How A Pencil Is Made How To Machines
How A Pencil Is Made | How To Machines
At the Pencil Factory a “Groover machine” cuts grooves into the slats to accept the writing core (or “lead”). Writing cores – made from a mixture of graphite and clay – are placed into the grooves. Coloring pencils may use wax-based cores while many other formulations are used in cosmetic pencils. 12 Steps to Pencil Perfection STEP 1 Chunks of graphite (a soft, dark mineral) and clay are placed inside a huge rotating drum. Large rocks inside the drum crush the graphite and clay into a fine powder. Then water is added, and the mixture is blended in the drum for up to three days. STEP 2 A machine squeezes all the water out of the mixture leaving behind a grey sludge. Here, a worker puts the sludge in a cabinet where it air dries and hardens for four days. STEP 3 Huge wheels grind the dried sludge into another fine powder, and water is blended in again to make a soft paste. STEP 4 The paste is pushed through a metal tube and comes out in the shape of thin rods. The rods are cut into pencil-length pieces, called leads, and sent along a conveyor belt to dry. STEP 5 After drying, the pencil leads are put into an oven heated to 1,800 degrees F. The intense heat makes the leads smooth and hard, which makes for good writing points. STEP 6 In another part of the factory, the wood is prepared. Machines cut blocks of Incense Cedar Wood, a renewable resource, into wide slats. Eight shallow grooves are sawed lengthwise into each slat. STEP 7 A thin coat of glue is applied to the slats, and one pencil lead is placed into each of the eight grooves. Within seconds, another wide grooved slat is glued on top, sandwiching the leads. STEP 8 When the glue dries, the slats are fed through a cutting machine. Fast revolving steel blades trim the wood into round or hexagonal shapes, one side at a time. STEP 9 The same machine cuts apart each slat into eight separate pencils. STEP 10 The pencils are sanded, and each one receives from five to eight coats of paint. STEP 11 A heated metal stamp presses the name of the company and a number – such as a number 2 – on the pencil in foil or paint. The number indicates how hard the pencil lead is. STEP 12 A metal band, called a ferrule, is wrapped tightly around one end of the pencil. It holds the eraser, which is being added here. The pencils are then ready to be sharpened, packaged, and used.