Pencils to create characters through physical wear and tear, leaving behind traces of a solid core material complies with a sheet of paper or other surface. They are significantly different from pens, which releases a liquid or gel ink stain on the light color of the paper.
Most of the nuclei of the pen is made of graphite mixed with clay binder, the gray or black marks, which can be easily removed. Graphite pencils are used as well as writing and drawing, and the result is lasting even if the writing can usually be removed with the eraser, it takes moisture, most chemicals, ultraviolet radiation and natural aging. Other types of pencil core are less widely used. Charcoal pencils are used primarily Artists drawing and sketching. Coloured pencils are sometimes used for teachers or journalists to correct the texts transmitted, but are generally regarded as art supplies, especially waxy core binders, which tend to smear on the paper instead of removed. Grease pencils are softer chalk-like waxy core, which can stain to smooth surfaces such as glass or porcelain.
The most common pen shell is a thin wooden cylinder permanently installed around the core. Similar permanent casings can be constructed of other materials such as plastic or paper. In order to use a pencil, the case has been carved or removed to reveal the work until the end Core sharp tip. Mechanical pencils are more complex cases, which are supported by mobile units pigment core, which may be extended or retracted through the housing need for the tip.
Some time before 1565 (some sources say in 1500), an enormous deposit of graphite was discovered approaching Grey Knotts from the hamlet Seathwaite in Borrowdale parish, Cumbria, England. 3 4 5 Local felt that was very useful for marking sheep. This particular deposit of graphite in a very clean and solid, and it could easily be sawn into sticks. This is the only large scale deposit of graphite ever found in this solid form. 6 Chemistry was in its infancy and the substance was thought to form lead. Consequently, it was called Plumbago (Latin for lead ore). 7 8, the nuclear black lead pencils is still referred to, even though it never contained the element lead. Words in pencil in German (Bleistift), Ireland (Peann Luaidhe), Arabic and other languages literally mean a pencil.
Value of graphite was soon realized to be enormous, mainly because it could be used to line molds cannonballs, and the mines have been transferred to the Crown and guarded. When sufficient stores graphite had been accumulated, the mines were flooded to prevent theft until more was needed. Graphite was smuggled out of use in pencils. Because graphite is soft, it requires some kind of encasement. Graphite sticks were originally wrapped in string, or the stability of sheep. News of the usefulness of these early pencils spread far and wide, attracting the attention of artists from all over the known world.
Although deposits of graphite had been found elsewhere in the world, they do not have the same purity and quality as the Borrowdale find, and had to be crushed to remove impurities, leaving only graphite powder. Edit England continued to enjoy the monopoly in the production of pencils until a method to reconfigure graphite powder was found. Distinctively square English pencils continued to do kepein cut from natural graphite into the duck in 1860. City of Keswick, close to the original results of the graphite block to produce pens, the factory is also the location of Cumberland Pencil Museum. 9
The first attempt to manufacture graphite sticks from powdered graphite was in Nuremberg, Germany, in 1662. It uses a mixture of graphite, sulfur, and antimony.
The remainder of the graphite pencil stick is not poisonous, and graphite is harmless if consumed.
Italian couple named Simonio and Lyndiana Bernacotti who? Where? Done what probably the first plans for a modern, wood-encased carpenters pencil. Their version was a flat, oval, more compact type of pencil. Their concept involved hollowing out of the stick of juniper wood. Shortly thereafter, a superior technique was discovered two wooden halves were carved graphite stick inserted, and the halves glued together-essentially the same method in use today. 11
English and German pencils were not available in French during the Napoleonic wars, France, under naval blockade of Great Britain, could not bring pure graphite sticks Britains Grey Knotts mines - the only known source in the world of solid graphite. France has also not succeeded in bringing the inferior German graphite pencil substitute. It took the efforts officer in Napoleons army to change this. In 1795, Nicholas Jacques Conté discovered a method by mixing powdered graphite with clay and forming dough bars were then fired in an oven. By varying the ratio of graphite in the clay, the hardness graphite rod could also vary. This method of manufacture, which had previously been found in Austria, Joseph Hardtmuth Koh-I-Noor in 1790 remains in use. Edit
In England, pens still made entirely of sawn graphite. Henry Bessemer first successful invention (1838) was a method of compressing graphite powder graphite in the solid waste can be re-cut. 12
Pencil manufacturing. Top sequence shows the old method, which requires copies of graphite can be cut to size, the lower sequence is new, the current method using rods of graphite and clay
American colonists imported pencils from Europe before the American Revolution. Benjamin Franklin advertised pencils for sale in his Pennsylvania Journal in 1729, and George Washington used a three-inch pencil when he explained the Ohio in 1762. Edit It is said who? That William Munroe, cabinetmaker in Concord, Massachusetts, made the first American wood pencils in 1812. This was not the only pencil-making occurs in Concord. According to Henry Petroski, transcendentalist philosopher Henry David Thoreau discovered how to make a good pencil out of inferior graphite using clay as the binder this invention was the inspiration behind his fathers pencil factory in Concord, which employed graphite found in New Hampshire in 1821 by Charles Dunbar.
