Published · 4 min read
The objective of stretch wrapping is not to pull film as hard as possible. It is to create a repeatable system that keeps a unit load together throughout distribution. Film gauge matters, but it cannot define performance by itself. Pre-stretch, force-to-load, layer count, overlap, load geometry and the load-to-pallet bond must work as one recipe.
Pre-stretch is not the same as wrap force
Pre-stretch elongates film before it reaches the load, commonly by running two carriage rollers at different speeds. It can improve roll yield and provide more controlled film delivery. Wrap force, or force-to-load, is the tension applied while that film is placed around the pallet. A high pre-stretch percentage on the control panel does not prove that the finished load has suitable containment.
If film, roller setting and load surface are mismatched, excessive pre-stretch may cause breaks, excessive neckdown or punctures at corners. Too much wrap force can crush corrugated cases or deform soft products; too little lets layers sit loosely. Record the two settings separately and do not assume that a recipe remains valid after changing film grade, roll supplier or carriage condition.
Check containment at three heights
Containment describes how the applied film layers hold the load inward at a selected point. It is related to both the number of effective layers and the force contributed by them. A reading at the middle alone misses critical behaviour: the bottom region anchors the load, the centre controls body movement and the top prevents upper cases from opening or tipping.
Bottom: Is the load positively connected to the pallet without blocking fork entry?
Middle: Is the widest or most flexible section supported?
Top: Are upper layers secure, or has film neckdown left them exposed?
There is no universal target suitable for every pallet. Heavy rigid cases, light irregular products and crush-sensitive cartons require different force profiles. Establish a starting recipe, then qualify it with actual shipping evidence and handling trials representative of the distribution route.
Run a controlled setup trial
Build the pallet with its normal pattern, corner boards, top sheet and production cases.
Record film identity, lot, nominal gauge, wrapper and carriage ratio.
Document pre-stretch, force-to-load, turntable or arm speed, carriage speed and wrap counts.
Check effective layers and containment behaviour at the bottom, middle and top.
Inspect the first cycle for breaks, holes, crushed corners, loose tails and excessive neckdown.
Observe the wrapped pallet through acceleration, braking, vibration and turns that resemble real handling.
Change one variable at a time. First measure the current program, then alter a single setting and record the result. This disciplined method shows whether film reduction preserves equivalent stability instead of merely producing an attractive stationary pallet.
Layer distribution explains more than total revolutions
A total wrap count does not describe where the film was placed. Fast carriage travel may leave little overlap; slow travel can pile unnecessary layers into one zone. Specify bottom and top reinforcement wraps, spiral overlap and carriage reversal points separately. A square, rigid load and an inward-sloping or overhanging load should not automatically receive the same pattern.
Wrapping film across fork-entry openings creates another failure path. A fork can puncture the web and allow the tear to propagate, reducing containment. Design the load-to-pallet bond with controlled bottom wraps or a suitable film cable above clear fork access. Do not apply a narrow cable against crush-sensitive products without a documented trial.
Symptoms and first checks
Film breaks repeatedly
Check pre-stretch, force-to-load, sharp corners, roller condition, film threading and roll damage. Increasing gauge alone can hide rather than remove the cause.
Top cases spread apart
Examine upper-layer count, force distribution, neckdown and top wraps. Stretch film cannot fully correct a structurally weak stacking pattern.
Case corners are crushed
Local force may exceed package compression tolerance. Trial lower local force, revised layer placement and corner protection as a system.
The load looks fine in storage but shifts in transit
A static appearance is not transport validation. Assess the pallet base, load-to-pallet connection and representative shock, vibration and motion. Where consequences justify it, use a documented unit-load test programme rather than visual judgement.
Create a repeatable operating recipe
Store the approved film description, threading direction, pre-stretch, force setting, speeds, bottom-middle-top layer distribution and acceptance criteria. Perform a short first-piece check after operator changes, maintenance or a new film lot. Track transit damage, film mass per load and break frequency together; optimising only purchase price can shift cost into damage and downtime.
Poşetsan Date approaches stretch-film selection together with load geometry and the application recipe. When planning a trial with Poşetsan, provide pallet photographs, mass, dimensions, wrapper details and the observed failure mode. Explore Date Plastik information on stretch film, wrapping films and complementary pallet protection.