Based on your previous focus on avoiding interference from adjacent hot runner cooling channels and the differences in spacing between different mold structures, common design errors in hot runner mold cooling channel systems are as follows:
I. Spacing Errors:
Channel spacing is too narrow, less than 3 times the channel diameter: This causes water flow interference and a significant decrease in heat exchange efficiency.
Channels are too close to the heating elements in the hot runner, less than 25mm: This excessively carries away heat, disrupting the temperature uniformity of the hot runner.
Channels are too close to the cavity surface, less than 10mm: This causes localized sudden cooling of the mold surface, leading to warping and deformation of the plastic part.
II. Layout Errors:
Disorganized water path routing: Excessive differences in branch lengths result in a cooling water inlet/outlet temperature difference exceeding 5℃, leading to severely uneven mold temperature distribution.
The hot runner nozzle area lacks an independent water channel, sharing a loop with surrounding conventional water channels, causing mutual interference between hot and cold water.
Channels are too close to ejector pin holes, screw holes, and hot runner sealing points: This causes structural interference and may even lead to leakage. III. Process-Related Errors: The inclined water channel lacked a positioning platform, causing drill bit slippage during machining and resulting in a misalignment of the water channel, leading to interference from neighboring systems.
The lack of a ball-passing test resulted in localized narrowing of the water channel diameter after machining, causing turbulent water flow and cooling effects far below design expectations.
The water channel inlet and outlet directions were incorrectly set, preventing the formation of stable turbulence and resulting in heat exchange efficiency more than 40% lower than the design value.
