Custom Injection Mold

I would agree that Engel used to and still does make an excellent machine BUT I would not agree on easy. Back in the mid 90's their CC90 controller was very good and straight forward, truly excellent. Today the CC200 is just another German/Austrian user UNfriendly controller. Still a good machine, but this goes back to my original comment a couple of weeks ago. Have a processor and maintenance person with you when making your evaluations.

I've been in the custom injection mold business for 39 years, consequently have worked with and/or around all the popular brands of IMM's. Your specific criteria is: "the best general purpose machine for the buck" and "tonnage range is 100 to 1000 tons". This was the exact criteria I had when I decided to start my own molding business 15 years ago. We chose Nissei and have never regretted it. We have 1 all electric and 10 Hydraulics. One note the Hydraulics are much cleaner because they do not have the toggle clamp movement, which need constant lubrication. Also the Hydraulics are very precise and extremely robust. The next press we will purchase will be the Nissei Hybrid....An incredible machine!

Build quality plastic injection molds in china, I have worked with flow simulations for last 20 years and I agree with John about the methodology to follow. However, the flow simulation will not give the full information and it has its own limitations. They will certainly give you the trends and sometimes exact answers. Again I am saying that the correct answer would depend on correct situation and Don should now give some more information. I personally feel that a member who starts a discussion should be actively involved and should provide inputs from time to time.

My mind goes directly to moisture if in fact the melt front joints exhibit reduced strength in summer months and the molding environment is not climate controlled.
1. Reduce the ambient dew point of the material in the hopper. If using a quality drier the process air temperature can be set as low as twenty degrees above ambient room temperature. Just enough to remove surface moisture.
2. Feed housing temperature. The surface temperature of the feed thought should be set slightly above the material being feed. This will eliminate the formation of condensation and rehydrating the material prior to it being feed into the screw.
3. What is the actual temperature of the core and cavity steel during automatic operation? Is the cooling water set higher than the ambient temperature of the molding room? Many times if the mold cooling circuits are not correctly designed processers lower the mold cooling temperatures to compensate. As Pradeep has pointed out, condensation can form severely effecting weld line strength. Try molding parts with higher mold temperatures as a trial and see what influence it has on weld line strength. Of course this should have been done on a humid day.