In 1564, a black mineral, graphite, was discovered in a place called Barrodale in England. Because graphite can leave traces on paper like lead, which is much darker than the traces of lead, therefore, people call graphite "black lead". At that time, shepherds in the Barodale area often used graphite to mark their sheep. Inspired by this, people cut graphite blocks into small strips for writing and painting. Soon, King George II simply took the Barrodale Graphite Mine into royal ownership and designated it as a royal patent. Writing it with graphite strips will both make your hands dirty and break easily. In 1761, the German chemist Faber first solved this problem. He rinsed the graphite with water to turn the graphite into graphite powder, then mixed it with sulfur, antimony, and rosin, and then formed this mixture into strips. This mixture is much tougher than pure graphite strips and is less likely to stain hands. This is the earliest pencil. Until the end of the 18th century, only Britain and Germany were able to produce such pencils. Therefore, after Napoleon Bonaparte launched a war against neighboring countries, Britain and Germany cut off the supply of pencils to France. Therefore, Napoleon Bonaparte ordered the French chemist Comte to find graphite on his own land. mine, and then make a pencil. However, the quality of graphite ore in France was poor and the reserves were small. Comte mixed clay into the graphite and roasted it in a kiln to make the best and most durable pencil lead in the world at that time. Different proportions of clay mixed into graphite produce pencil leads with different hardnesses and different color depths. This is why we see H (hard pencil), B (soft pencil), and HB (moderately soft pencil) marked on pencils today. The task of putting the wooden shaft jacket on the pencil was completed by American craftsman Monroe. He first built a machine that could cut out wooden strips, then carved a thin groove on the wooden strip, put the pencil lead into the slot, then aligned and glued the two wooden strips, and the pencil lead was tightly The ground is embedded in the middle, which is the pencil we use today. A pen core made of graphite or pigmented clay is used as a writing medium and is used as a writing or painting tool for study, office work, engineering drawing, art, painting, various markings, etc. In ancient Greece and Rome, lead metal was used to make lead rods similar to pencils. This kind of pen is mostly made into a tapered shape, and the lead is rubbed with other objects to leave traces of lead, which is used to draw lines and make marks. In the 14th century, pencils similar to modern ones appeared in Europe, and Dutch painters used them to draw on paper. The Italians used a mixture of lead and tin to create lead rods for painting and writing. In 1565, there were illustrations drawn with pencil in the collection of German C. Gesner, and it was recorded that “for drawing and taking notes, people used lead and other mixtures to make pen cores, and then attached wooden handles to draw lines. ..." text. In the same year, Britain began to hand-make the most primitive wooden pencils with graphite as the refill. In 1662, the world's first pencil factory, the Staedtler Pencil Factory, was built in Nuremberg, Germany. In 1761, the German F. Castel founded the Faber Castel Pencil Factory in Nuremberg. He used sulfur, antimony, etc. as binders and heated graphite to mix lead cores, which made pencil manufacturing technology a big step forward. From 1790 to 1793, French N.J. Kant first used the method of washing graphite to improve the purity of the graphite, and used clay to bond the graphite to make a pen core. This method is called the Kant method. The Kant Pencil Factory was established in 1793, laying the foundation for the modern pencil industry. China established its first Dahua Pencil Factory in Kowloon, Hong Kong in 1932. Later, Peking China Pencil Company and Shanghai Huawen Pencil Factory were built one after another, both of which were semi-finished product processing plants. In 1934, the China Standard Domestic Pencil Factory was established in Shanghai, and began to make its own lead cores and began research on using domestic raw materials to manufacture pencils. After the founding of the People's Republic of China, large-scale pencil factories with an annual output of 150 to 250 million pieces were successively built in more than 10 cities including Harbin, Beijing, Tianjin, Jinan, Dalian, Fuzhou, Shenyang, and Bengbu. Lead manufacturing and paint, printing and decoration technologies have also been continuously improved, and all-plastic pencils, resin thin lead and fine-core mechanical pencils have been developed. Developed new equipment such as glue board bundle clamp dryers, automatic painting machines, electric tunnel core burning furnaces, panel building machines and various packaging machines.
