

    Among parents of the under-5 set, spots for story time have become as coveted as seats for a hot Broadway show like “Hamilton.” Lines stretch down the block at some branches, with tickets given out on a first-come-first-served basis because there is not enough room to accommodate all of the children who show up.

    Workers at the 67th Street Library on the Upper East Side of Manhattan turn away at least 10 people from every reading. They have been so overwhelmed by the rush at story time — held in the branch’s largest room, on the third floor — that once the space is full, they close the door and shut down the elevator. “It is so crowded and so popular, it’s insane,” Jacqueline Schector, a librarian, said.

    Story time is drawing capacity crowds at public libraries across New York and across the country at a time when, more than ever, educators are emphasizing the importance of early literacy in preparing children for school and for developing critical thinking skills. The demand crosses economic lines, with parents at all income levels vying to get in.

    Many libraries have refashioned the traditional readings to include enrichment activities such as counting numbers and naming colors, as well as music and dance. And many parents have made story time a fixture in their family routines alongside school pickups and playground outings — and, for those who employ nannies, a nonnegotiable requirement of the job.

    In New York, demand for story time has surged across the city’s three library systems — the New York Public Library, the Brooklyn Public Library, and the Queens Library — and has posed logistical challenges for some branches, particularly those in small or cramped buildings. Citywide, story time attendance rose to 510,367 people in fiscal year 2015, up nearly 28 percent from 399,751 in fiscal 2013.

    “The secret’s out,” said Lucy Yates, 44, an opera coach with two sons who goes to story time at the Fort Washington Library every week.

    Stroller-pushing parents and nannies begin to line up for story time outside some branches an hour before doors open. To prevent overcrowding, tickets are given out at the New Amsterdam and Webster branches, both in Manhattan, the Parkchester branch in the Bronx, and a half-dozen branches in Brooklyn, including in Park Slope, Kensington and Bay Ridge.

    The 67th Street branch keeps adding story times — there are now six a week — and holds sessions outdoors in the summer, when crowds can swell to 200 people.

    In Queens, 41 library branches are scheduled to add weekend hours this month, and many will undoubtedly include weekend story times. As Joanne King, a spokeswoman for the library explained, parents have been begging for them and “every story time is full, every time we have one.”

    Long a library staple, story time has typically been an informal reading to a small group of boys and girls sitting in a circle. Today’s story times involve carefully planned lessons by specially trained librarians that emphasize education as much as entertainment, and often include suggestions for parents and caregivers about how to reinforce what children have learned, library officials said.

    Libraries around the country have expanded story time and other children’s programs in recent years, attracting a new generation of patrons in an age when online offerings sometimes make trips to the book stacks unnecessary. Sari Feldman, president of the American Library Association, said such early-literacy efforts are part of a larger transformation libraries are undergoing to become active learning centers for their communities by offering services like classes in English as a second language, computer skills and career counseling.

    Ms. Feldman said the increased demand for story time was a product, in part, of more than a decade of work by the library association and others to encourage libraries to play a larger role in preparing young children for school. In 2004, as part of that effort, the association developed a curriculum, “Every Child Ready to Read,” that she said is now used by thousands of libraries.

    The New York Public Library is adding 45 children’s librarians to support story time and other programs, some of which are run in partnership with the city government. It has also designated 20 of its 88 neighborhood branches, including the Fort Washington Library, as “enhanced literary sites.” As such, they will double their story time sessions, to an average of four a week, and distribute 15,000 “family literacy kits” that include a book and a schedule of story times.

    “It is clear that reading and being exposed to books early in life are critical factors in student success,” Anthony W. Marx, president of the New York Public Library, said. “The library is playing an increasingly important role in strengthening early literacy in this city, expanding efforts to bring reading to children and their families through quality, free story times, curated literacy programs, after-school programs and more.”

    For its part, the Queens Library plans to expand a “Kick Off to Kindergarten” program that attracted more than 180 families for a series of workshops last year. Library officials said that more than three-quarters of the children who enrolled, many of whom spoke a language other than English at home, developed measurable classroom skills.

From: www.nytimes.com/2015/11/02

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    Clifford the Big Red Dog looks fabulous on an iPad. He sounds good, too — tap the screen and hear him pant as a blue truck roars into the frame. “Go, truck, go!” cheers the narrator. But does this count as story time? Or is it just screen time for babies? It is a question that parents, pediatricians and researchers are struggling to answer as children’s books, just like all the other ones, migrate to digital media.

     For years, child development experts have advised parents to read to their children early and often, citing studies showing its linguistic, verbal and social benefits. In June, the American Academy of Pediatrics advised doctors to remind parents at every visit that they should read to their children from birth, prescribing books as enthusiastically as vaccines and vegetables.

     On the other hand, the academy strongly recommends no screen time for children under 2, and less than two hours a day for older children. 

