Packaging machine datasheets use inconsistent names for the same parameter, which makes direct comparison difficult. These are the specifications that decide whether a machine will run your product, what each one actually means, and the ones that are usually irrelevant to the decision.
The specifications that decide the purchase
| Specification | What it tells you | Watch out for |
|---|---|---|
| Sealing width | Width of the seal band in mm | Wider is not better; it must suit the film |
| Sealing length | Maximum seal the bar can make in one pass | Must cover the full bag opening |
| Speed (m/min or bags/min) | Throughput at rated conditions | Rated conditions are rarely your conditions |
| Chamber dimension | Internal L×W×H of a vacuum chamber | Compare to the bag laid flat, not the product |
| Ultimate vacuum | Deepest vacuum the pump reaches | Time to reach it matters as much as the value |
| Temperature range | Heater control span | Only useful alongside dwell |
| Connected load | Electrical demand in W or kW | Confirm phase as well as the number |
| Net weight | Machine mass | Decides floor loading and installation method |
Specifications that mislead if read alone
Speed without dwell is the most common. A band sealer rated at a high belt speed is only sealing well if the heaters can fuse the film in the time the belt allows. The two are specified together or not at all. Likewise, ultimate vacuum without pump capacity tells you the depth but not the cycle time.
Why the same parameter appears under different names
Manufacturers write datasheets for their own range, not for cross-comparison. External dimensions, overall dimensions and machine size are the same measurement. Sealing power, heating power and heater load often are too. When comparing, normalise the parameter names before comparing the numbers.
We publish specifications under a normalised set of labels across all 137 series so the same parameter carries the same name on every page — the raw manufacturer wording is preserved in the value, not the label.
What to ask for that is not on the datasheet
- Rate achieved with your product, not the rated maximum.
- Changeover time between your formats.
- Wear parts and their expected interval.
- Installation requirements: supply, air, floor loading, access.
- What is included in commissioning.
Compare normalised specifications side by side in the full catalogue.
Figures in this article are drawn from the 137 machine series SilverSeal currently supplies, not from generic industry averages. Specifications vary by model — check the individual series page before specifying.
Frequently asked questions
Why do two machines with the same speed perform differently?
Rated speed assumes ideal film, product and ambient conditions. Dwell, heater capacity and product behaviour decide the rate you actually achieve.
Is a higher ultimate vacuum always better?
Not for every product. What matters is reaching the vacuum your product needs within an acceptable cycle time.
What does connected load tell me?
The electrical demand to size the circuit. Always confirm phase alongside it.
Which specification is most often got wrong?
Chamber dimension on vacuum machines, because buyers size from the product rather than from the bag laid flat.
