Direct answer: rollstock should be specified as a machine-interface material, not only as a printed laminate. A buyer must match the web to the actual filling line: web width, repeat length, sealing layout, print orientation, unwind direction, core, maximum roll diameter and weight, registration-mark design, splice rules, sealant side and roll-winding quality all affect whether the material can run consistently.
A structure that protects the product can still perform poorly on a filling machine if one of these interface details is wrong. The safest RFQ starts with the filler or co-packer’s written roll specification and a machine-ready dieline, then adds the product, barrier and sealing requirements.
Start with the actual packaging machine #
Identify whether the material will run on vertical form-fill-seal equipment, a horizontal flow wrapper, a sachet or stick-pack machine, a lidding line, or another system. Also identify the machine model, forming set, number of lanes and intended pack dimensions. Equipment families may handle film differently, so a specification copied from another line should not be assumed compatible.
The published Rollstock vs Finished Pouches FAQ helps buyers decide whether a filling-equipment route is appropriate before they prepare the detailed web specification.
Machine-interface fields that belong in the RFQ #
| Specification field | Why the filling line needs it | What the buyer should confirm |
|---|---|---|
| Web width and tolerance | The film must track through guides, forming parts and sealing stations without drifting or wrinkling. | Nominal slit width, accepted tolerance and which party owns the final dimension. |
| Repeat or cut-off length | The machine must place seals and cuts in the intended relationship to the printed design. | Finished pack length, print repeat, seal zones and allowable registration tolerance. |
| Unwind direction and print orientation | Artwork can feed upside down, backwards or on the wrong face when winding instructions are ambiguous. | A numbered unwind diagram approved by the machine operator or co-packer. |
| Core, roll diameter and roll weight | The unwind shaft, lifting method and roll stand impose physical limits. | Core inside diameter, core material, maximum outside diameter, maximum roll weight and any roll-end requirements. |
| Registration or eye mark | The photo-eye needs a stable mark and contrast against its local background to control cutting and sealing position. | Mark size, color, location, clear zone, sensor type and whether a dedicated mark is required. |
| Sealant side and sealing window | The correct layer must face the sealing surfaces and work within the line’s actual time, temperature and pressure range. | Inside/outside orientation, sealant identity, product contamination risk and trial settings. |
| Splices and roll joints | Unreported or poorly made splices can stop the line or enter finished packs. | Maximum splices per roll, splice construction, flagging method, location records and rejection rule. |
| Winding quality | Telescoping, blocking, curl, loose edges or excessive tension variation can interfere with web handling. | Winding direction, tension expectations, roll-edge condition and packaging for transport and storage. |
Artwork must be tied to the web specification #
The artwork file should use the approved machine dieline rather than a generic pouch drawing. It should identify the repeat, cut position, front and back panels, gusset or fin-seal area, registration mark, color bar if required, seal-clear zones and the direction the web travels. The flexible-pouch artwork and dieline guide explains the files and approvals that should accompany the RFQ.
When several SKUs will run on the same line, confirm whether they share the same web width, repeat and forming set. Similar-looking packs do not automatically share a machine setup.
Material performance and machinability must be reviewed together #
Barrier, stiffness, slip, seal initiation, hot tack, curl, static behavior and surface treatment can influence line performance. These variables are structure- and equipment-dependent. Do not approve a roll only because its total thickness or nominal material names match a previous order.
ASTM F88/F88M describes seal-strength measurement for flexible barrier materials, but a seal-strength result does not by itself establish that the web will track, register, form and seal correctly on a particular machine. The final trial should therefore use the intended film construction and representative line conditions.
How Chinese rollstock quotations may be presented #
In Chinese flexible-packaging procurement, some suppliers may quote rollstock by material weight, roll count or an estimated number of packs. The quotation may also separate printing or cylinder costs from the converted-film price. This is not a universal China-wide rule. Overseas buyers should confirm the unit of sale, estimated yield basis, slit-width tolerance, core and winding details, permitted splices, setup waste and overrun or underrun treatment in writing.
UGI Packging recommends placing the machine specification, artwork approval and material structure in the same controlled RFQ package so that the converter, buyer and filling operation are working from one revision.
Approval sequence before production #
- Obtain the filler or co-packer’s current machine specification and approved unwind diagram.
- Confirm the product, filling temperature, sealing-area contamination risk, required barrier and storage conditions.
- Approve the machine dieline, print orientation, eye mark and seal-clear zones.
- Review a material sample or printed proof for structure and graphics.
- Where line compatibility is not already established, run a production-representative machine trial and record the settings and observations.
- Freeze the approved specification and require written approval for changes to film, adhesive, ink, slip system, sealant or winding details.
The custom flexible-pouch RFQ checklist can be used to collect the commercial and application details, while the flexible-film sample and quotation guide provides further preparation context.
Frequently asked questions #
Is web width alone enough to order rollstock? #
No. The RFQ should also identify repeat length, unwind direction, core, maximum roll diameter and weight, registration mark, sealant side, splice rules and the filling machine. These fields define how the roll interfaces with the line.
Who should approve the unwind direction? #
The operator, engineering team or co-packer responsible for the actual filling line should approve a numbered unwind diagram. A verbal description such as “labels out” is too ambiguous for a controlled order.
Can a converter guarantee line speed from the film specification? #
Not from the film specification alone. Sustainable speed depends on the machine, pack geometry, product feeding, seal area cleanliness, film behavior, controls and operating settings. A representative line trial is the appropriate confirmation when the combination is new.
Should buyers allow splices in rollstock? #
That is a project decision. Buyers should state whether splices are permitted, how many may occur in a roll, how they must be made and flagged, and how affected material is handled by the filling line.
Official technical references #
- Viking Masek guide to packaging-machine and film design coordination
- ASTM F88/F88M-23: Seal Strength of Flexible Barrier Materials
