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.
The Young's modulus of wet paper
Des mesures classiques de traction de papiers mouilles ainsi que des mesures rheologiques sur des papiers epais immerges ont ete realisees. Le module d'Young E wet P et le module de cisaillement hors-plan G wet P des papiers mouilles sont calcules, et a partir de ce dernier, nous obtenons le module de cisaillement hors-plan de fibres mouillees. Un modele de la deformation en tension d'un papier est developpe, qui prend en compte le cisaillement hors plan des fibres. Les predictions du modele sont comparees a nos resultats et nous discutons de la validite du modele.
On the in-plane elastic constants of paper
Abstract It is shown in this paper that the in-plane shear modulus and Poisson's ratio of paper can be predicted with reasonable accuracy if the Young's moduli of the paper in the machine and cross directions are known. The experimentally observed invariance of in-plane shear modulus with respect to sheet orientation is utilised to determine a relationship between the first two coefficients in a Fourier series expansion of the fibre distribution. Using Cox's classic model for paper this permits the sought-after relationships to be determined.