Yog vim li cas ib tug yooj yim mem hluav yog hu ua "tej yam yooj yim"? Yuav ua li cas mus kos tus cim ib tug cwj mem hardness nyob rau hauv ntau lub teb chaws?

Nyob rau hauv txhua txhua hnub lub neej thiab ua hauj lwm, peb txhua tus, nyob rau hauv cov zaubmov, yuav tsum cwj mem qhuav. Rau cov neeg xws professions li ib tug artist, engineer, Technologist, designer thiab draftsman teeb meem ntawm tej kev tseem ceeb raws li cov hardness ntawm tus xaum.

Cov zaj dab neeg ntawm tus xaum

Nyob rau hauv lub XIII xyoo pua thawj prototypes ntawm tus cwj mem qhuav no yog ua los ntawm cov nyiaj los yog cov hlau lead. Lwv yam uas lawv tau sau los yog kos, nws yog tsis yooj yim sua. Nyob rau hauv lub XIV xyoo pua, peb pib siv ib tug pas nrig ua los ntawm av nplaum dub slate, uas hu ua "Italian mem hluav."

Nyob rau hauv lub XVI xyoo pua nyob rau hauv lub English lub zos ntawm Cumberland yug yaj ntawd tuaj nyob rau ib deposit ntawm cov ntaub ntawv uas zoo heev uas zoo sib xws yuav ua. Cia nyias thiab zoo li tawm ntawm nws yog tsis muaj, tab sis lub kos thiab daim ntawv lo lub yaj lawv muab tawm zoo kawg thiab. Graphite steel rau tsim nyias rods sharpened thaum kawg, uas yog tsis haum rau kev sau ntawv thiab zoo heev puas.

Tej lub sij hawm tom qab ib qho ntawm qhov nyuab pom tias kos graphite nrog, fastened nyob rau hauv ib tsob ntoo, ntau npaum li cas yooj yim. Qhov ntawd yog yuav ua li cas yooj yim slate cwj mem qhuav thiab lub cev nyob. Ntawm cov hoob kawm, tsis muaj ib tug lwm yam, thiab kuv tsis tau xav hais tias nyob rau hauv lub sij hawm txog tus xaum hardness.

niaj hnub cwj mem qhuav

Lub hom nyob rau hauv uas tus cwj mem qhuav paub rau peb hnub no, yees ua nyob rau hauv lub lig XVIII xyoo pua Fabkis tus paub txog Nicolas Zhak Konte. Nyob rau hauv lub lig XIX thiab thaum ntxov XX caug xyoo. Ob peb kev hloov tseem ceeb tau ua nyob rau hauv lub tsim ntawm tus cwj mem qhuav.

Yog li, Graf Lotar von Faberkastl hloov qhov zoo ntawm ib tug cwj mem ntaub ntawv nrog ib puag ncig nyob rau hauv hex. Qhov no txo skatyvaemost cov cwjmem qhuav nrug txawv inclined chaw siv rau kev sau ntawv.

Ib tug US inventor Alonzo Townsend Cross, xav txog txo tus nqi ntawm cov consumable cov ntaub ntawv uas nyob rau hauv mem hluav nrog ib tug hlau cov ntaub ntawv thiab laub rau qhov kev kawm ntev ntawm lub graphite pas nrig.

Yog vim li cas yog nws thiaj li tseem ceeb hardness?

Neeg twg uas muaj tsawg kawg yog ib ob peb ntawm lub sij hawm uas ib tug kos los yog ntuj raug txim, hais tias cwjmem yuav tawm cwj nrag thiab kab, differing nyob rau hauv cov xim saturation thiab thickness. Tej yam ntxwv tseem ceeb heev rau engineering disciplines, rau tej yam ua ntej yog nqus yog ua ib tug khoom stick, piv txwv li T2, thiab nyob rau theem kawg - softer, sau tias M-2 m ua rau kom cov clarity kab.

Attendance tseem ceeb yog lub hardness ntawm tus xaum kev nyuab thiab ob cov tub txawg thiab amateurs. Yuav kom tsim sketches thiab drafts Siv ib tug cwj mem nrog mos lead, thiab ua hauj lwm rau lub qhov kawg kev cai - nyuab me ntsis.

Yuav ua li cas yog tus cwj mem qhuav?

