«*» RUKHSANA«*» Properties of Paper

 

Basis Weight (GSM) The weight or substance per unit area is obviously fundamental in paper and paper board products. The Basis weight of paper is the weight per unit area. This can be expressed as the weight in grams per square metre (GSM or g/M2), pounds per 1000 sq. ft. or weight in kgs or pounds per ream (500 sheets) of a specific size. REAM WEIGHT is a common term to signify the weight of a lot or batch of paper. Control of basis weight is important as all other properties are affected. Variations in moisture content in paper affects the grammage. Brightness, Whiteness and Colour Brightness is defined as the percentage reflectance of blue light only at a wavelength of 457 nm. Whiteness refers to the extent that paper diffusely reflects light of all wave lengths throughout the visible spectrum. Whiteness is an appearance term. Colour is an aesthetic value. Colour may appear different when viewed under a different light source. Brightness is an arbitrarily defined, but carefully standardised, blue reflectance that is used throughout the pulp and paper industry for the control of mill processes and in certain types of research and development programs. Brightness is not whiteness. However, the brightness values of the pulps and pigments going into the paper provide an excellent measure of the maximum whiteness that can be achieved with proper tinting. The colour of paper, like of other materials, depends in a complicated way on the characteristics of the observer and a number of physical factors such as the spectral energy distribution of the illuminant, the geometry of illuminating and viewing, the nature and extent of the surround and the optical characteristics of the paper itself. Bulk Bulk is a term used to indicate volume or thickness in relation to weight. It is the reciprocal of density (weight per unit volume). It is calculated from caliper and basis weight. Sheet bulk relates to all other sheet properties. Decrease the bulk or in other words increase the density, and the sheet gets smoother, glossier, less opaque, darker, lower in strength etc. Dimensional Stability An important consequence of the absorption and de-absorption of moisture by paper is the change in dimension that usually accompanies changes in moisture content. Such changes in dimension may seriously affect register in printing processes and interfere with the use of such items as tabulating cards. Uneven dimensional changes cause undesirable cockling and curling. Dimensional changes in paper originate in the swelling and contraction of the individual fibres. It has been observed that cellulosic fibres swell in diameter from 15 to 20% in passing from the dry condition to the fibre saturation point. It is impossible to be precise about the degree of this swelling because paper-making fibres differ considerably in this property, and because the irregular cross-section of fibres creates difficulty in defining diameter. Change that occurs in the dimensions of paper with variation in the moisture content is an important consideration in the use of paper. All papers expand with increased moisture content and contract with decreased moisture content, but the rate and extent of changes vary with different papers. Folding Endurance (Double Folds) Folding endurance is the paper's capability of withstanding multiple folds before it breaks. It is defined as the number of double folds that a strip of 15 mm wide and 100 mm length can withstand under a specified load before it breaks. It is important for printing grades where the paper is subjected to multiple folds like in books, maps, or pamphlets. Fold test is also important for carton, box boards, ammonia print paper, and cover paper etc. Folding endurance is a requirement in Bond, Ledger, Currency, Map, Blue Print and Record Papers. Formation Formation is an indicator of how the fibres and fillers are distributed in the sheet. Formation plays an important role as most of the paper properties depend on it. Paper that is poorly formed will have weak, thin spots and thick spots. These will affect properties like caliper, opacity, strength etc. Paper formation also affects the coating capabilities and printing characteristics of the paper. Gloss It is the specularly and diffusely reflected light component measurement against a known standard. Gloss is important for printing such things as magazine advertisements. The level of gloss desired is very dependent on the end use of the paper. Gloss and smoothness are different properties and are not dependent on each other. Machine and Cross Direction Paper has a definite grain direction due to greater orientation of fibres in the direction of travel of the paper machine. This grain direction is known as machine direction. The cross direction is the direction of paper at right angles to the machine direction. Some of the properties vary with the MD and CD and hence the values are reported in both the directions. While sheeting the paper, machine and cross direction are to be kept in mind and the sheet cutting to be done to suit the end use requirements. Examples: 1. All printing papers are to be cut in long grain (The biggest dimension in the grain direction). 2. Book papers fold better and the book stays open better if the sheets are out so that the machine direction runs up and down the pages. 3. Wrap around labels for metal cans and bottles are to be cut with the machine direction vertical to obtain greater flexibility about the can. Long grain and Short grain : The sheet is in long grain if the larger dimension is parallel to grain (MD) direction. The sheet is said to be in short grain if the larger dimension is parallel to cross direction (CD). Moisture Most physical properties of paper undergo change as a result of variations in moisture content. Water has the effect of plasticising the cellulose fibre and of relaxing and weakening the interfibre bonding. The electrical resistance and the dielectric constant of paper both vary with moisture content. The absorption and reflectance of certain bands of infrared and microwave radiation by paper are affected by its moisture content. The amount of water present in a sheet of paper is usually expressed as a percent. The amount of water plays an important role in calendaring, printing and converting process. Moisture control is also significant to the economic aspect of paper making. Poor moisture control can adversely affect many paper properties. Opacity Opacity is the measure of how much