Pencil cores aren t made of lead? So why is it called a pencil?

In the past, lead was used to write and paint, but later people gradually found that lead was too harmful to the human body, and gradually replaced lead with graphite. But people have long been accustomed to the name of pencil, which has been passed down to the present day.

The core of the pencil is a solid carbon called "graphite", because when humans discovered graphite, they thought it was very similar to metal lead, so it was called "black lead".

No, the core of the pencil is graphite and clay, and the reason why it is called pencil is because people called graphite black lead in the early days, and people have been calling it that way ever since.

Originally, the pencil lead was made of graphite, but the material was not rich in that year, and there was not so much graphite, because it was found that lead could also replace graphite, and it could also be painted, so it was replaced by lead (cheaper), and then the lead was poisonous, so it was changed to graphite, but the name was used to everyone, so it has been used until now.

The core of the pencil is indeed not made of lead, its main raw material is graphite-based, and the pencil is just a name for him, just like the name of each of us.

The pencil was indeed made of lead in the early days, but because the lead made of lead was easy to break and the handwriting was easy to paste, graphite was slowly replaced with lead.

The main component of the pencil lead is graphite. Because of the misunderstanding caused by history, the early chemistry was imperfect, and graphite ore was mistakenly recognized as galena, so it was called pencil.

The core of all our pencils does not contain lead, but uses a solid carbon called graphite, and the ancient Chinese believed that graphite was a kind of lead, so it was called a pencil.

The main components of the pencil lead are graphite and clay. According to the national standard, pencils are divided into 18 models according to graphite concentration. In the current standardized test in China, the computer can only read the pencil handwriting with a lead core concentration of 2b, and too thick or too light will cause the failure or error of computer reading.

Early pencils contained lead deficiency, but now people use pencil leads that are mainly composed of graphite and binders, and no longer contain lead.

Since the main component of pencils is graphite, and graphite is a conductor, pencil leads are electrically conductive. However, the conductivity of pencil leads is not very strong. Because of the arrangement of the atomic structure of graphite, it can only conduct electricity in two dimensions, that is, it is conductive between two points in the same plane, and the upper and lower sides of the plane are not conductive.

The graphite in the pencil lead is crushed and mixed with clay, so the atomic structure is disrupted, so the electrical conductivity is not very good.

Pencil 2b, hb, 2h meaning:b is black, the meaning of black, and it represents the depth of black drawn by the pencil, which is the degree of obviousness, so there are 2b, 3b, 4b, 6b, etc., 6b is the blackest and softest to write; H is hard, the meaning of hardness, it represents the hardness drawn by the lead pen, and it is also divided into different h, 2h, 4h, 6h, etc., 6h is the hardest, and it is not very obvious. In addition, HB is a commonly used marker.

1.Pencil leads are made of graphite lead core raw materials and auxiliary materials.

2.There is generally graphite and clay.

3.Graphite is a colorant, and using its slippery and malleable properties, the lead core can scratch black marks, adhere firmly to the paper, and can be erased with an eraser.

4.Graphite with high carbon content and fine particles should be selected.

5.Clay is used as a binder, which uses its plasticity and cohesiveness to bond graphite particles.

6.Clay with good plasticity, low iron content and wide sintering range is required.

7.Auxiliary materials include molding materials and materials that change the properties of the lead core.

8.Molding materials are used to improve plasticity and adhesion and improve core molding properties.

9.Commonly used are caramel syrup, astragalus gum and so on.

10.The material that changes the performance of the lead core is used for oil immersion treatment after the sintering of the lead core, so as to improve the physical properties of the lead core (such as abrasion, early concentration, core tip stress, slip, hardness, etc.).

11.Commonly used are paraffin, tallow butter, petroleum jelly, etc., usually two or more combinations.

12.Color lead core raw materials include pigments, physique raw materials, adhesives, greases and waxes.

13.Pigments (including pigments and dyes) play a coloring role, requiring good tinting strength, high hiding power, soft quality, high fineness, good heat resistance, and no mountain bend and toxicity.

14.Commonly used are titanium dioxide, carbon black, phthalocyanine blue, etc.

15.The raw materials of the constitution play the role of bonding, skeleton and adjusting hardness.

The main ingredient of pencil leads is graphite.

The lead of the pencil is made of a mixture of graphite and clay in a certain proportion, such as "h" is the prefix of the English "hard", which represents the content of the clay and is used to indicate the hardness of the pencil lead. The larger the number in front of the "h", the harder the pencil lead, that is, the larger the proportion of clay mixed with graphite in the lead, the less obvious the words are written, and it is often used to copy. "B" is the prefix of the English "black", which represents the content of graphite, which is used to indicate the softness of the pencil core and the degree of obviousness of the writing.

"6b" is the softest, the blackest handwriting, commonly used for drawing, ordinary pencil marking is generally "hb", and the pencil marking used to paint answer sheets during the exam is generally "2b".

The main component of the pencil lead is graphite. In fact, the lead of the pencil is made of a mixture of graphite and clay in a certain proportion. Such as:"h"i.e. English"hard"The prefix (hard) represents the content of clay and is used to indicate the hardness of the pencil lead.

h"The larger the number in front (e.g. 6h), the harder the pencil lead, that is, the greater the proportion of clay mixed with graphite in the refill, and the less obvious the words written, which are often used to repeat.

b"It's English"black"The prefix (black) represents the content of graphite, which is used to indicate the softness of the pencil core and the degree of obviousness of the writing. to"6b"It is the softest, the blackest handwriting, and is commonly used for painting, and the ordinary pencil marking is general"hb"。The pencil markings used to paint the answer sheets during the exam are generally numbered"2b"。

The pencil making process is as follows:

1. The production of pencils is divided into two parts: pencil cap and pencil shaft.

1. The material of the pencil cap is mainly polyester material, and the production process can be divided into molding, offset printing, assembly and other processes to complete it.

2. The main materials used for pencil barrels are nitro fiber pencil paint, printing ink, anodized aluminum foil, eraser head and aluminum hoop. The production process can be divided into lead potato pen board, lead core, pencil barrel, finished product decoration and other processes.

3. The pencil board processing will unravel and cut the logs, open the square saws and break them into wooden blocks, and cut them into pencil boards by the cutting machine after hydrothermal treatment. The plate is 184mm long, 73mm wide, and thick. After heating (60 120) drying and high temperature (130 200) denaturation, the pencil board can reach the degree of softening and easy rolling.

4. Lead core processing graphite lead core is made of graphite and clay in a certain proportion, after mixing by kneading machine and three-roller machine, extrusion of several acres of a certain size through the core pressing machine (such as HB 3H lead core diameter of the lead core, heated (50 150) drying and high temperature (800 1100) roasting, so that it has a certain mechanical strength and hardness, and finally made by oil immersion treatment.

5. The pencil board is planed into a groove plate with a thickness and a core groove that is suitable for the diameter of the lead core, and then the lead core and the pencil board are glued together with a glue, heated (50 120) and dried for 1 8 hours in a clamping state, and then processed by the planer to make a white pencil with a length of 178 180mm.

6. Exterior decoration processing: The white rod pencil is painted and printed for decoration, as well as cut light, printed trademarks, installed eraser heads, pen caps, etc., so as to make it a finished pencil with certain specifications, appearance colors and patterns.