Machine category
Paste sachet projects are governed by product behaviour at the pump, nozzle and seal. Viscosity, temperature, particles, stringing, aeration and cleaning determine whether the product can be dosed cleanly into a reel-fed sachet and sealed without contamination.
Verified machinery starting points
These machines are starting points from the current Lancing range. The final dosing system, product feed, sachet and accepted output must be confirmed against representative product and film.
LUFS200D1A compact piston-pump VFFS starting point for compatible sauces, gels and other flowable products where the dose, nozzle and sachet can be proven by trial.
LU-420GSYA pump-fed VFFS option for larger compatible liquid and paste packs, subject to confirmation of product feed, film, seal and finished-pack requirements.
Engineer the dose and the seal together
A paste can be accurately displaced by the pump yet still make an unacceptable sachet if the nozzle strings, the pack has insufficient headspace or product reaches the cross seal. The complete fill cycle needs to be tested rather than considering the dosing unit in isolation.
State viscosity at the intended filling temperature, whether the product is shear-sensitive, aerated, thixotropic or liable to separate, and whether particles or fibres can obstruct the valve or nozzle. Product name alone is not a sufficient specification.
Confirm how product reaches the machine, how hopper level or pressure is controlled and how the nozzle stops the dose. Suck-back, shut-off geometry, nozzle height and timing may be needed to prevent drips or strings.
Document product-contact materials, strip-down points, drainability, flushing or clean-out method, changeover boundary and safe access. Where several formulations run, include cross-contamination and allergen requirements.
Quotation and trial inputs
| Product | Representative sample, density, viscosity at operating temperature, particles, fibres, foaming, aeration, stringing, separation and material compatibility. |
|---|---|
| Dose and control | Nominal dose, permitted range, how it will be measured, sample frequency and whether product temperature or density must be recorded with each test. |
| Sachet and film | Finished dimensions, headspace, seal style and width, tear notch, laminate, reel data, print repeat, registration mark and code position. |
| Product feed | Source vessel, transfer distance and height, temperature control, agitation, level sensing, hose route and the boundary between site and machine supply. |
| Acceptance evidence | Recorded trial settings, labelled dose samples, packs from start-up and stable operation, seal or leak checks, print and code checks and a run video tied to the test record. |
Buyer questions
Provide representative product, viscosity over the operating temperature range, particles, stringing or aeration, nominal dose, finished sachet, film, output, cleaning method and the test used to judge dose and seal integrity.
A viscous tail, drip, string or overfilled pack can reach the cross-seal area. Nozzle cut-off, suck-back, fill timing, headspace and pack geometry should be assessed together with the actual product.
It may be possible, but pump, nozzle, feed, temperature and cleaning requirements can change substantially. Every intended formulation and operating condition should be declared and the demanding products included in trials.
Agree whether production control is by weight, volume or another validated method, then define sample size, tolerance and test conditions. Density, temperature and entrained air can affect the relationship between volume and weight.
Check dose repeatability, nozzle behaviour, product on the seal, seal appearance and integrity, print registration, code, cut, opening feature and finished-pack handling under recorded settings.
A premade pouch may be preferable for larger packs, gussets, zippers or premium pack features. For small reel-fed sachets, VFFS normally remains the more direct comparison.
Define the project around your product and pack
Provide representative product, operating temperature, dose and tolerance, sachet dimensions, film, output, feed, cleaning, coding and integrity-test requirements. Lancing Ltd can define the machinery and trial route around the real application.
Paste and gel trial plan
Creams, gels, sauces and other viscous products can string, trap air, carry particles or change flow with temperature. Those behaviours determine the filling and cleaning arrangement.
Provide viscosity or a practical flow description at minimum, normal and maximum operating temperature. State particles, fibres, foaming, settling, shear sensitivity and whether the product needs agitation or recirculation.
Trials should reproduce tank level, pump pressure and refill. A warm production product may fill differently after a pause or as it cools in the feed path.
Check the nozzle at dose completion, including strings, tails or drips that can enter the seal. Confirm contact-part materials, dismantling, drain-down, cleaning agents and drying against the actual formulation.
Use retained packs to assess dose, visible seal contamination and the agreed integrity method after representative stop and restart conditions.
Paste-filling questions
Stringing is the formation of a product filament after the nominal dose has ended, which can pull material from the nozzle into the seal area.
The effect depends on formulation, temperature, shear history, nozzle geometry, closure action and suck-back. It must be observed through repeated cycles because a single hand-dispensed sample may not show the production behaviour.
Temperature can change viscosity, pressure drop, dose response, tailing and the time needed for product to settle clear of the seal.
Declare the production temperature range and how it is controlled. A trial at an easier ambient condition may select the wrong nozzle, valve or timing for routine operation.
A larger nozzle may reduce restriction, but it can also increase product drop, require more headspace and worsen cut-off or seal contamination.
Nozzle size must be considered with valve closure, dose volume, pack opening, particles and the time between dosing and cross sealing. Trial geometry should represent the intended sachet rather than an open container.
Confirm line clearance, cleaning completion, correct product-contact parts, recipe, priming, dose, nozzle cut-off and seal cleanliness before releasing production.
Colour, fragrance or active residues may be visible at very low levels, while trapped air after reassembly can disturb the first doses. Define how start-up packs are segregated and when the line is considered stable.
Turn the answer into a testable machine brief
Include representative product, dose range, sachet dimensions, film or artwork data, required accepted output and any cleaning, coding, inspection or line-integration requirements. Lancing Ltd can then assess the machine route against the real production case.