light is kept away from passing through a sheet. A perfectly opaque paper is the one that is absolutely impervious to the passage of all visible light. It is the ratio of diffused reflectance and the reflectance of single sheet backed by a black body. Opacity is important in Printing Papers, Book Papers, etc. Porosity Because paper is composed of a randomly felted layer of fibre, it follows that the structure has a varying degree of porosity. Thus, the ability of fluids, both liquid and gaseous, to penetrate the structure of paper becomes a property that is both highly significant to the use of paper. Paper is a highly porous material and contains as such as 70% air. Porosity is a highly critical factor in Printing Papers Laminating Paper, Filter Paper, Cigarette Paper. Bag Paper, Antitarnish Paper and Label Paper. Porosity is the measurement of the total connecting air voids, both vertical and horizontal, that exists in a sheet. Porosity of sheet is an indication of absorptivity or the ability of the sheets to accept ink or water. Porosity can also be a factor in a vacuum feeding operation on a printing press. Sizing / Cobb Because paper is composed of a randomly felted layer of fibre, it's structure has a varying degree of porosity. Thus, the ability of fluids, both liquid and gaseous, to penetrate the structure of paper becomes a property that is both highly significant to the use of paper. The need to limit the spreading of ink resulted in "sizing" the paper with gelatinous vegetable materials which had the effect of sealing or filling the surface pores. Later, the term "sizing" was applied to the treatment of paper stock prior to the formation of the sheet, with water-repellent materials such as rosin or wax. Resistance towards the penetration of aqueous solution / water is measured by Sizing or Cobb values. Smoothness Smoothness is concerned with the surface contour of paper. It is the flatness of the surface under testing conditions which considers roughness, liveliness, and compressibility. In most of the uses of paper, the character of the surface is of great importance. It is common to say that paper has a "smooth" or a "rough" texture. The terms "finish" and "pattern" are frequently used in describing the contour or appearance of paper surfaces. Smoothness in important for writing, where it affects the ease of travel of the pen over the paper surface. Finish is important in bag paper as it is related to the tendency of the bag to slide when stacked. Smoothness of the paper will often determine whether or not it can be successfully printed. Smoothness also gives eye appeal as a rough paper is unattractive. Stiffness Stiffness is the measure of force required to bend a paper through a specified angle. Stiffness is an important property for box boards, corrugating medium and to certain extent for printing papers also. A limpy and flimsy paper can cause feeding and delivery problems in larger sheet presses. A sheet that is too stiff will cause problems in copier machines where it must traverse over, under, and around feed rollers. Bond papers also require certain stiffness to be flat in typewriters etc. Stretch (Elongation) Stretch is the amount of distortion which paper undergoes under tensile stress. Stretchlelongation is usually expressed, as percent stretch to rupture. Stretch can be related to the paper's ability to conform and maintain conformance to a particular contour, e.g. Copier paper, multicolor offset printing papers, liquids packing cartons base papers etc. It is an important property in sack kraft papers which are used for cement bags etc. Stretch is higher in cross direction than machine direction. Tearing Resistance Tearing resistance indicates the behaviour of paper in various end use situations; such as evaluating web runnability, controlling the quality of newsprint and characterising the toughness of packaging papers where the ability to absorb shocks is essential. fibre length and interfibre bonding are both important factors in tearing strength. The fact that longer fibres improve tear strength is well recognised. The explanation is straight forward; longer fibres tend to distribute the stress over a greater area, over more fibres and more bonds, while short fibres allow the stress to be concentrated in a smaller area. Temperature and Humidity: Conditioning of Paper Conditioning of paper is also of importance in many printing and converting operations. In addition to the effect of moisture content on physical properties, it also determines the build up of static of the paper sheet subjected to pressure and to friction. The tendency for paper to develop static becomes greater with increasing dryness. Cellulosic fibres are hygroscopic i.e. they are capable of absorbing water from the surrounding atmosphere. The amount of absorbed water depends on the humidity and the temperature of the air in contact with the paper. Hence, changes in temperature and humidity, even slight changes, can often affect the test results. So, it is necessary to maintain standard conditions of humidity and temperature for conditioning. Thickness Thickness or Caliper of paper is measured with a micrometre as the perpendicular distance between two circular, plane, parallel surfaces under a pressure of 1 kg./ CM2. Caliper is a critical measurement of uniformity. Variations in caliper, can affect several basic properties including strength, optical and roll quality. Thickness is important in filling cards, printing papers, condenser paper, saturating papers etc. Wax Pick No. (Surface Strength) This indicates the surface strength of the paper. This test is important for all uncoated printing papers. Wire side and Felt side Also referred as wire side and top side. The side which is in contact with the paper machine wire during paper manufacture is called the wire side. The other side is top side. Certain properties differ between wire and felt side and it is customary to measure these properties on both the sides. In case of paper to be printed on one side only, best results are obtained by printing on felt side. Postage stamps are printed on wire side and then gummed on felt side, where the smoothness is helpful for attaining an even application.                         WARM REGARDS, Akhtar khatri *****help what we can with others in need...the world is ONE big family*****   ALL THE MAILS POSTED BY ME R NOT MY PROPERTY, ALL R TAKEN FROM NET, IF SOMETHING IS COPYRIGHTED PLZ INFORM ME, SO THAT I MAY NOT POST THE MATERIAL IN THE FUTURE

