Process comparison
Shrink wrapping uses heat-shrinkable film to conform around a product or group; flow wrapping forms a continuous sealed pack around an oriented product. The required finished pack should decide the process.
Direct answer
Shrink wrapping positions film around a product, carton, tray or multipack and then applies controlled heat so the film contracts. Flow wrapping feeds an oriented product into a continuously formed film tube with longitudinal and cross seals. Select from the required enclosure, presentation, product orientation, heat tolerance, barrier, opening method, output duty and line interfaces—not from the word “wrapper” alone.
| Decision | Shrink wrapping | Flow wrapping |
|---|---|---|
| How the pack is formed | Film is sealed or sleeved around the product and then contracted with controlled heat | Film is formed continuously around an oriented product and closed with longitudinal and cross seals |
| Common pack objective | Close presentation wrap, open-sided bundle, tray pack, multipack or heat-shrunk sleeve | Individual sealed pillow-style pack around a repeatable product |
| Product presentation | Can accommodate individual products, cartons and grouped packs when the film envelope and heat process are suitable | Normally relies on controlled pitch and orientation into the former and sealing jaws |
| Critical process variable | Film shrink response, air release, sealing, airflow, dwell and cooling | Film tracking, product pitch, former geometry, longitudinal seal and cross-seal timing |
| Evidence needed | Production film, product extremes, heat response, pack finish and post-tunnel handling | Production film, product pitch, seal area, cut length, orientation and required barrier |
Selection framework
The alternative should be tested against what the pack must do through production, distribution, opening and disposal.
Shrink wrapping is a natural starting point for clear film around boxes or printed matter, sleeve-wrapped bottles and cans, tray packs, open-sided multipacks and products that need a film finish formed by controlled shrinking. The seal route, loose-film envelope and tunnel process must still suit the product.
Flow wrapping is normally investigated where repeat products are individually presented into a continuous film tube and a longitudinal seal with cross seals creates the required pack. Product pitch, orientation, film tracking and seal-area contamination become primary engineering questions.
Both processes can be manual, semi-automatic or automatic in different configurations. Sustainable output depends on the complete line, product presentation, film, changeovers, recovery, rejects and downstream handling. Define an accepted pack and test the production duty.
A product that cannot tolerate the proposed shrink exposure may require a different shrink route, shielding, lower thermal demand or another process. Conversely, a required sealed barrier should not be assumed from a shrink sleeve with open ends. State the barrier and opening requirement explicitly.
Buyer questions
These questions separate the pack requirement from the machine name.
No. Flow wrapping normally forms a continuous film tube around an oriented product and closes it with longitudinal and cross seals. Shrink wrapping uses film that is subsequently contracted with controlled heat around a product or group. The machines, seals, film behaviour and finished pack are different.
Describe the desired pack rather than asking for a generic “wrapper”.
A clear close-fitting presentation wrap around a carton often points towards an L-sealer or side-sealer with a shrink tunnel. A flow-wrapped carton may be appropriate where a continuous sealed bag format is required. Carton finish, corners, print, opening method, barrier and line rate determine the better route.
Shrink wrapping can accommodate some irregular products because film contracts around the geometry, but protrusions, voids, sharp edges and unstable orientation can still cause failures. Flow wrapping usually requires controlled presentation through a former. Representative trials are essential for either route when the product is not consistent.
Conventional flow wrapping forms and seals the pack without using a shrink tunnel as the primary finishing stage. Shrink wrapping normally needs controlled heat after the film is sealed or sleeved. A specialist film or application may differ, so the exact material and pack specification must be confirmed.
Provide the smallest and largest products, production-condition samples, intended films or supplier data, accepted pack examples, labels and any heat-sensitive components. Include the required opening method, barrier, sustained output, line pitch and downstream handling so each process is judged against the same result.
Send photographs or drawings, dimensions, weight, orientation, product variation, required pack appearance, barrier or tamper objective, opening method, output duty, site layout and upstream/downstream equipment. Lancing can then identify whether the shrink-wrapping route on this site is suitable or whether a flow-wrapping assessment is required.
This guidance is published by Lancing Ltd for initial process selection. Final suitability depends on the actual product, film, accepted pack, line duty and representative trials. Send the application details to Lancing.
Process review
Send products, dimensions, film information, required enclosure, output and line layout so the correct process can be reviewed against evidence.