Comparison Chart of Cold Runner, Semi-Hot Runner and Full-Hot Runner Molds for Disposable Syringes

Comparison Chart of Cold Runner, Semi-Hot Runner and Full-Hot Runner Molds for Disposable Syringes

| Criteria | Cold Runner Molds | Semi-Hot Runner Molds | Full-Hot Runner Molds |
| --- | --- | --- | --- |
| Material Wastage | High | Medium | Low |
| Product Quality | Good | Better | Best |
| Runner Cleaning | Required | Easy | Not Required |
| Mold Cost | Low | Medium | High |
| Maintenance | Easy | Complex | Complex |
| Mold Cycle Time | Long | Short | Shortest |
| Injection Speed | Slow | Fast | Fastest |
| Gate Vestige | Visible | Less Visible | Invisible |

Cold Runner Molds:
- Material wastage is high as a significant amount of plastic needs to be purged from the mold before the next shot.
- Product quality is good due to lower temperature, less shear stress and less pressure inside the mold cavity.
- Runner cleaning is required to remove the purged plastic, which can be time-consuming and laborious.
- Mold cost is low as no extra heating and control components are needed.
- Maintenance is easy with simple design and low-temperature operation.
- Mold cycle time is long due to the need to purge the cold runner and wait for the next shot.
- Injection speed is slow due to the lower temperature of the material.
- Gate vestige is visible on the final product.

Semi-Hot Runner Molds:
- Material wastage is medium as only the runner is heated and not the whole mold.
- Product quality is better than cold runner molds due to the reduced thermal stress and better filling of the material.
- Runner cleaning is easy as compared to cold runner molds, but not as convenient as full hot runner molds.
- Mold cost is more than cold runner molds due to the requirement of heating elements and control components.
- Maintenance is complex as compared to cold runner molds but easier than full hot runner molds.
- Mold cycle time is short as compared to cold runner molds due to the reduced cooling time.
- Injection speed is fast due to the increased temperature of the runner.
- Gate vestige is less visible on the final product.

Full-Hot Runner Molds:
- Material wastage is the lowest as the material is only melted when required, and there is no runner to remove.
- Product quality is the best due to the consistent temperature and pressure inside the mold cavity.
- Runner cleaning is not required, which saves time and effort.
- Mold cost is the highest among the three systems, primarily due to the need for more complex control units and heating components.
- Maintenance is complex due to the complex control units and heating components.
- Mold cycle time is the shortest due to the continuous injection of the material.
- Injection speed is the fastest as the material is always in a molten state.
- Gate vestige is invisible on the final product.

In conclusion, the use of each type of runner is dependent on the product quality, material wastage, mold cost and maintenance requirements of the specific project. It is essential to consider these factors to select the best runner system for the particular molding project.