kaanch

svachh paaradarshi kaanch ka bana prakaash balb

kaach, kaaainch ya kaanch (glass) ek akristaleeya thos padaarth hai. kaanch aamtaur bhangur aur aksar prakaasheeya roop se paaradarshi hote hain.

kaach athav sheesha akaarbanik padaarthon se bana hua vah paaradarshak athva apaaradarshak padaarth hai jisse sheeshi botal aadi banti hain. kaach ka aavishkaar sansaar ke liye bahut badi ghatna thi aur aaj ki vaigyaanik unnati mein kaach ka bahut adhik mahatva hai.

kintu vigyaan ki drushti se 'kaanch' ki paribhaasha bahut vyaapak hai. is drushti se un sabhi thoson ko kaanch kehte hain jo drav avastha se thanda hokar thos avastha mein aane par kristaleeya sanrachana naheen praapt karte.

sabse aam kaach soda-laaim kaach hai jo shataabdiyon se khidkiyaaain aur gilaas aadi banaane ke kaam mein aa raha hai. soda-laaim kaanch mein lagbhag 75% silika (SiO2), sodiym aaksaaid (Na2O) aur choona (CaO) aur anekon anya cheejein kam maatra mein mili hoti hain.

kaaainch yaani SiO2 jo ki ret ka abhinn ang hai. ret aur kuchh anya saamagri ko ek bhatti mein lagbhag 1500 degree sailsiys par pighlaaya jaata hai aur fir is pighle kaaainch ko un khaaainchon mein boond-boond karke undela jaata hai jisse manachaahi cheej banaai ja sake. maan leejiye, botal banaai ja rahi hai to khaaainche mein pighla kaaainch daalne ke baad botal ki satah par aur kaam kiya jaata hai aur use fir ek bhatti se gujaara jaata hai.

anukram

itihaas

kaaainch ka aavishkaar misr ya maisopotaamiya mein lagbhag dhaai hajaar saal isa poorv hua tha. shuru mein iska istemaal saaj-sajja ke liye kiya gaya. fir isa se lagbhag dedh hajaar saal pehle kaaainch ke baratan banane lage. pehli shataabdi aate-aate flasteen aur Syria mein, ek khokhali chhad mein foonk maarkar pighle kaaainch ko manachaahe roop mein dhaalane ki kala viksit hui aur gyaarahaveen shataabdi mein venis shahar kaaainch ki cheejein banaane ka kendra ban gaya.

aadhunik pariprekshya

aajkal ab kaanch banaane ka saara kaam masheenon se hota hai. uchch taap par kaanch ki shyaanata itni kam hoti hai ki usako hava bharake kisi aakaar mein dhaala ja sake, par ye itna taral bhi naheen hota ki paani ki bah jaaye. is prakriya ko glaas bloing kehte hain aur isse tarah tarah ke aakaar banaaye ja sakte hain.

aadhunik vaigyaanik bhaasha mein 'kaach' shabd se

  • (1) padaarth ki ek vishesh 'kaacheeya' avastha samajhi jaati hai athva
  • (2) vah padaarth samjha jaata hai jo kuchh akaarbanik padaarthon ko ooainche taap par dravit karke banaaya jaata hai.

drav kaach hi vaastavik kaach hai; keval drav kaach ke vidyut‌ aur prakaasheeya gun sab dashaaon mein ek se hote hain. drav kaach ko thanda karne par usamein shyaanata (Viscosity) badhti hai aur dheere-dheere bina kaacheeya gunon ka saadhaaran thos kaach ban jaata hai.

kaach banaane ke liye upayog ke anusaar kai prakaar ke kachche maal vibhinn maatraaon mein milaakar, ooainche taap par dravit kiye jaate hain. dravit kaach ko siliketon tatha boreton ka paarasparik vilyan kaha ja sakta hai. is vilyan mein taap ke anusaar bahut kuchh avayav aaksaaidon mein vimukt ho jaate hain. vilyan mein ve atirikt aaksaaid bhi hote hain, jo raasaayanik yogikon ke nirmaan ki aavashkataaon se adhik maatra mein hote hain.

kaach ko 'adhisheetalit' (Under-cooled) drav bhi kaha ja sakta hai, kyonki drav avastha se thos avastha mein kaach ka parivartan kramash: hota hai aur thos kaach mein usaki dravaastha ke sabhi bhautik gun, jaise ooshmaachaalakata ityaadi, hote hain.

kaach ke upaadaan (constituents)

silika kaach ki sanrachana : dhyaan dein ki sanrachana mein adhik doori tak ekaroopata ya punaraavrutti naheen hai ; arthaat yeh akristaleeya hai.

