{"id":1616,"date":"2026-10-22T09:04:17","date_gmt":"2026-10-22T01:04:17","guid":{"rendered":"https:\/\/jingrui-packingmachine.com\/weighing-accuracy-giveaway-cost\/"},"modified":"2026-10-22T09:06:37","modified_gmt":"2026-10-22T01:06:37","slug":"weighing-accuracy-giveaway-cost","status":"publish","type":"post","link":"https:\/\/jingrui-packingmachine.com\/es\/weighing-accuracy-giveaway-cost\/","title":{"rendered":"Lo que cuesta un gramo de desperdicio: la precisi\u00f3n del pesaje en una l\u00ednea de envasado."},"content":{"rendered":"\n

A nut exporter in Turkey sent us a video of his line running at 62 bags a minute. Everything looked right \u2014 clean seals, straight bags, no rejects. Then he put a checkweigher on the output for one shift. Target was 500 g. The average was 503.6 g. He had been giving away 3.6 g per bag for four years. At 6 million bags a year that is 21.6 tonnes of product. His raw material landed at about $5 a kilo, so the line had quietly handed over roughly $108,000 in product that nobody invoiced. This is the part of packing machine shopping that almost nobody puts in the spreadsheet. Buyers compare speed, price, and how the machine looks on the factory floor. They rarely ask what the filling error costs per year, because the number is invisible \u2014 it hides inside the bag, in a few grams the customer never notices.<\/p>\n\n\n\n

The arithmetic you should run before choosing a filler<\/h2>\n\n\n\n

The formula is short:<\/p>\n\n\n\n

annual giveaway = (average fill weight \u2212 target weight) \u00d7 bags per year \u00d7 ingredient cost per kilo<\/p>\n\n\n\n

Two things drive it: how wide the error band is, and how much the product is worth. We set 500 g bags with a \u00b13 g band on a volumetric cup machine and \u00b11 g on a multi-head scale. That difference sounds small. On a 6-million-bag run at $5\/kg it is $108,000 a year versus $36,000 \u2014 a $72,000 gap created by one component choice. And it gets worse with expensive product. Protein powder at $18\/kg turns the same 3.6 g of overfill into $388,000 a year. At that price the weighing head is not an accessory, it is the machine.<\/p>\n\n\n\n

Three filling methods, three error profiles<\/h2>\n\n\n\n
\"Multi-head<\/figure>\n\n\n\n

Volumetric cups<\/strong> fill by volume, not weight. They are fast, cheap, and mechanically simple \u2014 a cup of fixed size, a rotating plate, done. The problem is that volume and weight are not the same thing. A powder that picks up moisture overnight packs tighter; the same cup now holds 4 g more. Change supplier and the bulk density shifts again. Expect \u00b12\u20133% on powders, and plan to re-calibrate at every batch change. On a 500 g bag that is a 10\u201315 g swing. Auger fillers<\/strong> meter by screw revolutions and are the standard for flour, milk powder, and cocoa. Accuracy is \u00b11% when the product is consistent, and they handle dust well. They slow down on sticky or high-fat powders \u2014 the screw cavity does not empty cleanly and the weight drifts upward through the shift. Multi-head combination scales<\/strong> weigh every drop. Fourteen heads, each holding a small portion, and the controller picks the combination closest to target in milliseconds. Accuracy is \u00b10.3\u20130.5 g on granules and \u00b10.5\u20131 g on powders, at 60\u201380 bags a minute. This is why coffee, nuts, frozen vegetables, and detergents all run on them. Linear weighers<\/strong> sit between the two: two or four weighing buckets, \u00b11\u20132 g, half the price of a multi-head, and about half the speed. For 20\u201340 bags a minute on mid-value product they are the sensible middle.<\/p>\n\n\n\n

When accuracy is not worth paying for<\/h2>\n\n\n\n
\"Volumetric<\/figure>\n\n\n\n

