What are the factors that affect the stiffness of paperboard?

The importance of paperboard stiffness

Stiffness is a basic performance indicator for cardboard and whiteboard.

Paper stiffness is an important indicator that directly affects the stiffness of the crease (another influencing factor is die-cutting pressure), which affects the finished product. Stiffness is small, finished products are easy to crush and warp; stiffness is high, and finished products are difficult to form.

Packaging paper has stiffness requirements, different quantitative paper stiffness is different, generally proportional to the square of the thickness, the thicker the board is, the higher the stiffness is.

Factors that affect bending stiffness

There are many factors that affect stiffness. The thickness and elastic modulus of the board are the most basic factors affecting the stiffness of the board or paper. When the thickness is constant, the stiffness increases with the tightness. When the weight is constant, it slightly increases with the increase of the tightness and then slightly decreases, but the overall trend is a net increase.

Stiffness test method for paperboard

Stiffness measurement method has a fixed, but also a non-fixed angle test sample bending strength, the sample free bending to measure the change in strength. Some test methods both. The stiffness of the paper is often measured by Clarke or Grayer. For cardboard, commonly used Taber (Tybel), Orliston stiffness instrument.

Features

Drick paperboard stiffness tester is designed according to the static bending principle, that is, changing the free end of a vertically clamped specimen. When the specimen reaches a certain bending angle, the resistance is the bending stiffness, and its unit mN; or the product of resistance and test length in mN.m. Using high-tech digital motors (convert signals into a series of separate units, denoted by 0 and 1. This conversion is usually performed with a digital-to-analog converter) and streamline the practical drive structure. The measurement and control system uses a single-chip microcomputer as the center Processing unit digital power, equipped with the corresponding application software to control the whole machine, data acquisition and data processing, the report content has bending force (mN), stiffness is the bending moment mNm, the whole structure is simple, all the power is available, operation Particularly convenient

Applications

The paperboard stiffness meter is particularly suitable for determining the stiffness of paper and paperboards with a low basis weight and a thickness of less than 1 mm. The cardboard stiffness tester is a Taber type stiffness tester that is commonly used in international standards. The paperboard stiffness meter is suitable for the bending strength of paper and paperboard. It is a special instrument for determining the stiffness of paperboard.