Mold cooling flood

The production speed of blow-molded parts is generally limited by one of two factors extruder capacity or cooling time in the mold. Cooling of mold is accomplished by a water circuit into the mold. Flood cooling and cast-in tubes are most common in cast molds drilled holes and milled slots are the norm in machined blow molds. 

An alternative in cast molds is a large flood chamber (Figure 6.16). However, efficient water cooling requires turbulent flow and this may not be attained in a flood chamber or in large coolant channels (Chapter 17). Many small channels are better than a few large ones. The cooling circuits will normally be zoned so that different areas of the mold can be independently controlled. The coolant flow rate should be sufficient to ensure turbulent flow and to keep the temperature differential between inlet and outlet to about 3C. 

Figure 6.1 6 Examples of water flood cooling blow molding molds...

Some processes require cooling water for production molds, and the need for cooling lines or flooding jackets can increase the tooling cost. The combination of cooling lines and cavity replication represent the majority of the labor required to produce a mold. Large or complex parts require a substantial effort in machining for basic cavity replication. The presence of fine details normally... 

---