How to Specify a Sachet Form-Fill-Seal Machine for Your Product

Most quotations for packaging machinery differ so much that they are hard to compare. Two machines quoted for the same product can differ substantially in output, in how they dose, and in what happens to the film at the sealing jaw — and the price difference is usually explained by exactly those differences.

This article is the framework we use when customers ask us to recommend a machine. It works equally well as a checklist for comparing quotations from other suppliers.

The seven inputs that determine the machine

1. The product, physically

Not the marketing description — the physical behaviour. Is it a free-flowing powder, a granule, a gel, a free-flowing liquid or a viscous liquid? Does it bridge, cake, foam or stick to surfaces?

This single answer decides the dosing method. Free-flowing powder points to a volumetric cup or servo dosing system. Viscous liquid points to a piston pump or nozzle dosing. Anything that bridges points to an auger filler.

2. Fill weight and the tolerance you need

Two numbers matter: the target fill, and how much variation you can accept. A 2 g sachet and a 500 ml liquid sachet are different machines in almost every respect.

3. Pack dimensions

Bag width, length and, for stick packs, thickness. Pack size determines the former size and the machine's working width. If you plan to run more than one pack size, the machine needs tooling and adjustment range for all of them — say so at specification stage.

4. Film structure

The film is not a consumable detail; it is one of the main drivers of machine behaviour. Tell the supplier:

• Material: PE, PP, PA or combinations
• Total thickness and each layer's thickness
• Whether it is printed, and how many colours
• Barrier requirements: moisture, oxygen, light or odour
• Seal layer and its sealing temperature window

A machine specified without this is a machine that will have to be adjusted after it arrives.

5. Annual volume and realistic growth

Volume decides whether you need a single-lane machine or multi-lane tooling, and whether a single machine or a complete line makes sense. Ask for a quote at your current volume and at your volume in three years — the difference in configuration is often significant.

6. Changeover expectations

How many products will you run on this machine, and how often do you switch? A line running one product continuously can be optimised hard. A line running twelve SKUs needs fast changeover, which costs money in design.

7. Site conditions and compliance context

• Electrical supply: voltage, frequency, available capacity
• Floor space and ceiling height, including film reel loading
• Room classification requirements, if any
• Documentation requirements, particularly for pharmaceutical work

How to compare quotations fairly

Ask every supplier to fill in the same table. If a supplier cannot answer a row, that is useful information in itself.

Once that table is filled in for each quotation, the price spread stops looking arbitrary. In most cases two or three rows explain nearly all of it.

Three questions worth asking directly

1. "Have you run my product before?" Experience with a similar product is worth more than a longer equipment list.
2. "What speed can you guarantee on my film?" Not the headline maximum — the speed at which seals hold on real material at the specified thickness.
3. "What happens if it does not meet that speed?" A supplier confident in their own trial results will tell you what they will do. One who is not will avoid the question.

Frequently asked questions

Do I need a trial run before accepting the machine?

We recommend it, and most serious buyers require it. Seal behaviour varies considerably between film structures and suppliers, and it cannot be reliably predicted from a datasheet. Running your own film on your own product is the only way to confirm the sealing window and the achievable speed.

How much does multi-lane tooling actually help?

On a flat sachet machine, lanes multiply output substantially because the film is shared across several forming and filling stations. On a stick pack machine the gain is more limited. The practical question is whether your volume justifies the added tooling cost and the film waste it creates during changeover.

What documentation do I get?

Standard documentation includes wiring diagrams, operating procedures, machine drawings and a spare parts list, all in English. If your internal process requires additional validation documentation for pharmaceutical work, raise it during specification so it can be planned into the project rather than added afterwards.