About 3000 chemicals used in papermaking!
Mineral Fillers – They enhance internal structure of the paper, most commonly used substances are calcium carbonate and china clay. Coating binders – Added to provide paper with the surface that will increase water retention, and thus make paper more durable. Most commonly used agents are dextrin, oxidized starch, styrene butadiene latex, and styrene acrylic. CHEMICALS USED IN PULP & PAPER MANUFACTURING AND COATING. Modified starches, Styrene Maleic Anhydride (SMA), Styrene Acrylic Emulsion (SAE), Styrene Acrylic Acid (SAA), Ethylene Acrylic Acid (EAA), Gelatin and. Polyurethane (PUR).
Paper chemicals designate a group of chemicals that are used for paper manufacturingor modify the properties of paper. These chemicals can be used to alter the paper in many ways, including changing its color and brightnessor by increasing its strength and resistance to water. Chemical pulping involves dissolving lignin in order to extract the cellulose from the wood fiber. How to test ac capacitor with analog multimeter different processes of chemical pulping include the Kraft processwhich uses caustic soda and sodium sulfide and is the most common; alternatively, the use of sulfurous acid is how to find ip address on cell phone as the sulfite processthe neutral sulfite semichemical is treated as a third process separate from sulfite, and soda pulping which is the least ecologically hazardous utilizing sodium hydroxide or anthraquinone.
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. In the production of white paper, the wood pulp is bleached to remove any color from the trace amounts of lignin that was not extracted in the chemical pulping process. There are three predominant methods of bleaching:. Most paper types must have some water-resistance to maintain a specific writing quality and printability.
Untilthe typical manner of adding this resistance was by using a rosin in combination with alum. When the paper industry started using chalk instead of china clay as filler, the paper chemistry had to switch to a neutral process. Wet-strength additives ensure that paper retains its strength when it gets wet.
This is especially important in tissue paper. Chemicals typically used for this purpose include epichlorohydrinmelamineurea formaldehyde and polyimines. These substances polymerize in the paper and result in the construction of a strengthening network.
To enhance the paper's 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. Dry-strength additives, or dry-strengthening agents, are chemicals that improve paper strength normal conditions. These improve the paper's compression strengthbursting strengthtensile breaking strengthand delamination resistance. Typical chemicals used include cationic starch and polyacrylamide PAM derivatives. These substances work by binding fibers, often under the aid of aluminum ions in paper sheet.
Binders promote the binding of pigment particles between themselves and the coating layer of the paper. Common binders are styrene maleic anhydride copolymer or styrene-acrylate copolymer.
Some common examples are carboxymethyl cellulose CMCcationic and anionic hydroxyethyl cellulose EHECmodified starchand dextrin. Styrene butadiene latex, Styrene acrylic, dextrinoxidized starch are used in coatings to bind the filler to the paper. Co-binders are natural products such as starch and CMC Carboxymethyl cellulosethat are used along with the synthetic binders, like styrene acrylic or styrene butadiene.
Co-binders are used to reduce the cost of the synthetic binder and improve the water retention and rheology of the coating.
Mineral fillers are used to lower the consumption of more expensive binder material or to improve some properties of the paper. A Retention agent is added to bind fillers to the paper. Fillers, such as calcium carbonateusually have a weak surface charge. The retention agent is a polymer with high cationic, positively charged groups.
An additional feature of a retention agent is to accelerate the dewatering in the wire section of the paper machine.
Polyethyleneimine and polyacrylamide are examples of chemicals used in this process. 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 what is cat 7 ethernet cable optical-brightening agent.
To increase whiteness, a combination of pigments and an optical-brightening agent are often used. The most commonly used pigments are blue and violet dyes. Optical brightener is used to make paper appear whiter.
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.
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Chemistry portal. In Lahre, Thomas ed. Environmental Protection Agency. ISBN Retrieved 7 September Washington, D. October Institute of Quimica : what chemicals are in paper Tappi J. January CS1 maint: uses authors parameter link. Battle of Talas. Category Commons. Categories : Papermaking Chemical processes Cellulose Pulp and paper industry.
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Namespaces Article Talk. Views What chemicals are in paper Edit View history. Help Learn to edit Community portal Recent changes Upload file. Download as PDF Printable version. Diethylene Triamine Penta Acetate. Formamidine Sulphuric Acid or Thiourea Dioxide. Gypsum or Mineral White or Plaster. Hydrogen Peroxide. Calcium Carbonate. Magnesium bisulfite. Magnesium Carbonate. Calcium Hydroxide. Magnesium Hydroxide.
Abietic Acid. Makeup chemical in sulfate pulping chemical recovery Na 2 SO 4. Sodium Carbonate. An acid type cooking liquor chemical component sometimes used to neutralized residual chlorine in the pulp during the bleaching process.
Sodium Hydrosulfite. Na O Cl. Sodium tripolyphosphate. Titanium Dioxide. MA : NDL :
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Thus, paper is made mostly out of organic compounds: that is carbon, hydrogen and oxygen (C, H and O). Paper also contains non organic materials to improve its properties. These may be chalk (CaCO 3) and kaolin clay (Al 2 Si 2 O 5 (OH) 4). Titanium oxide (TiO 2) .
While there are about or so different types of chemicals which "can be used" in papermaking, in practice only about individual chemicals are typically used, each satisfying a specific need. In world paper industry used Following is a breakup of various pigment usage. Grades of Paper. Grades of Pulp. Grades of Waste Paper. Basis Weight. Paper Density. Pulp Properties. Bleaching Sequences. Paper ISO Sizes. Paper Properties.
Length of Paper In Roll. Paper Defects. Paper Thickness. Paper Calculators. It gives paper a greasy or soapy feel. Al 2 SO4 3. A calcium salt that is used for a variety of purposes including: building materials. Blanc fixe, fast white, pearl white or permanent white. Pigment coating Binder.
Casein is a heterogeneous globular, amphoteric phosphoprotein. Used for chelation removal of transition metals from pulp. Makeup chemical in sulfate pulping chemical recovery Na 2 SO 4. An acid type cooking liquor chemical component sometimes used to neutralized residual chlorine in the pulp during the bleaching process.
In waste paper deinking for wetting, peptization, ink dispersion, peroxide stabilization. Comprised of glucose units linked together by oxygen bridges called glycosides. Filler to increase the opacity and brightness of paper. Used in coating also. Grade of titanium oxide paper coating pigments which is water dispersible.