Cobb Sizing Tester for Core Board Water Absorption

Cobb ring apparatus that measures water absorptiveness of the paper cone and core board surface over 60 seconds. Used by core makers to control sizing and coating.

Specification

A metal ring with a 100 cm2 opening is clamped on the board, filled with 100 ml of water for a set time and then blotted. The mass gain gives the Cobb value in g/m2. Low values confirm effective surface sizing for adhesive and moisture resistance.

Features

• Cobb ring with 100 +/- 0.2 cm2 area
• Clamp with roller for even clamping
• Includes 10 kg blotting roller
• Brass or stainless steel construction
• Timer with audible alarm

Technical Specifications

Test area	100 cm2
Water volume	100 ml
Test times	30, 60, 120, 180 seconds
Roller mass	10 kg
Ring height	25 mm
Standards	ISO 535, TAPPI T 441, IS 1060
Material	Stainless steel ring and base

Standard Accessories

• Blotting paper
• Measuring cylinder
• Stopwatch