In fact, this is mainly from the pencil production process to consider. If the end is not cored or hollow at the end of the pencil, it is necessary to control the length of grooves in each board (the end is not open), and add one more part to allow the grooving tool to move up and down to leave a...

In fact, people who have this doubt often think that lead in pencil lead, the use of lead pencils, naturally lead poisoning. So, does the pencil lead contain lead? To answer this question, we have to start with the origin and development of pencils.

Resin lead cores have strict inspection criteria: 1. Lead core should be straight, round, smooth, no elbow, fracture, smooth cut surface, etc. 2. Length and diameter should be unified without obvious error. Diameter error: 0.5 mm+0.08+0.05, 0.7 mm+0.03-0.01; length error: +1 mm.

Lead core is not unfamiliar to everyone. The main components of pencil lead are graphite and clay. According to the national standard, the pencil can be divided into 18 types according to the concentration of graphite. Later, it was made into fine pencil lead and widely used in the replacement co...

A method for processing graphite 2B resin lead core is characterized in that the method comprises the following steps: (1) Squamous graphite is crushed into graphite powder with 680 meshes and 90-95 carbon content.

When pencils are writing, the freedoms and freeness of the pen's strokes and the slight rustling sound of the pen's tip touching the paper are really wonderful enjoyments. In recent years, neutral pens have replaced pens. With the popularity of computers and the abdication of handwriting, it i...