Bending stiffness is a very important material property of paper for packaging performance. Greater bending stiffness gives better carton strength. Therefore, bending stiffness is an important specification for paperboard manufacturers and purchasers. Several methods and instruments are developed to measure the stiffness of paper, textiles and many other flexible materials. The paper stiffness testers measure stiffness in an arbitrary and relative manner. It is used to measure the force required to bend a strip pf paper sample at an angle or to turn aside the end at a given amount. Some testers also measure the length on which a specified force acts to generate an effect. Stiffness of paper is referred to as force, moment, angle or length to create an effect on the sample of specified dimensions stretched in a particular manner. 

An important feature in which a paper and a paperboard differ is its greater stiffness. The economic value of paperboard relies on its stiffness. The property of stiffness is related to the amount of fiber in the board which directly affect the cost. Therefore, a quantitative evaluation is the main concern for users and manufacturers. Stiffness of paper affects a number of end use applications such as printing, wrapping etc.

The Stiffness tester uses a two directional pendulum type weighing system to measure material stiffness, resiliency, flexural strength and elasticity. Force is exerted at the lower end of the sample by two rollers which is attached to the driving disc. The resulting torque bends the pendulum marl which aligns itself with the driving disc mark i.e.15°

Stiffness tester offers a high quality machine to test the quality of the paper by determining its resistance. Weight of pendulum is 500,1000,2000,3000 and 5000 SU and the weight of stud is 10±0.001gm. The samle size is 70±1mm X 38.1 ± 0.3mm with unit scale range upto 0-100. The angle is 7.5° and 15° with a motor speed of 2 rpm. The machine adheres to TAPPI-T489 OM-08 standards.

Features of the stiffness tester are friction of the pendulum is of high procession bearing. Possess two clamps they are ratchet style and flat type. Strong legs with an aluminium steel body. The dimension of the instrument is  300 X 320 X 440 mm which occupies very little space. Manufactures and purchasers can avail this intrument at very competitive prices.