We turn down multi-head scale requests regularly, and here is when. If you run under 1.5 million bags a year on a cheap ingredient \u2014 salt, sugar, animal feed at $0.8\/kg \u2014 the giveaway math does not justify the price difference. Three grams on 1.5 million bags of $0.8 salt is $3,600 a year. A 14-head scale costs $9,000\u201314,000 more than a cup filler. That is a four-year payback on a machine you will replace in six. The same is true for produce sold by the box. Buyers accept a weight tolerance on a 10 kg carton of onions; nobody is weighing individual bags, and the 2% variance is inside the trade standard. Volumetric is the correct answer there, not a compromise. The other case is sticky product. Honey, chili paste, and thick sauce do not flow through a multi-head scale at all \u2014 the product bridges in the hoppers and the weights go wild. Paste needs a piston or servo pump filler, and the accuracy conversation moves to drip control at the nozzle, not to weighing.<\/p>\n\n\n\n

What to demand in the trial<\/h2>\n\n\n\n

Ask for three things before you sign, and get them in writing. Run your own product, not the demo powder. Bulk density, moisture, and particle shape change the error band more than the machine model does, and a supplier who only trials with his own material is telling you something. Ask for a one-hour continuous run with a checkweigher at the exit, and ask for the standard deviation, not the average. An average of 501 g with a \u00b19 g spread means you are short-weighting one bag in twenty and over-filling the rest \u2014 a compliance problem, not just a cost problem. Then ask what the target weight will be set to on delivery. Most factories ship set to +2% to stay clear of short-weight fines. If your acceptance test assumes 500 g and the machine ships at 510 g, you already paid for the difference in the quote. If you want to see how the numbers change at different production scales, our breakdown of [what a first packing line really costs](https:\/\/jingrui-packingmachine.com\/first-packing-line-cost\/) walks through three budget levels with the same math. For the equipment side, the [multi-head scale VFFS line](https:\/\/jingrui-packingmachine.com\/product\/multi-head-scale-packing-machine-vffs-packing-machine\/) is what most coffee and nut exporters end up on, the [volumetric cup machine](https:\/\/jingrui-packingmachine.com\/product\/volumetric-cup-packing-machine-vffs-packing-machine\/) covers the low-value high-volume case, and the [linear weigher](https:\/\/jingrui-packingmachine.com\/product\/linear-weigher-packing-machine-detergent-powder-packing-machine\/) is the middle ground. Powder lines usually run an [auger filler](https:\/\/jingrui-packingmachine.com\/product\/automatic-auger-filling-machine-by-weighing-and-lift-fall\/) instead, and if you are still deciding on the bag itself, the [pillow vs stand-up vs brick bag comparison](https:\/\/jingrui-packingmachine.com\/pillow-bag-vs-stand-up-pouch-vs-brick-bag\/) covers how the format affects the filling method. Send us your product, bag size, and annual volume, and we will run the giveaway math with you before quoting a machine \u2014 including the cases where the cheaper filler is the right answer.<\/p>\n\n\n\n\n

FAQ<\/strong><\/h2>\n\n\n\n
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Why is my 500 g bag actually 505 g?<\/summary>\n\n

Because most factories set the target above the label weight to avoid short-weight fines, and the filler’s error band sits on top of that. A bag labelled 500 g is often filled to a 505 g target so that the lowest bag in the run still clears 500 g. The overfill is the price of never being under.<\/p>\n\n<\/details>\n\n\n

Can I add a checkweigher to a line I already own?<\/summary>\n\n

Yes, and it is the cheapest way to find out what your line is really doing. A stand-alone checkweigher after the bagger logs the weight of every bag, so you see the average and the spread instead of guessing. Two shifts of data usually pays for the instrument in the first month on a high-value product.<\/p>\n\n<\/details>\n\n\n

Which filler fits 200,000 bags a year?<\/summary>\n\n

For that volume a linear weigher or a volumetric cup machine is normally the right spend, not a 14-head scale. At 200,000 bags the annual giveaway on a 3 g overfill of a $5 product is about $3,000 \u2014 less than the price gap between the two filler types. Spend the difference on a checkweigher and better sealing.<\/p>\n\n<\/details>\n<\/div>\n