Combiblock Changeover — Format Parts and Product Switch Time

1. Why changeover is an output question

Changeover is the time a line is not producing while it switches from one bottle format or product to another. On a multi-SKU plant, changeover recurs daily and the total lost time is often larger than the speed difference between two machines. The changeover time between your two most common formats is therefore a real output number, not a detail.

A combiblock changes over in two distinct ways: a format change swaps moulds, star wheels, filler height and capper parts; a product change flushes and re-sanitises the product path. They are different jobs with different times, and a quotation that quotes one while you mean the other is answering the wrong question.

The cost of a changeover is the lost output during it, summed over every switch in a year, not the minutes on a stopwatch. A plant that switches five times a day loses more to changeover than a slower plant that switches once, even if both quote the same rated speed. When you compare two lines, compare the changeover-weighted output, because that is what the warehouse actually receives, and it is the number the quotation tends to leave out.

2. Format changeover

A format change swaps the parts that define the bottle: blow moulds, neck and base handling, star wheels, filler height setting and capper tooling. A bottle-size change within one neck family is quicker than a change that also moves the neck finish or base, which pulls in more of the machine. Label or cap-only changes are faster still.

Tool-less design matters here. Parts that locate and lock without hand tools, and recipes stored in the controller rather than re-entered, turn a rebuild into a swap. A line designed for changeover with guided procedures is far faster than one rebuilt by hand each time, and the difference is the crew's time every shift.

Neck finish is the biggest lever on format time. Standardising on one neck across your range keeps every format change to moulds, star wheels and height; a second neck finish pulls the neck handling and often the capper tooling into the change. Where the market allows it, design the SKU range around one neck, because that single decision removes most of the long changeovers before the line is even ordered, and it is free to make at the bottle-design stage.

3. Product changeover

A product change flushes and re-sanitises the product path. Switching within one valve family — still water to another still drink — is quicker than switching to CSD or hot-fill, which need a different valve setup and a full clean. The product similarity, not just the format, sets the time.

On a block the bottle is blown and filled in one frame, so there is no air-conveyor reconfiguration during a format change, which is where the block's changeover edge mainly lies. The product path is still flushed and sanitised like any line, so the block advantage is on format change more than on product change.

Product change time depends on how different the two products are, not on the format. Moving between two still products in one valve family is a flush and a short sanitise; moving to CSD or hot-fill pulls in a different valve and seal set and a full clean, which is where the long hours sit. If your range mixes still, carbonated and hot-fill, expect the product change to dominate the downtime budget and plan the run sequence so the long cleans happen least often.

4. What drives the time

Four factors decide changeover time: the number of parts to swap, how tool-less the design is, whether recipes are stored or re-entered, and how practised the crew is. A line with few tool-less parts, stored recipes and a trained crew changes in a fraction of the time of a line that rebuilds by hand. The first three are set at build; the fourth is built during commissioning and maintained after.

5. Indicative changeover times

Times below are indicative and configuration-dependent; confirm on your actual formats and products. They are the order of magnitude to sanity-check a quotation, not a specification.

Treat the table as a planning tool, not a promise. It is the order of magnitude to challenge a quotation and to size the buffer stock you hold against each change; the real minutes come from your actual bottles and products, so confirm them at FAT before the line is accepted, and keep the timed result with the contract so later disputes are settled by measurement, not memory.

6. Reducing changeover time

The practical levers are set at build and during commissioning. Specify tool-less parts and stored recipes; have the supplier set the changeover procedure during commissioning and train the crew on it; and keep a changeover check list so the steps are not rediscovered each time. The basic part count cannot be added later, so the design decision is the one that matters.

Measure the changeover once the line is running, not just at acceptance. A timed run with your actual formats and products exposes the steps the procedure forgot, and it is the number to feed back into planning. Treat changeover like any other spec: write the target in the contract, time it at FAT and at site, and revisit it when a new SKU enters the range, because a line that was fast on three bottles can slow on the fourth if nobody re-measures and the crew falls back to hand-setting.

7. What to ask the supplier

Ask for the changeover time between your two most common formats, the time for your most common product switch, what parts are involved, and whether recipes are stored. Put the numbers in the contract alongside the rated speed, because they decide real output, not the brochure rate.

The block architecture and capacity bands are in combiblock capacity selection, the block vs separate decision is in combiblock vs separate line, and the installation sequence that follows changeover design is in combiblock installation and commissioning. The block family is in the combiblock range.

Frequently asked questions