| Abstract | Punila su slabo topivi anorganski pigmenti bijele boje, karbonati, silikati, sulfati, oksidi i sulfidi koji se mogu dodavati u masu papira prilikom industrijske proizvodnje papira ili naknadno u obliku premaza kod izrade premazanih papira. Utjecaj punila na svojstva papira je višestruk, od povećanja stupnja bjeline,gramature i upojnosti do utjecaja na opacitet, čime se doprinosi tiskovnoj kvaliteti, što posebno dolazi do izražaja kod tanjih papira,a naročito ako se oni koriste za obostrani tisak. Čestice punila ometaju međuvlaknasto vezivanje što prvenstveno utječe na smanjenje čvrstoće papira, otpornost papira na kidanje, savijanje i cijepanje. Kod jako punjenih papira, kod kojih udio punila dostiže i 30% ukupne mase papira, retencija punila u listu je nejednolika što se manifestira dvostranošću papira. Ispitivat će se sadržaj punila (pepela u papiru). Pod pojmom pepela u papiru, kartonu i lepenki podrazumjevaju se neispareni i nesagorivi neorganski sastojci koji ostaju nakon spaljivanja na temperaturi 550/925°C (zavisno od vrste papira i punila). U završnom radu će se ispitivati sadržaj punila na više različitih papira na uređaju Mufolna peć, te izvršiti usporedba sa optičkim svojstvima tih papira, poglavito sa opacitetom, na uređaju Elrepho. Očekuje se da papiri s većim sadržajem punila pokazuju veći opacitet bez obzira na njihovu debljinu i/ili gramaturu. |
| Abstract (english) | Fillers are poorly soluble inorganic white color pigments, carbonates, silicates, sulfates, oxides and sulfides that can be added into the paper during the industrial paper production, or later in the form of coatings in making coated papers.Filler can infuluence on many paper properties, like paper whitness increase, basis weights and water absorption, opacity, thereby contributing to the quality of the press, which is particularly evident in thin paper, especially if they are used for duplex printing. Filler particles interfere for bonding which primarily affects the reduction of paper strenght, tensile breaking strenght, bending stifness, and tearing resistance. In papers with high fillers percentage when filler reaches 30% of the total weight of paper, the retention of the fillers is uneven, which is manifested in duality of paper.In this paper, the filler content (ash content) of the paper sample will be determined. The term ash in paper and paperboard includes the non-evaporated and incombustible inorganic ingredients that remain after incineration at temperatures 550/925 °C (depending on the used method). This paper will examine filler content in several paper samples using muffle furnace unit and later comparison of the optical properties of the paper, especially with the opacity, on the device Elrepho. It is expected that papers with higher filler content will show greater opacity, regardless of their thickness and / or weights. |
