(1) In the design of extruded plastic bottles, if the material is high-density polyethylene or polypropylene, the cross section of the plastic bottles should be rectangular or oval. For low-density polyethylene or other flexible plastic bottles, the cross section should be round.
This makes it easy to squeeze the contents out of the plastic bottle.
The plastic parts used together with the plastic bottle mouth are mainly bottle cap and sealer.
The design of the plastic bottle mouth should focus on how to make the plastic bottle mouth fit better with the cap and seal.
The bottom of the plastic bottle is the weak part of its mechanical properties.
Therefore, the bottom of the plastic bottle is generally designed to be concave;
The corner of plastic bottle, reach inside sunken place, all make bigger arc excessive.
In order to facilitate the stacking of plastic bottles and increase the stacking stability of plastic bottles, the bottom of plastic bottles should be designed with internal grooves.
(2) When labeling is used on the surface of plastic bottles, make the labeling surface smooth.
A "frame" can be designed on the surface of the plastic bottle so that the label can be accurately positioned without moving.
In blow molding, the first part of the billet blown contact, always tends to harden.
So the wall thickness of this area is also larger.
The edges and corners are the last contact parts of the billet, and the wall thickness of this part is small.
So the edge of plastic bottle and wipe horn should be designed into a rounded corner.
Changing the surface shape of the plastic bottle, such as making the middle of the bottle relatively thin and increasing the circumferential groove or convex rib on the surface of the plastic bottle, can improve the stiffness and bending resistance of the plastic bottle.
Longitudinal grooves or stiffeners can eliminate the deviation, sagging or deformation of plastic bottles under long-term load.
(3) The printing surface of plastic bottles is the place where consumers pay the most attention.
The printing surface should be smooth and continuous;
If the plastic bottle contains handles, grooves, stiffeners, etc., it should be designed with care not to inconvenience the printing operation.
Oval plastic bottle, stiffness is higher, but the mold manufacturing cost is higher.
Therefore, in order to ensure the stiffness of plastic bottles, in addition to the choice of materials with high stiffness, the plastic bottle shape design should be adopted to enhance the stiffness and load-bearing strength of plastic bottles.
(4) Because most plastics are sensitive to notches, plastic bottles are prone to crack and crack at sharp corners, the root of mouth threads, neck and other parts, so these parts should be designed into rounded corners.
For the transfer point of rectangular plastic bottle, it is necessary to support most of the load of plastic bottle, so the partial increase of wall thickness there is also conducive to improve the stiffness and load strength of plastic bottle.