[Edit this paragraph] Classification
According to their properties and uses, they can be divided into three categories: graphite pencils, color pencils, and special pencils. Graphite pencils are pencils whose main raw material is graphite. Can be used for drawing and general writing. The hardness mark of graphite lead is generally expressed as "H" for hard pencils, "B" for soft pencils, "HB" for moderately soft and hard pencils, and "F" for pencils with a hardness between HB and H. Graphite pencils are divided into 18 hardness levels: 6B, 5B, 4B, 3B, 2B, B, HB, F, H, 2H, 3H, 4H, 5H, 6H, 7H, 8H, 9H, 10H. The number in front of the letter The larger the number, the harder or softer it is respectively. In addition, there are three grades of soft pencils: 7B, 8B, and 9B to meet special needs such as painting. Colored Pencils Pencils with colored lead. Lead core is composed of clay, pigments, talc, adhesives, greases and waxes. Used to mark symbols, draw, draw charts and maps, etc. Color pencils are usually packaged in sets (6, 12, 24, 36, 64 colors). Special pencils include glass pencils, color-changing pencils, charcoal pencils, drawing pencils, watercolor pencils, pastel pencils, etc. Each of them has its own special purpose. ①Glass pencil: The lead core is composed of pigments, grease and wax. Used to write or mark on glass, metal, enamel, ceramics, leather, plastic, plexiglass and other surfaces for use by industry, medicine, national defense, surveying and other departments. There are red, white, orange, light yellow, purple, dark green, light blue, black and other colors. ②Color-changing pencil: commonly known as copy pencil. The lead core contains dyes such as light-fast blue lotus lake, and the writing cannot be erased with an eraser. It is suitable for writing important documents that are kept for a long time and recording accounts. There are green lotus, red, blue, green, yellow and other colors, with the green lotus color being the most common. ③Charcoal pencil: also known as carbon pencil. Lead core is made of clay, charcoal powder, carbon black, etc. Used for painting and oil painting. ④Drawing pencil: also called tracing pencil. The graphite lead core is treated with red dyes such as oil-soluble wax red to provide light-shielding effect, and is used for direct printing after drawing. ⑤Watercolor pencil: The lead core is added with acid dyes such as water-soluble acid scarlet. When the lead core is wetted with water, it acts like watercolor paint and is used for photo coloring, sketching, drawing maps, statistical charts, etc. ⑥Pastel pencil: The lead core is made of pigments and porous soft raw materials (such as calcium carbonate), and does not contain grease and wax. Its hardness and writing feel are similar to chalk. for painting.
[Edit this paragraph] Raw materials
Pencil raw materials mainly include pencil shaft materials, graphite lead materials, color lead materials and appearance decoration materials. Pencil shaft materials mainly include wood and glue. Wood used to make pen holders requires straight texture, fine and even structure, soft or slightly soft texture, slightly brittle, less resin content, low hygroscopicity, small expansion and contraction, and no deformation. Mainly include pencil cypress (red cedar), cedar, cedar, basswood, alder, etc. The adhesive should have appropriate viscosity, fluidity and wettability. After hardening, the adhesive layer should be tough, cause little damage to the tool, have certain water resistance, heat resistance, aging resistance, easy curing at room temperature, short hardening time, non-toxic, etc. Mainly include animal glue, polyester vinyl emulsion, hot melt adhesive, etc. The raw materials of graphite lead core and auxiliary materials include graphite and clay. Graphite is used as a colorant, and its smoothness and plasticity are used to make lead cores that can draw black marks, adhere firmly to the paper, and can be erased with an eraser. Graphite with high carbon content and fine particles should be used. Clay is used as a binder to bind graphite particles together using its plasticity and adhesiveness. Clay with good plasticity, low iron content and wide sintering range is required. Auxiliary materials include molding materials and materials that change the performance of the lead core. Molding materials are used to improve plasticity and adhesion, and improve lead core molding performance. Commonly used ones include maltose, gum tragacanth, etc. Materials that change the performance of the lead core are used for oil immersion treatment after lead core sintering to improve the physical properties of the lead core (such as wear, concentration, core tip force, slipperiness, hardness, etc.). Commonly used ones include paraffin, beef and mutton fat, petroleum jelly, etc., usually two or more are used in combination. The raw materials of color lead core include coloring materials, physical materials, adhesives, grease and wax. Colorants (including pigments and dyes) play a coloring role and require good tinting power, high hiding power, soft texture, high fineness, good heat resistance, non-toxicity, etc. Commonly used ones include titanium dioxide, carbon black, phthalocyanine blue, etc. Constitution raw materials play the role of bonding, skeleton and adjusting hardness.