Munroes way of making pencils was painstakingly slow and neighboring city of Acton, a pencil mill owner named Ebenezer Wood began to automate their own pencil factory is located in Nashoba Brook along the old Davis Road. He used the first circular saw in pencil production. He constructed the first hexagon-and octagon-shaped wooden casings that we have today. Ebenezer did not patent his invention and shared the techniques with anyone asked. One of those was Eberhard Faber, New York, who became the leader in pencil production. 13
Joseph Dixon, an inventor and entrepreneur involved in Tantiusques granite mine in Sturbridge, Massachusetts, developed ways to mass produce pencils. By 1870, Joseph Dixon Crucible Company was the worlds largest retailer and the consumer graphite and later became the contemporary Dixon Ticonderoga pencil and art supplies company. 14 15
By the end of 19 century, more than 240 000 pens were used every day in the U.S. alone. Prefer wood pencils was Red Cedar as it was aromatic and splinter when sharpened. As early as the 20th century Red Cedar supplies were dwindling, so that the pencil manufacturers were forced to recycle the wood cedar fences and barns to maintain supply. Britain went so far as to declare the use of pencil sharpeners illegal to prevent unnecessary sharpening. Edit It was soon discovered that Incense cedar, when dyed and perfumed reminds Red Cedar, was a suitable option, and most of the pencils today are made from this tree, which is grown in managed forests. More than 14 billion pencils are manufactured each year worldwide.
30. March 1858 Hymen Lipman received the first patent for attaching an eraser end of pencil. 17 In 1862 Lipman sold the patent Joseph Reckendorfer for $ 100,000, which went to sue the device manufacturer Faber-Castell violation. 18 In 1875, the Supreme Court of the United States condemned the Reckendorfer declare a patent invalid.
Although lead is not used for writing since Roman times, lead poisoning, pens was not uncommon until the mid-century, the paint used for the outer coating may contain high concentrations of the element, and this could be ingested when the pen was sucked or chewed.
Modern pencils are made industrially by mixing finely ground graphite and clay powders, adding water, forming long spaghetti-like strings, and burning them in the oven. The resulting strings are dipped in oil or molten wax, which is absorbed into the small holes in the material, resulting in smoother writing. Juniper and Incense-cedar plank several long parallel grooves cut into the fashion slat and the graphite / clay strings inserted into the grooves. The second groove plank is glued on top, and the whole congregation is then cut into individual pencils, which are then painted or varnished. Afterward, people can then add your personal things, such as pencil grips and eraser toppers. Eraser toppers are extra gums, which can be removed after use.
Many of the pens in different parts of the world, and almost all of Europe criticized the European system using a continuum of the H (hardness) is a B (and darkness), and F (for fine point). The standard writing pencil is graded HB. According to Petroski, this system might be developed in the early 20th century, Brookman, English pencil maker. It uses the B for black and H is a hard, pencil grades has been described by a sequence or successive Hs or BS such as BB and BBB successively softer leads, and HH and HHH for successively harder ones. 21
As of 2009, a number of pencils ranging from hard, light-marking pencil to a very soft, black-marking pencil usually ranges from hardest to softest as follows Koh-i-Noor offers twenty grades from 10H and 8B of the 1500 series, 22 Derwent to twenty grades from 9H and 9B, the graphical pencils 23 and Staedtler produces seven p.m. from 9H to 8B, and Mars Lumograph pens. 24
The main market for such a variety of grades are artists who are interested in creating a comprehensive range of shades of light gray and black. Engineers prefer harder pencils which allow for greater control of lead form. This can be seen as pens, packaged and marketed. For example, its Graphic pencils Derwent offers three packages 12 pencils each Technical (with hard grades from 9H B), drew (soft grades H, 9B), and the designer (medium grades 4H and 6B). Quote is needed
Pencils graded using this system is used to measure the hardness and durability of varnishes and paints. Resistance coating (also known as its pencil hardness), among the hardest pencil grade that does not mean that when the coating is pressed firmly against the 45-degree angle. 25 26
Another common way to use numbers to describe the category of a pencil. It was originally created by Conté and approved in the United States, John Thoreau, Henry David Thoreaus father, in the 19th century. 27 The following table shows approximate equivalences between different systems
Although Conté / Thoreaus system is widely accepted that not all manufacturers follow it, for example, Faber-Castell uses a different equivalence table in its grip in 2001 pencils 1 = 2B, 2 = B, 2 ½ = HB, 3 = H, 4 = 2H.
Various graphite pencil grades are achieved by changing the part of the graphite in Clay more clay harder pencil. 29 30 31 Two pens of the same grade but different manufacturers are not necessarily a sign of the same hue and does not have the same hardness.
The majority of pencils made in the United States are painted yellow. 33 According to Henry Petroski, 34 This tradition began in 1890 when the L. & C. Hardtmuth Company in Austria-Hungary introduced their Koh-I-Noor brand, named after the famous diamond. It was intended to be the worlds best and most expensive pen, and at the same time, when most pencils were either painted in dark colors, or not at all, the Koh-I-Noor was yellow. As well as simply a distinctive, the color may have been inspired by the Austro-Hungarian flag, it was also suggestive of the Orient at a time when the best quality graphite came from Siberia. Other companies then copied to the yellow color, so that their pencils would be associated with this high-quality brand, and chose the brand with a clear Oriental references, such as Mikado (name Mirado) 35 36, and the Mongols. 37 38
Not all countries use yellow pencils, however, Germany and Brazil, pencils, for example, are often green, blue or black, which is based on the trademark colors of Faber-Castell, a major German stationery company, which has large plants in those countries. Southern European countries pencils usually black or dark red, yellow lines in Australia, they are red with black bars at the other end. In India the most common pencil color was dark red with black lines, and pencils with several color models producing different companies.
Pencils are usually round, hexagonal or sometimes triangular in section. Carpenters pencils (see below) are typically oval or rectangular in shape, so they can not easily roll off during the work.
ไม่มีความคิดเห็น:
แสดงความคิดเห็น