Relationship between the General Properties and Compression Strength of Commercial Linerboard and Corrugating Medium

Paper packaging is an important sector of the packaging industry. There are several advantages of paper packaging over other materials, such as the ease of obtaining raw materials, low price, high strength at low weight, easy conversion process, and environmentally friendly properties. Liner boards and mediums for corrugated board need adequate properties for end usage, and these properties change depending on the raw materials, production, and conversion processes.BRThe properties of 25 current commercial liner boards and mediums in the domestic market were analyzed for better understanding and utilization. The apparent density, air permeability, internal bond strength, tensile strength, and burst strength, were measured, and the ring crush test (RCT) and short-span compression test (SCT) were performed. The basis weights were changed from 115 to 300 g/㎡, and the air permeability was decreased with higher basis weight. The RCT and SCT compression strengths were increased as the tensile strengths at both of machine direction (MD) and cross-machine direction (CD). As the internal bond strength increased, the MD and CD tensile strengths increased, but a trend was not apparent. The burst strength was increased as the tensile strength increased. The tensile strength, burst strength, and compression strength were correlated very closely. The burst strength increased as the tensile strength increased, and the MD tensile strength had greater effect than the CD tensile strength on increasing the burst strength. Compression strength was improved to a greater degree by the MD tensile strength than by the CD tensile strength. The SCT compression strength with a 0.7 ㎜ span was higher than the RCT strength. The RCT and SCT compression strengths were higher in the MD than in the CD.