kaach nirmaan ke liye mukhya padaarth silika (Si O2) hai aur yeh prakruti mein mukt avastha evam siliket yaugikon ke roop mein paaya jaata hai. prakruti mein silika adhiktar kvaart‌aaj ke roop mein paaya jaata hai. iska vishuddh roop billaur patthar hai. kaach nirmaan ke liye sabse upayukt saamagri baaloo, baaluka prastar aur kvaart‌aajaait (Quratzite) chattaanein hain. yadi paane ki suvidha, praapya maatra aur dhulaai baraabar ho to baaloo hi sabse upayukt padaarth hai. kaach nirmaan ke liye sabse upayukt vahi baaloo hai jismein silika ki maatra kam se kam 99 pratishat ho aur ferik aaksaaid (Fe2O3) ke roop mein loha 0.1 pratishat se kam ho. baaloo ke kan bhi 0.5-0.25 mileemeetar ke vyaas ke hon. achhe kaach nirmaan ke liye baaloo ko jal dvaara dho bhi liya jaata hai. Allahabad mein shankaragadh aur varagadh ke baaloo ke nikshep kaach nirmaan ke liye ati uttam hain aur uttar pradesh sarkaar ne vahaaain par baaloo dhone ke kuchh yantr bhi laga diye hain.

saadhaaran kaach nirmaan ke liye kuchh kshaareeya padaarth jaise soda aish (Sodium carbonate) ka hona bhi ati aavashyak hai. is mishran se dravanank kam aur dravan kriya saral ho jaati hai. keval in do padaarthon ke dravan se jo kaach banta hai vah jal kaach (Water glass) ke naam se prasiddh hai, kyonki yeh jal vileya hai. kaach ko sthaayi banaane ke liye koi dvismaakshaareeya (dibasic) aaksaaid jaise kailsiym aaksaaid (choona) ya sees aaksaaid ko bhi milaana padta hai. raasaayanik niyam ke anusaar, jitne hi adhik padaarth milaae jaate hain dravanank bhi utana hi kam ho jaata hai. pratyek padaarth kaach mein kuchh vishesh gun utpann karta hai aur in gunon ko hi dhyaan mein rakhate hue kaach ke mishran banaae jaate hain.

kaisiym aaksaaid kaach ko raasaayanik sthaayitv pradaan karta hai, par adhik maatra mein hone par kaach mein vikaachan (devitrification) hone ki pravrutti aa jaati hai. saadhaaran kaach baaloo, soda aur choona ke mishran se banaaya jaata hai.

kailsiym aaksaaid ke liye kaach mishran mein choona ya choona-patthar milaaya jaata hai. borik aml ya suhaaga se kaach mein vishesh bhautik gun utpann ho jaate hain, jaise nyoon prasaar-gunaank aur adhik tanaav sahanasheelata, taapeeya sahan shakti evam adhik jal-pratirodhakata. in gunon ke kaaran taapamaapi nali, laalaten ki chimni aur bhojan pakaane ke paatr aadi aakasmik taap parivartan sahanevaali vastuon ka nirmaan karne mein, borik aaksaaid ki maatra adhik se adhik aur kshaar ki maatra kam se kam rakhi jaati hai.

sodiym korbonet ke sthaan mein anya kshaar jaise potaishiym kaarbenet ka bhi upayog vishesh kaachon mein kiya jaata hai. bahudha kshaar, salfet lavan ke roop mein prayukt hota hai.

sees aaksaaid ke liye adhiktar laal sees (sindoor) ka upayog kiya jaata hai. is aaksaaid dvaara kaach ka ghanatv aur vartanaank donon badhte hain aur is kaaran aisa kaach prakaasheeya (optical) kaachon, bhaajan evam peene ke paatron aur krutrim ratnon ke nirmaan ke upayog mein aata hai. seesayukt kaach sheegra hi kaate aur paalish kiye ja sakte hain. potaash kshaar ka seesayukt kaach sabse adhik chamakadaar hota hai.

ailyoominiym aaksaaid (Al2O3), adhiktar felspaar dvaara kaach mein sammilit kiya jaata hai. is aaksaaid se kaach mein ushmaajanit prasaar, kathorata, sthaayitv, pratyaasthata, tanan shakti, chamak aur aml pratirodhakata badhti hai. iske dvaara kaach mein samaangata aur vaigyaanik kaaryon mein upayogi anya gunon ki vruddhi hoti hai. yeh aaksaaid kaach ka prasaar gunaank aur mrudukaran (annealing) taap kam karta hai. yeh vikaachan ko rokata hai aur iske prayog se kaach ka dravan aur shodh saral ho jaata hai.

