How are pencils made?

Pencil slat

The crude wood is opened, cut, squared, and sawed into wooden slats, and cut into pencil boards by a board cutter after hydrothermal treatment. The length of the board is 184mm, the width is 73mm, and the thickness is 4.8～5.2mm. After heating (60～120℃) drying and high temperature (130～200℃) denaturation treatment, the pencil board can be softened and easily rolled.

The graphite lead core

The graphite lead core is prepared by mixing graphite and clay in a certain ratio. After mixing by kneading machine and three-roller, it is extruded to a certain size (such as HB～3H lead core diameter of 1.80～ 2.10mm) lead core, dried by heating (50～150℃) and roasted at high temperature (800～1100℃) to make it have certain mechanical strength and hardness, and finally made by oil immersion treatment. The color lead processing is similar to the graphite lead, but sintering is not required.

Processing of pencil lead

There are two methods for processing lead cores: one is to mix clay, talcum powder, adhesives, pigments, grease, and wax, etc., and then form and dry them. This is called the mixing method; the other is to mix porcelain clay. , Talcum powder, pigments, and adhesives are mixed evenly and then extruded into a lead core or the dried lead core is placed in an oil core container, and it is made by fully absorbing grease at a certain temperature, which is called the oil immersion method.

Production process of raw pencil

The production process of raw pencil, firstly, we use a planer to plan the pencil slat into a groove plate with a thickness of 4.1～4.2mm and a core groove corresponding to the diameter of the graphite lead core, and then use glue to glue the graphite lead core and the pencil slat together After heating (50～120℃) and drying for 1～8 hours in the clamped state, the plywood pieces are processed by planing to make raw pencils with a length of 178～180mm.

Appearance processing

The raw pencil is painted and printed, as well as cut, printed trademarks, rubber tips, pen caps, etc., making it a finished pencil with certain specifications, appearance colors, and patterns.