Pencil - pencil

Japanese: 鉛筆 - えんぴつ

A writing instrument made by mixing graphite (mineral name: graphite) and clay powder, then baking it at high temperature to harden it, and fitting the lead into a barrel made of wood or other material.

[Matsuo Nozawa]

history

In ancient Greece and Rome, there were pencil-like writing implements made from lead, but the invention of modern graphite-based pencils came much later. In 1564, during the reign of Queen Elizabeth, graphite was discovered in the Borrowdale Valley in the Cumbrian Mountains in England, and it was processed into a rod shape and used in writing implements, which marked the beginning of the pencil. In 1760, Castell-Faber of Germany mixed sulfur into graphite powder to create a lead, which later became the origin of the Bavarian pencil. It was only in the 19th century that France began to focus on pencil manufacturing. In 1795, N.J. Conté invented a method of making pencil leads by mixing graphite and clay and baking it at high temperatures. He did not simply devise a way to bake the mixture, but also discovered that the concentration of the lead could be changed by changing the mixture ratio of graphite and clay. This was, so to speak, the basis of today's pencil manufacturing method, and this manufacturing method was later spread to other countries, leading to the birth of the modern pencil industry. America in particular not only produced incense cedar, the ideal material for pencil shafts, but was also able to obtain graphite from Mexico, the raw material for the pencil leads. After the first pencil was manufactured in 1851, America was blessed with favorable conditions for capital, equipment, and markets, and the pencil industry developed rapidly.

They are said to have first been introduced to Japan as a gift from the Dutch to Tokugawa Ieyasu, and are still preserved today as a treasure at Kunozan Toshogu Shrine in Shizuoka Prefecture. They began to be imported in earnest from Germany in 1880 (Meiji 13), but the first domestically produced pencils were made in 1874 by Koike Uhachiro, who learned the manufacturing method from Iguchi Naoki and Fujiyama Tanehiro. In 1886, Masaki Niroku established a pencil factory in Yotsuya Naito-cho, Tokyo, and began domestic pencil manufacturing. Since then, quality has improved along with technological innovation, and today pencils have performance on a par with foreign products.

Pencil production in Japan peaked at 1.385 billion units in 1966 (Showa 41), and has since declined, falling below 1 billion to 855 million units in 1980. Production has continued to decline since then due to the decline in the number of school children caused by the declining birthrate, and was down to 313 million units in 2007 (Heisei 19).

[Matsuo Nozawa]

Manufacturing method

Graphite and clay are mixed with water, crushed and compressed into a thick rod, and then extruded into a core extrusion machine with strong pressure to a uniform thickness to create a green core. This is then baked evenly in a core baking furnace and oil is soaked into the core. This is then glued to a processed shaft, cut into individual pieces, and finished by painting. The main ingredients of the core of a black-core pencil are graphite, which contains more than 90% carbon, and the same clay used for ceramics. Incense cedar, cypress, Japanese cedar, and alder are often used for the shaft, and recently there are also synthetic resin shafts and, in special cases, paper-wrapped shafts. Colored pencils are made from different materials and are manufactured differently from black-core pencils. The raw materials are talc, talc gum, wax, and coloring dyes. The core is not baked, but is kneaded with talc paste to the wax and coloring dyes, which is then shaped and dried. The shaft is processed in the same way as black-core pencils.

[Matsuo Nozawa]

kinds

They are broadly divided into black-core pencils and colored pencils. Black-core pencils are available for drafting, office use, study use, copying, photosensitive paper, painting, carpentry, gardening, notebooks, glass, etc. Colored pencils include red and blue office pencils, various colored pencils with soft, medium, and hard cores, and special colored pencils such as paint pencils, graph pencils, and dermatographs (paper-wrapped pencils). In the case of black-core pencils, the hardness and darkness are determined by the ratio of graphite and clay. Hard cores are represented by H for Hard, and soft cores are represented by B for Black. The higher the H number, the harder the pencil is and the thinner the writing, while B is softer and the writing is darker. HB is the standard core hardness, but there is also F, which stands for Firm, to represent a hardness between HB and H. The hardness types of black-core pencils according to JIS (Japanese Industrial Standards) are as follows. 9H to 7H = special drafting used when writing on hard surfaces, 6H to 5H = ultra-precision drafting for drawing fine lines, 4H to 3H = precision drafting, 2H to H = general drafting and for fine writing, F to HB = general writing and drafting, B = office use, architectural drafting, writing pencil, 2B to 3B = for shorthand, 4B to 5B = general painting, 6B = special painting.

[Matsuo Nozawa]

How to Choose

In general, it is a good idea to keep the following points in mind when making your selection:

(1) The core has a smooth sliding motion.

(2) The core will not crumble and is strong.

(3) The writing lines should be uniform and there should be little wear.

(4) The shaft can be easily sharpened.

(5) The core is completely attached to the shaft so that there is no risk of the core coming loose.

(6) The paint film is strong and durable, protecting the shaft from moisture and dirt.

(7) The axis is not distorted.

(8) The core is in the center of the shaft.

(9) The ends of the shafts are not chipped and the joint surfaces of the cores are not chipped.

