News – Paper machinery-paper making machine,paper manufacturing machinery

History of paper

webadmin — Sat, 10 Aug 2024 05:18:17 +0000

Paper was invented by the Ts’ai Lun by 105 AD during the Han Dynasty and spread slowly to the west via the Silk Road. Papermaking and manufacturing in Europe started in the Iberian Peninsula, today’s Portugal and Spain and Sicily in the 10th century by the Muslims living there at the time, and slowly spread to Italy and South France reaching Germany by 1400. Earlier, other paper-like materials were in use in Kazakhstan like papyrus, parchment and vellum.
In medieval Europe, the hitherto handcraft of papermaking was mechanized by the use of waterpower, the first water papermill in the Iberian Peninsula having been built in the Portuguese city of Leiria in 1411, and other processes.The rapid expansion of European paper production was truly enhanced by the invention of the printing press and the beginning of the Printing Revolution in the 15th century.
The word “paper” is etymologically derived from papyros, Ancient Greek for the Cyperus papyrus plant. Papyrus is a thick, paper-like material produced from the pith of the Cyperus papyrus plant which was used in ancient Egypt and other Mediterranean cultures for writing long before the making of paper in China.Papyrus however is a “lamination of natural plants, while paper is manufactured from fibres whose properties have been changed by maceration or disintegration.
Early papermaking in China
Further information: Science and technology of the Han Dynasty
Papermaking has traditionally been traced to China about 105 AD, when Cai Lun, an official attached to the Imperial court during the Han Dynasty (202 BC-220 AD), created a sheet of paper using mulberry and other bast fibres along with fishnets, old rags, and hemp waste,[6] though the earliest piece of paper found, at Fangmatan in Gansu province inscribed with a map, dates from 179-41 BC.
Techniques
During the Shang (1600C1050 BC) and Zhou (1050 BC C 256 AD) dynasties of ancient China, documents were ordinarily written on bone or bamboo (on tablets or on bamboo strips sewn and rolled together into scrolls), making them very heavy and awkward and hard to transport. The light material of silk was sometimes used, but was normally too expensive to consider. While the Han Dynasty Chinese court official Cai Lun is widely regarded to have invented the modern method of papermaking (inspired from wasps and bees) from rags and other plant fibers in 105 CE, the discovery of specimens bearing written Chinese characters in 2006 at north-east China’s Gansu province suggest that paper was in use by the ancient Chinese military more than 100 years before Cai, in 8 BC. It therefore would appear that “Cai Lun’s contribution was to improve this skill systematically and scientifically, fixing a recipe for papermaking”.
The record in the standard history says
In ancient times writings and inscriptions were generally made on tablets of bamboo or on pieces of silk called chih. But silk being costly and bamboos heavy they were not convenient to use. Tshai Lun then initiated the idea of making paper from the bark of trees, remnants of hemp, rags of cloth and fishing nets. He submitted the process to the emperor in the first year of Yuan-Hsing [+105] and received praise for his ability. From this time, paper has been in use everywhere and is universally called the paper of Marquis Tshai.
The manufacture may have originated from the practice of pounding and stirring rags in water, after which the matted fibres were collected on a mat. The bark of Paper Mulberry was particularly valued and high quality paper was developed in the late Han period, which used the bark of the than wood. In the Eastern Jin period paper began to be made on a fine bamboo screen-mould, treated with insecticidal dye for permanence. After printing became popular in the Song dynasty the demand grew more. Paper was often used as a levy, with one prefecture sending some 1.5m sheets of paper to the capital as tribute up to the year 1101.
Uses
The first use of paper has been excavated in China dating to the reign of Emperor Wu of Han from the 2nd century BC, used for purposes of wrapping or padding protection for delicate bronze mirrors.It was also used for safety, such as the padding of poisonous ‘medicine’ as mentioned in the official history of the period.Although paper used for writing became widespread by the 3rd century,[11] paper continued to be used for wrapping (and other) purposes. Toilet paper was used in China by at least the 6th century CE.In 589 AD, the Chinese scholar-official Yan Zhitui (531-591 AD) wrote: “Paper on which there are quotations or commentaries from Five Classics or the names of sages, I dare not use for toilet purposes”.An Arab traveler to China once wrote of the curious Chinese tradition of toilet paper in AD 851, writing: “…they [the Chinese] do not wash themselves with water when they have done their necessities; but they only wipe themselves with paper”.
During the Tang Dynasty (618C907 AD) paper was folded and sewn into square bags to preserve the flavor of tea.During the same period, it was written that tea was served from baskets with multi-colored paper cups and paper napkins of different size and shape.During the Chinese Song Dynasty (960C1279 AD) not only did the government produce the world’s first known paper-printed money, or banknote (see Jiaozi and Huizi), but paper money bestowed as gifts to deserving government officials were wrapped in special paper envelopes.