jasta aaksaaid (Zn O) praaya: jasta kaarbonet (ZnCO3) dvaara kaach mein sammilit kiya jaata hai. yeh padaarth kaach ke prasaar gunaank ko bahut kam karta hai. kaach mein adhik sthaayitv evam ushmaajanit kam prasaar utpann karne ke kaaran yeh raasaayanik kaach ke nirmaan mein prayukt hota hai. kuchh kaachon mein maigneeshiym ya beriym aaksaaid bhi sammilit kiya jaata hai. kuchh padaarth kaach mein vishesh raasaayanik gun utpann karne ke uddeshya se sammilit kiye jaate hain. sees yukt kaachon mein kuchh aakseekaarak padaarth, jese potaishiym naaitret ya shora ka hona aavashyak hota hai.

kaach ke dravit hone par usamein gas ke bahudha asankhya chhote-chhote bulabule, jinko 'beej' kehte hain, fains jaate hain. kaach ko inse mukt karne ke liye kuchh raasaayanik padaarthon ka upayog kiya jaata hai. ye padaarth drav kaach mein gas ho jaate hain aur beejon ko apne saath kaach ke baahar nikaal laate hain. in padaarthon ko 'shodhak dravya' kehte hain. saadhaaranat: shodhak dravya ke liye kaarban aimoniym lavan ya aarasenik prayukt hota hai. aaloo, chukandar aur bheegi lakdi ke tukade dravit kaach mein daalkar bhi kaheen-kaheen kaach ka shodhan kiya jaata hai.

bhautik gun

kaach ka upayog aisi kai prakaar ki vasatuon mein kiya jaata hai jinmein vibhinn bhautik gunon ki aavashyakta rahati hai. kaach ke bhautik gunon mein bhinnata vibhinn aaksaaidon dvaara laai ja sakti hai. bhautik gun kaach mein upasthit pratyek aaksaaid ki aapekshik maatra par bhi nirbhar karta hai.

ghanatv- kaach mein sabse adhik ghanatv sees aaksaaid dvaara aata hai aur sabse kam borik aaksaaid dvaara.

vaidyut gun- kaach ki vidyuchchaalakata usaki rachana, taap evam vaataavaran par nirbhar hoti hai. aajkal kaach ka upayog achaalak (insulator) ke liye bhi kiya ja raha hai.

taapeeya gun- tapt karne par kaach prasaarit hota hai, par borik aaksaaid evam maigneeshiym aaksaaid ke kaach mein nyoonatam prasaar hota hai aur kshaareeya aaksaaid se adhiktam prasaar.

ushma chaalakata- kaach ushma ka adham chaalak hai; silika tatha borik aaksaaid se kaach mein ushma-chaalakata kam hoti hai. kaach ke anya bhautik gun, jaise yang ka pratayaasthata-gunaank, tanaav shakti, drudhta tatha taapeeya sahanasheelata, kaach mein pade aaksaaidon par nirbhar hote hain. kaach mein inke prabhaav ka vaigyaanik adhyayan karke raasaayanik kaach (jispar kisi raasaayanik padaarth ya taap ka prabhaav naheen padta), ushmaapratirodhak kaach, jo laal tapt kar ekdam barf mein thande kiye ja sakte hain aur taapamaapi kaach ka nirmaan kiya jaata hai.

pattika kaach ki shakti ke pareekshan ke liye pattika ko chaaron kinaaron par rakhate hain aur gyaat bhaar ke ispaat ke ek gole ko vibhinn ooainchaai ke kaach ke maadhya mein svatantrataapoorvak girne dete hain. jis ooainchaai se gole ko giraane par kaach mein daaraar pad jaae vah ooainchaai kaach ki pushtata ki maatrik maap hoti hai. botalon ki pushtata ki pareeksha ke liye botalon ke bheetar jal bharakar jal ki daab dheere-dheere badhaai jaati he ki botalein fat jaaeain.

taapeeya sahanasheelata- achaanak taap parivartan ki us maatra ko, jise kaach bina toote sahan kar sake, kaach ki taapeeya sahanasheelata kehte hain. is gun ke pareekshan ke liye kaach ki vastuon ko jal mein vibhinn taapon tak garam kar barf se thande kiye gaye jal mein achaanak dubo dete hain.

paashchareekaran, bhojan banaane ke bartan, lainp ki chimniyaaain, raasaayanik kaach aur taapamaapi ki nali ke liye, uchch taapeeya sahanasheelataavaale kaach ki aavashyakta hoti hai. kaach mein adhik taapeeya sahanasheelata utpann karne ke liye silika ki maatra adhik aur kshaar ki maatra kam honi chaahiye tatha kaach mein kuchh maatra mein jasta aaksaaid, boran aaksaaid aur ailyuminiym aaksaaid bhi hona chaahiye.

