Processing method of recycling pet material from bags
A processing method of recycling PET material from bags includes the steps of breaking a bag into a plurality of PET broken pieces and PET fragments; blending the PET broken pieces and PET fragments to form a plurality of plastic granules; thermally plasticizing the plastic granules into a continuous plastic bar; cooling the continuous plastic bar to cure the same into a cured plastic bar, which is cut into a plurality of recycled plastic pellets; thermally plasticizing a mixture of the recycled plastic pellets and a compatibilizer to form a continuous modified plastic bar; and lastly, cooling the continuous modified plastic bar to cure the same into a cured and modified plastic bar, which is cut into a plurality of modified plastic pellets. With the above PET recycling method, it is able to save the step of sorting materials and produce modified plastic pellets with enhanced mechanical strength.
1 . A processing method of recycling PET material from bags, the bags respectively having a body for holding things, a zipper and a fastener; the body made of a material consisting of a layer of polyethylene terephthalate (PET) woven fabric, a layer of PET knitted fabric, and a layer of polyurethane (PU) coating located between the PET woven fabric and the PET knitted fabric, and the zipper and the fastener both made of a PET material, the processing method comprising the following steps:
a breaking step, in which a breaker machine is used to cut the bags so as the body is cut into a plurality of PET broken pieces, and the zipper and the fastener are cut into a plurality of PET fragments;
a blending step, in which the PET broken pieces and the PET fragments are put into a blender machine for blending and rubbing with one another, then temperatures of the PET broken pieces and the PET fragments are risen to a frictional temperature for melting their surfaces, and the PET broken pieces and the PET fragments become adhered to one another to form a plurality of plastic granules with different sizes;
a shaping step, in which the plastic granules are put into a first shaper machine to be thermally plasticized into a continuous plastic bar;
a first pelletizing step, in which the continuous plastic bar is cooled in a first pelletizer machine to form a cured plastic bar, then the cured plastic bar is cut by the first pelletizer machine into a plurality of recycled plastic pellets having a same size;
a modifying and shaping step, in which the recycled plastic pellets and a compatibilizer are put into a second shaper machine to be thermally plasticized into a continuous modified plastic bar; and
a second pelletizing step, in which the continuous modified plastic bar is cooled in a second pelletizer machine to form a cured modified plastic bar, then the cured modified plastic bar is cut by the second pelletizer machine into a plurality of modified plastic pellets having a same size.
2 . The processing method of recycling PET material from bags as claimed in claim 1 , wherein, in the shaping step, the first shaper machine heats the plastic granules to a first melting temperature that is higher than the frictional temperature, such that the plastic granules melt to form first plastic slurry; and the first plastic slurry being thermally plasticized into the continuous plastic bar.
3 . The processing method of recycling PET material from bags as claimed in claim 1 , wherein, in the modifying and shaping step, the second shaper machine heats the recycled plastic pellets and the compatibilizer to a second melting temperature that is higher than the frictional temperature, such that the recycled plastic pellets and the compatibilizer melt to form second plastic slurry; and the second plastic slurry being thermally plasticized by the second shaper machine to form the continuous modified plastic bar.
4 . The processing method of recycling PET material from bags as claimed in claim 1 , wherein the second shaper machine includes a weight module; the weight module enabling the recycled plastic pellets to be fed in batches to mix with the compatibilizer, so that the recycled plastic pellets of a specific weight are mixed with a preset amount of the compatibilizer.
5 . The processing method of recycling PET material from bags as claimed in claim 1 , wherein the continuous modified plastic bar contains 93˜97 wt % of the recycled plastic pellets, and 3˜7 wt % of the compatibilizer.
6 . The processing method of recycling PET material from bags as claimed in claim 1 , wherein the woven fabric and the knitted fabric have a same melting point, and the PU coating has a heat-resistant temperature higher than the melting point of the woven fabric.
7 . The processing method of recycling PET material from bags as claimed in claim 1 , wherein the blender machine includes a heater for supplying external heat energy to aid in a heating of the PET broken pieces and the PET fragments, such that the plurality of plastic granules can maintain at the frictional temperature with help of the external heat energy supplied by the heater.
8 . The processing method of recycling PET material from bags as claimed in claim 1 , wherein each of the bags further includes a part connected to the body of each said bag; the part being made of an expandable polyethylene (EPE) material; and said each bag containing 6˜10 wt % of the EPE material and accordingly, 90˜94 wt % of the PET material.