What is the industry standard for a life of a molding machine?

Dennis, can you expand on the type of business markets or segments your company is in. Understanding your customer base by market will greatly influence your equipment life cycle (effective life cycle) and allow me to answer more accurately.

Used to be that people in molding would say that a top-notch company replaced presses after 7 years. This assumed 24/7 and faster cycles.
There is no reason though, that a world-class machine cannot perform "forever" though. With the proper PM, repairs, checks and calibration, keep the press as long as it is world-class. This means periodic diagnostics as well. Proper data collection on the process also is important to judge how your press performs.
One important aspect of PM is oil analysis (of hydraulic presses of course). Have your oil tested every 6 months. If there are abnormalities, then follow through with more frequent samplings after corrective action.
Shamefully, some companies get judged by the age of their presses, rather than the documented condition.

Keep on molding!

Brent

There are alternatives to replacing your injection molding machines. New controls, ANSI safety and hydraulic upgrades help to maintain injection molding machines at a fraction of the cost of a new machine. Investing in upgrades and proper PM as Brent Borgerson has suggested is better than purchasing new machines. The larger or the specialty of the machine improves economics of investing capital. Re-manufacturing, re-building, control upgrades keeps a competitive edge without the cost of new machines and the subsequent cost of moving the old machine out and installing new machines in your plant.

Brent also makes one other point, molding companies get judged by the age of their presses, but this can be offset with machine capabilities, upgrades, appearance and process control documentation.

I agree with what Randall says, especially the part where he agrees with me!. Seriously, Randall brings up a good point about rebuilding and upgrading. Years ago, I worked at a place that did this to about 30 presses when they became a proprietary closure molder, rather than a custom molder. They had more than 30 older presses with relay logic. Some got controller upgrades, others were rebuilt/re-manufactured, some got super fancy hydraulic and control packages.
Some were done in Ohio, but not at Randall's company, I don't think he was there at the time. The results were gratifying, in one case we got a press capable of running 3.3 second cycles. This was by no means a press designed for high speeds.
What Randall writes about is a great alternative to press replacement, especially if you have older American presses and you want to stay American. Just don't neglect PM AFTER the rebuild.

Brent

7 to 10 year max. Wear and tear - Contol systems - new innovations - new machine speeds - Energy consumption -etc.. All of these make the older machines unacceptable when comparing to a new machine. Will the older machine run - absolutely but not as effectively as a new machine. Good luck.

For small size (25 - 150) STANDARD machines we set an optimal lifetime 8-12 years (making auto parts). We had a 7-10 years rule like Tom mentioned (absolutely right!) and discovered that having good service we could increase the lifetime up to 12 years for 100-150 t machines without any loss of quality and costs, same time second hand value still competitive.
I suppose that for bigger size machines this age could be increased up to 15-20 y.
aged control could be replaced (reasonable for big machines) if injection molding machine itself is in good condition (machines are not human just change a brain if necessary)
But You have to consider that service MUST be proper, and technological process balanced with machine technical capabilities.
With extreme setup without service You can turn machine to scrap very fast (3-5 years).
So... 7-10 up to 12, for standard, well serviced, medium sized machines.
Good Luck!