Cosmetic plastic bottles are items that we often see in our daily lives. They are favored by consumers and businesses because of their portability and practicality. However, there are still some common problems in the manufacture of cosmetic plastic bottles.
When designing airless plastic bottles for cosmetic plastic bottles, if the plastic bottle is made of high-density polyethylene or polypropylene, the cross-section of the cosmetic plastic bottle should be rectangular or oval; for the material is low-density polyethylene or other flexible plastic bottles.
The cross-section of the cosmetic plastic bottle is preferably round, so that the contents can be easily squeezed out of the cosmetic plastic bottle. The plastic parts used in conjunction with the mouth of cosmetic plastic bottles are mainly bottle caps and sealers. The design of the mouth of cosmetic plastic bottles should be focused on: how to make the plastic bottle mouth better match the bottom of the plastic bottle with the cap and sealer.
It is the weak part of the mechanical properties of cosmetic plastic bottles. Therefore, the bottom of cosmetic plastic bottles is generally designed to be concave. The corners and inner recesses of cosmetic plastic bottles are all made with larger arcs. In order to facilitate the stacking of cosmetic plastic bottles and increase the stacking stability of cosmetic plastic bottles, the bottom of cosmetic plastic bottles should be designed with internal grooves.
When using labels on the surface of cosmetic plastic bottles, the labeling surface should be flat, and a "frame" can be designed on the surface of the cosmetic plastic bottle to make the labels accurately positioned without movement. In blow molding, the part where the parison first contacts with inflation always tends to harden first, so the wall thickness of this part is also larger. The edge and corner part is the contact part after the parison is inflated, and the wall thickness of this part is small.
Therefore, the edges and corners of cosmetic plastic bottles should be designed with rounded corners. Changing the surface shape of the cosmetic plastic bottle, for example, the middle part of the cosmetic plastic bottle is relatively thinner, and increasing the circumferential groove or rib on the surface of the plastic bottle can improve the rigidity and bending resistance of the cosmetic plastic bottle. Longitudinal grooves or ribs can eliminate the deviation, sagging or deformation of cosmetic plastic bottles under long-term load.