| The use of hot runner systems is increasing due to the | | | | frustrated with these systems and swear that they |
| fact that they provide a more efficient method of | | | | are too much trouble. This is usually due to the fact |
| molding plastic parts. The cost savings can be | | | | that the system is not properly installed or incorrectly |
| substantial, and the part quality is very often much | | | | operated in the molding process. |
| better than cold runner. | | | | The leading system manufacturers have a well-trained |
| With the increasing sophistication of today's plastic | | | | team of specialists on hand to assist in the proper |
| injection molds, the use of hot runners is becoming an | | | | installation and operation of the systems. The time |
| industry standard. Many applications simply are not | | | | spent listening to these specialists is time well spent! |
| possible with the old standard sprue and cold runner | | | | Are there different types of hot runner systems? |
| system, and hot runners offer a great way to maintain | | | | There are almost as many types as there are |
| uniform wall thickness and eliminate knit lines and flow | | | | suppliers! Most share some common features, |
| lines. | | | | however. There are sprue gated systems, valve |
| What are some advantages of hot runner systems? | | | | gates, tip gates (the most common), and edge gates. |
| - Ability to minimize gate vestige | | | | Any of the major suppliers can describe in great detail |
| - Uniform wall thickness | | | | why their system is the best for your application. Hot |
| - Lower cycle times | | | | runner systems are some of the most important mold |
| - Less waste | | | | components |
| - Reduction or elimination of knit lines | | | | Long term benefits |
| - Great for high cavitation molding | | | | Even though there is an initial investment with hot |
| - Often the only method for micro-molding. The center | | | | runner systems, it is easy to justify the long-term |
| to center distance of the hot runner tips is as little as | | | | benefits. Without increasing the complexity of the |
| 17 mm. | | | | design of the mold, a hot runner equipped mold can |
| - Standardization of components can mean significant | | | | significantly reduce costs. Because the hot runner is |
| savings in material and manufacturing. | | | | designed and manufactured independently, yet |
| - Many large molds rely exclusively on hot runners. | | | | concurrently, the lead times are not affected. |
| Cold runners cannot meet the demands. | | | | Mold makers should always suggest methods for his |
| What about the maintenance of hot runners? | | | | customer to reduce molding costs and increase the |
| Hot runner systems require a new level of expertise | | | | output of the mold. Being knowledgeable with various |
| on the part of the mold maker. However, this does not | | | | runner systems is a good way to demonstrate an |
| mean that it is overly complicated or highly specialized. | | | | active role in helping the molders bottom line. This in |
| A well designed system is relatively free from | | | | turn makes the likelihood of increased business even |
| maintenance, once it is properly installed. | | | | greater for the mold maker. |
| It can, and does happen, that mold makers become | | | | |