Papers and Boards
Paper plays a key role in our daily life and papers have been used for many years from now. Papers are made with the pulp of the woods, which is an Eco-friendly product.
Paper is made through the following processes:
1) Pulping procedure will be done to separate and clean the fibers
2) Refining procedure will be followed after pulping processes
3) Dilution process to form a thin fiber mixture
4) Formation of fibers on a thin screened
5) Pressurization to enhance the materials density
6) Drying to eliminate the density of materials
7) Finishing procedure to provide a suitable surface for usage
Pulp and paper are made from cellulosic fibers and other plant materials. Some synthetic materials may be used to impart special qualities to the finished product. Paper is made from wood fibers, but rags, flax, cotton linters, and bagasse (sugar cane residues) are also used in some papers. Used paper is also recycled, and after purifying and sometimes deinking, it is often blended with virgin fibers and reformed again into paper. Products such as cellulose acetate, rayon, cellulose esters that are made from cellulose will be used for packaging films, explosives.
The pulping process is aimed at removing lignin without loosing fiber strength, thereby freeing the fibers and removing impurities that cause discoloration and possible future disintegration of the paper.
Paper is made through the following processes:
1) Pulping procedure will be done to separate and clean the fibers
2) Refining procedure will be followed after pulping processes
3) Dilution process to form a thin fiber mixture
4) Formation of fibers on a thin screened
5) Pressurization to enhance the materials density
6) Drying to eliminate the density of materials
7) Finishing procedure to provide a suitable surface for usage
Pulp and paper are made from cellulosic fibers and other plant materials. Some synthetic materials may be used to impart special qualities to the finished product. Paper is made from wood fibers, but rags, flax, cotton linters, and bagasse (sugar cane residues) are also used in some papers. Used paper is also recycled, and after purifying and sometimes deinking, it is often blended with virgin fibers and reformed again into paper. Products such as cellulose acetate, rayon, cellulose esters that are made from cellulose will be used for packaging films, explosives.
The pulping process is aimed at removing lignin without loosing fiber strength, thereby freeing the fibers and removing impurities that cause discoloration and possible future disintegration of the paper.
Pulping is generally carried out mechanically or chemically. The main difference between these two is that, in mechanical pulping, the fibres are separated without removing the lignin, whereas in chemical pulping, the lignin is dissolved from the wood using chemicals.
Mechanical pulping is the original form of pulping. It has been largely replaced by chemical pulping, is still used for lower grade papers such as newsprint, and is the only process used for recycled paper. Mechanical pulping relies more so on mechanical actions to separate and develop wood fibers, rather than using chemical means. electricity is the main source of energy for generating the mechanical forces necessary to produce mechanical pulp. The principle behind all mechanical pulping is to take a raw material and grind it down into individual fibers. The advantage of mechanical pulping is that it produces much higher yields than chemical pulping (90–95% of the wood ends up as usable pulp). However, a problem with leaving impurities in the pulp is that it produces a weaker paper with less resistance to aging.
Chemical pulping results in a higher quality wood pulp with longer, stronger fibres that contain fewer impurities. The waste lignin from the process can be burnt as a fuel oil substitute, often supplying power to the national grid or steam to local domestic heating plants.Unfortunately, it produces a lower yield than mechanical pulping, as the lignin has not completely dissolved and separated from the fibres. Also, no chemical pulp is produced in the UK, therefore is has to be imported
Mechanical pulping is the original form of pulping. It has been largely replaced by chemical pulping, is still used for lower grade papers such as newsprint, and is the only process used for recycled paper. Mechanical pulping relies more so on mechanical actions to separate and develop wood fibers, rather than using chemical means. electricity is the main source of energy for generating the mechanical forces necessary to produce mechanical pulp. The principle behind all mechanical pulping is to take a raw material and grind it down into individual fibers. The advantage of mechanical pulping is that it produces much higher yields than chemical pulping (90–95% of the wood ends up as usable pulp). However, a problem with leaving impurities in the pulp is that it produces a weaker paper with less resistance to aging.