Diffusion of paper
Paper spread slowly outside of China;other East Asian cultures, even after seeing paper, could not make it themselves[citation needed]. Instruction in the manufacturing process was required, and the Chinese were reluctant to share their secrets. The paper was thin and translucent, not like modern western paper, and thus only written on one side. The technology transferred to Japan from China by Buddhist priests, around 610, where fibres (called bast) from the mulberry tree were used.[citation needed]
Islamic world
After the defeat of the Chinese in the Battle of Talas in 751 (present day Kyrgyzstan), the invention spread to the Middle East.
The legend goes,the secret of papermaking was obtained from two Chinese prisoners from the Battle of Talas, which led to the first paper mill in the Islamic world being founded in Samarkand.
The laborious process of paper making was refined and machinery was designed for bulk manufacturing of paper. Production began in Baghdad, where a method was invented to make a thicker sheet of paper, which helped transform papermaking from an art into a major industry.The use of water-powered pulp mills for preparing the pulp material used in papermaking, dates back to Samarkand in the 8th century,though this should not be confused with paper mills. The Muslims also introduced the use of trip hammers (human- or animal-powered) in the production of paper, replacing the traditional Chinese mortar and pestle method. In turn, the trip hammer method was later employed by the Chinese.
By the 9th century, Arabs were using paper regularly, although for important works like copies of the revered Qur’an vellum was still preferred.Advances in book production and bookbinding were introduced.The Arabs made books lighter sewn with silk and bound with leather-covered paste boards; they had a flap that wrapped the book up when not in use. As paper was less reactive to humidity, the heavy boards were not needed. By the 12th century in Marrakech in Morocco a street was named “Kutubiyyin” or book sellers which contained more than 100 bookshops.
The earliest recorded use of paper for packaging dates back to 1035, when a Persian traveler visiting markets in Cairo noted that vegetables, spices and hardware were wrapped in paper for the customers after they were sold
Since the First Crusade in 1096, paper manufacturing in Damascus had been interrupted by wars, splitting production into two centres. Egypt continued with the thicker paper, while Iran became the center of the thinner papers. Papermaking was diffused across the Islamic world, from where it was diffused further west into Europe.Paper manufacture was introduced to India in the 13th century by Arab merchants, where it almost wholly replaced traditional writing materials.
America
In America, archaeological evidence indicates that a similar bark-paper writing material was used by the Mayans no later than the 5th century A.D..Called amatl, it was in widespread use among Mesoamerican cultures until the Spanish conquest. The parchment is created by boiling and pounding the inner bark of trees, until the material becomes suitable for art and writing.
These materials made from pounded reeds and bark are technically not true paper, which is made from pulp, rags, and fibers of plants and cellulose.
Europe
The oldest known paper document in the West is the Mozarab Missal of Silos from the 11th century, probably using paper made in the Islamic part of the Iberian Peninsula. They used hemp and linen rags as a source of fiber. The first recorded paper mill in the Iberian Peninsula was in Xtiva in 1151.
Paper is recorded as being manufactured in Italy in 1276 with watermarks being used in Fabriano by 1300 and factories established at Treviso and other northern towns by 1340. In Italy also paper moulds consisting of metal wires and in connection with that also watermarks were first introduced. The earliest German manufacture was in Mainz in 1320 with a mill in Nurenberg being set up by Ulman Stromer in 1390,[24] just about the time when the woodcut printmaking technique was transferred from fabric to paper in the old master print and popular prints. The first known mill in England was set up by John Tate in 1490 near Stevenage in Hertfordshire,but the first commercially successful paper mill in Britain did not occur before 1588 when John Spilman set up a mill near Dartford in Kent and was initially reliant on German papermaking expertise.
Paper mills
A paper mill is a water-powered mill that pounds the pulp by the use of trip-hammers. The mechanization of the pounding process was an important improvement in paper manufacture over the manual pounding with hand pestles.
While the use of human and animal powered mills were known to Chinese and Muslim papermakers, evidence for water-powered paper mills is elusive in both of them.The general absence of the use of water-power in Muslim papermaking is suggested by the habit of Muslim authors to call a production center not a “mill”, but a “paper manufactory”.
Donald Hill has identified a possible reference to a water-powered paper mill in Samarkand, in the 11th-century work of the Persian scholar Abu Rayhan Biruni, but concludes that the passage is “too brief to enable us to say with certainty” that it refers to a water-powered paper mill.While this is seen by Halevi nonetheless as evidence of Samarkand first harnessing waterpower in the production of paper, he concedes that it is not known if waterpower was applied to papermaking elsewhere across the Islamic world at the time;Burns remains altogether sceptical given the isolated occurrence of the reference and the prevalence of manual labour in Islamic papermaking elsewhere.
