Container Glass for French Wine: Why Colour Campaigns Kill OEE

It's 2am on a Tuesday and your colour change from dead-leaf to antique green is already 40 minutes behind schedule. Section 4 is throwing settle waves. Nobody's sure whether it's the new mould set or the forehearth still finding its profile after the cullet ratio shifted. The hot-end superintendent is on the phone with the mould shop. The operator is adjusting gob weight independently, which is the last thing you want at this point in a campaign transition.

That's a French wine bottle production line mid-campaign changeover. Most plants running Bordeaux and Languedoc contracts cycle through three to five colour families in a typical quarter. The commercial logic is obvious. The OEE logic is brutal.

The colour change isn't the problem. The cullet is.

Most plant managers treat French wine bottle production as a forming problem. Change the mould set, adjust the recipe, run first ware. But the real downtime isn't in the IS machine. It's in the furnace feed cycle.

When you shift from a clear flint campaign to dead-leaf or antique green, your cullet ratio changes with it. A typical wine bottle line running 70% cullet, which many European container glass plants now target under EU ETS Phase IV to reduce carbon intensity, carries a lag time before the colour in the furnace bath actually stabilises. That lag can run six to twelve hours on a well-managed line. On a poorly managed one, I've seen it stretch past 18.

In 2017, I was advising on a forming audit for a two-furnace plant in southern France running eight-section Emhart IS machines, some with control systems that hadn't been updated since the early 2000s. They were producing Bordeaux-style 750ml bottles across two colour families off the same furnace. Colour striations were appearing three to four hours into what should have been a stable campaign, tracing directly back to mixed-colour cullet at intake. The cullet sort specification required colour contamination below 0.5% by weight. It wasn't hitting that number. Nobody owned that KPI.

Colour striations. A defect that operators blame on the forehearth, but is almost always a cullet contamination problem wearing a furnace disguise.

Varietal specs make your process window smaller than you think

French wine production has AOC-level requirements that flow directly into bottle specifications, and they're not gentle. A Champagne flute needs a defined wall-thickness profile and a pressure-resistance standard. A Bordeaux bottle has a shoulder angle and punt depth that aren't suggestions. A Burgundy bottle has a belly diameter tolerance that can reject an entire run if the mould set has drifted even 0.3mm off nominal.

Gob weight CV has to sit at ≤0.4% if you want consistent wall thickness on a 75cl Bordeaux. Miss that by a tenth of a percent and you'll see wall thickness variance show up as choked necks on the lehr or, worse, as field failures. In a high-end AOC supply chain, field failures aren't a quality statistic. They're a commercial event.

The hot-end superintendent owns the recipe lock on these specs. Not the operator, not the shift lead. When I audit plants running French varietal bottles and find operators adjusting set points mid-campaign without sign-off, that's always where process drift starts. And it almost always surfaces at the 0600 handover, when the night shift's undocumented adjustments land in the lap of a day-shift team who have no idea what changed or why.

The gap between your best shift and your worst shift on an identical colour campaign isn't a machine problem. It's a knowledge-transfer problem, and it shows up in your OEE every single week.

What higher cullet ratios are doing to colour transition time

Under EU ETS Phase IV, carbon allowance costs have put real margin pressure on European container glass production. The instinct to push cullet ratios higher is correct for carbon cost. But it compounds the colour-campaign problem directly.

Higher cullet ratios mean colour contamination travels further through the furnace cycle and takes longer to flush out. If your cullet sorting isn't tight, colour transition time blows out with it. Every extra hour of unstable-colour production is an extra hour of elevated rejects or reduced pack rate. Neither shows up as a carbon saving on your ETS compliance report, but both come straight off EBITDA.

Look, nobody's telling you to run fewer colour campaigns. The AOC contract won't allow it, and the commercial premium on varietal-specific bottles is the reason the line exists. But the way most plants handle colour family transitions leaves 4-7 OEE points on the table compared to a plant that has systemised the process.

What a systemised campaign changeover actually looks like

It starts at T-72h before line down with cullet pre-staged to the correct colour sort ratio. Not the day before. Not the shift before. Seventy-two hours out, because the furnace needs time to settle and you need to confirm the sort is within spec before you commit the line to the campaign.

The recipe for each colour family should be versioned and locked in the control system, not in a supervisor's notebook and not in a shared folder nobody maintains. The mould preheat curve should be documented: 480°C ±10°C is the target on most wine bottle sets, and hitting it consistently requires that the mould shop owns the preheat schedule with a defined start time relative to line down. (And yes, I know the mould shop will tell you they always hit that number. Pull the preheat records from the last five campaigns and then decide.)

Thirty-eight minutes. That was the time-to-stable-pack variance between the best and worst operators on the same colour campaign at one plant I audited. Same machine, same mould set, same recipe in theory. The difference was entirely in how each operator managed the first-ware sequence and how quickly they called for QA stabilisation sign-off.

This is exactly what a Job Change Tool built for container glass addresses. A vendor-neutral system that maps the full nine-stage changeover lifecycle with defined owners at every step, from cullet pre-staging through to post-mortem KPI review. It's not a generic SMED template rebadged for forming lines. It's a systemised methodology with a digital execution layer, built by people who have actually run these lines. When cullet sort, recipe load, and mould preheat are all managed to the same documented standard, time-to-stable-pack on a colour campaign typically drops 35-50% against a plant still running on tribal knowledge.

An independent container glass consultant working without OEM ties will map your actual changeover sequence against your real KPI variance. On most French wine bottle lines I've audited, the gap between best-shift and worst-shift performance sits at 4-7 OEE points, and it doesn't require a capital spend to close it.

If your team isn't working from a shared vocabulary across shifts and departments, the glass glossary on the Lean Glass resources page is a practical first step before you formalise the changeover programme.

So if you already know which colour campaign is your worst-performing transition, and every plant manager reading this does know, what's the actual plan for the next one?