Product identification
- Batch and supplier
- Storage and temperature
- Normal and worst credible condition
- Handling before the trial
VFFS sample trial
What samples are needed for a VFFS trial?
A useful VFFS trial needs representative product, production-intent film, an approved pack reference and a written acceptance method. The quantity must support setup, stable running and normal interruptions rather than only a few demonstration bags.
Direct answer
The sample set should reproduce the controlling production conditions.
Provide enough consistent product and film to establish settings, run a meaningful comparison and repeat important events such as refill, stop and restart. Include the credible variation that could change dosing, forming or sealing. The trial should identify every sample and setting so accepted and failed packs can be traced to the conditions that produced them.
Define the product sample
Identify the batch, storage condition, age, temperature and any preparation before filling. For powders and granules, record bulk density and visible size distribution where available. For liquids and pastes, state temperature, viscosity-related conditions, particulates, foaming and any tendency to settle or separate.
If production varies by supplier, season or formulation, agree which samples represent normal and worst credible behaviour. Mixing unlike batches into one trial can hide the effect of variation.
Use film that can prove the intended process
A production-intent reel should identify structure, width, print repeat, unwind direction, registration mark, core and roll build. Plain film can support initial setup, but it cannot prove printed registration, artwork position or the exact seal response of the approved material.
Where the film specification is not final, record the trial material and the properties that still require revalidation before order acceptance.
Bring a clear pack reference
Use a dimensioned drawing and, where available, an approved filled pack. Define bag width, length, gusset or depth, seal widths, headspace, tear feature, coding area and presentation requirement. State which dimensions are critical and how they will be measured.
A competitor pack can show the target presentation, but it does not automatically define the reel or forming geometry needed on the proposed machine.
Retain evidence from more than the best run
Keep labelled samples from initial setup, stable running, refill, restart, reel change and any deliberate challenge. Retain failed examples that illustrate dose, registration, seal, cut or code boundaries. Record the matching machine recipe, product and film references and the time or sequence.
The result is more useful when another person can understand why each sample was accepted or rejected without relying on memory.
Decision aid
Trial evidence pack
Agree the required evidence before samples are shipped or a factory date is booked.
| Evidence | Minimum description | What it helps confirm |
|---|---|---|
| Product | Representative batch, condition and known variation. | Dosing, feed, fall, dust, foam, drip, breakage and settling. |
| Film | Production-intent structure, width, repeat and unwind. | Forming, pulling, registration, seals, cut and code position. |
| Pack reference | Drawing, approved sample and critical measurements. | Bag geometry, headspace, presentation and inspection method. |
| Acceptance plan | Pass criteria, test duration, interruptions and sampling. | Whether the result is repeatable and commercially relevant. |
| Retained record | Labelled accepted and failed packs with settings. | Traceability from evidence to the conditions that produced it. |
Quotation preparation
Information to prepare before the machinery review
Film identification
- Structure and width
- Print repeat and eye mark
- Unwind direction and reel build
- Approved or provisional status
Acceptance evidence
- Dose and dimensional checks
- Seal and leak method
- Registration, cut and code
- Rejected-pack recording
Buyer questions
Questions buyers ask about VFFS sample trials
How much product should be provided for a VFFS trial?
Provide enough product for setup, stabilisation, the agreed performance run and normal events such as refill and restart. The amount therefore depends on target dose, output and test duration. Calculate it from the written trial plan and include a sensible allowance, rather than sending an arbitrary small sample that only supports a few demonstration packs.
Does a trial need production film or can plain film be used?
Plain film can help establish basic forming and sealing, but production-intent film is needed to prove the final structure, friction, registration marks, artwork repeat, unwind and seal window. Where printed film is unavailable, record which results remain provisional and schedule confirmation before the configuration is finally accepted.
What product conditions must remain controlled during a trial?
Control or record batch, temperature, moisture or storage condition, bulk density or viscosity, mixing, settling, refill method and time out of storage where those variables affect behaviour. The purpose is not to make the product artificially uniform, but to know which condition produced each result and whether it represents production.
How should the trial distinguish machine faults from product or film variation?
Change one controlled variable at a time and label the corresponding packs. Record reel, product batch, recipe and event sequence. If the fault follows a specific reel section or product condition, that evidence differs from a fault that follows a machine setting, change part or mechanical position across several controlled inputs.
What result should be agreed before the trial begins?
Agree the finished pack, dose tolerance, dimensional and registration checks, seal or leak method, code requirement, accepted-output calculation, test duration and treatment of interruptions and rejects. A trial cannot produce a clear decision when success is defined only after the machine has run.
Application review