Vim li cas tus cwj mem yooj yooj yim hu ua "simple"? Yuav ua li cas lub hardness ntawm ib tug cwj mem cim nyob rau hauv txawv teb chaws?

2024 Tus sau: Howard Calhoun | [email protected]. Kawg hloov kho: 2023-12-17 10:28

Nyob hauv lub neej txhua hnub thiab kev ua haujlwm, peb txhua tus, rau ib qib lossis lwm qhov, xav tau xaum. Rau cov neeg ntawm cov hauj lwm xws li ib tug kws kos duab, engineer, technologist, designer thiab draftsman, xws li ib tug nqi raws li lub hardness ntawm ib tug cwj mem yog ib qho tseem ceeb.

keeb kwm ntawm xaum

Nyob rau xyoo pua 13th, thawj cov qauv ntawm cov xaum ua los ntawm cov nyiaj lossis txhuas tau tshwm sim. Nws tsis yooj yim sua kom tshem tawm yam uas tau sau lossis kos los ntawm lawv. Nyob rau hauv lub xyoo pua 14th, lawv pib siv ib tug pas nrig ua los ntawm av nplaum dub slate, uas hu ua "Italian mem hluav".

Nyob rau xyoo pua 16th, nyob rau hauv lub nroog Askiv ntawm Cumberland, cov neeg yug yaj yuam kev poob rau ntawm qhov tso nyiaj ntawm cov khoom uas zoo ib yam li txhuas. Nws tsis tuaj yeem tau txais cov mos txwv thiab cov plhaub los ntawm nws, tab sis lawv tau zoo heev ntawm kev kos duab thiab kos cov yaj. Lawv pib ua cov pas nrig nyias los ntawm cov graphite, ua kom tiav thaum kawg, uas tsis haum rau kev sau ntawv thiab qias neeg heev.

me ntsis tom qab, ib qhocov kws kos duab pom tias nws yooj yim dua los kos nrog graphite sticks tsau rau hauv tsob ntoo. Qhov no yog li cas yooj yim slate mem hluav tau txais lub cev. Tau kawg, tsis muaj leej twg xav txog qhov nyuaj ntawm tus cwj mem thaum lub sijhawm ntawd.

cwj mem niaj hnub

Qhov saib uas xaum paub rau peb niaj hnub no tau tsim nyob rau thaum xaus ntawm lub xyoo pua 18th los ntawm Fabkis tus kws tshawb fawb Nicolas Jacques Conte. Thaum kawg ntawm XIX thiab pib ntawm XX caug xyoo. Ntau qhov kev hloov pauv tseem ceeb tau ua rau tus qauv siv xaum.

Yog li, suav Lothar von Fabercastle hloov cov duab ntawm lub cwj mem los ntawm puag ncig mus rau hexagonal. Qhov no tau pab txo cov cwj mem dov tawm ntau qhov chaw sau ntawv inclined.

Thiab tus kws tsim khoom Asmeskas Alonso Townsend Crossa, xav txog kev txo qis cov khoom siv, ua tus cwj mem nrog lub cev hlau thiab lub pas nrig graphite uas txuas mus rau qhov ntev uas xav tau.

Vim li cas hardness thiaj tseem ceeb?

Txhua tus neeg uas tau kos lossis kos ib yam dab tsi tsawg kawg yog ob peb zaug yuav hais tias xaum tuaj yeem tawm ntawm cov hlab ntsha thiab cov kab sib txawv ntawm cov xim saturation thiab tuab. Cov yam ntxwv zoo li no yog qhov tseem ceeb rau cov kws tshaj lij engineering, vim tias thaum xub thawj ib qho kev kos duab yog ua tiav nrog cov xaum tawv, piv txwv li T2, thiab nyob rau theem kawg - softer sawv daws yuav, cim M-2M, ua kom pom tseeb ntawm kab.

Qhov nyuaj ntawm tus cwj mem tsis yog qhov tseem ceeb rau cov kws ua yeeb yam, ob qho tib si cov kws tshaj lij thiab cov neeg nyiam ua haujlwm. Cov cwj mem mos mos yog siv los tsim cov duab kos duab thiab kos duab, thiabqhov kawg ua haujlwm ntawm cov khoom yog qhov ruaj khov.

xaum yog dab tsi?

