The probability of the impurities to be separated is determined by:

• Physical characteristics of impurity particles
• Characteristics of the pulp
• Conditions in the screen
• Construction and operating principle of the screen

Furthermore, the screen can only separate a certain relative part of the impurities, the operating conditions being stable. This means that with increasing dirt content in feed, the dirt content in accept also increases.

With an increasing consistency, there is a growing network formation. The pulp consistency increases ***while the pulp is forwarded on the screen plate ***as the liquid penetrates even a thick fiber layer.

Не соображу перевод предлогов while/as и их увязку в последнем предложении.
Спасибо за помощь.