Film Press (Application Press) in Paper Machine

The film press, also known as the application press, is positioned directly after the pre-drying section in a paper machine. It functions as a two-roll press with an inclined axis, utilizing a lever mechanism with hydraulic or pneumatic pressure to control the load.

Design Features

Pressure Control:

• Pressure is adjustable from 0 kN/m to a maximum load of 40 kN/m, controlled according to technological requirements.

Coating Medium:

• Coating medium (e.g., a mixture of starch, sizing agent, AKD, pigment) is transported to a dosing chamber and then to the calibrating space.
• The thickness of the applied media on the paper surface is calibrated using profiled bars.

Press Rolls:

• Designed to handle maximum load and dynamically balanced for the required speed.
• Covered with special coatings based on the type of paper produced.
• Bearing structure is made of common or stainless steel, as per customer requirements.
• Profiled bars, with diameters ranging from 10 to 38 mm, are made of stainless steel and chrome-plated.

Paper Surface Treatment

1. Surface Sizing:

   • Improves paper quality and reduces sizing agent consumption due to better retention compared to sizing in substance.

2. Surface Treatment with Special Agents:

   • Achieves hydrophobic and greaseproof properties.

3. Surface Dyeing:

   • Saves costs compared to dyeing in substance, achieves special color effects, and reduces wastewater pollution.

4. Application of Thin Special Coatings:

   • Thermoplastics, pigments, clays, etc.

Main Parts

1. Bearing Structure (1):

   • Comprises stands fixed by bolts and locks.

2. Stationary Press Roll (2):

   • Provides a stable press surface.

3. Movable Press Roll (3):

   • Adjustable to control the pressure applied.

4. Coating Head with Profiled Bar (4):

   • Distributes and calibrates the coating medium on the paper surface.

5. Paper Guide Roll:

   • Guides the paper through the press.

6. Sizing Agent Supply (5) and Outlet:

   • Manages the flow of the sizing agent to and from the press.

7. Hydraulic and Pneumatic System (6):

   • Controls the loading and operation of the press.

8. Safety Guards and Machine Foot Bridges (7):

   • Ensures operator safety and provides maintenance access.

Accessories

• Press Rolls and Profiled Bars Drive:

  • Powers the movement and operation of the press rolls and bars.

• Control System with Console:

  • Manages the operation and adjustments of the film press.

• Paper Rope Threading:

  • Assists in threading the paper through the press.

• Sizing Agent Preparation System:

  • Includes a working station and starch kitchen for preparing the sizing agent.

• Cross Knife Before Film Press:

  • Cuts the paper web before it enters the film press.

• Air Blowing (Air Turn) After Film Press:

  • Dries the paper after it exits the film press.

• Infra-Drying:

  • Provides additional drying using infrared technology.

• Retaining Tank Under Film Press:

  • Collects excess sizing agent.

Advantages

1. Thicker Coated Layer:

   • Provides a thicker coating layer compared to standard size presses.

2. Operating Cost Savings:

   • Reduces energy consumption in the after-drying section due to sizing at higher concentrations.

3. High Operating Reliability:

   • Ensures consistent performance and minimal downtime.

4. Optimal for High Speeds:

   • Replaces size press for speeds higher than 650 m/min.

The film press enhances paper quality through effective surface treatment, offering significant benefits in terms of coating thickness, operational efficiency, and cost savings. It is an essential component for high-speed paper machines aiming for superior product quality and performance.