System’s Benefits Exceeded Detecting ‘Sneaky Leaks’
Sometimes, when a product provides a solution to a problem being dealt with, moldmakers find unexpected ways to make that product multi-useful. This is one of those times.
In MoldMaking Technology’s April 2017 issue, I wrote a case study feature titled Toolroom Systems Boost Safety, Productivity. It discusses how 3M Company’s New Ulm, Minnesota, plant invested in a Die-Sep Water Leak Tester system that provided a solution to the company’s undetected water leak issues in molds that had just returned from its toolroom. Well, there’s more to the story.
Once the Die-Sep leak tester was on-site, David Youngblom, plant engineering supervisor, says his team discovered another unexpected, but valuable, benefit: The ability to flush out the company’s rubber molds and their water lines.
Most of the 3M’s plastic injection molds use an open-loop system, where one chiller provides all the water to cool all the tools and it’s plumbed to each press. However, with rubber molds, the company uses a closed-loop system, meaning there’s a smaller, 30-gallon water vessel dedicated to each press and when that gets low, which it does from time to time due to evaporation, it is filled up again. “Closed-loop systems can be very problematic because they are not well circulated or filtered like chillers are, so the water often gets very black and tarry, and a lot of bugs grow in the tanks, making it necessary to treat the water with expensive chemicals,” Youngblom says. (I admit, this is where I thought “Ick!”) “We have 120 presses molding parts in the second building, and without the Die-Sep leak tester we would have to flush those molds every week to make a significant difference in chemicals usage.
“The Water Leak Tester has not only solved our mold water leak issue, it has provided a much easier way to treat and control the water in our rubber molds as well,” Youngblom concludes. “There is no question that purchasing it was money well spent.”
As previously mentioned, the water tester has its own 25-gallon water reservoir. Other features include the digital flow meter with thermometer and a pressure gauge. This combination allows a shop to assemble the figures needed to calculate a mold’s Reynolds Number.
A USB interface (D type mouth USB socket) is also provided to connect the unit to a plant’s software. This allows the tool room to log any information from the digital flow meter including flows. Deterioration of flows over a period indicates the buildup of scale or the presence of some other obstruction.
In addition to leak testing, the April feature also discussed how the company’s mold separator machine, also from Die-Sep (Lake Geneva, Wisconsin), has greatly reduced the risk of safety hazards when opening large molds for repairs and maintenance. Both the water leak tester and mold separator helped 3M’s New Ulm employees boost productivity. If you missed it, find the feature and video here.
Molders offer a moving target for moldmakers to adjust to by producing parts with different cavity pressures.
Mold cleaning is just one part of a systematic and comprehensive approach to mold maintenance. Here’s one moldmaker’s strategy for injection mold cleaning and an explanation of where and why different techniques are employed.
If you have not set up a proactive mold maintenance program, your facility runs efficiently only until the next major problem or repair.