How is a pencil manufactured?
The conventional pencil consist of a a central core called lead, enclosed in a wooden casing. The manufacturing process of pencil consists of three main processes. These are:
- Making of the central core. Though this this commonly described by its old name - that is lead, it is made of graphite.
- Making the wood casing.
- Shaping the pencil.
The lead is made by mixing graphite with wax or some special clays for binding the graphite and then forcing this mixture through a suitable die to form a continuous length of the core. This process is called extrusion. The long leads thus produced are then cut to required size. For some types of pencils such as coloured pencils the core may be made of some other material rather than graphite. However the process of making the lead remains same.
The wooden casing is made by sawing thin strips of wood called slats. Then parallel semicircular grooves are cut in the slat for accommodating the leads. The distance between the parallel groove corresponds to the thickness of the pencils to be made.
Half of the slats required for making the required number of pencils are then glued on the grooved side and the leads are placed in the grooves. The other half numbers of unglued slats are placed on glued slats with lead so that the slats match. The paired slats are then pressed to achieve good bonding between them.
Next step is called shaping in which the hexagon shape of the pencil is formed by cutting suitable grooves on both sides of the pairs slats running in the center of position of adjoining leads. Once these grooves are made, individual pencils are sawed off from the slat.
The cut pencils are then finished by smoothing and painting. The finished pencils are then suitably packed for selling in shops.