Chemical pulping results in a higher quality wood pulp with longer, stronger fibres that contain fewer impurities. The waste lignin from the process can be burnt as a fuel oil substitute, often supplying power to the national grid or steam to local domestic heating plants.Unfortunately, it produces a lower yield than mechanical pulping, as the lignin has not completely dissolved and separated from the fibres. Also, no chemical pulp is produced in the UK, therefore is has to be imported
Paper is defined in weight or GSM (Grams per Square Metre). A low quality sheet used in photo copiers is often 80gsm, where as a letterhead would commonly be printed on either 100gsm or 120gsm. Papers weighing either 130gsm or 150gsm are generally used for leaflets or flyers.Anything weighing more than 170-220 gsm is generally classified as board. At this weight a second measure can be used that indicates the thickness of the sheet. This measurement is given in microns where 1 micron = 1/1000 of a millimetre. This can be confusing as different sheets may weigh the same in GSM but have different thicknesses in microns. For example a piece of balsa wood and a piece of oak may be the same thickness but will weigh very different amounts. This is due to a number of factors during the manufacture of the board. These can include the type of coating on the board, the amount of virgin fibres used or bulkiness of the raw material.
Although paper is not quite as extreme, variations can occur between printed jobs that use different boards that might weigh the same but that have different thicknesses. This is most notable in uncoated boards with cheaper grades having the same thickness but weighing less than more superior grades.
Common board weights and their approximate thicknesses are:
As it is more common for paper and board to be sold in GSM it is easier to use this measure for both paper and board grades however if in doubt, samples can always be supplied.
Although paper is not quite as extreme, variations can occur between printed jobs that use different boards that might weigh the same but that have different thicknesses. This is most notable in uncoated boards with cheaper grades having the same thickness but weighing less than more superior grades.
Common board weights and their approximate thicknesses are:
- 200gsm = 150 to 220mics
- 250gsm = 190 to 285mics
- 300gsm = 237 to 342mics
- 350gsm = 284 to 395mics
- 400gsm = 315 to 460mics
As it is more common for paper and board to be sold in GSM it is easier to use this measure for both paper and board grades however if in doubt, samples can always be supplied.
All ISO 216, ISO 217 and ISO 269 paper sizes (except some envelopes) have the same aspect ratio, √2:1, within rounding to millimetres. This ratio has the unique property that when cut or folded in half widthways, the halves also have the same aspect ratio. Each ISO paper size is one half of the area of the next larger size in the same series.
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A) Drawing papers
Layout paper - This is a thin transparent paper with a smooth surface. As it is translucent it allows the tracing of images through from one sheet onto another and is therefore used for sketching and developing ideas. Although sometimes considered as a cheaper medium because it is thin it is actually quite expensive. It can be used for all media except paints so is good for marker pens. When placed on a white background it looks like standard copier paper. It is typically 50gsm.
Tracing Paper - This is a thin transparent paper that is similar to layout paper with similar uses (developing ideas) however it is heavier (60-90gsm) and grey in appearance. As it is heavier it is preferred by draughtsmen for designing as you can scrape off ink with a craft knife if needed.
Copier Paper - At 80gsm this is a lightweight grade of quality paper with a good bleached surface. This is the paper you will have the most experience of. It is widely used in the office and school environment using black an white photocopying and printing from inkjet and laser printers. It is also has a more general use for sketching and writing. It is bright white in appearance and also available in a variety of colours. As it is widely used it is quite inexpensive when bought in large quantities.
Cartridge Paper - This is heavier than copier paper and is more of a creamy-white colour and 120-150gsm. It is a good general purpose paper for drawing and because of its heavier weight it can be used with paint. It is completely opaque and accepts most drawing media however is more expensive than copier paper.