Tag nrho cov cwjmem yuav tau muab faib ua ob pawg: yooj yooj yim thiab muaj yeeb yuj.

Cwj mem qhuav muaj no npe vim hais tias nws yog structurally yooj yim heev, thiab nws sau cov feem ntau graphite mem hluav, tsis muaj additives. Tag nrho lwm yam cwj mem qhuav muaj ntau nyuaj thiab yuav tsum tau cov kev taw qhia txog ntau yam dyes.

Hom xaum zoo nkauj npaum li cas rau feem ntau - yog:

• txheem xim, uas tej zaum yuav yog ib tug-ib tog los yog ob mog;
• siv quav ciab;
• thee;
• watercolor;
• pastel.

Ib suam ntawm tej yam yooj yim graphite cwj mem qhuav

Raws li twb tau hais, nyob rau hauv ib tug yooj yim mem hluav set mem hluav graphite. Qho kev taw qhia xws li ib tug cwj mem hardness ntawm mem hluav txhuas, yog lub hauv paus rau kev sib faib.

Txawv teb chaws muaj kev sib txawv cim ua qhia lub hardness ntawm tus cwj mem qhuav, ntawm uas lub feem ntau lug siv European, Lavxias teb sab thiab American.

Lavxias teb sab thiab European labeling chernografitnyh no kuj hu ua tus cwj mem qhuav, txawv los ntawm lub American muaj raws li ib tug literal raws li cov signage.

Yuav kom xa mus rau ib tug cwj mem hardness nyob rau hauv Lavxias teb sab labeling system, nws yog assumed tias: T - ruaj M - mos mos, TM - nruab nrab. Yuav kom meej lub degree ntawm softness los yog hardness tswvcuab nyob ze ntawm lub alphabetic, numeric qhov tseem ceeb.

Nyob rau hauv European lub teb chaws, ib tug yooj yim mem hluav hardness li denoted los ntawm cov tsiaj ntawv, coj los ntawm cov lus characterizing lub hardness. Yog li ntawd, siv tsab ntawv «B» los ntawm cov cia li tsaus tsaus ntawm lo lus (dub), thiab rau ib qho nyuaj rau cov mos mos cwj mem qhuav - tsab ntawv «H» los ntawm cov lus Askiv hardness qhab nias (hardness). Nyob rau hauv tas li ntawd, muaj kuj yog npav lub F, mus los ntawm lus Askiv zoo point (fineness) thiab cov uas qhia qhov nruab nrab hom cwj mem. Nws yog ib lub European system ntawm labeling ntawv hardness yog xav tau lub ntiaj teb no tus qauv thiab yog feem ntau.

Nyob rau hauv lub American system, uas yog txiav txim los ntawm lub hardness ntawm tus cwj mem qhuav, npav yog nqa tawm tsuas yog nyob hauv cov nuj nqis. Qhov twg 1 - me ntsis, 2 - nruab nrab, thiab 3 - khoom.
Nyob rau hauv cov ntaub ntawv uas, yog tias ib tug cwj mem yog tsis sau tseg qhia, tsis muaj npav, los ntawm neej ntawd hais, nws belongs rau lub hard-mos (TM HB) ntaus ntawv.

Yuav ua li cas txiav txim rau lub hardness?

Niaj hnub no, rau qhov siv thiab ua cov cwj mem lead graphite mem hluav siv kaoline (av nplaum dawb) thiab graphite. Lub proportions ntawm cov tshuaj yuav tsum tau tov nyob rau hauv thawj zaug rau theem ntawm ntau lawm nyob rau hauv lub hardness ntawm tus xaum. Qhov ntau pw dawb kaolin av nplaum, lub nyuab me ntsis rau tus xaum ntawv yog tau. Yog hais tias lub zog npaum li cas ntawm graphite, tus xaum yog softer.
Tom qab nws tag nrho cov tsim nyog Cheebtsam ntawm lub resulting sib tov yog noj mus rau hauv lub extruder. Qhov no yog qhov twg lub rods txoj kev lub teeb tus nqi. Ces calcined graphite rods nyob rau hauv ib tug tshwj xeeb cua sov nyob rau qhov kub thiab txias nce mus txog 10 000 ⁰ C. Tom qab tua, lub rods yog immersed nyob rau hauv ib tug tshwj xeeb cov roj tov, tsim ib tug saum npoo kev tiv thaiv zaj duab xis.