The earliest certain evidence to a water-powered paper mill dates to 1282 in the Spanish Kingdom of Aragon.A decree by the Christian king Peter III addresses the establishment of a royal “molendinum”, a proper hydraulic mill, in the paper manufacturing centre of Xtiva.The crown innovation appears to be resented by the local Muslim papermakering community; the document guarantees the Muslim subjects the right to continue their way of traditional papermaking by beating the pulp manually and grants them the right to be exempted from work in the new mill.Papermaking centres began to multiply in the late 13th century in Italy, reducing the price of paper to one sixth of parchment and then falling further; papermaking centers reached Germany a century later.
The first paper mill north of the Alps was established in Nuremberg by Ulman Stromer in 1390; it is later depicted in the lavishly illustrated Nuremberg Chronicle.From the mid-14th century onwards, European paper milling underwent a rapid improvement of many work processes.
Fiber sources
See also: wood pulp and deinking
Before the industrialisation of the paper production the most common fibre source was recycled fibres from used textiles, called rags. The rags was from hemp, linen and cotton.A process for removing printing inks from recycled paper was invented by German jurist Justus Claproth in 1774.Today this method is called deinking. It was not until the introduction of wood pulp in 1843 that paper production was not dependent on recycled materials.
19th century advances in papermaking
Although cheaper than vellum, paper remained expensive, at least in book-sized quantities, through the centuries, until the advent of steam-driven paper making machines in the 19th century, which could make paper with fibres from wood pulp. Although older machines predated it, the Fourdrinier paper making machine became the basis for most modern papermaking. Nicholas Louis Robert of Essonnes, France, was granted a patent for a continuous paper making machine in 1799. At the time he was working for Leger Didot with whom he quarrelled over the ownership of the invention. Didot sent his brother-in-law, John Gamble, to meet Sealy and Henry Fourdrinier, stationers of London, who agreed to finance the project. Gamble was granted British patent 2487 on 20 October 1801. With the help particularly of Bryan Donkin, a skilled and ingenious mechanic, an improved version of the Robert original was installed at Frogmore, Hertfordshire, in 1803, followed by another in 1804. A third machine was installed at the Fourdriniers’ own mill at Two Waters. The Fourdriniers also bought a mill at St Neots intending to install two machines there and the process and machines continued to develop.
However, experiments with wood showed no real results in the late 18th-century and at the start of the 19th-century. By 1800, Matthias Koops (in London, England) further investigated the idea of using wood to make paper, and in 1801 he wrote and published a book titled Historical account of the substances which have been used to describe events, and to convey ideas, from the earliest date, to the invention of paper.His book was printed on paper made from wood shavings (and adhered together). No pages were fabricated using the pulping method (from either rags or wood). He received financial support from the royal family to make his printing machines and acquire the materials and infrastructure need to start his printing business. But his enterprise was short lived. Only a few years following his first and only printed book (the one he wrote and printed), he went bankrupt. The book was very well done (strong and had a fine appearance), but it was very costly.
Then in the 1830s and 1840s, two men on two different continents took up the challenge, but from a totally new perspective. Both Charles Fenerty and Friedrich Gottlob Keller began experiments with wood but using the same technique used in paper making; instead of pulping rags, they thought about pulping wood. And at about the same time, by mid-1844, they announced their findings. They invented a machine which extracted the fibres from wood (exactly as with rags) and made paper from it. Charles Fenerty also bleached the pulp so that the paper was white. This started a new era for paper making. By the end of the 19th-century almost all printers in the western world were using wood in lieu of rags to make paper.
Together with the invention of the practical fountain pen and the mass-produced pencil of the same period, and in conjunction with the advent of the steam driven rotary printing press, wood based paper caused a major transformation of the 19th century economy and society in industrialized countries. With the introduction of cheaper paper, schoolbooks, fiction, non-fiction, and newspapers became gradually available by 1900. Cheap wood based paper also meant that keeping personal diaries or writing letters became possible and so, by 1850, the clerk, or writer, ceased to be a high-status job.
The original wood-based paper was acidic due to the use of alum and more prone to disintegrate over time, through processes known as slow fires. Documents written on more expensive rag paper were more stable. Mass-market paperback books still use these cheaper mechanical papers (see below), but book publishers can now use acid-free paper for hardback and trade paperback books.

