PET Strapping Specifications: What to Put in Your RFQ

A specification for pet strappings is only useful if it is unambiguous to someone who cannot see your project. Most disputes on this product do not come from bad manufacturing — they come from a drawing that could reasonably be read two ways, where the supplier read it the cheap way and the buyer read it the expensive way.

This is a practical specification checklist, written around what the standards actually require.

The three specification families you will meet

Suppliers will quote against whichever family your market uses, and the part can usually be built to any of them:

• ASTM D3950 — specification for nonmetallic (plastic) strapping.
• ASTM D882 — tensile properties of thin plastic sheeting reference.
• ISO 4892-3 — UV ageing for the outdoor grade.

The mistake is to specify a standard reference without specifying the class or grade within it. If you write only the standard number, the supplier will quote the lowest class that satisfies it. Write the standard and the level you want.

Dimensional data that has to be on the drawing

For this product the critical dimensions are: width 12.7–32 mm; thickness 0.6–1.3 mm; breaking loads 300–850 kg; core 200 or 406 mm.

Three rules that prevent most dimensional disputes:

1. Give tolerances on every functional dimension, not just the nominal values. A nominal dimension with no tolerance is legally “as the supplier chooses”.
2. Say which dimensions are functional and which are cosmetic. Suppliers prioritise what you prioritise, and they cannot guess.
3. State the gauge or measuring method where a dimension is critical. Two inspectors with different methods will disagree about the same part.

Material and grade

The base specification is polyethylene terephthalate (PET) embossed strap, UV-stabilised. Grades commonly offered include:

• hand grade 12.7–16 mm
• machine grade 15.5–19 mm
• heavy duty 19–32 mm
• UV-stabilised outdoor grade
• printed (customer logo) strap

Ask the supplier to state the grade on the quotation, not on an assumption. Grade substitution is the single most common silent cost reduction, and it is usually invisible in the finished part — a 201 stainless component looks exactly like a 304 one until the second winter.

Surface treatment

The usual finish for this product is embossed both faces; green (standard), black, or printed custom colour.

Two points worth writing into the order:

• A measured requirement, not a process name. “Hot-dip galvanised” is a process; “70 µm minimum, tested by coating mass on three parts per batch” is a requirement.
• What happens at cut edges and drilled holes, if any. These are where coatings are habitually broken and where corrosion starts.

Type tests and routine tests

These are different things and are frequently confused in quotations:

• Type tests qualify the design once. On this product: breaking load and elongation per roll lot; system strength with the specified buckle/seal; UV ageing 1000 h (outdoor grade).
• Routine tests are run on every batch: weld joint efficiency of friction-welded seals; coil wind and camber check.

Specify which type-test reports you want supplied as documents, and which routine test results must accompany each shipment. On a first order, ask for the type-test report before you place it.

The failure modes your specification should be closing

• Strap losing tension on the pallet — strap stressed near its limit at tensioning; PET creeps back a few percent — tension to 50–60 % of breaking load, not 80
• Weak friction welds — wrong weld time for the gauge on the tool; the joint fails at 60 % of strap strength instead of 80+
• Roll deforming in heat — strap wound too tight or stored in the sun; the coil sets an oval and then feeds badly on the machine

Each of these can be turned into one line in the specification. That is the real purpose of writing it out: not bureaucracy, but making the specific failure you are worried about somebody’s explicit responsibility.

A specification skeleton you can reuse

1. Scope: PET Strapping to be supplied as PET strapping band, polyester strapping, plastic steel strapping, embossed PET strap.
2. Dimensions and tolerances: width 12.7–32 mm; thickness 0.6–1.3 mm; breaking loads 300–850 kg; core 200 or 406 mm.
3. Material: polyethylene terephthalate (PET) embossed strap, UV-stabilised; grade hand grade 12.7–16 mm or better.
4. Standard: ASTM D3950 — specification for nonmetallic (plastic) strapping; ASTM D882 — tensile properties of thin plastic sheeting reference; ISO 4892-3 — UV ageing for the outdoor grade.
5. Finish: embossed both faces; green (standard), black, or printed custom colour.
6. Tests: breaking load and elongation per roll lot; system strength with the specified buckle/seal; UV ageing 1000 h (outdoor grade); weld joint efficiency of friction-welded seals; coil wind and camber check.
7. Marking and packing: coils cartoned 2 per box, palletised; keep out of direct sun in the yard.
8. Inspection: pre-shipment, against this specification, with photo evidence and test records.

Related: the pet strapping quality inspection checklist turns this specification into an inspection plan you can hand to a third-party inspector.