The invention discloses a machinable PETG composite foam material and a preparation method thereof. The preparation method of the PETG composite foam material mainly comprises the following steps:
drying 100 parts by weight of PETG resin, 5-20 parts by weight of
calcium carbonate, 5-20 parts by weight of a flexibilizer and 0.5-3 parts by weight of a chain
extender, and then carrying out
melt blending to obtain modified PETG particles; the dried modified PETG particles are added into an
injection molding machine, supercritical
nitrogen is introduced, and the PETG composite foaming material is obtained through a
melt blending and under-injection molding method. According to the method,
calcium carbonate, a flexibilizer and a chain
extender are used for synergistically modifying PETG, and a supercritical
nitrogen injection molding foaming process is combined, so that the technical problems that the PETG melt is low in strength, easy to break and collapse in foaming, poor in
toughness and the like are effectively solved, and the PETG composite foaming material prepared by the method has good expandability and
machinability, and is suitable for industrial production. The material can be applied to
eyebrow pencil shell packaging materials.