Rate-dependent effects on the mechanical behaviour of paper

Abstract: It is established that paper properties depend on the loading rate. The rule of thumb is that the in-plane strength and stiffness increases about 10\%, when the strain rate increases by a factor of 10. Converting of paperboard into packages requires creasing of the paperboard followed by folding to make 3 dimensional packages. Crease response is controlled by in-plane properties, which contribute to the loading and the spring back of the crease which gives the paperboard its final geometry.  This work aims to characterize the rate and time dependent properties of paper, done by tensile testing at high strain rates of up-to 100 000 mm/min using an electro-mechanical testing machine. Also investigated in this work are the rate dependence and characterization of the plies for a deeper understanding of the contributing factors to this rate dependence. At the end of this work the aim is to retrieve the rate dependent behavior of the materials and compare them with the existing rule of thumb. In this work it was concluded that the rule of thumb is accurate for the ultimate strength of the material in the strain rate range of 10^4 to 10^1 strains/second. It was also observed that stiffness of the material increases, but at a rate lower than the stated rule of thumb.