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Chemicals for papermaking

webadmin — Fri, 10 May 2024 05:16:15 +0000

There are various kinds of paper product,different paper product has different characteristics.Chemicals are necessary for their characteristics when paper machine produces the paper.The following are some common chemicals in papermaking.
Optical brightener
Optical brightener is used to make paper appear more white. Optical brightening agents use fluorescence to absorb invisible radiation from the ultraviolet part of the light spectrum and re-emit the radiation as light in the visible blue range. The optical brightening agent thus generates blue light that is added to the reflected light. The additional blue light offsets the yellowish tinge that would otherwise exist in the reflected light characteristics. It thus increases the brightness of the material (when the illumination includes ultraviolet radiation).
Pigment
Pigments that absorb in the yellow and red part of the visible spectrum can be added. As the dye absorbs light, the brightness of the paper will decrease, unlike the effect of an optical brightening agent. To increase whiteness, a combination of pigments and optical brightening agent are often used. The most commonly used pigments are blue and violet dyes.
Retention agent
Retention agent is added to bind fillers to the paper. Fillers, such as calcium carbonate, usually have a weak charged surface. The retention agent is a polymer with high cationic, positively charged groups. An additional feature of a retention means to accelerate the dewatering in the wire section of the paper. Polyethyleneimine and polyacrylamide are examples of chemicals used.
Caustic soda
Caustic soda is added to increase the pH in the pulping process of fibers. The higher pH of the paper fiber solution causes the fibers to smoothen and swell, which is important for the grinding process of the fibers.
Sizing agent
Internal sizing of paper, most paper types must have some water-resistance in order to have a specific writing quality and / or printability. Until 1980 mainly a rosin in combination with alum was used. When the paper industry started using chalk instead of china clay as filler, the paper chemistry had to switch to a neutral process. Today mainly AKD (alkyl ketene dimer) and ASA (alkenyl succinic anhydride) are used.
Wet strength additive
Wet strength additives ensure that when the paper becomes wet, it retains its strength. This is especially important in a tissue paper. Typical chemicals used are as epichlorohydrin, melamine, urea formaldehyde and polyimines. These substances polymerize in the paper and result in construction of a strengthening network.
Dry strength additive
Dry strength additives, or dry strengthening agents are chemicals that improve paper strength of normal or not wet condition. Those strength including compression strength, bursting strength, tensile breaking strength, delamination resistance etc. Typical chemicals used are as cationic starch and polyacrylamide (PAM) delivertives. These substances act as binder of fibers, often under aid of aluminum ion in paper sheet.
Cationic starch
To enhance the paper strength, cationic starch is added to wet pulp in the manufacturing process. Starch has a similar chemical structure as the cellulose fibre of the pulp, and the surface of both the starch and fibre are negatively charged. By adding cationic (positive charged) starch, the fibre can bind with the starch and thus also increase the interconnections between the fibres. The positively-charged portion of the starch is usually formed by quaternary ammonium cations. Quaternary salts that are used include 2.3-epoxy propyl trimethyl ammoniumchloride (EPTAC, also known as or Glytac Quab) and (3-chloro-2-hydroxypropyl) trimethyl ammonium chloride (CHPTAC, also known as Quat 188).
Mineral Fillers
China Clay, Calcium carbonate
Coating binders
Styrene butadiene latex, Styrene acrylic, dextrin, oxidized starch
Pulping chemicals
For the production of chemical pulp from wood chips, following chemicals can be used:
Caustic soda, Sodium sulfide for the Kraft process
Sulfurous acid for the Sulfite process
Caustic soda, Anthraquinone for the Soda pulping
Bleaching chemicals
Sodium dithionite, Chlorine dioxide, Hydrogen peroxide, Ozone
Bleaching additives
Sodium silicate
Sequestering agents: EDTA, DTPA

