Printable View
I know that the answers will be all over the map, but what is a typical life for a general purpose feedscrew in an injection machine? What is your experience? And while we are at it, anyone want to identify where you purchase replacements feed screws?
Its a little harder to offer help when we're not sure where your at and what brand of press your talking about! In the US, there are no shortage of replacement screw suppliers. But I need to caution you that replacing the screw without diagnosing the failure mode and measuring the barrel for wear is like a reservation to do this again long before you're ready. I purchase EOM most of the time, but here in the Southeast Donnelly Brothers does a great job and has many of the smaller OEM screws in stock. MD Plastics is another supplier I'm sure others can give you suppliers closer to you.
Depending on the resin and fillers processed, and considering a standard screw; the unit may last as long as 12 years or more. If running highly filled resins, some that give off corrosive gasses, or using very fast recovery or high back pressure; you might be lucky with a standard unit for it to last two years. I know of an Engel that ran 70% filled PP most everyday, and it was ordered with an abrasion resistant injection unit; this unit had to be totally replaced after 8 years to correct long screw recovery times. Amazing that the press still ran good parts but the non-filled resins required more than twice their original times.
Rick.
Attachment 62
I think the Rick summarized it well.
What is interesting is the topic itself for me because we will change the screw on the 2700t machine next week. Especially on this machine where we use glassfilled and talcfilled PP and also talcfilled SMA the life time of the screw (hardened, high abrasion resistant) is generally 2 years. For illustration I add the picture of the screw from the change at 2010. You can see what glass can do with the steel there is completly missing helix as the abrasive materials took it away.
I would appreciate if you could share any of your pictures from screw changes with some comments.
J