COBB Water Absorbency Test For Cardboards Paper Quality Testing And Cardboard Circular Sample Cutter Paper Cobb Sampler

Introduction to the COBB-01 Tester

The COBB Water Absorbency Test is an essential method for evaluating the water absorption capacity of paper and cardboard materials. The COBB-01 COBB Tester is specifically designed for this purpose, effectively assessing water absorption through the Cobb method. It is particularly useful for sizing paper and determining water absorbency on cardboard surfaces. However, it’s important to note that this test is not recommended for basic paper, embossed paper with a basis weight below 50 g/m², or unsized paper, as these materials can lead to inaccurate results.

Understanding the COBB Test

The COBB Water Absorbency Test measures the water absorption capability of paper and cardboard surfaces. The resulting Cobb value indicates the mass of water absorbed by the material per unit area, expressed in grams per square meter (g/m²), under specific testing conditions and timeframes.

Recommended Test Timing

According to international standards, the following times are recommended for the removal of excess water and for completing the absorption process:

• 30 seconds: Remove excess water in 20±1 seconds; absorb water for 30±1 seconds.
• 60 seconds: Remove excess water in 45±1 seconds; absorb water for 60±2 seconds.
• 120 seconds: Remove excess water in 105±2 seconds; absorb water for 120±2 seconds.
• 300 seconds: Remove excess water in 285±2 seconds; absorb water for 300±2 seconds.
• 1800 seconds: Remove excess water in 1755–1815 seconds; absorb water for 15±2 seconds after excess water removal.

What is the COBB Sample Cutter?

The COBB sample cutter is a vital accessory for conducting the COBB Water Absorbency Test. This precision tool quickly and accurately cuts a sample with a specified area of φ125 mm, making it ideal for various applications, including quality supervision, research, inspections, and production in the corrugated board and carton industries.

Importance of the COBB Tester

Understanding the water absorption properties of paper and cardboard is critical for ensuring the quality of printed materials. The Cobb value obtained from the COBB Water Absorbency Test helps in selecting suitable materials that minimize issues related to ink smudging or poor print quality. Moreover, it acts as a quality control measure to ensure compliance with industry standards. Material scientists utilize this data to optimize the composition of paper and cardboard, tailoring these materials for specific applications based on their absorption characteristics.

Advantages of the COBB-01 COBB Tester

• Durable Construction: Made from high-quality stainless steel.
• Standard Compliance: Features a metal roller that conforms to industry standards.

Test Principle of the COBB-01 COBB Tester

Before initiating the COBB Water Absorbency Test, the sample should be weighed. Once one side of the sample comes into contact with water for the specified duration, excess moisture is removed, and the sample is weighed again. The results are expressed as the increase in mass per unit area of the sample (g/m²).

Applications of the COBB Test

The COBB Water Absorbency Test is commonly employed to evaluate the water absorption capacity of porous materials, particularly paper and cardboard. This evaluation is critical for various applications, including printing, packaging, and the production of paper-based products. The COBB test is especially relevant for materials where water absorption characteristics significantly impact performance and quality.

Key Specifications of the COBB-01 Tester