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Heat from plastic injection machines

Heat from plastic injection machines

Heat from plastic injection machines

(OP)
Anyone have any data on heat output of plastic injection machines (for cooling loads)? Specifically Nissei.

RE: Heat from plastic injection machines

Maybe Nissei?

RE: Heat from plastic injection machines

try a post in the plastics engineering forum  712.
B.E.

RE: Heat from plastic injection machines

This may sound like a simple request but the load is very difficult to estimate. The manufacturer should be able to give you data based upon a known load. The units are never operated at that point. The load is a function of cavity area, product flow (cycle time) and mold cooling. I have designed and built room cooling systems for clean room injection molding. The room load is very dynamic due to the molds are being continuously changed as the need for the product changes. Be very careful with humidity control.

RE: Heat from plastic injection machines

The "cheat sheet" used by AEC for chiller sizing is as follows:

Injection Molding
30#/Hr HD Polyethylene = 1 ton
35#/Hr LD Polyethylene = 1 ton
35#/Hr LD Polypropylene = 1 ton
50#/Hr Polystyrene = 1 ton
75#/Hr P.V.C. = 1 ton
45 #/Hr P.E.T. = 1 ton

Extrusion and blow molding numbers are different.


 

RE: Heat from plastic injection machines

The AEC tables are for the mold cooling. I take the total electrical power over an hour, less mold cooling (actual) and add accessories such as dryer, conveyors and portable chillers. The leftover is heat rejection to room.

RE: Heat from plastic injection machines

(OP)
Me situation is a plant addition into which they are move the existing machines. The existing machines are the main load in the existing plant. They have four 25 ton roof top units which seems like a lot. I know the building electric demand so I thought I would work backwards.
I assumed that all electric that did not go to cooling went to heat in the space (which is very conservative)
This is my very rough calculation:
Demand (KVA) = cooling load/3.41 + cooling load/SHF/EER
cooling load is the unknown sensible cooling load (internal heat). It sort of ignores the building skin load which is basically the roof and I have know idea how much ventilation(as I said very rough). It works out to 50 tons in my case.

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