[Matsuo Nozawa]

Pencil manufacturing process
©Shogakukan ">

Pencil manufacturing process

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

Japanese:

黒鉛（鉱物名石墨(せきぼく)）と粘土の粉末を混ぜ合わせ、さらに高温で焼き固めてつくった芯(しん)を、木などの軸にはめた筆記具。

［野沢松男］

歴史

古代ギリシア・ローマ時代にも鉛を原料とした鉛筆状の筆記具があったが、現在のような黒鉛を主体とする鉛筆の発明は、ずっとあとのことである。1564年、つまりエリザベス女王時代に、イギリスのカンブリア山地のボローデル渓谷でグラファイト（黒鉛）が発見され、これを棒状に加工して筆記具に用いたのが鉛筆の始まりである。また1760年に、ドイツのカステル・ファーバーが黒鉛の粉末に硫黄(いおう)を混入して芯をつくったのが、後のババリア鉛筆の起源となった。フランスが鉛筆製造に力を入れだしたのは、19世紀に入ってからのことである。1795年N・J・コンテが、黒鉛と粘土を混合してそれを高温で焼き固め、鉛筆の芯をつくる方法を発明したが、単に焼き固めるくふうをしただけでなく、黒鉛と粘土の混合比率を変えることによって芯の濃度が変化することも発見した。これはいわば今日の鉛筆製法の基礎をなすものであり、この製法が後に各国に伝わって、近代的な鉛筆工業が誕生することになった。とくにアメリカは、鉛筆の軸材として最適なインセンスシダー（ベイスギ）を産出するばかりでなく、芯の原料となる黒鉛もメキシコから得ることができたため、1851年に最初の鉛筆を製造してからは、資本、設備、市場などの好条件に恵まれて、鉛筆工業は急速な発展を遂げた。

　日本への渡来は、オランダ人が徳川家康に献上したものが最初といわれ、これは静岡県久能山(くのうざん)東照宮の宝物として現在でも保存されている。ドイツから本格的に輸入されるようになったのは1880年（明治13）であるが、国産では1874年に井口直樹、藤山種広に製造法を伝授された小池卯八郎が作ったのが最初である。1886年には真崎仁六(まさきにろく)が東京の四谷内藤町に鉛筆工場を設け、国産鉛筆製造に乗り出した。その後、技術革新とともに品質も向上し、現在では外国製品と並ぶ性能をみるに至っている。

　なお日本における鉛筆の生産量は、1966年（昭和41）の13億8500万本をピークに以後漸減し、1980年には10億本を切り8億5500万本となった。その後も少子化による学童の減少の影響を受けて生産量は減少を続け、2007年（平成19）には3億1300万本となっている。

［野沢松男］

製法

黒鉛と粘土に水を加え、混合しながら粉砕したものを太い棒状に圧縮して押し固め、芯出し機にかけて強い圧力で一定の太さに押し出し、生芯をつくる。次にこれを芯焼き炉で均一に焼き、油を浸透させて芯をつくる。これを加工した軸材に接着して1本ずつ切断し、塗装して仕上げる。黒芯(くろしん)鉛筆の芯の原料は、90％以上の炭素を含んだ黒鉛と、陶磁器に使われるものと同一の粘土が主成分である。軸木にはインセンスシダー、ヒノキ、アララギ、ハンノキなどが多く使われ、最近は合成樹脂の軸や、特殊なものでは紙巻きのものもある。色鉛筆は、黒芯鉛筆と材料、製法が異なる。原料はタルク（滑石(かっせき)）、タカラントゴム、ろう分、着色染料である。芯は焼成せず、ろう分と着色染料にタルク糊(のり)を加えて練り合わせたものを成形乾燥させてつくる。軸加工は黒芯鉛筆と同じである。

［野沢松男］

種類

大別して黒芯鉛筆と色鉛筆に分けられる。黒芯鉛筆には製図用、事務用、学習用、コピー用、感光紙用、絵画用、大工用、園芸用、手帳用、ガラス用などがある。色鉛筆には赤・青の事務用、芯の軟質・中質・硬質に分かれた各種色鉛筆、それに特殊色鉛筆として絵の具鉛筆、グラフ用、ダーマトグラフ（紙巻き鉛筆）などがある。黒芯鉛筆の場合、黒鉛と粘土の配合割合で硬さおよび濃さが決まる。硬い鉛芯はHardのHで表し、軟らかい鉛芯はBlackのBで表す。Hの数字が増えるほど硬く、また薄く書け、Bの場合は逆に軟らかく濃く書ける。HBは標準の硬度を表す芯だが、HBとHの中間の硬さを表すのにFがあり、これはFirmの略である。JIS(ジス)（日本工業規格）による黒芯鉛筆の硬度の種類は次のとおりである。9H～7H＝硬質面に書写する場合に用いる特殊製図用、6H～5H＝細かい線を描く超精密製図用、4H～3H＝精密製図用、2H～H＝一般製図用、細字用、F～HB＝一般筆記用、製図用、B＝事務用、建築製図用、かきかた鉛筆、2B～3B＝速記用、4B～5B＝一般絵画用、6B＝特殊絵画用。

［野沢松男］