context: Mechanical pulping yields almost a tonne of pulp per tonne of dry wood used, which is why mechanical pulps are sometimes referred to as "high yield" pulps. With almost twice the yield as chemical pulping, mechanical pulps is often cheaper. Mass-market paperback books and newspapers tend to use mechanical papers. Book publishers tend to use acid-free paper, made from fully bleached chemical pulps for hardback and trade paperback books.
question: రసాయన పల్పింగ్ ప్రక్రియతో పోలిస్తే యాంత్రిక పల్పింగ్ ప్రక్రియ ఎన్ని రెట్లు ఎక్కువ దిగుబడి ఉత్పత్తి చేస్తుంది?
answers: twice