Waste corrugated board was ground to paper pulp

which was used to prepare the foamed waste paper pulp/high density polyethylene（HDPE）composites by compression molding with HDPE.The Rosand  double-barrel capillary rheometer was used to study the influences of the blowing agent AC(azodicarbonamide)content，waste paper pulp content，temperature and different blowing agents on the melt of the composites.Scanning electron microscopy（SEM）was also used to observe the effects of different contents of AC and waste paper pulp on cell morphology.The results showed that the melt behavior of the foamed waste paper pulp/ HDPE composites was pseudoplastic flow

and when shear rate was up to 600 s-1 wall slip was observed.The viscosity of the melt was significantly reduced with increasing content of AC

but increased with increasing content of waste paper pulp.When shear rate was reduced to 275 s-1 or below

the viscosity of the melt was reduced as temperature increased；while when shear rate went up to 275 s-1 or higher

the viscosity of the melt increased as temperature increased.When shear rate was reduced to 325 s-1 or below

the melt with endothermic blowing agent(NaHCO3）showed the highest viscosity；when shear rate went up to 325 s-1 or higher

the melt with exothermic blowing agent AC showed the highest viscosity.The number of cell increased and the size of cell became smaller with increasing AC content

but the number of cell was reduced and the size of cell became larger with increasing content of waste paper pulp as observed by SEM.