prakaasheeya gun- leinson (leinjon) mein prakaasheeya gun, jaise uchch vartanaank evam vikshepan bhi, kaach mein bhinn aaksaaidon ki maatraaon par nirbhar hain aur isliye sees aaksaaid, beriym aaksaaid aur kailsiym ki maatraaon ko ghataakar badhaakar pratyek bhaaainti ke vishesh vartanaank aur vikshepan ke bahumoolya kaach taiyaar kiye ja sakte hain.

paraabaingani (ultra-violet) prakaash ke paaragaman ke liye paaradavaashpadeep ka kaach kaacheeya silika ka banaaya jaata hai, kyonki ye rashmiyaaain saadhaaran vyaapaarik kaach ke paar naheen ja sakti hai; parantu dravit kvaart‌aaj ke paar ye saralata se ja sakti hain.

shyaanata- kaach nirmaan mein shyaanata bhi ek aavashyak gun hai, kyonki kaach ka dhaman (fooainkana), peedan, karshan aur belana, bahut kuchh kaach ki shyaanata par hi nirbhar rahate hain; abhitaapan mein vikruti ko hataana bhi shyaanata se hi seedha sambandhit hai. kaach ki shyaanata kaach ke aaksaaid avayavon par nirbhar karti hai. silika ki maatra badhaane se kaach ka shyaanata-paraas (reinj) badh jaata hai; choone ki vruddhi se shyaanata badhti hai, parantu shyaanata-paraas kam hota hai. soda ki maatra badhaane se shyaanata ghatati hai, par shyaanata-paraas badhta hai.

vikrutiyaaain

jab kaach ki vastu ko garam kiya jaata hai to baahar ki satah bheetar ke bhaagon ke apeksha adhik garam ho jaati hai aur isi prakaar jab tapt dravit kaach ko thanda karke thos kiya jaata hai tab thos hote samay kaach ke baahar ki satah bheetar ki apeksha adhik thandi ho jaati hai. taap mein antar hone ke kaaran kaach mein asamaan prasaar ya aakunchan aa jaata hai, jiske falasvaroop uske bheetar pratibl utpann ho jaate hain aur kaach mein tadanuroop vikrutiyaaain aa jaati hain.

nirmaan ke samay kaach tapt rahata hai, isliye thanda hone par kaach ki vastuon mein pratibl aur vikrutiyaaain aa jaati hain. inko hataane ki kriya ko kaach ka abhitaapan (annealing) kaha jaata hai. is vidhi mein kaach ki vastuon ko fir se kaach ko komal honevaale taap se kuchh kam taap par ek samaan tapt kar diya jaata hai. isse shyaanata ke parivartan ke kaaran kaach vikrutiyon se mukt ho jaata hai. tab kaach ko bahut dheere-dheere thanda kiya jaata hai. yeh abhitaapan-paraas bhi kaach ke aaksaaid avayavon par nirbhar rahata hai. adhik kshaarayukt kaach paryaapt nimn taap par abhitaapit kiye ja sakte hain. jatil kaach ka, jaise raasaayanik kaach ushma pratirodhak kaach ka, abhitaapan taap bahut ooaincha hota hai. prakaasheeya kaachon ke abhitaapan mein bahut adhik sam lagta hai; kyonki unako bahut dheere-dheere thanda karna hota hai jinmein ve praaya: vikrutiheen hon. sansaar ke sabse bade 200 inch vyaas vaale dooraveekshan yantr ke kaach ko thanda karne ke liye ek varsh se oopar samay laga tha.

sthaayitv

jin kaach paatron mein aushadhi, bhojan ya peya rakha jaata hai, unke kaachon par bahut samay tak dravon ki raasaayanik kriyaahone ki sambhaavana rahati hai. sabhi raasaayanik kaach-vastuon ko jal, aml aur kshaar ka sankshaaran (corrosion) sahana padta hai. dvaaravaale evam prakaasheeya kaachon ko ritukshaaran sahana padta hai. at: yeh aavashyak hai ki in kaachon mein aise gun hon ki poorvokt sankshaaranon ka unapar nyoonatam prabhaav pade.

