Effects of component properties and orientation on corrugated container endurance

Abstract

Experiments are performed to determine the impact of several physical properties on the creep behavior of three different sets of corrugated containers subjected to static loading and a cyclic humidity environment ranging from 50% to 80% relative humidity in a 24 h period. One sample set had basis weights of the fl uted medium varied from 68 to 205 g/m 2 while keeping the basis weight of the linerboard facings at 205 g/m 2 . This varied the out-of-plane shear rigidity of the single wall board by a factor of three. Another set of corrugated samples investigated effects of lateral or linear corrugating by rotation of either linerboards, fl uted medium or both. This equalizes hygroexpansivity and affects lifetime. A third series of boxes had barrier coatings applied to their surfaces to determine the effect on lifetime. Creep and lifetime are determined to be inversely related and a multiple regression model for lifetime was sought based on the data set. Homogenization of the corrugated board properties through either increased medium basis weight or component rotation (lateral or linear corrugating) and application of barrier coating will in general, increase the endurance of edge loaded corrugated board in cyclic humidity. C-fl ute and exposed to 50% RH or 90% RH. Bronkhorst 15 more recently showed that lifetime (L) can be predicted from the secondary creep rate (dε/dt) through the relationship: 192 R. E. POPIL AND B. HOJJATIE 25. Peterson WS, Schimmelpfenning WJ. Panel edge boundary conditions and compressive strengths of tubes and boxes. Tappi Journal 1975; 65(8): 108-110. 26. Morgan DG. A mechanistic creep model and test procedure. Appita Journal 2003; 57(4): 543-549. 27. Whitsitt WJ. Papermaking factors affecting box properties. Tappi Corrugated Container Conference; 1988: 163-167. 28. Brodeur PH, Hutten IM, Jonakin JL. MD and CMD properties of linerboard components and the resulting box compressive strength. Tappi Journal 1997; 80(10): S27-S35.

Characterisation of time-dependent, statistical failure of cellulose fibre networks

“…Similar large scatters of box creep lifetime were also reported in the literature from early days (e.g., Kellicutt and Landt 1951;Stott 2017;Moody and Skidmore 1966;Koning and Stern 1977;Popil and Hojjatie 2010). This large uncertainty of lifetime is a source of overdesign (i.e., taking higher safety factor) of boxes which are subjected to creep or long-term loading.…”

“…The basic limitation of these approaches is, however, that they are mainly deterministic, and thus there is no systematic treatment of the huge scatter inherent to fatigue and creep strength. In the area of cellulosic materials, the subject has been actively investigated as creep failure of container box under constant or cyclic humidity conditions (Kellicutt and Landt 1951;Stott 2017;Moody and Skidmore 1966;Koning and Stern 1977;Bronkhorst 1997;Kirkpatrick and Ganzenmuller 1997;Popil and Hojjatie 2010). Although enormous scatters of creep lifetime data were recognised in the early literature, systematic treatment of time-dependent, statistical failure has been still in infancy for cellulosic materials (e.g., for review, Coffin 2011).…”

Investigating Creep in Corrugated Packaging

“…Results from previous studies suggest that cyclic humidity will lead to lower box lifetimes in comparison to constant humidity. 12,19,22 This a crucial finding as it contradicts the commonly accepted theory that cyclic humidity will significantly lower box lifetime in comparison to constant humidity under similar applied loadings. This suggests a possible transition point in applied load where the detrimental effects of cyclic humidity are limited and the mechanisms that lead to failure under regular creep conditions are more effective.…”

“…Cyclic humidity conditions accelerate creep deformation in plastics, wood, paper, board and boxes leading to premature failure. [13][14][15][16][17][18][19][20][21][22][23] Based on observations reported in the literature for wood, Byrd 24 performed creep tests of paper in a cyclic humidity environment initiating a multi-decade effort to understand Moisture Accelerated Creep (MAC) in paper-based materials. MAC is a phenomenon characterized by a significant increase in creep rate due to exposing the creep-loaded sample to cyclic humidity conditions as compared to constant high humidity.…”

“…In previous studies, applied loads were also chosen as a percentage of the BCTs. 12,22 Moisture content A lower elastic modulus indicates plasticization of the material and likely increased creep deformation provided that the applied load is the same. Table 3 lists the moisture contents from the different tests.…”