Oil-proof Paper Production Process

Raw Material Selection: The main raw material for greaseproof paper is wood pulp, typically bleached sulfate wood pulp or bleached sulfite wood pulp, to ensure the paper's purity and strength. Some high-end greaseproof papers also add chemical additives to enhance their oil-resistant properties.

Pulping and Mixing: The wood pulp is pulped using a pulper to adjust fiber length and pulp concentration. Subsequently, oil-resistant agents, wet-strength agents, and other chemical additives are added according to product requirements, and the mixture is thoroughly mixed to form the mixed pulp.

Paper Forming: The mixed pulp is formed on the wire section of a paper machine to create a wet paper sheet. During this process, the wire speed and dewatering rate have a significant impact on the paper's uniformity and strength. Typically, the wire speed is controlled at 500-800 meters per minute, and the dewatering rate needs to be adjusted according to the pulp characteristics.

Pressing and Drying: The wet paper sheet passes through the press section to remove excess water and then enters the drying section. The drying temperature is typically controlled at 100-120℃ to ensure the paper's smoothness and strength. The moisture content of the dried paper needs to be controlled between 5% and 8%.

Coating Treatment: To improve oil resistance, some oil-resistant papers undergo a coating treatment. The coating solution is usually made of materials such as polyethylene (PE) or polypropylene (PP), and is evenly applied to the paper surface using a coating machine. The coating amount is generally 5-10 g/m².

Slitting and Packaging: The dried paper is slitting into the required specifications using a slitting machine. Common specifications are 300mm × 300mm or customized sizes. After quality inspection, the slitting paper is packaged and stored.