There are two types of sizing agent that are internal sizing agent and surface sizing agent. Internal sizing agents are used in papermaking process at the wet end. The wet-end sizing agent decrease dusting, control the spread of inks, improve paper quality, smoothness, dimension stability and decrease porosity. The most important internal sizing chemicals are alkyl ketene dimer (AKD), rosin and alkyl succinic anhydride (ASA). The basics characteristic of sizing agent, it should have strongly bonded fibers. The internal sizing agent can also be classified into acidic type sizing chemical and basic or neutral type sizing chemical.
Surface sizing agent contain hydrophilic and hydrophobic end that forms a thin film on paper. The thin film reduces paper dust then improves the strength of the paper surface, printability and water resistance of the paper. There are numerous different chemical that contain acid that used as surface-sizing agent such as modified starches, styrene maleic anhydride, ethylene acrylic acid and many more. The acidity in paper sizing not only make the paper last longer but it will slowly deteriorate the paper with the interaction of chemical substances in the paper.
Acidity in inks also can make paper deteriorate. Much permanent writing ink contains iron sulfate, gallic and tannic…show more content… The material in paper basically contains acid based. The pH number on scale from 0 to 14 measures acidity. A pH of 7 is neutral. Above pH7 is the alkaline range while below pH7 is the acidic range. Materials with pH above than 7 are described as alkaline-buffered. In some cases, such materials offer additional long-term protection against acids. In 1850, papers were produced from cotton rags and linen. Such papers are literally for centuries. After 1850, as the demand for papers and utilization of them increased, linen and cotton rags began to be used in paper manufacturer as the