An yi tubalin rufi na yumbu mai sauƙi da aka yi da tokar yumbu mai wuta a matsayin kayan da aka yi amfani da shi da kuma yumbu mai filastik a matsayin abin ɗaurewa sannan a ƙara mai ƙonewa ko kumfa mai dacewa ta hanyar harbawa. Rufin rufi na yumbu yana toshe ramukan da ke bayyana a fili kusan 40-85% kuma yawan yawa yana ƙasa da 1.5 g/cm3. Ana amfani da tubalin rufi na yumbu galibi azaman kayan rufi a cikin murhun masana'antu don rage asarar zafi na murhun, adana kuzari da rage ingancin kayan aikin zafi.
Ana samar da tubalin rufi na yumbu mai sauƙi daga yumbu mai ƙarfi da manne mai ƙarfi, ta hanyar yin siminti ta hanyar zafi mai yawa. tubalan rufi na yumbu sune tubalan rufi masu rahusa masu ƙarancin farashi tare da aiki mai girma. Manyan fa'idodin toshe rufin yumbu sune ƙarfin juriya mai yawa a ƙarƙashin kaya, ƙarancin faɗaɗa layi, kyakkyawan juriyar girgizar zafi da ƙarfi mai ƙarfi don tsayayya da zaizayar ƙasa. Wanda aka yi shi da kayan katako na gida mafi girma a ƙarƙashin zafin jiki mai yawa bisa ga ƙa'idar ƙasa mai ɗorewa, wanda ke da yawan yawa, ƙarfi mai yawa, ƙarancin juriyar zafi da ƙarancin ƙazanta.
Blki mai rufi da yumbu samfurin argillaceous ne wanda ke da kusan kashi 30% na abun ciki na Al2O3. An yi shi da yumbu mai laushi 50% da kuma chamotte mai tauri 50% bisa ga wasu ƙananan abubuwa, ana buƙatar a haɗa shi a wuta a zafin jiki mai zafi 1300 ~ 1400 ℃ bayan an yi masa gyare-gyare da bushewa. Babban ma'adinan da ke cikin rufin yumbu ya haɗa da kaolinite (Al2O3·2SiO2·2H2O) da ƙazanta 6 ~ 7% (K, Na, Ca, Ti, Fe oxide).
| Abubuwa | NG-0.6 | NG-0.8 | NG-1.0 | NG-1.3 | NG-1.5 | |
| Matsakaicin Zafin Aiki | 1200 | 1280 | 1300 | 1350 | 1400 | |
| Girma Yawa, g/cm3 | 0.6 | 0.8 | 1.0 | 1.3 | 1.5 | |
| Bayyanannen Porosity, % | 70 | 60 | 55 | 50 | 40 | |
| Ƙarfin Murkushewar Sanyi (Mpa) ≥ | 2.0 | 2.5 | 3.0 | 4.0 | 6.0 | |
| Sake Dumamawa Canjin Layi (%)℃ × 12h ≤ | 1300℃ -0.5 | 1350℃ -0.5 | 1350℃ -0.9 | 1350℃ -0.9 | 1350℃ -0.9 | |
| Maida wutar lantarki mai zafi W/(m·K) | 600℃ | 0.16 | 0.45 | 0.43 | 0.61 | 0.71 |
| 800℃ | 0.18 | 0.50 | 0.44 | 0.67 | 0.77 | |
| Al2O3 | 40 | 40 | 40 | 40 | 42 | |
| SiO2 | 1.5 | 1.5 | 1.5 | 2 | 2 | |
| Fe2O3 | 55 | 55 | 55 | 55 | 55 | |
Ana amfani da tubalin rufin laka musamman don rufin rufin zafi ko kuma rufin rufin zafi na wasu kayan da ba su da ƙarfi. Rufin da ba su da ƙarfi ko kayan da ba su da zafi na masana'antu, kamar, tanderun ethylene pyrolysis, tanderun bututu, tanderun gyaran ammonia na roba, janareto na iskar gas da kuma murhun murhu mai zafi, da sauransu.