In the process of producing plastic squeeze bottles, dents are the most frequent occurrence of undesirable phenomena. The plastic injected into the mold shrinks in volume when it is cooled. The early cooling part, that is, the surface hardens first, and bubbles are generated inside. The so-called dent is that the part with slow cooling has a conspicuous concave surface in the direction of bubble shrinkage. The following are the causes of dents in plastic squeeze bottles and specific treatment methods.
Causes of dents
1.The thickness of each part of the empty plastic squeeze bottle is different
2.The internal pressure of the mold is insufficient
3. Insufficient mold cooling
4. Deformation due to insufficient cooling time
Increase injection pressure, extend injection holding time, reduce barrel temperature and mold temperature, and force cooling where dents are generated.
Fill up the flow edge where the dent is generated. Thicken this part when there is a narrow place on the edge of the material where the dent is generated.
The difference in the thickness of the designed product should be completely avoided. For ribs that are prone to dents, the long and narrow shape should be as short as possible.
1. The pressure in the mold of the material surrounding the mold is the static pressure, which is not always true no matter where it is. The pressure of the part close to the gate is high. If the material has a wide through edge, because of the transmission of pressure to each corner, the pressure difference between the part near the gate and the place far away from the gate is very small compared with the overall pressure, and no depression will occur. It is also possible to obtain products without residual internal stress. When part of the material flows into a difficult place, this place has high pressure, and the pressure in other places is reduced, which will cause dents. This part of the residual high pressure is the internal stress of the product. In an ideal state, the material temperature rises with the mold temperature, the fluidity of the material is better, and the injection becomes lower in the static pressure state.
2. When changing the molding conditions, the combination of temperature, pressure, and time should be prepared in advance, and the results can be known early by proceeding in order. First of all, after the time has become very long, it is easy to know every small change in pressure. It should be noted that the results when the temperature changes are obtained, and the results should be obtained when the temperature drops after the injection of the material.
3. Materials with large shrinkage are also prone to dents. When changing the molding conditions to eliminate dents, the setting conditions should be set in the direction where the shrinkage is small. That is, the mold temperature and barrel temperature decrease, and the injection pressure increases, but it should be noted that this may cause residual internal stress.
If the plastic squeeze bottle has dents in daily use, we can change the internal pressure through some methods to restore its shape. If you want to know more about plastic squeeze bottles after reading the above, you can contact us for detailed solutions.
As a professional manufacturer of plastic squeeze bottle packaging, we have accumulated rich manufacturing experience in this field. We have a professional production department and a complete management team, which can conduct a comprehensive inspection of the quality of the products. We focus on producing high-quality plastic squeeze bottles of various shapes and colors, which can meet your diverse needs, and we can also provide thoughtful one-stop service according to your needs. If you want to buy our high-quality plastic squeeze bottles, please contact us immediately!