Why Cooling Time Runs Your Cycle Time
When plastic gets injected into a mold, it is hot. Before the part can be ejected and the next cycle can begin, that plastic needs to cool and solidify. How quickly it cools depends directly on how cold and how consistent your mold coolant is. In most injection molding operations, cooling accounts for more than half of every cycle — which means a better cooling system directly translates into faster production.
What Inconsistent Cooling Looks Like
When mold temperatures drift — because the chiller is struggling, or temperatures are not uniform across the mold surface — you see it in the parts. Warping, sink marks, flash, and dimensional variation are all signs that cooling is not where it needs to be. Fixing the chiller often fixes the parts.
Typical Temperature Targets
| Material | Typical coolant temperature |
|---|---|
| Polypropylene (PP), Polyethylene (PE) | 50–65°F (10–18°C) |
| ABS, Polystyrene | 50–65°F (10–18°C) |
| Nylon, Polycarbonate | 55–75°F (13–24°C) |
| High-speed / rapid cycling | 40–50°F (4–10°C) for maximum heat removal |
One Chiller Per Machine or One Central System?
One Chiller Per Machine
Each machine gets its own chiller with its own temperature setting. You have full control, easy troubleshooting, and if one chiller goes down it only affects one machine. The tradeoff is more units to buy and maintain.
One Central System
One large chiller serves the whole production floor through a distribution system. Lower overall cost and simpler maintenance — but every machine shares the same coolant temperature. Works well when your machines all run similar materials and temperatures.
The Sizing Mistake That Gets Everyone
On a typical production floor, not all machines are running at full load at the same time — but sometimes they are. When every machine fires simultaneously, the heat load spikes well above average. A chiller sized to the average load falls behind during these peaks, cooling temperatures rise, and quality suffers.
Size for peak simultaneous demand, not average demand. Yes, it means a slightly bigger chiller. No, you will not regret it.
Quick estimate: Roughly 1 ton of cooling for every 40–50 tons of clamp force is a common starting point. But actual sizing depends on your material, shot size, and cycle time — use our sizing tool or Support for a real number.
See the full Plastics & Injection Molding page for system configurations.
FAQ
One chiller per machine or one central system?
Per-machine gives independent control and isolation; central is cheaper and simpler when machines run similar temperatures. We'll help you weigh it for your floor.
Is there a quick rule for sizing?
Roughly 1 ton of cooling per 40–50 tons of clamp force is a starting point — but material, shot size, and cycle time set the real number.
Still Not Sure What You Need?
Tell us what you are cooling and we will figure out the right chiller for you. No jargon, no catalog. Just a straight answer.