Degradable industrial packaging foam trays made from cellulose fibers were fabricated using a hot-press baking process. Bleached softwood pulp fibers with a concentration of 30% were dispersed at a high speed under the action of a dispersant. The effects of the dispersant dosage of the fibers on the porosity, foam density, and static compression characteristics were discussed. Furthermore, the effects of the reinforcing adhesive including polyvinyl alcohol (PVA), and cassava starch on the physical and mechanical properties of the foam trays were studied, as well as the relationship between these properties and the microstructure of the foam trays. The dispersant enhanced the rheological and blistering properties of the fiber dispersion. As the dispersant dosage increased from 2% to 4%, the foam density gradually increased and the compressive strain performance and residual compressive strain of the foam trays decreased. Under the condition of constant dosage of dispersant, increasing the fiber proportion from 67% to 77% improved the porosity and foam density and slightly reduced the static compression performance. In additioton, the static compression resistance of the foamed materials was improved by increasing the PVA dosage since PVA was beneficial for improving the strength of the foam trays.

In this study, we investigated the barrier properties of different kinds of microfibrillated cellulose (MFC) coating layers. The air, oxygen, and water vapor permeability, as well as the water contact angles (WCA), were measured to quantify the barrier efficacy of the applied coatings. The WCA data showed that the surfaces of MFC-coated cardboards are more hydrophilic than those of uncoated cardboards. However, different MFC coatings realize different oxygen transmission rates (OTRs) and water vapor transmission rates (WVTRs). The MFC coating derived from bleached bamboo pulp subjected to carboxyethylation pretreatment (MFC_CBP) gave the best oxygen and water vapor barrier performances. The OTR of the virgin cardboard (> 16500 cm³/(m²·24 h)) decreased to 4638 cm³/(m²·24 h) after coating with the MFC_CBP. The WVTR similarly decreased from 1016.7 g/(m²·24 h) to 603.2 g/(m²·24 h).

Microfibrillated cellulose (MFC) was obtained by mechanical grinding of different pulps. MFC-modified ground calcium carbonate (GCC) was prepared in two different ways, designated MFC-GCC composite filler and MFC-GCC flocs filler. The opacity of pulp handsheets loaded with MFC-modified GCC was measured. The effects of MFC originated from different pulps, pretreatment method, and filler modification on the opacity of handsheets loaded with MFC-modified GCC were discussed. The results show that MFC originated from alkaline peroxide mechanical pulp (APMP) was optimal for improving the opacity of the handsheets and PFI grinding pretreatment for MFC provided a denser structure in the corresponding MFC_APMP-GCC floc filler while enzyme pretreatment was more effective in increasing the opacity of the filled paper. Under the experimental conditions, the opacity of handsheets increased from 81.0% to 82.7% when the unmodified GCC was replaced by an equivalent amount of MFC_APMP-GCC composite filler, while other properties were unchanged.

Microfibrillated cellulose (MFC) was first prepared by 2,2,6,6-tetramethylpiperidine-1-oxyl(TEMPO) oxidation pretreatment and mechanical grinding in the presence of a certain amount of ground calcium carbonate (GCC). The effects of GCC dosage and grinding concentration on the fibrillation were investigated. The obtained MFC was then added to the bulk GCC to form MFC-modified GCC fillers. The properties of MFC-modified GCC fillers were compared to those of the traditional GCC fillers. Results showed that the resulting fibrils became more uniform when the dosage of GCC was 10%~15% and the concentration of the suspension was 6.97%. Compared to traditional GCC, the average particle size of the MFC-modified GCC fillers was larger. Scanning electron microscopy images showed that GCC and MFC formed a bridge structure in the MFC-modified GCC fillers. In the process of papermaking, the MFC-modified GCC fillers decreased the drainage rate but increased the retention of fillers. The prepared papers filled with MFC-modified GCC fillers had higher tensile strength than those filled with traditional GCC fillers.