Two factories can process the same number of parts and need very different cleaning crews. The difference is rarely the cleaning machine; it is everything the machine was never told to handle — the pre-wipe someone does by hand, the rack that has to be loaded twice, the part that cannot go in the line at all. Comparing labour needs for removing cutting-oil residue from machined workpieces means counting those hidden minutes before comparing any quotation. This article sets out how to do that comparison on your own floor.
Define the residue before you count the labour
"Oily parts" covers at least four different jobs. Fresh cutting fluid that has not dried comes off easily. Fluid that has been allowed to dry or baked by a warm part is a film that needs heat or chemistry. A mix of oil with fine swarf, abrasive grit and way oil is a mechanical problem as well as a chemical one. And a part with blind holes, tapped bores, or a ground surface that must stay dry in places needs a fixture or a blow-off step, not a longer cycle.
Write the actual contamination on your worst three part families and let that define the target condition: what a clean part has to be for the next operation — coating, welding, assembly, inspection, packing. The target sets the cycle; the cycle sets the crew. Teams that skip this step end up comparing machines on price and discovering later that the chosen method cannot meet the target, so the crew has to rework parts by hand.
Break the routine into counted stages
Stand at the cleaning station for an hour with a stopwatch and record each stage in seconds per part or per batch:
- Handling in — moving parts to the station, unloading from the machine or rack.
- Pre-clean — the hand wipe, blow-off, or swarf removal that nobody writes into the process.
- Loading and fixturing — how many parts per cycle and what orientation they must sit in.
- Process time — the machine's actual cycle including dwell.
- Unloading and drying — including any wait before handling or packing.
- Inspection and rework — how many parts fail the target condition and what happens to them.
- Consumables and servicing — changing bath fluid, filters, nozzles, clearing swarf traps.
Convert to minutes per part. Then multiply by the annual volume per part family. That single number is what a method comparison is for: the machine that saves seconds on the cycle but adds a pre-wipe has not saved anything.
Compare methods by what they remove and what they add
Solvent and aqueous immersion routines lift fresh oil well and are labour-light per batch, but they add consumable handling, bath changes and a waste stream that somebody manages — and they do little to a baked film without a long soak, which is itself labour in the form of handling time.
High-pressure water with detergent moves swarf and bulk oil but leaves a wet part and a lot of run-off, and it adds a drying step and a drainage question.
Heat changes the arithmetic on bonded deposits. Cutting oil removal equipment working on the factory machinery degreasing principle delivers water hot enough to soften dried fluid, so the deposit lifts with less agitation and less scrubbing. In a workpiece context, that shows up as the pre-wipe stage disappearing: where an operator was wiping each part before it could go into a bath, heat at the point of contact replaces the wipe. Fewer touches also means fewer parts dropped, fewer fingerprints on finished surfaces and fewer parts re-run.
Where parts are processed in batches with no dedicated line — a job shop, a tool room, a maintenance cell — a mobile unit is often the right answer, because the cleaning comes to the part rather than the part travelling to a fixed bath. PowerDe's mobile cleaning range lists dry steam, wet steam and hot-water modes on the driving-style units, plus tap-water inlet and a clean-water tank in the 50–60 L class, which sets how far the operator works before a refill. Those are labour figures, not spec figures: refill distance, tank size and mode changeovers are exactly the hidden stages above. Confirm the exact figures for the model you are considering on its product page, since the range is sold in battery and non-battery variants.
Watch the parts that cannot go in the line
Every comparison breaks down on the awkward minority: heavy castings that need an overhead lift, long bores that hold fluid, assemblies where oil must be removed from a bearing area without flooding the rest, thin parts that vibrate and mark. Count them as a separate family with their own labour figure. In most shops 10–15 percent of parts absorb 40 percent of cleaning labour, and a method that halves the easy 85 percent while doing nothing for the awkward 15 percent produces a smaller saving than the spreadsheet promised.
Trial on your worst families and record four numbers
Run a two-week comparison on real parts, and record only four figures for both the current method and the proposed one: operator minutes per part, first-pass yield against the cleanliness target, consumable and disposal use per part, and any downstream complaint from coating, welding or assembly. Minutes per part is the labour answer. First-pass yield is the answer people forget to measure and the one that usually decides the comparison, because rework labour hides in the downstream cell rather than in cleaning.
Keep the trial honest: same operators, same shift pattern, same inspection standard. And run it on the dirty families, not the easy ones.
Turn the result into a staffing decision
Once you hold minutes per part by family, the decision becomes arithmetic. Multiply the proposed minutes by annual volume, price it at your loaded labour rate, and compare against the capital and consumable cost of the method. Then ask the follow-up questions that determine whether the saving survives: does the new method free a person for other work or merely shorten a shift; does it need a second operator at peak; does the maintenance burden fall on the same person; and does the method scale if volume rises by half again.
If your part mix is awkward or your volumes are lumpy, specify against that mix rather than buying a catalogue unit. Shenzhen PowerDe Automation Precision Equipment publishes parameters for its cleaning range and supports customized steam cleaning equipment for site-specific duties. Send photographs of your worst part families, the annual volume by family, the current minutes-per-part figure and your cleanliness target to the contact page, and ask for a method and configuration proposed against your numbers rather than a throughput claim.
