In , the wood is ground against a rotating stone. This method yields a high volume of pulp – up to 95% of the wood becomes paper – but the resulting product is relatively low quality, yellowing quickly due to residual lignin. This type is typically used for newsprint and telephone directories.
The fifth stage is , where the recovered fibres are beaten to swell and roughen them, improving their ability to bond. Finally, stage six: paper making , where the cleaned pulp is diluted, spread onto a wire mesh screen to drain water, pressed between rollers, and then heated to dry. paper production and recycling ielts listening
Stage four is , arguably the most complex step. Air bubbles are forced through the pulp while a chemical – a surfactant – attaches to the ink particles. The bubbles rise to the surface, forming a frothy layer of ink that is skimmed off. This process can remove up to 90% of printing ink. In , the wood is ground against a rotating stone