Based on your previous discussion of avoiding interference from adjacent hot runner cooling channels, common design errors in hot runner cooling channels are as follows:
I. Spacing Errors:
The channel spacing is too narrow, less than three times the channel diameter, causing mutual interference between water flows and a significant decrease in heat exchange efficiency.
The channel is too close to the heating element in the hot runner, less than 25mm, excessively carrying away heat and disrupting the temperature uniformity of the hot runner.
The channel is too close to the cavity surface, less than 10mm, causing localized sudden cooling of the mold surface, leading to warping and deformation of the plastic part.
II. Layout Errors:
The water channel routing is chaotic, with excessive differences in the length of each branch, resulting in a cooling water inlet/outlet temperature difference exceeding 5℃ and 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.
The water channels are too close to ejector pin holes, screw holes, and hot runner sealing points, causing structural interference and even potential leakage.
III. Process-Related Errors
The inclined water channel lacked a positioning platform, causing the drill bit to slip during machining, resulting in a misalignment of the water channel and causing interference from neighboring systems.
The lack of a ball-passing test resulted in localized narrowing of the water channel diameter after machining, leading to 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.
