Paper Cobb Sizing Tester

The Cobb Sizing Tester evaluates the water absorbency of paper-based materials by measuring the weight increase of a sample after exposure to water for a specified time. It is an essential quality control tool for assessing the material's resistance to water, ensuring performance in various applications like printing and packaging.

Features and Design

1. Material Construction:

   • Made of stainless steel, ensuring durability and resistance to corrosion.
   • Includes a stainless steel roller for drying the wet sample after testing.

2. Rotational Mechanism:

   • Equipped with a circular pan that rotates 180°, facilitating even water exposure.

3. Spring-Loaded Clamping System:

   • Ensures a leak-proof seal by pressing the cylinder against the sample on a rubber mat.
   • The clamping force is adjustable, and the cylinder can be easily lifted by pinching two handle bars together.

4. Tilting Lid Design:

   • The lid is secured using spring-loaded finger grips, allowing for smooth operation.

Operational Process

1. Sample Preparation:

   • Measure the GSM (grams per square meter) of the circular sample of paper or paperboard.
   • Place the sample in the circular pan filled with water.

2. Testing:

   • Rotate the pan 180° to ensure uniform water exposure.
   • Allow the sample to sit in the water for a specified duration.

3. Absorbency Measurement:

   • After exposure, remove the sample and weigh it to determine the water absorbed.
   • Use the stainless steel roller to press and dry the sample.

4. Final Calculations:

   • Measure the GSM of the dried sample.
   • Compare the before-and-after weights to calculate the water absorptiveness or Cobb value.

Key Parameters and Insights

• Cobb Value Definition:
  The mass of water absorbed in a specific time by one square meter of material under controlled conditions.
• Applications:
  Evaluates additives applied during manufacturing that enhance printing quality and liquid resistance.
• Materials Tested:
  Paper, paperboard, and corrugated fiberboard.

Benefits

• Provides accurate and reproducible results.
• Ensures better material selection for water-resistant applications.
• Enhances the quality of products by verifying resistance to liquids.

The Cobb Sizing Tester is a simple yet indispensable tool for ensuring paper-based materials meet industry standards for water resistance