FOR300H1 Study Guide - Final Guide: Sheet Moulding Compound, Headbox, Compression Molding
Document Summary
Paper coating is a cheap paint that covers up defects in the paper surface structure. 80% of the coated paper properties depend on the properties of the base paper. The coating solution may also contain clay, fumed silica, and talcum powder as these are also common pigments used in paper coatings. To reduce the demand on forest biomaterials paper is made with less and less fibre and more and more fillers (such as clay). The headbox is located at the beginning of the paper machine. Here, the pulp solution is injected into the space directly between two continuously rotating wires. These wires carry the pulp into the gap former, which rapidly drains the excess water from both sides. This immobilizes the pulp within milliseconds from leaving the headbox and takes it from being pulp suspended in a solution to a continuous web of paper.
