When the surface of the plastic barrel is marked, the surface of the label should be flat. A “sash” can be designed on the surface of the plastic bottle to make the label accurately positioned without moving. At the time of blow molding, the portion where the parison inflates first contacts always tends to be hardened first. Therefore, the wall thickness of this part is also larger. The edge and the corner portion are the portions where the parison inflates the last contact, and the wall thickness of the portion is small. Therefore, the edges and horns of the plastic bottle should be designed to be rounded. Changing the surface shape of the plastic bottle, such as the middle of the plastic bottle is relatively thin, increasing the circumferential groove or rib of the surface of the plastic bottle, which can improve the rigidity and bending resistance of the plastic bottle. Longitudinal grooves or ribs eliminate the offset, sagging or deformation of plastic bottles under long-term load.
The printed surface of the plastic bucket is the most concentrated part of the consumer's attention. The printing surface should be flat and continuous; if the plastic bottle contains handles, grooves, ribs and other structures, care should be taken not to inconvenience the printing operation. Elliptical plastic bottles have higher stiffness, but the manufacturing cost of the mold is higher. Therefore, in order to ensure the rigidity of the plastic bottle, in addition to selecting the material with high rigidity, the shape of the plastic bottle is also designed to enhance the rigidity and load resistance of the plastic bottle.