Recycling
The terms the rest of this library uses: mechanical and chemical recycling, post-consumer content, intrinsic viscosity, melt strength, chain extension, contact-sensitive packaging.
A short reference for the terms that appear throughout this site, written so that the rest of the library can use them without redefining them each time.
Mechanical recycling
Sorting, washing and re-melting plastic waste into new pellets. The polymer stays the same polymer and gets slightly shorter chains each time it is melted. Essentially all plastic recycled in Europe today is recycled this way. See mechanical versus chemical recycling.
Chemical recycling
Breaking the polymer down into monomers or a feedstock and building new polymer from it. In principle it produces virgin-equivalent material from streams mechanical lines reject. In practice it costs more, exists at small scale, and its treatment under European recycled content rules is still being written: Regulation (EU) 2025/40 leaves the calculation method to an implementing act due at the end of 2026.
Post-consumer recycled content, PCR
Material recovered from waste that reached a consumer, as opposed to factory offcuts. European recycled content minimums count post-consumer material only, collected in the Union or under equivalent standards.
Intrinsic viscosity
A measure of molecular weight for polyesters such as PET, obtained by dissolving the polymer and comparing how the solution flows against the pure solvent. Higher intrinsic viscosity means longer chains, more entanglement and a melt that holds itself together better.
Melt flow rate and melt strength
Melt flow rate measures how easily a molten polymer flows through a standard opening under a standard load: it goes up as chains get shorter. Melt strength is how well the melt resists being stretched, which is what holds up a film bubble or a parison. They are related but not the same, and a recycled grade often fails on melt strength while its melt flow rate still looks acceptable.
Chain scission and chain extension
Chain scission is chains breaking, from heat, shear, oxygen or water. Chain extension is the reverse operation performed on purpose: a reactive additive couples the chain ends left behind, rebuilding length. Branching chemistries build structure as well as length, which helps in film and sheet and hurts in fiber spinning.
Environmental stress crack resistance, ESCR
How long a plastic part survives under load in contact with a chemical such as detergent. It falls as chains shorten, which is why recycled polyethylene bottles can pass a short mechanical test and fail in service.
Contact-sensitive packaging
The European regulation's term for packaging of food, feed, medicinal products, medical devices and similar sensitive contents. It carries lower recycled content minimums than other packaging, because food-contact rules restrict how much recycled material may be used. Food contact with recycled plastic is separately governed by Regulation (EU) 2022/1616.
Design for recycling and recycled at scale
Two conditions the packaging regulation sets in Article 6. Design for recycling is about whether a package can be recycled at all; recycled at scale is about whether it actually is, in practice, in volume. Packaging is graded A, B or C, with the lowest grades excluded from the market in stages from 2030 to 2038.
Masterbatch
A carrier polymer with additive concentrated in it, dosed into the main material during processing. It is how an additive that would be impossible to disperse in its pure form gets into a production line at a fraction of a percent.
Sources
- Regulation (EU) 2025/40, Articles 6 and 7, for the regulatory terms.
- Commission Regulation (EU) 2022/1616, for recycled plastic in food contact.
- Eurostat, packaging waste statistics, for what is collected and recycled in practice.