Counter and cleaning card

A counter on each of the eight molds that stop most, and a card that says at which count to clean it between jobs.

Cost	About $2,300 once, and $7,200 per year
Payback	About 2 months
Limitation	It prevents only the stops that build-up and wear cause, and only if someone reads the counters.

What changes

Each of the eight molds that stop most gets a counter that adds one each time the mold closes.

A card on the mold says at which count to clean its vents and check its moving parts.

The mold shop does that cleaning between jobs, when the mold is out of the press anyway.

What it costs and could save

The counters and a first full cleaning of each mold cost about $2,300 once.
Planned cleaning then takes about $7,200 per year of mold shop time.
After that cost it could save about $13,700 per year, a payback of about 2 months.

Why it works

Mechanism	Residue builds up a little with every shot, so a mold nears a fault by use and not by date. A counter shows that use on the mold itself. Cleaning at a set count clears the vents and the moving parts before a part sticks or plastic leaks out. Done between jobs, it takes mold shop time and no press time, because the mold is out of the press anyway.
Math	Avoiding five of the nine stops per week, over 50 working weeks, is 250 stops per year. Each one loses about 1.2 hours of press time and 25 pounds of plastic. A freed press hour is counted at $38.50: $55 for an hour an order fills, times the 70 percent of freed hours we assume orders fill. With plastic at $1.50 per pound, those stops cost about $20,900 per year today. Planned cleaning takes about 150 mold shop hours per year at $48, about $7,200. That leaves about $13,700 per year. The counters and the first cleaning cost about $2,300 once, a payback of about 2 months. By the same count, all nine stops per week cost about $37,700 per year.
Industry evidence	Resin suppliers' guides name clogged vents as a cause of burned and incomplete parts, and list cleaning the vents as the remedy. Mold makers' maintenance guides set cleaning by the count of shots, not by the calendar. Published cases put planned mold care at roughly 60 to 80 percent less unplanned mold downtime. Those cases are from other plants, so the stops avoided here are our estimate: five of the nine per week, 56 percent.
Limitations	A freed press hour is money only when an order fills it, and we count 70 percent of them. With no order waiting, what is left is the plastic, about $9,400 per year against about $7,200 of cleaning. Cleaning prevents only the stops that build-up and wear cause. A stop that comes from press settings or a damaged part still happens. We did not see a mold fail, so the time and the plastic lost per stop are our estimates. The plan lasts only if one named person reads the counters and the mold shop keeps time for the cleaning.

Implementation plan	3 steps
Risks	2