Appearance decoration materials mainly include nitrocellulose pencil paint, printing ink, anodized aluminum foil, eraser heads and aluminum hoops. The production process can be divided into pencil board, lead core, pencil shaft, finished product decoration and other processes. Pencil board processing involves unraveling, cutting, and square sawing the logs into wooden blocks. After hydrothermal treatment, the wood is cut into pencil boards through a board cutting machine. The board length is 184mm, width is 73mm, and thickness is 4.8~5.2mm. Then it is heated (60~120℃), dried and denatured at high temperature (130~200℃) to make the pencil board soft and easy to curl. Lead core processing: Graphite lead core is made of graphite and clay in a certain proportion. After being mixed by a kneader and a three-roller machine, it is extruded through a core press to a certain size (such as HB~3H lead core with a diameter of 1.80~ 2.10mm) lead core is heated (50~150℃), dried and roasted at high temperature (800~1100℃) to give it a certain mechanical strength and hardness, and is finally made by oil immersion treatment. The processing of color lead core is similar to that of graphite lead core, but sintering is not required. There are two processing methods: one is to mix clay, talcum powder, adhesives, colorants, grease and wax evenly, then shape and dry it, which is called the mixing method; the other is to mix china clay, talcum powder , colorants and adhesives are mixed evenly and then extruded into lead cores or the dried lead cores are placed in an oil core container and allowed to fully absorb grease at a certain temperature, which is called the oil immersion method. Pencil shaft processing uses a planer to plan the pencil board into a groove board with a thickness of 4.1~4.2mm and a core groove suitable for the diameter of the lead core. Then use glue to glue the lead core and pencil board together. After heating (50~120℃) and drying for 1~8 hours in a tight state, the pencil is processed by a planing machine to make a white pencil with a length of 178~180mm. Appearance decoration processing involves painting and printing decoration on white pencils, as well as cutting, printing trademarks, installing eraser heads, etc., to make them into finished pencils with certain specifications, appearance colors and patterns
[Edit Section] Type
These represent the hardness of the pencil, which is determined according to the hardness of the pen core. From soft to hard, they are 6B, 5B, 4B, 3B, 2B, B, HB, H, 2H, 3H, 4H, 5H, 6H B--BLACK H--HARD Hardness The higher the B number, the darker and softer the pencil is. The higher the H number, the harder the color and the lighter the color. HB is in the middle. Pencil specifications are usually Represented by H and B, "H" is the initial letter of "Hard" in English, indicating the hardness of the pencil lead. The larger the number in front of it, the harder the lead and the lighter the color. "B" is the first letter of "Black" in English, which represents the composition of graphite, indicating the softness of the pencil lead and the obviousness of writing. The larger the number in front of it, the thicker and darker the color. The following table lists the reference values ??(Europeans) of different types of pencil lead resistors: Model -------- Resistance value (Euros) Zhonghua 6B-----3 Zhonghua 5B-----3.5 Zhonghua 4B- ----4.5 Zhonghua 3B-----6 Zhonghua 2B-----9 Zhonghua B------13 Great Wall HB----16 Zhonghua H-----22 Zhonghua 2H--- -40 Zhonghua 3H----47 Zhonghua 4H----59 Zhonghua 5H----76 Zhonghua 6H----143 Most pencils use graphite, one of the allotropes of carbon, as the refill. Pencils are classified according to the amount of graphite in the refill. Generally divided into three categories: H, HB and B. Among them, type H pencils have a relatively high core hardness and are suitable for use on objects with relatively hard or rough interfaces, such as woodworking markings, field drawings, etc.; type HB pencils have a moderate core hardness and are suitable for writing under normal circumstances; type B Pencils have relatively soft cores and are suitable for drawing. They can also be used to fill in some cards that can be recognized by machines. For example, currently we often use 2B pencils to fill in answer sheets. In addition, colored pencils, also known as crayons, are commonly used for drawing. Many people may not know that pencils can also identify the authenticity of diamonds. After the diamond is moistened with water, scratch it with a pencil. The surface of a real diamond will not leave traces of pencil scratches. Fake diamonds made of crystal, glass, tourmaline, etc. will leave traces.
[Chinese Famous Brand]
The China No. 1 Pencil Factory (China No. 1 Pencil Co., Ltd.), founded in 1935, specializes in the production of two major brands: "Zhonghua" and "Great Wall". Wooden pencil is one of the famous time-honored pencil brands in China. It has won many honorary titles, among which the "Zhonghua Brand" D pencil has won the "National Quality Silver Award", the only highest award in the national pencil industry, and the "Golden Bridge Award" for the best-selling domestic product in the country. In 2004, it won the only "National Quality Silver Award" in the national pencil industry. In 2005, the "Zhonghua Brand" pencil won the title of the only national inspection-free product in the national pencil industry.
10,000 yuan! ?