The main components of the pencil core are graphite and clay, not the lead or charcoal we think.Early pencils contained lead, but with the development of technology, lead has been removed.The core of the pencil is made of graphite and clay mixed in a certain proportion. The graphite and clay are not toxic, but the graphite dust is inhaled by the human body and may cause respiratory disease. ThereforeLets take a look together.
Pencil is a type of pen for writing and drawing sketches. It has a history of more than 400 years. Among them, the pencils of painting sketches are divided into many types.Pen making and hats with a pencil; in addition, its color is red, white, black, white, yellow and black.
What is the main component of the pencil core
The main components of the pencils lead are graphite and clay. According to national standard pencils, they are divided into 18 models according to graphite concentration.In the current standardized examination of my country, computers can only read pencil strokes with a lead core of 2B. Excessive or too light will cause the failure or error of computer reading. Early pencils contain lead, but people used pencil cores The main ingredients are graphite and adhesive, which no longer contain lead, harmless to the human body.
Because the main component of the pencil is graphite, and graphite is a conductor, the pencil core can conduct electricity.However, the conductivity of the pencil core is not very strong.Because graphites atomic structure is ranked, it determines that it can only conduct two -dimensional conductivity, that is, it is conductive between the two points of the same plane, and the upper and lower sides of the plane are not conductive.The graphite in the pencil core is mixed with clay after being crushed, so the atomic structure is disrupted, so the conductive performance is not very outstanding.In the experiment, the length of the 2B pencil core exceeds 15cm, and the small bulb will not glow.
Is the pencil core poisonous?
The core of the pencil is made of graphite and clay mixing in a certain proportion. Graphite is a solid with a metallic luster. Among them, there are carbon-carbon chemical bonds.Stable, it is difficult to destroy.There is nothing in the human body that can destroy the carbon-carbon chemical bond, so graphite is non-toxic.Clane has the characteristics of non -toxic and tasteless, safe and environmentally friendly, and puzzle development. Because graphite and clay are not toxic, the pencil core is not toxic.However, the pencil core dust inhaled into the human body, which can cause respiratory disease, so you must pay attention to use.
At present, most of the pencils are a layer of wood protective layer to prevent the pencil core from being broken. The wood part is non -toxic. The main component is cellulose, and the human body cannot digest and use cellulose.However, the problem is that its shell needs to be used for adhesives. At present, many adhesives use formaldehyde during the manufacturing process. This is recognized as carcinogenic substances in one.Higher than the formaldehyde containing formaldehyde, because the adhesives are mostly organic compounds, it is not easy to separate formaldehyde, so it is still dangerous.