Copperplate silicone paper, a specialty paper widely used in food packaging and baking, undergoes a solvent evaporation process during its production that is directly related to product safety and health risks. The core goal of this process is to completely remove the solvent from the paper base through physical means, preventing residual substances from migrating into food under high-temperature conditions. However, improper control can pose serious safety risks.
Copperplate silicone paper typically consists of a backing paper, a solvent layer, and a silicone oil layer. The solvent layer serves to bond the silicone oil to the backing paper, forming a stable coating structure. In standard production processes, the solvent undergoes two drying processes: the first drying process removes most of the solvent, and the second drying process ensures that the residual amount is reduced to below safety standards. However, some small workshops or "three-no" products may shorten the drying time, lower the temperature, or reduce the number of drying cycles to reduce costs, resulting in incomplete solvent evaporation. These solvents often contain hazardous substances such as hydrogenated terphenyls, toluene, and xylene, which can precipitate and leach into food during high-temperature baking. Long-term ingestion can cause chronic poisoning or cancer risks.
The safety of the solvent evaporation process is also reflected in the control of the production environment. Reputable manufacturers equip their enclosed drying equipment with exhaust gas treatment systems, which recover solvents through condensation, adsorption, or catalytic combustion, reducing volatile organic compound (VOC) emissions. However, non-regulated production sites may lack such equipment, resulting in solvents being released directly into the air. This not only pollutes the environment but can also harm workers' health through respiratory or skin contact. For example, workers exposed to high concentrations of toluene over a long period of time may experience dizziness, nausea, and even neurological damage.
From a materials science perspective, solvent selection is closely linked to evaporation efficiency. High-quality copperplate silicone paper production often utilizes low-toxic, volatile, and environmentally friendly solvents, such as ethanol or isopropanol. These solvents have low boiling points and easily evaporate completely during the drying process. However, some inferior products may use benzene-based solvents, which have higher boiling points and strong residual properties. These solvents require higher temperatures or longer times to evaporate, increasing production energy consumption and safety risks. Furthermore, the compatibility of the solvent with the silicone oil must be rigorously tested. If the solvent fails to evenly dissolve the silicone oil, uneven coating thickness can result, further impacting release properties and high-temperature resistance.
The integrity of the solvent evaporation process also directly impacts the heat resistance of copperplate silicone paper. The temperature resistance range marked on legitimate products assumes complete solvent evaporation. If residual solvent is not completely removed, high temperatures may accelerate its decomposition, releasing harmful gases and reducing the stability of the silicone oil layer. For example, when used in an air fryer or oven, copperplate silicone paper from which the solvent has not evaporated may experience localized overheating, leading to cracking of the coating and even fire.
Consumers can indirectly assess the compliance of the solvent evaporation process by observing product labeling and user experience. A pungent chemical odor after opening the package, or signs of coating peeling or discoloration during use, may indicate excessive solvent residues and require immediate discontinuation.
The solvent evaporation process for copperplate silicone paper is a critical step in ensuring its safety. From raw material selection to production equipment and quality testing, every step must strictly adhere to environmental and health standards. Consumers should prioritize reputable brands, verify compliance standards, and avoid reuse to minimize health risks.
