Process and sealing analysis of plastic bottle cap

Update:16 Jul 2020

Plastic bottle caps are common in our life, especially those who like to drink. Today, it mainly introduces its technology and sealing. Welcome to check.

Process analysis of plastic bottle cap
1. The injection molding cover needs to heat the material to the melt flow state, and the temperature is about 250 ℃; the injection molding cover only needs to be heated to about 180 ℃, so the energy consumption of the injection molding cover is higher than that of the pressure injection cover;
2. The processing temperature is lower, the shrinkage is small, and the cover size is more accurate;
3. All cavities are filled with injection molding at one time, and one bottle cap material is extruded by pressing molding at a time. The extrusion pressure is very small, but the injection pressure is high;
4. The volume of injection mold is large and the replacement of single cavity is troublesome;
5. The cap pressing machine is a special machine for bottle cap, which has a special demoulding design for the bottle cap; the bottle cap injection molding machine basically has no special design for the bottle cap, so the pressure plastic cap can be made into a bell mouth, with high cap hanging rate, and users like to use it.

Sealing analysis of plastic bottle cap
The sealing property of bottle cap is one of the measures of the matching between the bottle cap and the bottle body. The sealing performance of the bottle cap directly affects the quality and storage time of the beverage. Good sealing performance can ensure the integrity and barrier of the whole package. Especially for carbonated drinks, due to the carbon dioxide contained in the beverage itself, the carbon dioxide will escape from the beverage after shaking and collision, and the air pressure in the bottle will increase. If the sealing performance of the cap is poor, the quality problems such as beverage overflow and cap tripping will easily occur.
For the quality control of bottle cap, it is required to be easy to open and avoid leakage due to poor sealing performance.
Torque is another major quality control point for bottle caps. Too much torque not only wastes energy, but also affects the convenience of package opening, which is not conducive to user experience. However, if the torque is too small, the cap will not be sealed firmly and the cap will trip off, which will reduce the sealing of the package and even cause the leakage of the contents. Therefore, the cap torque should be controlled in a reasonable range.