Paper Types-Tissue paper

webadmin — Sat, 10 Feb 2024 05:14:58 +0000

Tissue pper is a lightweight paper or, light crepe paper. Tissue can be made both from virgin and recycled paper pulp.
Properties
Key properties are: Absorbency, basis weight, thickness (bulk), brightness, stretch, appearance and comfort.
Production
Main article: Fourdrinier machine
Tissue paper is produced on a paper machine that has a single large steam heated drying cylinder (yankee dryer) fitted with a hot air hood. The raw material is paper pulp. The yankee cylinder is sprayed with adhesives to make the paper stick. Creping is done by the yankee’s doctor blade that is scraping the dry paper off the cylinder surface. The crinkle (creping) is controlled by the strength of the adhesive, geometry of the doctor blade, speed difference between the yankee and final section of the paper machine and paper pulp characteristics.
The highest water absorbing applications are produced with a through air drying (TAD) process. These papers contain high amounts of NBSK and CTMP. This gives a bulky paper with high wet tensile strength and good water holding capacity.The TAD process uses about twice the energy compared with conventional drying of paper.
The properties are controlled by pulp quality, creping and additives (both in base paper and as coating). The wet strength is often an important parameter for tissue paper.
Applications
Hygienic tissue paper
Hygienic tissue paper is commonly used for facial tissue (paper handkerchiefs), napkins, bathroom tissue and household towels. Paper has been used for hygiene purposes for centuries, but tissue paper as we know it today was not produced in USA before the mid-1940s. In Western Europe large scale industrial production started in the beginning of 1960s.
Facial tissues
A box of facial tissues
Facial tissue (paper handkerchiefs) refers to a class of soft, absorbent, disposable paper that is suitable for use on the face. The term is commonly used to refer to the type of facial tissue, usually sold in boxes, that is designed to facilitate the expulsion of nasal mucus from the nose although it may refer to other types of facial tissues including napkins and wipes.
The first tissue handkerchiefs were introduced in the 1920s. They have been refined over the years, especially for softness and strength, but their basic design has remained constant. Today each person in Western Europe uses about 200 tissue handkerchiefs a year, with a variety of ‘alternative’ functions including the treatment of minor wounds, the cleaning of face and hands and the cleaning of spectacles.
The importance of the paper tissue on minimising the spread of an infection has been highlighted in light of fears over a swine flu epidemic. In the UK, for example, the Government ran a campaign called Catch it, bin it, kill it, which encouraged people to cover their mouth with a paper tissue when coughing or sneezing.
Paper towels
Paper towels are the second largest application for tissue paper in the consumer sector. This type of paper has usually a basis weight of 20 to 24 g/m2. Normally such paper towels are two-ply. This kind of tissue can be made from 100% chemical pulp to 100% recycled fibre or a combination of the two. Normally, some long fibre chemical pulp is included to improve strength.
Wrapping Tissue
Wrapping tissue is a type of thin, translucent paper used for wrapping presents and cushioning fragile items.
Toilet Tissue
Rolls of toilet paper have been available since the end of the 19th century. Today, more than 20 billion rolls of toilet tissue are used each year in Western Europe.
Table napkins
Table napkins can be made of tissue paper. These are made from one up to four plies and in a variety of qualities, sizes, folds, colours and patterns depending on intended use and prevailing fashions. The composition of raw materials varies a lot from deinked to chemical pulp depending on quality. Tablet tissue papers also available in the market.
The Industry
Out of the world’s estimated production of 21 million tonnes of tissue, Europe produces approximately six million tonnes.
The European tissue market is worth approximately 10 billion Euros annually and is growing at a rate of around 3%. The European market represents around 23% of the global market. Of the total paper and board market tissue accounts for 10%. In North America, people are consuming around three times as much tissue as in Europe.[7]
In Europe, the industry is represented by The European Tissue Symposium (ETS), a trade association. The members of ETS represent the majority of tissue paper producers throughout Europe and about 90% of total European tissue production. ETS was founded in 1971 and is based in Brussels since 1992.
Sustainability
The paper tissue industry, along with the rest of the paper manufacturing sector, has worked hard to minimise its impact on the environment. Recovered fibres now represent some 46.5% of the paper industry’s raw materials. The industry relies heavily on biofuels (about 50% of its primary energy) and it is highly energy-efficient. Its specific primary energy consumption has decreased by 16% and the specific electricity consumption has decreased by 11%, due to measures such as improved process technology and investment in combined heat and power (CHP). Specific carbon dioxide emissions from fossil fuels decreased by 25% due to process-related measures and the increased use of low-carbon and biomass fuels. Once consumed, most forest-based paper products start a new life as recycled material or biofuel
EDANA, the trade body for the non-woven absorbent hygiene products industry (which includes products such as household wipes for use in the home) has reported annually on the industry’s environmental performance since 2005. The industry’s impact on the environment is, in fact, relatively small. For example, less than 1% of all commercial wood production ends up as wood pulp in absorbent hygiene products. In addition, the industry contributes less than 0.5% of all solid waste and around 2% of municipal solid waste (MSW) compared with paper and board, garden waste and food waste which each comprise between 18 and 20 percent of MSW.
There has been a great deal of interest, in particular, in the use of recovered fibres to manufacture new tissue paper products. However, whether this is actually better for the environment than using new fibres is open to question. A Life Cycle Assessment study indicated that neither fibre type can be considered environmentally preferable. In this study both new fibre and recovered fibre offer environmental benefits and shortcomings.
Total environmental impacts vary case by case, depending on for example the location of the tissue paper mill, availability of fibres close to the mill, energy options and waste utilization possibilities. There are opportunities to minimise environmental impacts when using each fibre type.
The Confederation of European Paper Industries has published reports focusing on the industry’s environmental credentials. In 2002, it noted that a little over 60% of the pulp and paper produced in Europe comes from mills certified under one of the internationally recognised eco-management schemes.There are a number of ‘eco-labels’ designed to help consumers identify paper tissue products which meet such environmental standards. Eco-labelling entered mainstream environmental policy-making in the late seventies, first with national schemes such as the German Blue Angel programme, to be followed by the Nordic Swan (1989). In 1992 a European eco-labelling regulation, known as the EU Flower, was also adopted. The stated objective is to support sustainable development, balancing environmental, social and economical criteria.

