How are pencils produced?
Traditional wooden pencils are still produced in a process for the first time in the 16th century. Modern woodworking machines and automation methods definitely make the production process more efficient, but most of them remain that they are not much different from their centuries -old predecessors. Basically, they are the final result of the sandwich process including graphite and cedar wood boards.
The first step in the production of pencils is the preparation of the graphite center or "lead". Graphite is a dark, soft mineral that is ground and added to clay and water in a mixing chamber. After the water is squeezed, the remaining graphite/clay is allowed to dry until it becomes powder again. This graphite powder is mixed again with water to form a soft paste. The graphite paste is then extruded with thin metal tubes to form a pencil size. These rods are overheated to form hard and smooth wires.
Meanwhile, the woodworking slices of Cedar Wood machines into thinner slats. Another machine cuts eight grooves pabout the entire length of these slats. Pencils are not carved out of one empty, but in fact start, because the two half loads are blind together. Because both halves are sandwiched and glued, another machine places the graphite rod on each of the eight shallow grooves. The entire non -descending board may dry before further processing.
The special cutting machine gets uninhabited sandwiches made of wood and graphite, then the blades cut the sides to create a well -known hexagonal or round shape. The cutting machine also surprises the plate into individual pencils. Grinding machines smooth the surfaces and prepare them for accepting several coats of color. It is not uncommon for pencils to receive up to eight layers of paint to form a surface without splitting necessary for the safe use of the product.
Painted pencils then receive hot stamping usually containing the name of the manufacturer and the number corresponding to the relative hardness of the graphite oLova. The most common hardness has #2, but those who have a hardness level up to #4 can often be found in hobbies or office stores. Hardness in general means how much graphite is released for stroke. The higher the hardness number, the less it is released, resulting in a lighter line.
The pencils are then equipped with a metal collar known as Ferrule. The Ferrule is mechanically inserted rubber made of soft rubber and pencils are now considered complete. Interestingly, pieces of bread were often used as rubber until the first rubber rubber was developed around 1770. Until 1858, rubber rubber would actually be connected to the goals.