Liquid and paste VFFS
Use this guide to compare liquid sachet packing, pump filling and paste form fill seal machinery before sending product samples, pack drawings and output targets to Lancing for a practical machine shortlist.
SEO focus
Lancing helps UK manufacturers compare packaging machinery by product behaviour, dosing technology, film and seal requirements, target bags per minute, available utilities and line layout. The aim is to specify the correct form fill and seal machinery route before a formal proposal is prepared.
Liquid sachet packing machinery is built around viscosity, temperature, fill volume, drip control and product compatibility. Thin liquids, sauces, gels, oils, creams and chemical liquids can require different pumps, tank feeds, nozzles and seals.
Liquid products make seal integrity especially important because any product on the seal face can create leaks. Film choice, seal temperature, dwell time, nozzle cut-off and bag presentation should be confirmed before the line is specified.
Single-machine liquid and paste form fill seal systems suit many bag sizes, while multi-channel liquid sachet machines can suit high-output portion packs. The right route depends on output, pack dimensions, fill volume and cleaning requirements.
Relevant machinery
Automatic filling and sealing machinery for liquid and paste products using tank, pump and film sealing components for sauce, gel, cosmetic and chemical packs.
Model: LU-420GSY · Voltage: 380V 50–60Hz · Power: Approx. 5kW View machine details
Multi-channel liquid bagging machine for small liquid sachets and portion packs, using controlled pump filling and multi-lane sealing.
Model: LU-FSMP8 · Filling method: Magnetic pump · Application: Liquid sachets View machine detailsQuestions buyers search for
Some machines can fill pastes and viscous products when fitted with the correct pump, tank and nozzle arrangement.
Viscosity, fill volume, pump type, seal dwell time, film material and cleaning requirements all affect achievable speed.
Send product type, viscosity, fill volume, pack size, film material, target output, cleaning needs and whether product temperature is controlled.
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Liquid VFFS engineering
Viscosity, foaming, dissolved gas, particulates and chemical compatibility influence pump and nozzle choice. Where temperature changes flow, provide the expected operating range rather than a single room-temperature description.
The dose should stop cleanly and clear the seal path before jaw closure. Nozzle shut-off, suck-back, fill height, hose bore, pump timing and bag length may all affect contamination. The trial should inspect seals after the product has reached its normal operating condition.
Confirm whether contact parts are removed, flushed or cleaned in place, and identify drainage, hot-water or chemical requirements. The user’s hygiene and compatibility assessment should determine materials and procedures.
This page covers liquid dosing within a vertical form fill seal process. Projects primarily defined by sachet format, lane configuration or specialist portion packs should also use sachetfillingmachines.co.uk.
Buyer questions
Many liquids and pastes change flow as temperature changes. Pump fill time, drip control and dose repeatability should be assessed at the expected operating condition.
State the maximum particle size, shape and concentration. Pump, valve, hose and nozzle passages must be compatible and tested for blockage or product damage.
Drip, splash, foaming, overfill, stringing or premature jaw closure can contaminate the sealing surfaces.
Verify correct reassembly, dry and clean seal areas, pump priming, leak-free connections, the first accepted dose and traceable release back to production.
Application review
Liquid process questions
Temperature can change viscosity, flow rate, foaming, stringing and the pressure needed to move the product. A recipe proven with a warm product may not behave the same when it is colder, and heated products may affect film and seal conditions. State the expected production temperature range and test the credible extremes where they control performance.
Drip can develop as temperature, viscosity, pressure, valve timing, seal wear or product level changes. Entrained air and particulates can also prevent a shut-off valve from closing consistently. The investigation should record when the drip begins and whether it follows refill, speed change, temperature change or an increasing number of cycles.
Observe foam generation during pumping, nozzle discharge and impact in the forming bag. Measure whether foam settles before the horizontal seal and whether it changes dose or contaminates the film. Nozzle position, fill profile, product temperature and bag headspace may be more important than simply slowing the entire machine.
Particles can lodge in small valves, nozzles or pump clearances, while hard or abrasive inclusions may accelerate wear. Provide the maximum particle size, concentration and tendency to settle, not only the base-liquid viscosity. The product path should be selected and trialled so the dose remains consistent without crushing, separating or trapping the inclusions.
Pump and nozzle selection
Viscosity, temperature, particulates, foaming, separation and clean-down can change the practical pump, valve, hose and nozzle arrangement. The same formulation may behave differently when warm, cold, mixed or held in a hopper.
| Product condition | What the machinery assessment must establish | Evidence to record |
|---|---|---|
| Thin, free-flowing liquid | Metering stability, drip-free shut-off, splash control and compatibility with the hose and wetted path. | Fill volume, temperature, cycle samples, nozzle cut-off and seal-area inspection. |
| Viscous liquid or paste | Pressure, dose time, positive shut-off, stringing and the effect of temperature on flow. | Product at normal and worst credible temperature, particulates, consecutive doses and clean-down method. |
| Foaming product | Fill profile, nozzle position, headspace, bag support and time before the horizontal seal closes. | Foam height, settling time, accepted fill level and leak/seal checks through a timed run. |
| Product that settles or separates | Hopper mixing, recirculation, dwell time and whether the first and last packs remain equivalent. | Sampling plan, mixing method, start/stop duration and retained packs from across the batch. |
Buyer questions
The pump must be selected from the product's flow behaviour, target dose, required cycle, particulates, temperature, chemical compatibility, cleaning method and shut-off requirement. A product name alone is not enough to choose between metering, magnetic, piston or other application-matched pumping routes.
Liquid or product strings that continue after dosing can reach the horizontal seal before the jaws close. The nozzle, valve, bag-open time, fill profile and product-clear delay must therefore be assessed together, with seals checked during stable running and normal interruptions.
Yes where temperature changes viscosity, foaming, separation, dose time or seal contamination. Record the product temperature at the hopper and nozzle, not only its nominal process temperature, and agree which temperature range the machinery must handle.
State the product-contact materials, allergen or cross-contamination boundaries, cleaning chemicals, temperature, drainage, disassembly expectations, changeover sequence and acceptable residual condition. The machine and pump arrangement should be reviewed against that real cleaning method before approval.