Paper Types-Coated paper

webadmin — Wed, 10 Jan 2024 05:12:50 +0000

Coated paper is paper which has been coated by a compound or polymer to impart certain qualities to the paper, including weight, surface gloss, smoothness or reduced ink absorbency. Kaolinite, calcium carbonate, Bentonite, talc…are used to coat paper for high quality printing used in packaging industry and in magazines. The chalk or china clay is bound to the paper with synthetic viscofiers, such as styrene-butadiene latexes and natural organic binders such as starch. The coating formulation may also contain chemical additives as dispersants, resins, PE: to give water resistance and wet strength to the paper,or to protect against ultraviolet radiation.
Varieties
Machine-finished coated paper
Machine-finished coated paper (MFC) has a basis weight of 48-80 g/m2. They have good surface properties, high print gloss and adequate sheet stiffness. MFC papers are made of 60-85% groundwood or TMP and 15-40% chemical pulp with a total pigment content of 20-30%. The paper can be soft nip calendered or supercalendered.These are often used in paperbacks.
Coated fine paper
Coated fine paper or woodfree coated paper (WFC) are mainly produced for offset printing:
Standard coated fine papers
This paper quality is normally used for advertising materials, books, annual reports and high quality catalogs. Grammage ranges from 90-170 g/m2 and ISO brightness between 80-96%. The fibre furnish consists of more than 90% chemical pulp. Total pigment content are in the range 30-45%, where calcium carbonate and clay are the most common.
Low coat weight papers
These paper grades have lower coat weights than the standard WFC (3-14 g/m2/side) and the grammage and pigment content are also generally lower, 55-135 g/m2 and 20-35% respectively.
Art papers
Art papers are one of the highest quality printing papers and are used for illustrated books, calendars and brochures. The grammage varies from 100 to 230 g/m2. These papergrades are triple coated with 20 – > 40 g/m2/side and have matte or glossy finish. Higher qualities often contain cotton.
Others
Other types of paper coatings include polyethylene or polyolefin extrusion coating, silicone, and wax coating to make release liners, paper cups and photographic paper. Biopolymer coatings are available as more sustainable alternatives to common petrochemical coatings.

Duplex Board

webadmin — Mon, 20 Nov 2023 08:47:17 +0000

A duplex board is a sheet of double-ply paper, similar to the kind of thick paper used to make cards. Duplex board is often used in packaging and has a distinctly smooth, almost waxy feel.
Duplex board is a kind of paperboard or cardboard. It is called duplex board because it is made up of two layers, or plies. The exterior of the board is very often coated to make it more water-resistant and to give it a glossy sheen, but even uncoated duplex board is strong enough to make disposable cups.
Duplex board is tough, thin and able to take on a bright white appearance, unlike common corrugated cardboard. It is commonly used to create boxes for a variety of small goods. For example, it is often used in pharmaceutical packaging. It is also used to make garment boxes and cigarette packs, paper plates and cups, and in the food industry.
Milk cartons can be made out of duplex board, and wines and liquors packaged in boxes may be inside duplex board containers. Duplex board used in the food industry is not made from recycled paper for hygiene reasons, but sometimes waste paper is used when the board is designated for other purposes.
Other common uses for duplex board is match boxes, book covers, and greeting cards. This kind of duplex board is relatively lightweight.

Paper Types-Crepe paper

webadmin — Wed, 10 May 2023 05:08:47 +0000

Crepe paper is tissue paper that has been coated with sizing (a glue-like substance) and then creped (creased in a way similar to party streamers) to create gathers.
Production
Paper that is creped is produced on a paper machine that has a single large steam-heated drying cylinder (yankee) fitted with a hot-air hood. The raw material is paper pulp. The Yankee cylinder is sprayed with adhesives to make the paper stick. Creping is done by the Yankee’s doctor blade that is scraping the dry paper of the cylinder surface. The crinkle (creping) is controlled by the strength of the adhesive, geometry of the doctor blade, speed difference between the yankee and final section of the paper machine and paper pulp characteristics.
Properties
Crepe paper and tissue are among the lightest papers and are normally below 35 g/m2.
The Crepe ratio reflects how much the paper has shortened during creping. The figure is normally between 10 – 30%. Creping is used to adjust the paper’s stretch and thickness, both of which have a marked effect on softness and absorbency.
Creping can also be applied to specialty papers, such as microcreping in sack paper.
Applications
Crepe paper is popular for streamers and other party decorations.
Props and costume accessories can be made of Crepe paper. It can be soaked in a small amount of water to create a dye for Easter eggs, white cardstock, and other materials
Crepe paper can also be used to make paper flowers, appliqu, and paper sculpture.
Crepe paper is important as the backing for various types of tape, including masking tape and electrical tape.
Can be used in place of corn husks to make tamales.
In the former Soviet Union, undyed, unbleached Crepe paper is widely used for toilet paper
Used in recovery systems in small model rockets.
Crepe paper is one of the main components used in costume building for Junkanoo the most popular street parade in the Bahamas.

