(1) When designing extruded plastic bottles, if the material is made of high density polyethylene or polypropylene, the cross section of the plastic bottle shall be rectangular or oval. For materials with low density polyethylene or other flexible plastic bottles, The cross section is rounded as well. This facilitates the extrusion of the contents from the plastic bottle. Plastic parts used in conjunction with plastic bottles are mainly caps and sealers. The design of the plastic bottle should focus on how to make the plastic bottle can be better with the cover and seal with. The bottom of the plastic bottle is a weak part of the mechanical properties of plastic bottles. Therefore, the bottom of the plastic bottle is generally designed to concave; plastic bottle corner, and the concave, are doing a larger arc over. In order to facilitate the stacking of plastic bottles, increase the stability of the plastic bottle stacking, plastic bottles should be designed at the bottom of the groove.
(2) plastic bottle surface with labels, the standard surface should be flat. Can be designed in the plastic bottle surface of a “grid”, so that accurate positioning of the label, does not produce mobile. In the blow molding, the first part of the parison blowing contact, always tend to first hardened parts. So the wall thickness of the site is also larger. Edge and corner parts, is the last part of the parison inflation contact, the site of the wall thickness is small. So the edge of the plastic bottle and the horn parts should be designed rounded. Change the surface shape of the plastic bottle, such as the middle of the plastic bottle is relatively thin, increase the surface of the plastic bottle groove or ribs, can improve the plastic bottle stiffness and bending resistance. Longitudinal grooves or ribs can eliminate the offset, sag or deformation of plastic bottles under long term loads.
(3) plastic bottle printing surface, is the most concentrated areas of consumer attention. If the plastic bottle contains handles, grooves, ribs and other structures, the design should be noted that the printing operation can not cause inconvenience. Oval plastic bottles, the stiffness is also higher, but the mold manufacturing costs higher. Therefore, in order to ensure the rigidity of plastic bottles, in addition to select the high rigidity of the material, but also through the plastic bottle shape design, enhance the plastic bottle stiffness and load resistance.
(4) As most of the plastic has a concave sensitivity, plastic bottles at the corners, the mouth of the root thread, neck and other parts, prone to cracks and cracking phenomenon, so these parts should be designed rounded. For the transfer of rectangular plastic bottles, the need to support most of the plastic bottle load, so the local increase in the wall thickness, but also help to improve the plastic bottle stiffness and load resistance.