Standard bags
How to Measure Pre-Opened Bags on a Roll Before Ordering
To specify pre-opened bags on a roll correctly, measure more than bag width and length. Opening orientation, perforation, unwind direction, core diameter, film thickness and overall roll dimensions should also be checked.
Pre-opened bag measurements at a glance
If an existing roll already runs correctly on your bagging machine, use it as the reference.
- bag width and length
- film thickness or gauge
- open end and perforation
- unwind direction
- roll-core inside diameter
- roll width and outside diameter
Lay the bag flat and measure width
Place the bag on a clean, flat surface. Do not stretch the film; smooth out major wrinkles without pulling the material out of shape.
Measure straight across the bag from side to side with the material lying flat. Record the value in millimetres when working with European packaging specifications.
Measure length and identify the construction
First identify the open end, bottom seal and perforation connecting the next bag. These features must be clear before you record bag length.
A seal permanently joins the film layers; a perforation creates the controlled tear line between bags. They can be close together, so photographs are useful when specifying an existing roll.
Record opening orientation and roll dimensions
The open end has to arrive at the loading position in the correct orientation. Record or photograph the open side, bottom seal, perforation and direction of travel.
Measure the core inside diameter, roll width and outside diameter. Also note bags per roll and, if useful, roll weight. Overall roll size can matter just as much as the individual bag dimensions.
Document unwind direction and film thickness
Take a side photo with one or two bags unwound. It should show the relationship between the roll, opening, seal and perforation; there is no need to guess a technical winding code.
Film thickness may be specified in microns or mil. Use the roll label, technical data sheet, current quotation or a suitable micrometer rather than an ordinary ruler.
Need us to identify your current bag?
Send your roll label, existing technical specification, supplier quotation or clear photographs with measurements. We can compare the main parameters and prepare an individual proposal for your packing process.
FAQ
Are bags with the same width and length interchangeable?
Not necessarily. Film, thickness, opening orientation, perforation, winding, core and roll configuration can all differ.
What photos should you send?
The roll label, complete roll, two consecutive bags unwound, one bag with a ruler or tape measure, and the exact bagging-machine model if available.
What if I do not know every specification?
A current roll label, supplier quotation, photographs and the exact machine model are usually the best starting point.