Txhua xaum tuaj yeem muab faib ua ob pawg loj: yooj yim thiab xim.

Ib xaum yooj yim muaj lub npe zoo li no vim tias nws yog cov qauv yooj yim heev, thiab nws sau nrog cov graphite txhuas zoo tib yam, tsis muaj tshuaj ntxiv. Tag nrho lwm hom xaum muaj cov qauv ntau dua thiab yuav tsum tau qhia txog ntau yam xim.

Muaj ob peb hom xim xaum xim, feem ntau yog:

• xim tsis tu ncua, uas tuaj yeem ua tau ob qho tib si thiab ob sab;
• wax;
• coal;
• watercolor;
• pastel.

Kev faib cov cwj mem yooj yim graphite

Raws li twb tau hais lawm, graphite leads raug ntsia rau hauv cov cwj mem zoo tib yam. Xws li qhov taw qhia raws li qhov nyuaj ntawm cov xaum xaum yog lub hauv paus rau lawv cov kev faib tawm.

Ntau lub tebchaws tau txais cov cim sib txawv uas qhia qhov nyuaj ntawm cov xaum, uas feem ntau yog European, Lavxias thiab Asmeskas.

Lavxias teb sab thiab European cov cim ntawm cov hlau lead dub, raws li cov cwj mem zoo tib yam kuj raug hu ua, txawv ntawm Asmeskas ib qho ntawm ob qho tib si ntawm tsab ntawv thiab tus lej tsim.

Qhia qhov nyuaj ntawm tus cwj mem nyob rau hauv Lavxias teb sab cim system, nws tau lees tias: T - tawv, M - mos, TM - nruab nrab. Txhawm rau kom paub meej qhov degree ntawm softness los yog hardness, tus naj npawb qhov tseem ceeb nkag mus rau ib sab ntawm cov tsiaj ntawv tus nqi.

BHauv cov tebchaws nyob sab Europe, qhov nyuaj ntawm cov cwj mem zoo tib yam kuj tau qhia los ntawm cov ntawv sau los ntawm cov lus uas qhia txog hardness. Yog li, rau cov xaum mos, tsab ntawv "B" yog siv los ntawm lo lus blackness (dub), thiab rau cov xaum tawv, tsab ntawv "H" yog siv los ntawm lus Askiv hardness (hardness). Tsis tas li ntawd, tseem muaj qhov cim F, los ntawm lus Askiv zoo point (thinness) thiab qhia qhov nruab nrab hom cwj mem. Nws yog European tsab ntawv hardness marking system uas suav hais tias yog lub ntiaj teb tus qauv thiab yog qhov feem ntau.

Thiab nyob rau hauv American system, uas txiav txim siab hardness ntawm mem hluav, lub npe yog nqa tawm tsuas yog nyob rau hauv cov zauv. Qhov twg 1 yog mos, 2 yog nruab nrab, thiab 3 yog ib qho nyuaj. Yog tsis muaj cim qhia ntawm tus cwj mem, ces los ntawm lub neej ntawd nws yog hom tawv-mos (TM, HB).

Dab tsi txiav txim siab hardness?

Hnub no, kaolin (dawb av nplaum) thiab graphite yog siv los ua graphite mem hluav coj. Lub hardness ntawm tus cwj mem nyob ntawm qhov proportions ntawm cov khoom sib xyaw ntawm thawj theem ntawm kev tsim khoom. Qhov ntau dawb kaolin av nplaum yog pw, lub cwj mem nyuaj dua. Yog hais tias tus nqi ntawm graphite yog nce, ces cov hlau lead yuav softer.

Tom qab sib tov tag nrho cov tsim nyog Cheebtsam, cov resulting sib tov yog pub rau hauv lub extruder. Nws yog nyob rau hauv nws cov rods ntawm ib tug muab loj yog tsim. Tom qab ntawd cov graphite rods raug rho tawm haujlwm nyob rau hauv ib lub qhov cub tshwj xeeb, qhov kub ntawm qhov nce mus txog 10,000 0 C. Tom qab tua hluav taws, cov rods yog immersed nyob rau hauv ib tug tshwj xeeb roj tov uas tsim ib tug nto tiv thaiv txheej.movie.