The invention discloses a composite plastic tube which consists of a plurality of
layers, wherein the outermost layer is an anti-wearing layer consisting of 100 parts by weight of
low density polyethylene, 3-10 parts by weight of EVA (
ethylene vinyl acetate copolymer) and 0.5-2 parts by weight of an
antioxidant; the middle layer is a reinforcing layer consisting of 80-85 parts by weight of
high density polyethylene HDPE 100 and 5-15 parts of nano
calcium carbonate; the inner layer is a clean type
water delivery layer consisting of 96-100 parts of
high density polyethylene HDPE 100, 4-6 parts of antibacterial master batch and 2-4 parts of an
antioxidant; the antibacterial master batch is prepared as follows: adding 70-75 parts by weight of
high density polyethylene HDPE 100 into 20-25 parts by weight of a nano inorganic
antibacterial agent containing sliver irons to obtain a mixture; mixing the mixture with 1-3 parts by weight of a
silane coupling agent to obtain a mixture II; and
drying the mixture II and 3-5 parts by weight of POE or a bulking agent to prepare the antibacterial master batch. According to the composite plastic tube disclosed by the invention, three
layers of tube materials are different and are formed under the same
thermoplastic process condition, and therefore, the
layers are tightly embedded and are firmly connected.