Trial runs on a customer’s line: who pays for the waste

The invoice arrived eight weeks after the trial: 400 kg of product written off, six hours of line time, two operators, and a disposal charge for 3 tonnes of gelled material that had to go out as special waste. The customer had assumed the trial was free because the powder was. The supplier had assumed the opposite because nothing had been agreed. Both were reasonable and neither had written anything down.

Trials are where good technical work turns into a commercial argument. The fix is not a longer contract; it is a one-page sheet agreed before the first bag is opened, covering what will be consumed, what will be produced, and who owns each of those.

Four cost lines, not one

Every line trial has the same four costs. Product consumed — not just the sample, but the whole trial volume at production dose. Line time, which is the largest number on most sites and the one most often left out. Labour for setting up, sampling and cleaning. And waste: the liquid you started with becomes a solid you now have to dispose of, and that disposal is often more expensive than the liquid was.

Put a number against each before the trial. A half-day on a filling line at 8,000 per hour is not a free experiment, and a trial that produces 3 tonnes of gel has just created a waste stream the site did not have that morning. Both facts belong on the sheet.

The split that most sites accept

The arrangement that gets agreed most often: the supplier provides the sample and the technical support at no charge, the customer provides the line, the labour and the liquid, and the disposal of trial material is split according to who asked for the trial. If the customer approached the supplier, the customer pays disposal. If the supplier proposed the trial as part of a specification change, the supplier covers the disposal up to an agreed tonnage.

Write the tonnage in. “Up to 2 tonnes” is a number; “reasonable volume” is a future argument. And write the exit: what happens if the trial fails at the first stage — who removes the material, who cleans the tank, and by when.

Stage the trial so failure is cheap

The most useful commercial protection is technical. Run the trial in three stages: a bench test on 5 litres to establish the dose, a pilot on 200 litres in an IBC to establish mixing and set time, then the line. Each stage has a go/no-go, and the cost of failing at stage one is a few kilos of powder and an afternoon.

Most failed trials I have seen skipped the middle stage. A dose that works in a beaker often fails in an IBC because the mixing energy is different, and a dose that works in an IBC can fail on a line because the residence time in the pipe is thirty seconds rather than five minutes. Each of those failures costs ten times more than the stage that would have caught it.

Then there is the waste question, which nobody raises until the invoice arrives. Gelled material from a trial is a waste stream, and in many jurisdictions it needs a classification before it can leave site. If the trial liquid was hazardous, the gel is hazardous too — gelling changes the physical form, not the chemistry. A trial that produces 3 tonnes of hazardous gel can generate a disposal bill larger than the entire product order that follows.

Decide before the trial where the material goes. If the site has a permitted route for the liquid, it may be cheaper to keep the trial volume small enough to go through that route rather than to gel it. Two hundred litres in an IBC is a very different disposal problem from three tonnes in a pit.

What goes on the one-page sheet

Scope and stages, with the go/no-go for each. Volumes of liquid and product. The four cost lines with owners. Who supplies what, including PPE and sampling bottles. The disposal route and the tonnage cap. The data to be recorded and who gets a copy. A named contact on each side, reachable on the day. And a signature and date from someone with budget authority, not just the process engineer.

That sheet takes an hour to write and it has saved more customer relationships than any technical presentation. If the trial is the first one on the site, the application data for super absorbent powder will tell you which stage is likely to fail, so you can size the pilot before you commit the line.