The most common shapes of medicinal plastic bottles are […]
The most common shapes of medicinal plastic bottles are round, square, oval, and the like. From the point of view of use, they each have their own advantages and disadvantages. Round plastic bottles have a high stiffness but are not aesthetically pleasing. The square plastic bottle has a beautiful appearance, but it is not easy to control the uniform thickness of the plastic bottle during molding. 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 a material with high rigidity, the shape of the plastic bottle is also designed to enhance the rigidity and load resistance of the plastic bottle.
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. When designing extruded plastic bottles, if the material is high-density polyethylene or polypropylene, the cross-section of the plastic bottle should be rectangular or elliptical. For low-density polyethylene or other flexible plastic bottles, the cross section is round. Shaped as good.
This facilitates the extrusion of the contents from the plastic bottle. In order to make the plastic bottle wall thickness uniform, it should be noted that the shape of the plastic bottle should be symmetrical. Minimize extreme stretching points and parts. Arc transitions are used at all transitions. The printed surface of the plastic bottle 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. When the surface of the plastic bottle 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. Since most plastics have notch sensitivity, plastic bottles are prone to cracks and cracks at sharp corners, roots of the mouth threads, necks, etc., so these parts should be designed to be rounded.
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