Polypropylene Strapping: Hand vs Machine Poly Strap, and When to Use Polyester
Polypropylene strapping, or poly strap, is the light plastic banding used to hold cartons, bundles and light pallets together. It's cheap, easy to handle and safe to cut, which is why it's the first choice for most warehouses.
This guide covers the difference between hand and machine poly strap, which width to choose, the tools and seals you'll need, and when it's time to move up to polyester.
What is polypropylene strapping?
It's a flat plastic band made from polypropylene (PP). It stretches a little under load, which helps it grip cartons that settle or shift in transit. It won't rust, it's light to carry around the warehouse, and the cut ends don't spring back the way steel does.
Poly strap comes in two forms: hand strap for manual strapping with a tensioner and seals, and machine strap made to feed through strapping machines.
Hand poly strap
Our hand strap comes in dispenser packs. The carton doubles as the dispenser, so you can pull strap straight from the box on the bench or the floor. Choose standard blue for cartons and lighter loads, or heavy-duty black when you need more strength.
| Strap | Width x thickness | Roll length | Min break strain |
|---|---|---|---|
| Standard blue | 12mm x 0.50mm | 1,000m | 70kg |
| Standard blue | 15mm x 0.50mm | 1,000m | 115kg |
| Standard blue | 19mm x 0.50mm | 700m | 140kg |
| Heavy-duty black | 12mm x 0.75mm | 900m | 170kg |
| Heavy-duty black | 15mm x 0.75mm | 700m | 210kg |
| Heavy-duty black | 19mm x 0.75mm | 600m | 270kg |
| Heavy-duty black HD400 | 19mm x 0.95mm | 1,000m | 400kg |
Machine poly strap
Machine strap is made to tighter tolerances than hand strap. The width and thickness stay consistent along the whole roll, so it feeds smoothly through a strapping machine without jamming. It also comes on much longer rolls, which means fewer changeovers on a busy line.
Using hand strap in a machine is a common cause of misfeeds and weak welds, so it's worth matching the strap to the job.
| Strap | Width x thickness | Roll length | Min break strain |
|---|---|---|---|
| Premium blue | 12mm x 0.63mm | 3,000m | 70kg |
| Premium clear | 12mm x 0.63mm | 3,000m | 70kg |
| Premium blue | 15mm x 0.63mm | 2,500m | 115kg |
Clear strap is popular for retail and printed cartons where you don't want the strap to stand out. Need a machine to go with it? The TMS300 semi-automatic strapping machine suits most carton lines, or browse our full strapping machines.
Which width do I need?
As a rule of thumb, 12mm suits light cartons, bundles and mail items. 15mm is the everyday all-rounder for cartons and light stacked loads. Go 19mm or heavy-duty black for heavier cartons and palletised goods.
Keep in mind that break strain is the point where the strap snaps, not a safe working load. Leave a good margin, use more straps on heavier loads, and add corner protectors where the strap crosses sharp edges.
Tools, seals and buckles for poly strap
Tensioner and seals
The classic setup. A tensioner pulls the strap tight, then a crimper closes a metal seal over the overlap. Try the PT34 tensioner for everyday use or the MIP380 tensioner, which handles poly and polyester strap. Pair them with a polystrap crimper and open-flange metal seals, or heavy-duty seals for HD strap.
Buckles
Buckles let you join strap without a crimper. Plastic buckles suit light cartons and bundles. Wire buckles hold more tension and are the go-to for heavier loads and the 19mm strap.
Battery tools
Strapping a lot of pallets? A battery friction-weld tool tensions, welds and cuts in one go with no seals at all. See our Siat strapping tools and the guide to choosing a Siat tool.
For a deeper look at tool setups, read choosing the right strapping and strapping tools.
Polypropylene vs polyester strapping
Polyester (PET) is the step up when poly strap isn't holding. It's much stronger for its size and keeps its tension far better on heavy or rigid loads, where polypropylene can stretch and slacken over time.
| Polypropylene (PP) | Polyester (PET) | |
|---|---|---|
| Best for | Cartons, bundles, light pallets | Heavy pallets, bricks, timber, steel and rigid loads |
| Break strain | 70kg to 400kg in our range | 250kg to 750kg in our range |
| Holding tension | Can stretch and loosen under constant load | Holds tension well over time |
| Cost | Lowest cost per metre | Higher, but still lighter and safer than steel |
See our polyester strap range.
Other alternatives to poly strap
Polywoven strap is a soft woven band with break strains from 800kg up to 1,000kg. It's gentle on the load, joins with metal buckles and needs no crimper.
Composite strap is made from polyester fibres coated in polypropylene. It's very strong and works with buckles for heavy or awkward loads.
Steel strapping is still the strongest option for very heavy, sharp-edged or hot loads, but it's heavier, can rust and needs care when cutting.
Poly strap questions
What's the difference between hand and machine poly strap?
Machine strap is made to tighter tolerances so it feeds cleanly through strapping machines, and it comes on longer rolls. Hand strap comes in dispenser packs for manual strapping with a tensioner and seals or buckles.
What's the difference between polypropylene and polyester strapping?
Polypropylene is lighter, cheaper and suits cartons and light pallets. Polyester is much stronger and holds its tension better, so it's the better choice for heavy or rigid loads.
What width of poly strap should I use?
12mm suits light cartons and bundles, 15mm is the everyday all-rounder, and 19mm or heavy-duty strap is best for heavier cartons and pallets.
What tools do I need for poly strapping?
For hand strapping you need a tensioner plus either a crimper and metal seals, or buckles. For high volumes, a battery friction-weld tool or a strapping machine is much faster.
Can polypropylene strap be used outdoors?
For short periods, yes. Long exposure to strong sun weakens polypropylene over time, so for loads stored outside for weeks, polyester is the safer choice.
Not sure which strap to use?
Tell us what you're strapping and how you do it now. Our Villawood team will recommend the right strap, tools and seals.