Mechanical properties of crepe paper and chickpaper Mechanické vlastnosti krepového a “chickpaper“ papierov
The paper deals with the evaluation of the mechanical properties of the crepe paper and chickpaper. The thickness of crepe paper was 300 m with the surface mass 150 g*m and chickpaper paper thickness was 100 m with the surface mass 40 g*m. Crepe paper and chickpaper are usually used for chicken breeding. Longitudinal and transversal tensile properties were studied. The tensile behavior was monitored on the motorized test stand ANDILOG STENTOR 1000 (Andilog Technologies, Vitrolles, France).There were measured the tensile properties as modulus of elasticity, maximal elongation, maximal tensile force, tensile strengths, tensile index and strain at break of the longitudinal and transversal samples by testing paper strips. Mean values of the maximal elongation b of longitudinal chickpaper samples were three times smaller than maximal elongation of transversal samples. Mean values of maximal tensile force Ft, tensile strength  b tensile indexand maximal strain at break T of longitudinal chickpaper samples were two times smaller than maximal quantities of transversal samples. Mean values of the tensile modulus of elasticity of longitudinal and transversal chickpaper samples were almost equal. Chickpaper mechanical properties in tension were different in the longitudinal and transversal direction of the original paper surface. Mean values of the maximal elongation b and maximal strain at break T of longitudinal crepe paper samples were sixty times smaller than maximal elongation and maximal strain at break of transversal samples. Mean values of maximal tensile force Ft, tensile strength andtensile index w of longitudinal crepe paper samples were fourth times smaller than maximal quantities of transversal samples. Mean values of the tensile modulus of elasticity of longitudinal samples of crepe paper were thirty eight times smaller than values of transversal samples.
An Analysis of Young's Modulus Distribution in the Paper Plane
Within our research work we determined the Young’s modulus distribution in the paper plane on the basis of results of tensile tests in selected directions. Using mathematical relationships valid for orthotropic materials, the moduli were calculated theoretically. The tensile stiffness orientation angle (TSA), and the TSO and TSI indices were also determined in order to define the deviations of the main axes of orthotrophy in the paper plane as determined by the machine and the cross directions. The calculation results were compared with measured values. They justified the conclusion that paper may be treated as an orthotropic material.
Cushioning properties of moulded pulp
Cushion curves for a moulded pulp material were constructed and compared with cushion curves for an expanded polystyrene (EPS) foam. The ability of the moulded pulp material to provide some shock absorption resulted from a number of ‘dimples’ moulded into the pulp sheet. As an impact was applied to the moulded pulp, these dimples crushed and thereby mitigated the shock. Results showed that the moulded-pulp test samples had good cushioning characteristics for low static loadings, low drop heights, and single impacts. However, the cushioning characteristics of the material were inferior to those of EPS foam at static loadings above about 5kPa, and where higher drop heights or multiple impacts occurred. These properties were improved by using two samples with interlocking dimples. It was concluded that the material had the potential to replace EPS foam in a limited number of situations, and several recommendations for future research were given.