Recycled PET Strap: What to Check Before You Buy

Published 26 October 2026 · By Ranjeet Kumar, Proprietor, Solution Enterprises

Short answer: recycled PET strap is normal, and good recycled strap performs like virgin strap. What separates good from poor is the polymer’s intrinsic viscosity (IV), which falls if flake is badly dried or degraded, plus joint strength, resistance to splitting and consistent weight per metre. Ask for test figures on those, check a few things on the dock, and treat colour and price as no guide at all.

At least one large European strap maker states that its PET strap is, in most cases, already made from recycled material. So the useful question for a buyer is not “is it recycled?” but “was it made well?”

Why recycled PET can go wrong

PET’s strength comes from long polymer chains. IV is a lab measure of chain length: higher IV, longer chains, tougher strap. Bottle flake arrives with a lower and more variable IV than strap needs, and PET absorbs moisture. If wet flake is melted, water breaks the chains and IV drops further. Industry literature describes producers once blending in around a third virgin resin to make up the loss, and processes such as solid-state polymerisation that rebuild IV before extrusion.

Low IV shows up as strap that is brittle, splits along its length, or welds poorly. A strap can also be over-stretched during drawing to reach a break-strength figure, which makes it brittle in a different way.

What India’s revised standard now asks for

IS 15559, the Indian standard for polyester (PET) strapping, was revised as IS 15559:2025. BIS’s implementation guidelines dated 30 January 2026 list the main changes, and the 2004 version was withdrawn on 3 April 2026:

• IV (clause 4.4): the material must have an IV in the range 0.70 to 1.0 dl/g, measured as per ISO 1628-5. This replaced the old minimum of 0.84 measured in a phenol and tetrachloroethane solution.
• Joint strength (clause 5.4): a joint-strength requirement has been added.
• Surface finish (clause 4.2): visual check for uniform finish, no sharp side edges and consistent embossing.
• Types (clause 3): a Type III added to Types I and II.

Internationally, ASTM D3950-23 covers non-metallic strapping and its joints and lists breaking strength, elongation, transverse strength and joint strength among the properties tested. Transverse strength is the one that relates to splitting.

The buyer’s checklist

Check	Ask for or do	Why it matters
IV	Test figure and method (ISO 1628-5)	The best single sign that the polymer was handled well
Break strength	Figure for the exact width and thickness	Nominal size alone tells you little
Joint strength	Figure with your seal or weld method	The joint limits usable tension
Splitting	Transverse or split test result; bend a sample	Brittle recycled strap splits lengthwise
Weight per metre	Weigh ten metres on receipt	Shows whether you got the material you paid for
Batch record	Lot number on each roll	Lets a complaint be traced

For the weighing step, our note on PET strap roll length per kg gives the formula. For choosing the size in the first place, use the PET strap size chart.

Simple checks on the dock

• Bend and flex. Fold a short length sharply a few times. Good strap creases and stays whole; brittle strap whitens badly or starts to split along its length.
• Edges and pattern. No sharp edges, even width, embossing that does not fade in patches.
• Weld a sample. Make three joints on your own tool and pull them apart by hand or on a simple rig. A joint that peels cleanly with little effort is a warning.
• Compare rolls. Weigh ten metres from two or three rolls of the same lot. A wide spread suggests the process is not steady.

Red flags in a quote

• A break-strength figure with no width, thickness or test method next to it.
• “100% recycled” or “virgin grade” with nothing on paper to support it.
• A price well below others for the same stated size. Check grams per metre; the roll may simply carry less plastic.
• No lot number on the roll or the delivery note.
• No joint-strength figure, or one quoted without saying which seal or weld it was measured with.
• An IV figure with no method. Values from different test methods are not directly comparable, which is one reason the revised Indian standard names ISO 1628-5.

None of these proves a strap is poor. Each one is a reason to ask a question before the strap reaches your packing line rather than after a pallet arrives loose.

If your buyer asks about recycled content

Export customers increasingly ask packaging suppliers about recycled content and recyclability (see recyclable packaging is becoming a buyer requirement). A percentage on a datasheet is a claim, not proof. If your customer needs evidence, ask what documentation stands behind it, such as a third-party chain-of-custody scheme. Do not pass on a recycled-content figure you cannot support.

Common questions

Is recycled PET strap weaker than virgin?

Not inherently. Well-dried flake with its IV restored makes strap that meets the same specifications. Poor processing, not recycled content, is the risk.

Does colour tell me anything?

No. Green and black are common colours for PET strap and say nothing measurable about IV or strength.

Can used PET strap be recycled again?

Yes, it is a single material. Keep it free of metal seals and mixed waste so a recycler can take it.

We make PET strap in Greater Noida. See what we need from you on the PET strap page, or ask for figures for your size through request a quote.

Sources

• Bureau of Indian Standards, Central Marks Department-2, Guidelines for implementation of revised IS 15559:2025, Polyester (PET) Strapping, 30 January 2026 — IV range and method, joint strength, surface finish, Type III, withdrawal date of IS 15559:2004.
• ASTM International, D3950-23 Standard Specification for Strapping, Nonmetallic (and Joining Methods) — scope and tested properties.
• EREMA, Passes the Tensile Test, Kunststoffe international 2/2009 — IV loss of bottle flake in extrusion; virgin blending.
• US Patent 6,376,563, Inline solid state polymerization of PET flakes for manufacturing plastic strap — low and variable IV of bottle flake; rebuilding IV before extrusion.
• Teufelberger, PET straps — most PET strapping made from recycled material; mono-material recyclability.
• JB rPET, How to verify if your rPET is truly recycled — chain-of-custody documentation for recycled-content claims.

Last verified: 26 October 2026. General information; for compliance, read the current text of IS 15559 and confirm requirements with your customer.