Paper Types-Newsprint

webadmin — Wed, 03 May 2023 05:11:57 +0000

Newsprint is a low-cost, non-archival paper most commonly used to print newspapers, and other publications and advertising material.Also called newspaper. Invented in 1844 by Charles Fenerty, it usually has an off-white cast and distinctive feel. It is designed for use in printing presses that employ a long web of paper (web offset, letterpress and flexographic) rather than individual sheets of paper. Newsprint mainly consists of wood pulp.
Newsprint is favored by publishers and printers as it is relatively low cost (compared with paper grades used for glossy magazines and sales brochures), strong (to run through modern high-speed web printing presses) and can accept four-color printing at qualities that meet the needs of typical newspapers.
Use
The web of paper is placed on the press in the form of a roll delivered from a paper mill (surplus newsprint can also be cut into individual sheets by a processor for use in a variety of other applications such as wrapping or commercial printing). World demand of newsprint in 2006 totaled about 37.2 million metric tonnes, according to the Montreal-based Pulp & Paper Products Council (PPPC). This was about 1.6% less than in 2000. Between 2000 and 2006, the biggest changes were in Asia which saw newsprint demand grow by about 20%and North America, where demand fell by about 25%. Demand in China virtually doubled during the period, to about 3.2 million metric tonnes.
About 35% of global newsprint usage in 2006 was in Asia, with approximately 26% being in North America and about 25% in Western Europe. Latin America and Eastern Europe each represented about 5% of world demand in 2006, according to PPPC, with smaller shares going to Oceania and Africa.
Among the biggest factors depressing demand for newsprint in North America have been the decline in newspaper readership among many sectors of the population particularly young adults along with increasing competition for advertising business from the Internet and other media. According to Newspaper Association of America, the United States U.S. newspaper trade group, average U.S. daily circulation in 2006 on a typical weekday was 52.3 million (53.2 million on Sundays), compared with 62.5 million in 1986 (58.9 million on Sundays) and 57.0 million in 1996 (60.8 million on Sundays). According to NAA, daily ad revenues (not adjusted for inflation) reached their all-time peak in 2000, and by 2007 had fallen by 13%. Newsprint demand has also been affected by attempts on the part of newspaper publishers to reduce marginal printing costs through various conservation measures intended to cut newsprint usage.
While demand has been trending down in North America in recent years, the rapid economic expansion of such Asian countries as China and India greatly benefited the print newspaper, and thus their newsprint suppliers. According to the World Association of Newspapers, in 2007 Asia was the home to 74 of the worlds 100 highest-circulation dailies. With millions of Chinese and Indians entering the ranks of those with disposable income, newspapers have gained readers along with other news media.
Newsprint is used worldwide in the printing of newspapers, flyers, and other printed material intended for mass distribution. In the U.S., about 80% of all newsprint that is consumed is purchased by daily newspaper publishers, according to PPPC. Dailies use a large majority of total demand in most other regions as well.
Typically in North America, newsprint is purchased by a daily newspaper publisher and is shipped from the mill to the publisher’s pressroom or pressrooms, where it is used to print the main body of the newspaper (called the run-of-press, or ROP, sections). The daily newspaper publisher may also be hired by outside companies such as advertisers or publishers of weekly newspapers or other daily newspapers to produce printed products for those companies using its presses. In such cases the press owner might also purchase newsprint from the mill for such contract printing jobs.
For the roughly 20% of demand which is not purchased by a daily newspaper, common end-uses include the printing of weekly newspapers, advertising flyers and other printed products, generally by a commercial printer’a company whose business consists largely of printing products for other companies using its presses. In such a case, the newsprint may be purchased by the printer on behalf of an advertiser or a weekly newspaper publisher, or it may be purchased by the client and then ordered to be shipped to the printer’s location.
Economic issues
The biggest inputs to the newsprint manufacturing process are energy, fiber and labor. According to the Newsprint Producers Association, a North American trade group affiliated with the Pulp & Paper Products Council, the average North American newsprint mill in 2005 spent 31% of its mill-level budget in fiber and pulp, 24% on energy, 22% on labor and 19% on various other materials, with the balance including other raw materials and miscellaneous costs.[citation needed] Mill operating margins have been significantly affected in the 2006 C2008 time-frame by rising energy costs. Many mills’fiber costs have also been affected during the U.S. housing market slowdown of 2007 C8 by the shutdown of many sawmills, particularly in Canada, since the virgin fiber used by mills generally comes from nearby sawmills in the form of wood chips produced as a residual product of the saw milling process.
Distribution
Another cost consideration in the newsprint business is delivery, which is affected by energy cost trends. Newsprint around the world may be delivered by rail or truck; or by barge, container or break-bulk shipment if a water delivery is appropriate. (Aside from delivery cost, another consideration in selecting freight mode may be the potential for avoiding damage to the product.) All things being equal, for domestic shipments in areas like North America or Europe where modern road and rail networks are readily available, trucks can be more economical than rail for short-haul deliveries (a day or less from the mill), while rail may be more economical for longer shipments. The cost-competitiveness of each freight mode for a specific mill’s business may depend on local infrastructure issues, as well as the degree of truck-vs-freight competition in the mill’s region. The appropriate freight mode for delivery from a mill to a specific pressroom can also depend on the press room ability to accept enough trucks or rail cars.
Manufacturing
Main articles: Wood pulp and Paper machine
Newsprint is generally made by a mechanical milling process, without the chemical processes that are often used to remove lignin from the pulp. The lignin causes the paper to become brittle and yellow when exposed to air and or sunlight. Traditionally, newsprint was made from fibers extracted from various softwood species of trees (most commonly, spruce, fir, balsam fir or pine). However, an increasing percentage of the world’s newsprint is made with recycled fibers.