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«*» RUKHSANA«*» Paper Making Process

 

WARM REGARDS, Akhtar khatri *****help what we can with others in need...the world is ONE big family*****   ALL THE MAILS POSTED BY ME R NOT MY PROPERTY, ALL R TAKEN FROM NET, IF SOMETHING IS COPYRIGHTED PLZ INFORM ME, SO THAT I MAY NOT POST THE MATERIAL IN THE FUTURE

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«*» RUKHSANA«*» Paper Types......DID YOU KNOW ?

 

Paper Types Abrasive Kraft Used For : Abrasive Kraft is used for making sand paper used in roughening applications. Absorbent Kraft Used For : Used for Laminates, tube making and defence applications. Alkaline Paper Paper having pH values greater than 7 made by an alkaline manufacturing process. Anti Rust Paper Paper which has the property of protecting the surfaces of ferrous metals against rust. Antique Paper Printing paper having good bulk and opacity with rough or matt surface. Art Paper Normally, china clay (kaolin) coated on both sides of the paper. This finish of both the sides is same, be it glossy or matt. Used For : Brochures, calendars, magazine covers, magazine text, where high quality printing is required Azurelaid Paper A laid paper usually bluish green in colour having a good writing surface. Barograph Paper Red thin paper coated on one side with a white wax, so that the needle of the barograph leaves a red line on a white ground, sold in rolls and coils and to suit the type of barograph. Base Paper This paper is generally used by a converter to either coat or laminate. Different grades are available for different applications. Used For : Mostly used for converting into a value added grade Battery Jacket Used For : Used for Laminates, tube making and defence applications. Beedi Wrap Paper Used For : Used for decorative purposes in different colours. Bible Paper Thin white opaque heavily loaded, used for printing bibles. Not suitable for pen and ink, because of its absorbency. Blade Wrapper (SS) Used For : Used for making of small packs for keeping razor blades. Bond Paper This paper has good strength properties, good stiffness and good aesthetical look. The name "bond" was originally given to a paper which was used for printing bonds, stock certificates, etc. Important characteristics are finish, strength, and freeness fro Used For : Mostly used for letterheads and for image building stationery Book Paper A general term used to define a class of papers used by the book publishing industry; most commonly used for the book text paper but also for book cover paper. Business Forms Paper Paper made for the manufacture of business forms. Used For : Used for business forms and data processing such as computer printouts. Carbon Base Carbon is normally manufactured in lower grammages like 20 gsm or less. The most important property in this paper is porosity which should be controlled at about 15-20 ml/min, so that absorption leads to cost increase while less absorption makes poor quality of carbon paper which is used many a time. Carbon Paper This thin paper could be either coated on one side or both sides with dry impressionable ink. The main function being to impart an identical copy of the original on the substrate. Used For : Mostly used where more than one copy is required simultaneously. Carbonless Paper Paper stock specially treated or coated to provide copies without the use of interleaved carbon. The copy process requires mechanical pressure such as from writing or typing and sometimes a chemical reaction. Used For : Application forms, computer stationery, time saving stationery. Also used in copying applications without carbon paper. Cardboard A range of various boards such as pulp board, paste board, bristol board, ivory board, art board, chromo board in the form of a coherent sheet or web used for printing, packaging, decorating etc. Cast Coated Paper A coated paper with high gloss and absorptivity in which the coating has been allowed to harden or set while in contact with a mirror like polished chrome surface. Chromo Paper China clay (kaolin) coated on one side. The coating on one side could be glossy or matt as per requirement of the customer. Used For : Mainly used for self adhesive stickers, calendars , posters, labels and for applications where only one side has to be printed Cigarette Slide Used For : Used for making of Cigarette Slides (180-200 gsm).Pulp board are multi layer boards can be used Cigarette Tissue It is a product of fashion. Hence brightness and whiteness of paper needs to be maintained. It is highly technical. Used For : Used in bobbins of 25 mm width or so. Cinema Poster Used For : For printing Cinema posters, Wall papers Clay Coating Base Paper Used For : Used for coating with Clay for making chromo and art paper Coated Paper Paper could be coated on either or both sides. Coating applied on the paper could be as per the requirement. For example, china clay coating for glossy paper used for high quality printing or gum coated paper for use of printing stamps Used For : Could have different applications for different coated papers Copier Paper Mainly used for copying. Used extensively in photocopiers, plain paper faxes, etc. and other office stationery. Thickness could range from 70 GSM onwards. Used For : Copying, typing, plain paper faxes, general stationery Creamwove Paper Used For : Used for Computer Stationery purposes. Defence Krafts Used For : Used for Laminates, tube making and defence applications. Diary Paper Used For : Used for making of diaries and sometimes for book printing and other applications. Diazo Base Paper The process involves coating of paper with Diazo solutions and a coupler. This is exposed to ultra violet rays coming through the image. The final print is developed by making the coating alkaline. In some cases it is developed by ammonia vapour. Used For : Used for making of ammonia paper for image recording. Electrical Insulating Papers Used For : Used for Electrical insulation. Extensible Sack Kraft This paper is characterised by very high stretch and high capability to absorb tensile energy. Used For : Used