At present, the more common products in the sales market of plastic bottles for medicine are round, square and oval. But from the perspective of use, they have their own advantages and disadvantages. The round plastic bottle has high rigidity, but its shape is not beautiful. The square plastic bottle has a beautiful appearance, but it is not easy to control the uniform wall thickness of the plastic bottle during molding. Elliptical plastic bottles also have high rigidity, but the mold manufacturing cost is high. Therefore, in order to ensure the rigidity of plastic bottles, in addition to selecting materials with high rigidity, the rigidity and load-bearing strength of plastic bottles should be enhanced through the shape design of plastic bottles.

The rigidity and bending resistance of plastic bottles can be improved by changing the surface shape of plastic bottles for medicine, such as the middle part of plastic bottles is relatively thinner, and adding circumferential grooves or ribs on the surface of plastic bottles. Longitudinal grooves or stiffeners can eliminate the deflection, sagging or deformation of plastic bottles under long-term load. In the process of designing extrusion plastic bottles for medicine, if the material is high-density polyethylene or polypropylene, the cross section of the plastic bottles should be rectangular or elliptical, and if the material is low-density polyethylene or other flexible plastic bottles, the cross section should be circular. This allows the contents to be squeezed out of the plastic bottle. In order to make the wall thickness of medicinal plastic bottles uniform, the shape of plastic bottles should be symmetrical. Minimize extreme stretch points and positions. Arc transition is adopted at all transitions. The printing surface of plastic bottles is the focus of consumers. The printing surface shall be flat and continuous; If the plastic bottle contains handles, grooves, stiffeners and other structures, attention should be paid to avoid inconvenience to printing operation during design. When the surface of plastic bottles is labeled, the label surface should be flat.

You can design a "frame" on the surface of the plastic bottles for medicine, which needs to be accurately positioned with labels, so there will be no movement. During blow molding, the first contact part of parison expansion always tends to harden first. Therefore, the wall thickness of this part is also larger. The edge and corner are the part where the parison is blown and contacted, and the wall thickness of this part is small. Therefore, the edges and corners of the design shall be designed as rounded corners. Because most plastics have notch sensitivity, plastic bottles are prone to crack and crack at sharp corners, root of mouth thread, neck and other parts, so these parts should be designed as rounded corners.