Meta description: Pre-stretched stretch film explained: gauge equivalence, residual stretch, wrapper settings, cost per pallet and the checks that keep break rates low.
Pre-stretched stretch film is machine film that the converter has already drawn, commonly to two or three times its original length, before it is wound on the roll. The wrapper then applies it with little or no additional stretch. The film arrives thinner, longer per kilogram and less dependent on operator technique.
That change moves cost, break rate and consistency at once, in both directions. This guide covers how the film is made, how to compare a pre-stretched gauge with the conventional gauge it replaces, and where the economics stop working.
Table of Contents
- What Is Pre-Stretched Stretch Film?
- How Pre-Stretched Film Is Made
- Grades and Gauges Available
- Pre-Stretched vs Conventional Machine Film
- Setting the Wrapper for Pre-Stretched Film
- Where Pre-Stretched Film Pays Off
- Specifications Buyers Should Confirm
- Cost and Yield per Pallet
- Common Procurement Mistakes
- Inspecting Pre-Stretched Film
- Choosing a Pre-Stretched Film Supplier
- Frequently Asked Questions
- Source Pre-Stretched Film from Pefilmpack
What Is Pre-Stretched Stretch Film?
It is a PE stretch film elongated at the converting stage and wound under tension, so part of its elongation capacity is already spent. The roll behaves like a thinner film with a narrow working window.
Three figures define the product and are often confused: the converter pre-stretch ratio, commonly 2:1 to 3:1; the residual elongation left for the wrapper, often 10 to 25 percent; and the nominal gauge, often 7 to 17 micron on machine grades.
Because the web is thinner, meters per roll rise sharply at equal roll weight. That drives the saving, and most purchasing errors, since a 12 micron pre-stretched roll gets compared with a 20 micron conventional roll as if the number meant the same thing.
How Pre-Stretched Film Is Made
- Resin selection. A cast blend of LLDPE and metallocene LLDPE, chosen for drawability rather than maximum puncture. The blend sets how far the film can be drawn without tearing.
- Casting and gauging. Melt is cast on a chill roll and measured inline. Cast film gives the gauge uniformity a stretch line needs, since a thick band becomes a weak point once drawn.
- Machine-direction stretching. Rollers running at increasing speed draw the sheet. Draw ratio, temperature and line speed set the mechanical profile.
- Annealing. Controlled cooling stabilizes the drawn structure so the roll does not keep relaxing in the carton. Film drawn hard and cooled fast can lose tension in a hot container.
- Slitting and rewinding. The web is slit to width, wound to length at consistent tension, then checked for gauge, edge quality and winding.
Grades and Gauges Available
Light gauges, 7 to 10 micron
For stable loads where film cost dominates: beverage, canned goods, bagged goods on regular pallets. These gauges need good film-path control, since little material absorbs a snag.
Standard machine grades, 12 to 15 micron
The working range for most export operations, commonly offered as the equivalent of 17 to 23 micron conventional film. The equivalence depends on resin and draw ratio, not on the number alone.
Heavy and hand-roll formats
17 to 20 micron for sharp corners and mixed carton heights. Hand rolls mainly reduce operator fatigue, but hand wrapping gives no controlled tension.
Pre-Stretched vs Conventional Machine Film
| Factor | Pre-stretched | Conventional machine film |
|---|---|---|
| Typical gauge | 7 to 17 micron | 17 to 30 micron |
| Wrapper pre-stretch | 0 to 30 percent | 150 to 300 percent |
| Meters per roll at equal weight | Highest | Moderate |
| Containment consistency | Set at the converter | Settings and operator |
| Tuning force to the load | Narrow window | Wide window |
| Break risk on sharp edges | Higher unless grade suits it | Lower |
| Cost per kilogram | Highest | Middle |
If a line wraps the same pallet profile daily and the wrapper holds tension, pre-stretched film removes a variable and cuts film mass per pallet. If the product mix changes daily, the narrow window becomes a liability and adjustable pre-stretch is safer.
Setting the Wrapper for Pre-Stretched Film
The most common failure is running pre-stretched film on a wrapper still set for conventional film. At 250 percent pre-stretch, a film that left the converter with 20 percent residual elongation has nothing left, so it necks and breaks at corners.
- Reduce pre-stretch to the low end of the machine range, commonly 0 to 30 percent, and let the converter’s draw do the work.
- Recalibrate carriage tension. Lower pre-stretch changes the dancer or load-cell setting; without adjustment, containment force drops.
- Recheck the film path. Worn guide rollers that were acceptable at 23 micron will mark a 10 micron web.
Trial the heaviest and lightest load; a grade that holds 900 kg but shears 200 kg does not suit a mixed schedule.
Where Pre-Stretched Film Pays Off
Export pallet wrapping at volume
Fixed loading patterns wrapped on the same machine every shift, where fewer roll changes and predictable force are the gains. Buyers usually start from thickness and width selection and then test the pre-stretched equivalent.
High-speed automatic lines
Lower film mass per revolution allows faster carriage travel without raising motor load; the machine sets throughput. See machine-grade film for high-speed wrapping.
Distribution centers with standard pallets
Film consumption becomes a controllable cost line and wrap quality auditable. This is where load stability complaints are traced to film force rather than gauge.
Specifications Buyers Should Confirm
- Nominal and equivalent gauge in writing, with the basis for the equivalence claim.
