As desirable food
packaging materials, pulp molded products have
attracted great attention from both academia and industry. To endow
the products with high mechanical strength and water barrier properties
by low-cost wet-end additives to broaden their application fields,
polyamide epichlorohydrin (PAE) or/and cationic starch (CS) were added
to the pulp slurry after the addition of oil- and water-proof agents.
Results showed that the optimal pulp molded product was obtained at
a PAE and CS content of 1.0 and 0.6%, respectively. The resulting
product had a dry strength of 24.4 kN/m, a wet strength of 4.22 kN/m,
and a water absorption of 51.5%. The addition of CS was beneficial
to the properties of the PAE wet-end added product due to the formation
of hydrogen bonding with cellulose fibers and PAE, which also led
to a decreased PAE dosage for health concern as food packaging materials.
Finally, the PAE/CS wet-end added pulp molded product was applied
for orange fresh-keeping in the fridge. The product displayed much
more shape stability and lower weight increase in comparison with
that of the product without the addition of PAE and CS. This indicated
the great application prospects of our designed pulp molded product
as a fruit freprospectssh-keeping packaging material.