Shrink film

Polyolefin vs. PVC vs. polyethylene shrink film, what gauge to use, how to size centerfold film, perforation, and the temperatures each film shrinks at.

Updated October 2, 2026

Polyolefin, PVC, or polyethylene

Choose the film material, grade, and gauge first. Then confirm the film works with your exact sealer and heat source. Don’t assume an L-bar sealer runs all three materials. Some models recommend POF (polyolefin) only, and polyethylene may need different sealing hardware. The machine types guide includes a model-specific example.

This guide covers material selection, gauge, and package sizing. For roll formats, core and roll dimensions, and price comparisons, use shrink wrap rolls.

Shrink percentages and clarity ratings are from the Uline shrink film guide and the IPG brochure. IPG’s figures are unrestrained shrink at 250°F (ASTM D2732). The makers test in different ways, so compare figures within one source. Eastey’s sealer manual warns that some plastic films “may result in the release of hazardous fumes” at high temperatures. It says to ventilate at all times.

Polyolefin is the default choice for new L-bar lines. It is strong, clear, and many grades are sold as FDA compliant for food contact. Clysar’s ABL film is “specifically designed to function on the complete range of L-sealers and tunnels”.

PVC shrinks at a lower temperature than Uline’s polyolefin (250°F vs. 300°F). It has the lowest sealing temperature of Uline’s films, and it looks very clear. Uline rates its PVC lower for puncture resistance than its polyolefin grades and warns that it may emit fumes. Uline’s PVC film is not rated for direct food contact. Check the data sheet for any PVC you plan to use near food. A PVC shrink film safety data sheet lists hydrogen chloride gas as a hazardous decomposition product. The CDC’s ATSDR says hydrogen chloride “is irritating and corrosive to any tissue it contacts”. Plan ventilation if you run it. A 1974 study measured air contaminants from cutting and sealing PVC film.

Polyethylene shrinks only 15 to 20% in Uline’s bundling film. So it is used more for bundling heavy products than for retail wrapping. Thicker bundling grades may need different sealing hardware and a tunnel designed for that application. Confirm the exact film and machine combination.

Cross-linked polyolefin

Cross-linked polyolefin has its polymer chains bonded into a network. IPG says this gives a wider seal and shrink window. It also says it leaves less buildup on seal wires and knives and causes less burn-through in the tunnel. IPG says its cross-linked Exlfilmplus GPL and 365 films “offer similar performance to thicker standard gauge film”. It says the thinner 365 gauges give “7% - 11% yield savings when compared to traditional films.” Cross-linked film costs more per roll, but a thinner gauge can offset that.

Choose a gauge

Film thickness is measured in gauge. 100 gauge equals 1 mil, which equals 0.001 inch or 25.4 microns.

These are Uline’s starting points. Thinner film shrinks more easily and wraps more packages per roll. Thicker film resists punctures. Check the maximum gauge your sealer accepts. The Uline H-2378 hand sealer, for example, is rated for film up to 100 gauge.

Size centerfold film

L-bar sealers run centerfold film. The film is folded in half lengthwise and wound on the roll. The fold closes one side of the package. The L-bar seals the other side and the end. The listed roll width is the folded width.

To estimate the folded width you need:

1. Measure the product’s width and height in inches.
2. Add them together.
3. Add 2 to 4 inches. Uline adds 2 inches “for shrinkage”.
4. Round up to the next whole inch.

Example: an 8 in. wide by 3.5 in. tall box. 8 + 3.5 + 2 = 13.5, so 14 in. centerfold film is a starting candidate for a trial.

Uline adds 2 inches. Eastey’s film width chart works out to about 4 inches for small packages. For round items, Uline uses diameter × 3.14 × 1.1 ÷ 2, rounded up.

Then check that the width fits your sealer. Eastey’s 20 in. wide L-sealers take film up to 24 in. wide, and its 30 in. models take up to 34 in. Centerfold film has two layers. So for the same film area and listed roll width, a centerfold roll is half as long as a single-wound roll. IPG’s 100 gauge polyolefin comes in 2,625 ft centerfold rolls versus 5,250 ft single-wound rolls.

Perforation

A sealed bag traps air. If the air cannot escape, the bag balloons in the tunnel and seals can blow out. Eastey’s manual says “perforation is required to allow air to vacate when the product passes through the shrink tunnel”.

You have two options:

• Machine perforation. Many L-bar sealers have a pin perforator that punches small holes as the film feeds. Reposition it when you change product or film size. On Eastey machines, the first few bags after loading film have no holes, so don’t put product in them.
• Pre-perforated film. Clysar says most of its film can be ordered pre-perforated, and IPG offers pre-perforation on most grades in its brochure. Clysar says this “significantly improves air evacuation and overall package appearance”.

Too few holes cause ballooning and dog ears. Too many can cause wrinkles at the corners. Don’t punch holes by hand with a drill or soldering iron. Clysar warns this fuses the film. If your product needs an airtight package, have the film supplier specify and validate the whole film, seal, and shrinking process. Leaving out the holes does not by itself make a package airtight.

Shrink temperatures

The Uline guide calls these shrink temperatures. It does not define them as universal machine settings. Use each film’s processing guidance and the machine manual. Tunnel settings also depend on exposure time and airflow. For published seal bar and tunnel starting points, see shrink tunnel settings by film.

Shrink wrap vs. stretch wrap

Shrink film and stretch film are both plastic wraps, but they work in different ways. Shrink film is placed loosely around a product and heated, and it shrinks to fit the product. Stretch film is stretched as it is wrapped around a load. It needs no heat, and it holds the load by pulling back and clinging to itself.

Machine stretch film is often cling on one side only. Uline’s one-sided film “holds load tight without sticking to nearby pallets”.

The two are not interchangeable. An L-bar sealer and tunnel run shrink film. Stretch film is not sealed or heated, so it goes on a hand roll or a stretch wrapper. IPG, which makes both, says they “serve very different purposes”.

Storage

Store film in a cool place. Clysar recommends 90°F or below to keep the layers on the roll from sticking together.

To buy film, see shrink wrap rolls.