- Pre-stretch ratio and residual elongation on the specification sheet, not only in conversation.
- Width and tolerance, with edge straightness stated, since thin film is less forgiving of edge damage.
- Roll length and weight. State which is contractual; length is what the wrapper consumes.
- Core. 76 mm (3 inch) is the usual machine core; confirm wall thickness, which collapses under tension if too light.
- Puncture and tensile targets with the method named, such as ASTM D5748 and ASTM D882 or ISO 527-3.
Requirements may vary by application, market and applicable standard. Two buyers running identical pallets can specify different gauges because their wrappers differ.
Cost and Yield per Pallet
Price per kilogram is the wrong unit here, because fewer kilograms are meant to do the same work. Work from cost per pallet: kilograms per pallet times price per kilogram, plus roll-change labor, plus downtime from breaks.
Index arithmetic shows the threshold. If a pre-stretched grade costs 12 percent more per kilogram and the pallet consumes 25 percent fewer kilograms, film cost per pallet falls by roughly 10 percent before labor. If consumption falls only 8 percent, the premium is not recovered.
Density gives a cross-check on meters. At equal roll weight and width, 12 micron film yields roughly 1.6 to 1.7 times the meters of 20 micron film; a claimed yield far outside that ratio needs explaining.
Common Procurement Mistakes
- Comparing micron to micron. A 12 micron pre-stretched film is not half the protection of a 24 micron conventional film; test the equivalence.
- Buying on price per kilogram. The cheapest roll often has the highest cost per pallet once break rate is counted.
- Leaving the wrapper at high pre-stretch. This turns a workable film into a high break rate within one shift.
- Omitting roll length from the order. Short rolls can raise changeover labor more than they save.
- Trialling on a light pallet. Square, light loads do not predict behavior on heavy loads with overhang.
- Storing rolls in heat. Film wound under tension relaxes in a hot warehouse and arrives softer than the sample.
Inspecting Pre-Stretched Film
- Gauge at several points across the web with a calibrated micrometer, against the stated tolerance.
- Length by meter counter on a sample roll, not inferred from roll weight.
- Winding: telescoping, dishing, soft edges and hard bands, all more common on thin film.
- Residual stretch by cutting a strip, allowing recovery and comparing recovered length.
- Run test on your own wrapper at production speed, logging break points and force per revolution.
Gauge, length, winding and packing suit pre-shipment checks. Tensile, puncture and elongation data normally come from batch records, which should name the method.
Choosing a Pre-Stretched Film Supplier
Ask for the draw ratio and how it is held between batches. A supplier who can state the ratio, the annealing conditions and the retained sample per lot is controlling the variables behind most complaints.
Then check production fit: whether the line can run your width without heavy trim, and what length tolerance applies per roll.
Frequently Asked Questions
Is pre-stretched film stronger?
Per unit of thickness, usually yes, because the polymer chains are already oriented. Per roll it depends on gauge, so compare results at the gauge you will run.
Can it run on my existing wrapper?
Most machines can once pre-stretch is reduced and carriage tension recalibrated. Very old wrappers with fixed gearing may lack a suitable setting.
Why does it break at the corners?
Usually excess pre-stretch, or a grade without enough puncture resistance for the load. Reduce pre-stretch first, then move up one gauge.
Does it suit light or unstable loads?
It can, but the narrow force range makes fine-tuning harder. Light loads often suit conventional film.
How should rolls be stored?
Out of direct sun and away from heat sources, on the original pallet or carton. Film wound under tension relaxes at high temperature.
What is the minimum order for a custom width?
It depends on slit width and master roll size. Ask for the minimum per width and per gauge together, since the two constraints interact.
Source Pre-Stretched Film from Pefilmpack
Weishan Litong Packing Material Co., Ltd. supplies PE stretch film in conventional, machine-grade and pre-stretched formats, with width, thickness, length, roll weight, color and core size made to order. Pre-stretched rolls carry the finished micron alongside the conventional gauge they replace. Film ships with stretch wrapping machines and other packing materials so one container can be consolidated. Send your pallet profile through the contact page.
Send your specifications: finished and equivalent gauge, width, roll length or weight, core inner diameter, cling side, hand or machine grade, monthly quantity and destination port.
Recommended Images and Alt Text
| Image Placement | Image Description | Recommended File Name | Recommended Alt Text |
|---|---|---|---|
| Hero | Pre-stretched roll on an automatic wrapper | pre-stretched-stretch-film-roll-wrapper.jpg | Pre-stretched stretch film roll loaded on an automatic pallet wrapper |
| Production | Stretching rollers drawing cast film | pre-stretched-film-mdo-rollers.jpg | Stretching rollers drawing cast PE film in machine direction |
| Comparison | Two film strips held up for a gauge check | pre-stretched-vs-conventional-film.jpg | Pre-stretched and conventional machine film compared for thickness |
| Application | Wrapper applying film to an export pallet | pre-stretched-film-export-pallet-wrapping.jpg | Pre-stretched film applied to an export pallet in a loading bay |
| Inspection | Operator measuring gauge with a micrometer | pre-stretched-film-gauge-measurement.jpg | Operator checking pre-stretched film thickness with a micrometer |
| CTA | Wrapped pallet ready for container loading | wrapped-pallet-ready-container-loading.jpg | Wrapped export pallet with secured film tail ready for loading |