How to size a confectionery line in kg/h without over- or under-buying

The most expensive number in any equipment quote is the one nobody checks: kg/h. A line sized on a sales-sheet peak is either idle capital you paid for or a bottleneck you find three months in. Sizing quietly sets your cost per kilo for the next decade.

Rated capacity and real capacity are not the same. The rated figure is a clean number on ideal product; real output is what remains after changeovers, cleaning, warm-up, recipe differences, and the slowest machine in the chain setting the pace.

Start from demand, not from the machine

Work backwards: annual volume divided by working days, by shifts, and by effective hours per shift gives the kg/h you actually need — then add headroom for growth, not for marketing. A plant that needs 200 kg/h of finished product does not need a 200 kg/h machine; it needs a line whose slowest stage delivers 200 kg/h after losses.

The peak-number trap

Rated throughput is usually quoted on one easy recipe at full run with no stops. Real product changes it: higher viscosity, more inclusions, a stickier mass, a wetter raw material all slow the line, often 20-40% below the rated figure. The honest question to ask a supplier is not what is the maximum but what is the sustained kg/h on my recipe, with my changeovers.

Rated capacity is what the machine does in the brochure; sustained capacity is what it does on your worst recipe on a Friday. Buy for the second number.

Batch vs continuous, and the bottleneck rule

Batch equipment is flexible and cheaper to start with; continuous lines give higher, steadier output once volume justifies them. Either way, a line is only as fast as its slowest stage — adding a faster depositor in front of a cooling tunnel that cannot keep up buys nothing. Size the whole chain to one target and find the bottleneck before you sign, not after.

Where sizing decisions cost money

Oversizing to be safe: you pay for capacity, floor space and energy you never use, and the line runs inefficiently at low load. Undersizing on a peak figure: within a season you are hitting volume with extra shifts and overtime, which costs far more than the bigger line would have. Forgetting uptime: a line rated at 300 kg/h running at 60% effective time delivers 180 kg/h, and that gap is where the business plan breaks.

The right size is set by your sustained demand and your slowest stage, not by the biggest number on the quote. Get those two right and the rest of the line specification follows.