     At a time when reading increasingly means swiping pages on a device, and app stores are bursting with reading programs and learning games aimed at infants and preschoolers, which bit of guidance should parents heed? 

     The answer, researchers say, is not yet entirely clear. “We know how children learn to read,” said Kyle Snow, the applied research director at the National Association for the Education of Young Children. “But we don’t know how that process will be affected by digital technology.” 

     Part of the problem is the newness of the devices. Tablets and e-readers have not been in widespread use long enough for the sorts of extended studies that will reveal their effects on learning.

     Dr. Pamela High, the pediatrician who wrote the June policy for the pediatrics group, said electronic books were intentionally not addressed. “We tried to do a strongly evidence-based policy statement on the issue of reading starting at a very young age,” she said. “And there isn’t any data, really, on e-books.”

    But a handful of new studies suggest that reading to a child from an electronic device undercuts the dynamic that drives language development. “There’s a lot of interaction when you’re reading a book with your child,” Dr. High said. “You’re turning pages, pointing at pictures, talking about the story. Those things are lost somewhat when you’re using an e-book.”

     In a 2013 study, researchers found that children ages 3 to 5 whose parents read to them from an electronic book had lower reading comprehension than children whose parents used traditional books. Part of the reason, they said, was that parents and children using an electronic device spent more time focusing on the device itself than on the story (a conclusion shared by at least two other studies).

     “Parents were literally putting their hands over the kids’ hands and saying, ‘Wait, don’t press the button yet. Finish this up first,’ ” said Dr. Julia Parish-Morris, a developmental psychologist at Children’s Hospital of Philadelphia and the lead author of the 2013 study that was conducted at Temple University. Parents who used conventional books were more likely to engage in what education researchers call “dialogic reading,” the sort of back-and-forth discussion of the story and its relation to the child’s life that research has shown are key to a child’s linguistic development.

     Complicating matters is that fewer and fewer children’s e-books can strictly be described as books, say researchers. As technology evolves, publishers are adding bells and whistles that encourage detours. “What we’re really after in reading to our children is behavior that sparks a conversation,” said Kathy Hirsh-Pasek, a professor of psychology at Temple and co-author of the 2013 study. “But if that book has things that disrupt the conversation, like a game plopped right in the middle of the story, then it’s not offering you the same advantages as an old-fashioned book.”

     Of course, e-book publishers and app developers point to interactivity as an educational advantage, not a distraction. Many of those bells and whistles — Clifford’s bark, the sleepy narration of “Goodnight Moon,” the appearance of the word “ham” when a child taps the ham in the Green Eggs and Ham app — help the child pick up language, they say.

     There is some evidence to bear out those claims, at least in relation to other technologies. A study by the University of Wisconsin in 2013 found that 2-year-olds learned words faster with an interactive app as opposed to one that required no action.

     But when it comes to learning language, researchers say, no piece of technology can substitute for a live instructor — even if the child appears to be paying close attention.

     Patricia K. Kuhl, a director of the Institute for Learning and Brain Sciences at the University of Washington, led a study in 2003 that compared a group of 9-month-old babies who were addressed in Mandarin by a live instructor with a group addressed in Mandarin by an instructor on a DVD. Children in a third group were exposed only to English.

    “The way the kids were staring at the screen, it seemed obvious they would learn better from the DVDs,” she said. But brain scans and language testing revealed that the DVD group “learned absolutely nothing,” Dr. Kuhl said. “Their brain measures looked just like the control group that had just been exposed to English. 

     The only group that learned was the live social interaction group.” In other words, “it’s being talked with, not being talked at,” that teaches children language, Dr. Hirsh-Pasek said. 

     Similarly, perhaps the biggest threat posed by e-books that read themselves to children, or engage them with games, is that they could lull parents into abdicating their educational responsibilities, said Mr. Snow of the National Association for the Education of Young Children. 

    “There’s the possibility for e-books to become the TV babysitters of this generation,” he said. “We don’t want parents to say, ‘There’s no reason for me to sit here and turn pages and tell my child how to read the word, because my iPad can do it.’ ” 

     But parents may find it difficult to avoid resorting to tablets. Even literacy advocates say the guidelines can be hard to follow, and that allowing limited screen time is not high on the list of parental missteps. “You might have an infant and think you’re down with the A.A.P. guidelines, and you don’t want your baby in front of a screen, but then you have a grandparent on Skype,” Mr. Snow said. “Should you really be tearing yourself apart? Maybe it’s not the world’s worst thing.” 

     “The issue is when you’re in the other room and Skyping with the baby cause he likes it,” he said. Even if screen time is here to stay as a part of American childhood, good old-fashioned books seem unlikely to disappear anytime soon. Parents note that there is an emotional component to paper-andink storybooks that, so far, does not seem to extend to their electronic counterparts, however engaging. 

From: www.nytimes.com, OCT. 11, 2014