Paper Types-copy paper

webadmin — Fri, 10 Jun 2022 05:07:33 +0000

Copy paper
Copy paper is used for copying and laser printers. The basis weight is 70-90 g/m² and ISO brightness 80-96%. It is made of 90 C100% virgin chemical pulp or 100% deinked pulp with total pigment content of 10-15%. The most important quality is smooth run in a copying machine / printer and good dimensional stability. It must not show curling nor cockling nor retain dust.

Chemicals in papermaking

webadmin — Tue, 10 May 2022 05:04:41 +0000

Paper machine needs different chemicals when papermaking.Chemicals are a group of chemicals that are used to influence paper properties.
Optical brightening agent
Optical brightener is used to make paper appear more white when Paper machine make paper. Optical brightening agents use fluorescence to absorb invisible radiation from the ultraviolet part of the light spectrum and re-emit the radiation as light in the visible blue range. The optical brightening agent thus generates blue light that is added to the reflected light. The additional blue light offsets the yellowish tinge that would otherwise exist in the reflected light characteristics. It thus increases the brightness of the material (when the illumination includes ultraviolet radiation).
Pigment
Pigments that absorb in the yellow and red part of the visible spectrum can be added. As the dye absorbs light, the brightness of the paper will decrease, unlike the effect of an optical brightening agent. To increase whiteness, a combination of pigments and optical brightening agent are often used. The most commonly used pigments are blue and violet dyes.
Retention agent
Retention agent is added to bind fillers to the paper. Fillers, such as calcium carbonate, usually have a weak charged surface. The retention agent is a polymer with high cationic, positively charged groups. An additional feature of a retention means to accelerate the dewatering in the wire section of the paper. Polyethyleneimine and polyacrylamide are examples of chemicals used.
Caustic soda
Caustic soda is added to increase the pH in the pulping process of fibers. The higher pH of the paper fiber solution causes the fibers to smoothen and swell, which is important for the grinding process of the fibers.
Sizing agent
Internal sizing of paper, most paper types must have some water-resistance in order to have a specific writing quality and / or printability. Until 1980 mainly a rosin in combination with alum was used. When the paper machine industry started using chalk instead of china clay as filler, the paper chemistry had to switch to a neutral process. Today mainly AKD (alkyl ketene dimer) and ASA (alkenyl succinic anhydride) are used.
Wet strength additive
Wet strength additives ensure that when the paper becomes wet, it retains its strength. This is especially important in a tissue paper. Typical chemicals used are as epichlorohydrin, melamine, urea formaldehyde and polyimines. These substances polymerize in the paper and result in construction of a strengthening network.
Dry strength additive
Dry strength additives, or dry strengthening agents are chemicals that improve paper strength of normal or not wet condition. Those strength including compression strength, bursting strength, tensile breaking strength, delamination resistance etc. Typical chemicals used are as cationic starch and polyacrylamide (PAM) delivertives. These substances act as binder of fibers, often under aid of aluminum ion in paper sheet.
Cationic starch
To enhance the paper strength, cationic starch is added to wet pulp in the manufacturing process. Starch has a similar chemical structure as the cellulose fibre of the pulp, and the surface of both the starch and fibre are negatively charged. By adding cationic (positive charged) starch, the fibre can bind with the starch and thus also increase the interconnections between the fibres. The positively-charged portion of the starch is usually formed by quaternary ammonium cations. Quaternary salts that are used include 2.3-epoxy propyl trimethyl ammoniumchloride (EPTAC, also known as or Glytac Quab) and (3-chloro-2-hydroxypropyl) trimethyl ammonium chloride (CHPTAC, also known as Quat 188).
Mineral Fillers
China Clay, Calcium carbonate
Coating binders
Styrene butadiene latex, Styrene acrylic, dextrin, oxidized starch
Pulping chemicals
For the paper machine production of chemical pulp from wood chips, following chemicals can be used:
Caustic soda, Sodium sulfide for the Kraft process
Sulfurous acid for the Sulfite process
Caustic soda, Anthraquinone for the Soda pulping
Bleaching chemicals
Sodium dithionite, Chlorine dioxide, Hydrogen peroxide, Ozone
Bleaching additives:
Sodium silicate
Sequestering agents: EDTA, DTPA

Testliner Paper

webadmin — Sun, 20 Mar 2022 08:51:32 +0000

The term testliner refers to papers of different bursting strengths. Since some grades of testliner have lower burst factors due to containing high amounts of recycled fibres, the lower grades of testliner are often associated with recycled fibres.
Testliner is a recycled base liner board for container board. The products consist of three layers. It is used for the inner and outer layers (face paper) of carton boxes, and is divided into three quality grades: LH, LE, LF.
Testliner is ideal for use in corrugated boards as the top and bottom layers and can also have a white top (White Top Testliner).
Testliner can be produced from 100% recycled fibres. Colouring agents give it a stable optical colour. Addition of starch guarantees the strength of Testliner and a surface treatment, involving the addition of synthetic adhesives optimizing the printability of paper.
Testliner paper can be used for the production of:
1.Food packaging
2.Packaging for consumer durables
3.Corrugated cardboard tray packaging