for packaging in sacks, the bulk commodities. Fax Base Paper It is first coated with photo conductive zinc oxide on which images exposed. Hence electrical conductivity / resistivity is to be controlled to ensure that the image is not conducted through the paper to the other side Used For : For making Fax images Flexible Carton Board Used For : Used for making Flexible Cartons. Fluorescent Paper Used For : Used for Labels, Posters and decorative applications. Fluting Medium Used For : Used for Corrugated Board manufacturing. Foil Base Poster, Board Paper is laminated with metal foil using a suitable adhesive. Hence paper must have porosity to accept glue. Used For : Used for lamination of paper with metal foil. General Writing Paper (Note book) Paper used for Note Books should have excellent bulks because note book should appear bulky, as otherwise it will be perceived as having less number of pages. Another important factor is cobb, since writing ink must go into the paper instantly and dry. Used For : Used for note books. Glassine Paper These papers are characterised by very low porosity (air permeability less than 10 cubic cm min. Preservation of aroma and perfection against attack of external environment to the packed contents are also important qualities of the subject papers. Used For : Used for food packagings and other special wrapping applications. Greaseproof Paper These papers are characterised by very low porosity (air permeability less than 10 cubic cm min. This gives resistance to grease and moisture. Preservation of aroma and perfection against attack of external environment to the packed contents are also important qualities of the subject papers. Used For : Used for food packagings and other special wrapping applications. Gypsum Board Used For : This is used for making panel boards for interior partitions, false ceiling etc. Ice Cream Cup Used For : Used for making Ice Cream Cups. Inter Leaving Kraft Used For : Inter Leaving Kraft is used for separation of steel sheets in a stack. Kite Poster Used For : Used for decorative, purpose, Kites Label Paper Labels are normally printed on offset machine. Hence good wax pick is required. Wire side of the paper used for application of gum should have adequate porosity. Good printability, compressibility, absorbency and ink hold out give satisfactory printing. Used For : Used for printing of labels in multi colour. Laser Paper Used For : Used for printing purposes where Laser beams are used. Liner Board Used For : Used for Corrugated Board manufacturing. Metalisation Base Paper Used For : Used for vacuum metalisation for packaging applications. MICR Cheque Paper MICR stands for Magnetic Ink Character Recognition. Codes, figures and words are read by computer by magnetic field created on them. By careful formulations the paper is designed to react against a wide range of ink eradicators. It gives a characteristic coloured stain of "flare up" on contact with acid, alkali, bleach and organic solvents like acetone, benzene, ethanol. Used For : Used in making of cheques which are processed by computer. Multi Part Stationery Used For : Multi part stationery paper is used for computer applications where number of copies are printed in one attempt. Newsprint It has to be made with adequate strength properties and surface characteristics; especially wax pick. Optical properties brightness is required for better readability and appeal (with ink to paper contrast which improves readability of print) and opacity. Used For : Used for printing our daily news papers and associated issues. It is used under very stringent shop-floor conditions by the news paper blouses for printing our daily news papers and associated. One Time Carbon (OTC) Paper A carbon paper intended to be used once as opposed to many times or multiple use carbon papers. Used For : Mostly used in multi-part continuous stationery. Poly Extrusin Base Paper Used For : Used for Poly Extrusin for packaging. Sanitary Tissue Sanitary Tissues are made with rag pulp content in lower grammages from 5 gsm onward. Normal gsm range is 15 to 30. These papers are made in soft loosely felted conditions in order to obtain max. absorbency so that they can take water quickly and hold it after absorption. Made with high content of Alpha Cellulose or Rag %, they are treated with wetting agents to improve absorbency. Used For : Used as Paper Towels, napkins, toilet tissues etc. Shell Boards Used For : Used for making of Cigarette Slides (180-200 gsm).Pulp board are multi layer boards can be used Soap Wrapper Poster (ARSR) Used For : Used for Wrapping of Soaps and detergents. Soap Wrapper Poster (TDL) Used For : Used for Wrapping of Soaps and detergents. Tea Bag Paper Used For : Used for retail packing of tea. Textile Tubes and Cones Used For : Used for Laminates, tube making and defence applications. Twist Wrap tissue It possess properties of with standing breaking stress when twisted during packing of toffees. High bursting strength combined with excellent machine runnability makes it suitable for special packing operations which require papers with high twisting properties. Used For : It is used in packing of pharmaceutical products after poly lamination or coating. Wall Paper Coated with multiple colours or floral designs. Used For : Used as an alternative to paint. To give better aesthetic appeal to the walls. Yellow Pages Paper used for this needs to have high bulk (1.1 to 1.2), high tensile strength of about 2 kg/15 mm in MD and good opacity (90%) so that the fine print made on thin paper like 40 gsm would be readable on both side. Excellent reel build up is required for smooth feeding during printing. This requires every uniform profile of bulk, gsm, caliper, moisture etc. Used For : Used for printing classified addresses and information in telephone directory.                     WARM REGARDS, Akhtar khatri *****help what we can with others in need...the world is ONE big family*****   ALL THE MAILS POSTED BY ME R NOT MY PROPERTY, ALL R TAKEN FROM NET, IF SOMETHING IS COPYRIGHTED PLZ INFORM ME, SO THAT I MAY NOT POST THE MATERIAL IN THE FUTURE

