The HDPE microporous membranes were obtained by a melt-extrusion

annealing

cold stretching

hot stretching and heat setting method.The effect of roller rates and roller temperatures on the structure of the lamellae and the HDPE stretched microporous membranes was characterized by dynamic rheology

FTIR

DSC

SEM and other characterization methods.The results show that the molecular weight

molecular weight distribution and the relaxation time of the HDPE resin used in this experiment can meet the requirements of the present processing conditions for obtaining precursor films with arranged lamellar structure of larger lamellar orientation.Under the same roller temperature

the lamellar orientation of the unannealed and annealed precursor films increases

the lamellar thickness decreases

the micropores distribution regions of the microporous membranes increase and the micropores are more uniform with the roller rates increasing.The lamellar structures arrange more regularly when the roller temperature is 90℃ under the same roller rate

it is a perfect roller temperature to prepare large lamellar orientation precursor films for the resin used in this experiment.Under roller temperature of 90℃

the precursor film with the maximal lamellar orientation

the thinnest lamellar thickness and the narrower lamellar thickness distribution can be obtained

and the structures of the micropore and the micropore distribution are more uniform.