Defoamers, as a subset of paper auxiliaries, wield significant influence within the paper industry despite their relatively minor quantity. Foam interference during coating processes can disrupt normal production flows and paper quality. Consequently, various methods are employed to counteract foam accumulation, including chemical, physical, and mechanical approaches. Among these, chemical methods prevail due to their widespread application.

The primary operational principle involves introducing specialized additives during production, thereby regulating foam via defoamers. These substances exhibit robust surface activity, displacing or neutralizing foaming agents within the production system. By reducing surface tension, they prevent the formation of durable bubble films, leading to foam collapse.

Foam suppression mechanisms aim to disrupt the conditions conducive to foam formation. Two mechanisms govern bubble inhibition: Firstly, foam inhibitors initially adsorb onto bubble membranes, subsequently displacing or nullifying the foaming agent. Due to their strong spreading properties and minimal cohesion, foam formation is impeded. Secondly, defoamers replace foaming agents within bubble films, generating an inelastic film prone to destruction under gas pressure, thereby preventing foam formation.

Defoamers are categorized into silicone, non-silicone, and polyether types. Silicone defoamers boast potent defoaming effects, albeit incomplete emulsification can compromise their efficacy. Non-silicone variants encompass organic compounds like fatty amides and phosphoric esters, albeit they exhibit limited ability in dense foam elimination. Polyether defoamers comprise block copolymers of propylene oxide and ethylene oxide.

Typically, defoamer products encompass three components: active ingredients, dispersants, and carriers. Active ingredients confer defoaming properties, often comprising oily substances with poor hydrophilicity. Dispersants aid in defoamer dispersion, enhancing efficacy. Carriers serve to dilute and disperse defoamers and dispersants, commonly utilizing water or organic solvents.

Presently, coating defoamers predominantly feature polyether and modified silicone as active ingredients. These compounds not only offer robust anti-foaming capabilities but also exhibit diverse functionalities such as glazing, lubrication, and emulsification. They demonstrate excellent thermal and chemical stability, rendering them ideal for coating applications. In practice, polyether is often combined with other defoamers like fatty acid derivatives and silicone to form composite defoamers.

Qingdao Jieruixin Machinery & Technology Co., Ltd. offers a diverse range of defoamers tailored for paper coating processes. For inquiries, please do not hesitate to contact us!