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«*» RUKHSANA«*» *The cowboy and the Genie*

 

 

 *The cowboy and the Genie*

A modern day cowboy has spent many days crossing the Texas plains without water.  His horse has already died of thirst.  He’s crawling through the sand, certain that he has breathed his last breath, when all of a sudden he sees an object sticking out of the sand several yards ahead Of him. He crawls to the object, pulls it out of the sand, and discovers what looks to be an old briefcase.  He opens it and out pops a genie. But this is no ordinary genie. She is wearing a FEMA (Federal Emergency Management Agency) ID badge and a dull gray dress.  There’s a calculator in her pocketbook. She has a pencil tucked behind one ear.  â€™Well, cowboy,’ says the genie.. ‘You know how I work….You have three wishes..’ ‘I’m not falling for this,’ said the cowboy… ‘I’m not going trust a FEMA genie…’ ‘What do you have to lose? You’ve got no transportation, and it looks like you’re a goner anyway!’ The cowboy thinks about this for a minute, and decides that the genie is right. ‘OK!, I wish I were in a lush oasis with plenty of food and drink.’ ***POOF*** The cowboy finds himself in the most beautiful oasis he has ever seen, and he is surrounded with jugs of wine and platters of delicacies. ‘OK, cowpoke, what’s your second wish?’ ‘My second wish is that I was rich beyond my wildest dreams..’ ***POOF*** The cowboy finds himself surrounded by treasure chests filled with rare gold coins and precious gems. ‘OK, cowpuncher, you have just one more wish. Better make it a good one!’ After thinking for a few minutes, the cowboy says…’I wish that no matter where I go, beautiful women will want and need me.’ ***POOF*** He was turned into a tampon. The moral of the story:  If the government offers to help you, there’s going to be a string attached.

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«*» RUKHSANA«*» *HALLOO....IT'S WEEKEND *

 

 

 

 *HALLOO....IT'S WEEKEND *

 

Its the weekend! So, what have you got planned?
I'm not gonna do much,
I'm just gonna chill and hang out on my back
porch, mostly

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