Method for making carton bottom

A method for making a bottom of a packaging carton for fragile glass substrate, wherein the method includes the steps of:

• a) preparing a mold and a plastic blowing machine, wherein the mold is designed with ribs so as to create a bottom with hollowed configuration;
• b) disposing plastic particles within the mold and heating up to molten state or disposing molten plastic particles into the mold;
• c) blowing air into the mold with the plastic blowing machine so as to transform the molten plastic particles into a bottom of a packaging carton with skeleton configuration within the mold, and a peripheral wall with skeleton configuration surrounding the bottom, wherein the bottom and the peripheral wall are all with hollowed configuration;
• d) providing a buffering tray having a lower configuration matched within the skeleton configuration of the bottom of the plastic carton and securing the buffering tray onto the bottom of the packaging carton, wherein a peripheral an upper surface of the bottom of the packaging carton is arranged with a first retaining device, and the bottom surface of the buffering tray is provided with a second retaining device corresponding to the first retaining device so as to securely attach the buffering tray with the bottom when the first and second retaining devices engaged with each other, wherein the buffering tray is made from polyethylene terephthalate or polystyrene, wherein the peripheral side wall and the bottom of the packaging carton are made from plastic.