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Pencil body and lead producing methods
Source: | Author:business-101 | Published time: 2019-09-07 | 1218 Views | Share:
In pencil board processing, the logs are unwrapped, cut, squared and sawed into wooden blocks, and cut into pencil boards by a cutting machine 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.


Lead core processing Graphite lead core is prepared by mixing graphite and clay according to a certain ratio. After mixing by kneading machine and three-roller, a certain specification size is extruded by core pressing machine (for example, the diameter of HB～3H lead core is 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. There are two processing methods: 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 and talcum powder. , Colors 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.


For pencil shaft processing, use a planer to plan the pencil board into a groove board with a thickness of 4.1～4.2mm and a core groove corresponding to the diameter of the lead core. Then use glue to glue the lead core and the pencil board together. After heating (50-120°C) in a tight state and drying for 1-8 hours, it is processed by a planer to make a white pencil with a length of 178-180mm.