The Tricky Bits - Sprues

Suppose you have a job that is a bread and butter one – conventional mold, multi-cavity and the job just bangs out parts forever.  When you have an hour, do a mold flow analysis on the runner and sprue in terms of the cycle time.  Now do another analysis eliminating the sprue.  Usually you'll save (1) material and (2) cycle time.

Now for the Tricky bit:  See what it would take to pull the sprue bushing and either put an extension nozzle on the machine or a heated sprue in the mold.  Hot sprues are spendy and require a controller.  Nozzle extensions mean changing the nozzle when you hang the mold.
Balance the costs against the profits.  Remember a nozzle extension or a hot sprue can be used with multiple molds.  Usually the return on investment is a month's worth of production from a single mold.

Do the math.  Don't tell your customer just keep the profits.

Call with questions
Bill Tobin – President WJT Associates
wjtassociates.com
303 604 9592