The hold time for a preform mould depends on the shape and material of the mould

The temperature control sections of a preform mould can be integrated into an apparatus for blow molding. These preform cooling sections can shorten the injection molding cycle by reducing the time required to cool the preform. In addition, they can be used to make the container transparent.

The most important consideration for the preform mould's coolant composition is its water temperature. The water temperature should be between 8 C and 10 C (46 and 50 F). The water temperature should be maintained at this level during the drying cycle, which takes about 2 seconds for a 35-g preform with a wall thickness of 2 mm.

The coolant composition should be set at the temperature specified in Table 14.3. Depending on the plastic part, the cooling time may be shorter or longer, depending on the wall thickness. If the wall thickness is doubled, the cooling time will increase by four times.

The hold time for a preform mould depends on the shape and material  Edible Oil Bottle Cap Mold Manufacturers  of the mould. The neck finish part of the preform is usually thicker than the rest. This portion retains heat and is susceptible to deformation during handling. To prevent neck finish crystallization, aggressive post-mold cooling is needed.

The hold time of a preform mould is a crucial component of the process of injection molding. The time during which the preform is injected is important because it shrinks from its melt density of 1.15 g/cm3 to its solid density of 1.33 g/cm3. This process also results in voids in the preform, which are filled during the hold time. The hold time should be between six to eight seconds for a thin preform, but up to 20 seconds for a thick one. Adjust the hold time for each preform mould to ensure the desired demolding temperature.