B) Commercial Printing Papers
Bond Paper - This is a high quality durable writing paper that often carries a watermark . It gets its name from its use for documents such as bonds produced by the government that needed protection over them using the watermarks to make them authentic. It is used for letterheads and other stationery for electronic printers and widely used for graphic work with pen, pencil and felt tip markers. It Is largely made from rag pulp with makes it a stronger paper than wood pulped derivatives. It is available in a range of weights 50gsm upwards but can be inexpensive when purchased in bulk.
Coated Paper - This is coated with a fine covering of china clay, pigment and an adhesive to give a smooth surface finish. It has a wide range of availability from 70-300gsm and is used for a wide range of high-quality print jobs. The coating levels off the tiny pits between the fibres in the underlying base paper rather like plastering a rough wall t make it smooth and flat. There is a range of finishes from matt, satin, silk and high gloss. As there is a nother process that needs to be undertaken it is relatively expensive.
C) Boards
Mounting Board - This is a relatively thick board of between 1000-1500microns with a colour on one side and white on the back. It is used for mounting work or displays and can be mounted flat or behinds a frame mounting. It is a strong and rigid board available in a range of colours including pastel. It is quite expensive.
Foam Board - This is a foam core board with the outer surfaces being made of paper. Foamboard is commonly used to produce architectural models, prototype small objects and to produce patterns for casting. Scenery for scale model displays, dioramas, and computer games are often produced by hobbyists from foamboard. The surface of the regular board, like many other types of paper, is slightly acidic. However, for modern archival picture framing and art mounting purposes it can be produced in a neutral, acid-free version with a buffered surface paper, in a wide range of sizes and thicknesses.
It is also often used by photographers as a reflector to bounce light, in the design industry to mount presentations of new products, and in picture framing as a backing material; the latter use includes some archival picture framing methods, which utilize the acid-free versions of the material. Another use is with aero-modellers for building radio-controlled aircraft.
It is also often used by photographers as a reflector to bounce light, in the design industry to mount presentations of new products, and in picture framing as a backing material; the latter use includes some archival picture framing methods, which utilize the acid-free versions of the material. Another use is with aero-modellers for building radio-controlled aircraft.
Carton boards
The following boards are all carton boards, used extensively in the retail industry where specific properties are required. They need to be able to be used in high volume so need to be suitable for high speed automated production using printing, die cutting, creasing and gluing.
Corrugated Board - We should all be familiar with corrugated board especially if you order from amazon! It is constructed of a sandwich of 2 paper liners with a fluted paper middle. This provides excellent impact resistance and is designed to reduce the force of impact by crumpling at point of impact therefore protecting what is inside. In saying that is, it is useful for use in the postal system as it has an excellent strength to weight ratio and is relatively inexpensive and recyclable.
Folding Box Board - You’ll find folding box board just about anywhere you look as it is perfect for a vast variety of packaging applications. For example, you find a lot of Folding Box Board in supermarkets and chemists where the major end uses of folding boxboard are frozen and chilled food, confectionary and pharmaceuticals. You probably wouldn’t be able to walk through a shopping centre without coming across it in some form or another. It is widely used in the food packaging industry and general carton applications.
It is relatively cheap and is made up of multiple layers of chemical and mechanical pulp. The top layer consists of bleached surface (with an optional pigment coating) and this makes it easy to print on giving good results. The reverse layer may be bleached or unbleached chemical pulp as this would be used in the inner part of the box so usually does not need to be printed on. This paperboard is characterised by air between the fibres that gives it a high thickness and makes it a good printing surface.
It is relatively cheap and is made up of multiple layers of chemical and mechanical pulp. The top layer consists of bleached surface (with an optional pigment coating) and this makes it easy to print on giving good results. The reverse layer may be bleached or unbleached chemical pulp as this would be used in the inner part of the box so usually does not need to be printed on. This paperboard is characterised by air between the fibres that gives it a high thickness and makes it a good printing surface.