kaach ka sthaayitv kaach ke bhinn aaksaaid avayavon ki maatraaon par nirbhar hai. sthaayitv badhaane ke liye sarvottam padaarth jasta aaksaaid hai aur iske baad ailyoominiym, maigneesiym aur kailsiym aaksaaid hain. kshaar ki maatra adhik haane par kaach ka sthaayitv ghatata hai. borik aaksaaid 12 pratishat tak kaach ka sthaayitv badhaata hai aur taduparaant sthaayitv ghatata hai. kshaareeya aaksaaid ke sthaan mein silika badhaane se bhi sthaayitv mein vruddhi aati hai.

rangeen kaach

rangeen kaachon ke nirmaan ke liye vibhinn prakaar ke varnakon ko kaach-mishran mein daala jaata hai. inka byora neeche diya jaata hai.

kaach ka rang -- varnaka—aavarnak ki maatra (prati 1,000 bhaag baaloo)

peela -- kaidimiym salfaaida—a20-30 bhaag, gandhak 5-10 bhaag

bhoora (amber) -- kaarbana—a5-10 bhaag, gandhak 2-4 bhaag

hara -- kromiym aaksaaida—a1-2 bhaag

neela -- kobaalt aaksaaida—a1-3 bhaag

upala—aakraayolaaita—a100-120 bhaag

aasamaani -- kyooprik aaksaaida—a10-20 bhaag

laal -- svarn kloraaida—a1-4 bhaag

laal -- sileeniyma—a8-15 bhaag

kaach nirmaan ke liye pise kachche padaarthon ko taulakar khoob milaaya jaata hai aur taduparaant unhein bhatthi mein rakhakar dravit kiya jaata hai.

kuchh aadarsh kaachon ki sanrachana

kuchh aadarsh kaachon ki sanrachana aur upayukt kaachamishran neeche diye ja rahe hain :

saamaanya kaach

saamaanya kaach avayav aur unki maatra
avayav % nyoonatam % adhiktam
SiO2 68,0 74,5
Al2O3 0,0 4,0
Fe2O3 0,0 0,45
CaO 9,0 14,0
MgO 0,0 4,0
Na2O 10,0 16,0
K2O 0,0 4,0
SO3 0,0 0,3

dhamanaad dvaara nirmit bhaarateeya kaach

sanrachana -- mishran

silika (SiO2) 74ऽ baaloo 1000 bhaag

kailsiym aaksaaid (CaO) 7ऽ choona patthar 169 bhaag

sodiym aaksaaid (Na2O) 19ऽ soda aish 439 bhaag

yantranirmit chaadari kaach

sanrachana -- kaach-mishran

silika (SiO2) 72ऽ baaloo 1000 bhaag

ailyumina (Al2O3) 1.6ऽ ailyumina 22 bhaag

kailsiym aaksaaid (CaO) 10.4ऽ choona patthar 257 bhaag

sodiym aaksaaid (Na2O) 16.0ऽ soda aish 380 bhaag

poorn manibh kaach (crystal glass)

sanrachana kaach mishran

silika (SiO2) 52.5ऽ baaloo 100 bhaag

sees aaksaaid (PbO) 33.8ऽ laal sees 660 bhaag

potaisiym aaksaaid (K2O) 13.3ऽ potaash 330 bhaag

shora 40 bhaag

yantranirmit vidyut‌-prakaash-deep ke liye kaach

sanrachana kaach-mishran

silika (SiO2) 72.5ऽ baaloo 1000 bhaag

ailyumina (Al2O3) 1.6ऽ ailyumina 22 bhaag

kailsiym aaksaaid (CaO) 4.9ऽ choona patthar 121 bhaag

maigneeshiym aaksaaid (MgO) 3.5ऽ maignesaait 101 bhaag

sodiym aaksaaid (Na2O) 17.5ऽ soda aish 413 bhaag

ushma pratirodhak kaach

sanrachana kaach-mishran

silika (SiO2) 73.9ऽ baaloo 1000 bhaag

ailyumina (Al2O3) 2.2ऽ ailyumina 30 bhaag

sodiym (Na2O) 6.7ऽ soda aish 155 bhaag

borik aaksaaid (B2O3) 16.5ऽ borik aml 395 bhaag

raasaayanik kaach (paaireks)

saranchana kaach-mishran

silika (SiO2) 80.6ऽ baaloo 1000 bhaag

ailyumina (Al2O3) 2.2ऽ ailyumina 25 bhaag

maigneeshiym aaksaaid (M2O) 0.3ऽ maignesaait 8 bhaag

borik aaksaaid (B2O3) 11.9ऽ borik aml 262 bhaag

sodiym aaksaaid (Na2O) 3.9ऽ soda aish 83 bhaag

potaishiym aaksaaid (K2O) 0.7ऽ potaash 13 bhaag

inhein bhi dekhein

baahari kadiyaaain