The invention discloses a preparation method of a
polylactic acid transparent
straw. According to the preparation method, 94-96% of PLA, 2-3% of PEO, 1-2% of ParaloidKM-355P, 0.4-0.8% of VINNEX*2525 and 0.1-0.2% of EBS. The preparation method comprises the following steps of: adding the PLA into a double-screw extruder, adding the PEO, the ParaloidKM-355P, the VINNEX*2525 and the EBS into the double-screw extruder from a side feeding port, and carrying out
extrusion, bracing, cooling,
drying and
slicing to obtain a modified resin for PLA straws, wherein a
barrel temperature is 160 DEG C, a diehead temperature is 165 DEG C and a screw length-
diameter ratio of the extruder is 52: 1; adding the obtained modified resin for PLA straws into a beverage
straw manufacturing
machine to carry out
extrusion, traction, cooling and trimming so as to obtain a transparent a
polylactic acid straight tube, wherein the
barrel temperature is 160 DEG C, the die head is additionally provided with a melt pump, the die head temperature is 165 DEG C, and a
cooling water temperature is 40-50 DEG C; and putting the transparent a
polylactic acid straight tube into a full-automatic bendable
straw forming
machine to obtain a PLA high-transparency straw. According to the preparation method, the PLA application field is extended, traditional PP straws can be replaced so that the white
pollution can be decreased, and the PLA is a natural bacteriostasis material and is beneficial for
human health.