year roughly 2 billion low-tech pencils are sold in the U. S and 14 billion are sold worldwide so how do they do it the Journey of a pencil begins with the procurement of essential raw materials the primary components of a pencil are graphite clay and wood graphite a naturally occurring form of carbon is extracted from lines worldwide the highest quality graphite known as vein graphite comes from Sri Lanka and Madagascar simultaneously the clay required for the pencil's core is collected from deposits and queries this Clay is crucial in determining the pencil's hardness and the Darkness of the lead in addition to graphite and Clay Wood plays a pivotal role in pencil construction the most commonly used wood is Cedar more specifically California Cedar the choice would for many years Cedar has a pleasant odor does not warp or lose its shape and is readily available pencil manufacturers often rely on sustainable forestry practices to ensure the responsible sourcing of wood once the raw materials are obtained the pencil cores preparation begins first the graphite and Clay are ground into fine powders separately the ratio of graphite to Clay determines the pencil's lead hardness with higher graphite content producing softer leads and vice versa next the powdered graphite and Clay are mixed together with water to form a homogeneous paste the paste undergoes a refining process to ensure uniformity the mixture is the been extruded through a machine to shape it into long thin rods these rods are cut into lengths corresponding to the pencil's final size the process of mixing graphite with Clay can be traced back to a chemist named Nicholas Jacques Conte interestingly his Discovery came as a result of the graphite shortage in the late 18th century Conte discovered that when powdered graphite powdered clay and water were mixed molded and baked the finished product wrote as smoothly as pure graphite The Invention was so revolutionary that it's still used in pencil production to this date the next step in pencil manufacturing is the encasing process where the prepared graphite cores are encased in wooden slats these slats are typically made from Cedar Wood the cedar usually arrives at the factory already dried stained and waxed to prevent warping logs are then sawed into narrow strips called slats these are about 7 0. 25 inches long .
25 inches thick and 2. 75 inches wide slats are then placed into a feeder and dropped one by one onto a conveyor belt which moves them along at a constant rate One By One The slats pass under a giant cutting wheel this wheel carves grooves into the slats that will become the channel in the middle that holds the lead continuing along the conveyor belt half of the slats are coated with a layer of glue and the cut graphite is laid in the grooves of these slats the slats without glue and without graphite in the grooves are placed on another belt that carries them to a machine that picks them up and turns them over so they're laying on the belt with the grooves facing down the two conveyor belts then meet and each unglued slat is placed over a slat with glue and graphite forming a sandwich after the sandwiches have been removed from the conveyor belt they are placed into a metal clamp and squeezed by a hydraulic press and left clamped together until the glue is dry once bonded the pencils go through shaping machines these machines cut the pencil slats into their iconic hexagonal shape which is the most popular due to its ergonomic design and resistance to Rolling off surfaces this is done in two steps first the upper cutter of the machine forms three sides on top then its lower cutter shapes three sides on the bottom as soon as the bottom sides form the pencils separate after shaping the pencils undergo sanding to smoothen their surfaces this step helps to remove any imperfections and provides a comfortable grip for users the pencils are then coated with a protective layer to improve durability and appearance a lacquer or enamel coating is applied and the pencils are dried and Polished to achieve a smooth finish sometimes pencils may receive additional treatments such as a heat treatment to enhance their strength and resistance to breakage many pencils come equipped with erasers at one end making them versatile tools for riding and correcting mistakes the erasers are typically made of synthetic rubber or a combination of rubber and other materials the idea of attaching an eraser to a pencil is traced to Hyman W lippman an American whose 1858 U. S patent was bought by Joseph reckendorfer in 1872 for a reported one hundred thousand dollars a process of making an eraser starts with putting a batch of rubber into a mill the rubber passes repeatedly between large heated rollers additives including pigments fillers and Vulcanizing agents are thrown in between the rollers the mixture is Blended thoroughly to ensure uniform distribution of the ingredients loganization is a critical process in eraser manufacturing it typically occurs in specialized machines known as vulcanization presses or vulcanizers these machines are designed to apply heat and pressure to the rubber compound allowing the cross linking of polymer chains and transforming the raw rubber material into a more durable and resilient form on top of making it more elastic and resilient vulcanization also helps make the rubber more effective in erasing pencil marks to make plugs which will be attached to the pencils an extrusion process is usually used the mixture in the form of a soft solid is forced through a dye to form a long cylinder the cylinder is repeatedly cut as it emerges forming plugs to attach the Eraser a ferrule a metal or plastic piece is inserted at the opposite end of the Eraser and the assembly is fixed onto the pencil this process may involve some automated steps but certain pencil rules are still assembled manually pencils are often initially packaged in bulk quantities for distribution to retailers wholesalers and stationary suppliers bulk packaging typically involves packing large quantities of pencils into sturdy cardboard boxes the boxes are designed to accommodate various pencil sizes and can hold hundreds or even thousands of pencils for pencils intended for direct sale to Consumers retail packaging is used retail packaging typically includes individual pencil sets or packs the pencils are neatly arranged and secured inside a cardboard plastic or blister pack the packaging may also include branding product information and barcode labels for easy scanning at the point of sale because they travel along a conveyor belt during the manufacturing process pencils are thoroughly scrutinized before they're distributed to the public workers are trained to discard pencils that appear dysfunctional and a select number are sharpened and tested when the process is complete a common problem is that the glue of the sandwich is sometimes don't adhere but this nuisance is usually caught when the sandwiches are being cut even with the world going electronic the pencil industry continues to steadily grow the global market size of the pencil industry currently sits at 15.
