Technical Glossary for Flexible Packaging

RecyClass v3.1

Standardised European methodology for assessing the recyclability of plastic packaging, developed by Plastics Recyclers Europe and updated in August 2025. It uses its own four-level scale: CLASS A, CLASS B, CLASS C and NOT RECYCLABLE. The percentage obtained is the maximum theoretical grade of the structure, which design incompatibilities then pull down. RecyClass is not a regulatory body, and its classes are not the performance grades set out in the Regulation.

→ What a RecyClass claim can and cannot say

CEFLEX D4ACE

Circular Economy for Flexible Packaging methodology (Phase 2, Design for a Circular Economy) - a European alternative to RecyClass for assessing the recyclability of flexible packaging in PE and PP streams. It draws on an extensive testing programme dedicated to flexible packaging, carried out in European laboratories and universities. Like RecyClass, it is an industry methodology and does not produce the performance grades set out in the Regulation.

ISO 1183-1

International standard for determining the density of non-cellular plastic materials. Used to calculate film roll weight and classify polymers in technical calculations. Reference values: BOPP 910 kg/m³, BOPE 940 kg/m³, PET 1390 kg/m³.

ISO 14040 / 14044

Standards for Life Cycle Assessment (LCA), international methodologies for evaluating the environmental footprint of products across their full life cycle. Used to calculate CO₂-equivalent emissions and for sustainability reporting (CSRD Scope 3).

REP-PEflex-001

Recyclability Evaluation Protocol for flexible PE films, version 6.0, published in January 2025. Official RecyClass testing procedure for certifying Grade A, B or C for polyethylene films. Covers washing, float-sink, NIR sorting tests and post-recycling material recovery.

ASTM D1709

Standard test method for the impact resistance of polymeric films by the free-falling dart method. The result is expressed in grams - the weight at which 50% of samples fail. Essential for specifying industrial polybags, stretch films and mechanical protection films.

ASTM D3985

Standard test method for measuring OTR (Oxygen Transmission Rate) through polymeric films using a coulometric sensor. The global technical reference for evaluating the oxygen barrier performance of multilayer structures and metallised or EVOH films.

ASTM F1249

Standard test method for measuring WVTR (Water Vapor Transmission Rate) through polymeric films using an infrared-modulated sensor. Standard conditions: 37.8°C / 100% RH. Applicable to food, pharmaceutical and moisture-sensitive packaging.

ASTM F1927

Standard test method for measuring OTR under controlled humidity. Complements ASTM D3985, particularly relevant for structures with an EVOH layer, whose barrier performance varies significantly with humidity. More closely reflects real-world packaging use conditions.

Decision 97/129/EC

Establishes the harmonised European system for identifying packaging materials to facilitate sorting and recycling. Plastic codes: 01 PET, 02 HDPE, 03 PVC, 04 LDPE, 05 PP, 06 PS, 07 Other. Marking with the recycling triangle and numeric code is voluntary but commonly used on commercial packaging.

EN 13432

European standard for packaging recoverable through industrial composting and biodegradation. Requires ≥90% biodegradation within 6 months and disintegration into fragments under 2 mm within 3 months. The basis for OK Compost Industrial and Seedling (TÜV Austria) certifications. Does not cover home composting - EN 17427 applies there.

EN 14995

European standard for assessing the compostability of plastic materials outside the packaging category (single-use products, agricultural products, household items). Criteria are similar to EN 13432: biodegradation, disintegration, final compost quality, absence of ecotoxic effects.

EN 18120

A series of European standards published in 2026, "Design for recycling of plastic packaging", developed by technical committee CEN/TC 261. The first part, EN 18120-1, sets out the fundamental principles and terminology; EN 18120-3 covers sortability assessment, including NIR, magnetic and eddy-current sorting. Other parts address specific material streams, among them flexible PE and PP packaging.

Relationship with PPWR: EN 18120 is not a harmonised standard. Until the delegated acts under Article 6(4) enter into force, the harmonised reference for recyclability remains EN 13430:2004.

→ The standards behind mono-material film

ISO 527

Standard test method for determining the tensile properties of plastic materials. Parameters measured: tensile strength (MPa), elongation at break (%), Young's modulus. Reference for the technical specifications of BOPP, BOPE and MDO-PE films and for packaging-line specification sheets.

ISO 536

Standard method for determining grammage (mass per unit area) for paper and board, applied by analogy to flexible films as well. Result expressed in g/m². A key technical parameter for comparing packaging structures and optimising material consumption.

ISO 1043-1

International system of symbols and terms for plastic materials. Defines the industry-accepted official codes: PE, PP, PET, PS, PVC, PA, EVOH, etc. Used in technical documentation, the Declaration of Conformity and packaging marking.

ISO 1133

Determination of MFI (Melt Flow Index, g/10 min) and MVR (Melt Volume Rate, cm³/10 min) for thermoplastic polymers. Measures melt flow behaviour at defined temperature and pressure. A critical parameter for designing coextruded structures and matching layers in lamination.

ISO 4593

Determination of plastic film thickness using the mechanical method with a precision gauge. Unit: μm (micron). Standard applied in roll quality control and for verifying compliance with structure specifications.

ISO 9001:2015

International standard for quality management systems. Requires a process-based approach, leadership, customer focus and continual improvement. VLM Poliplast holds ISO 9001:2015 certification.

ISO 11607

Standard for packaging of terminally sterilised medical devices. Part 1 sets general requirements for sterile barrier systems (SBS). Part 2 covers validation of forming, sealing and assembly processes. Relevant for pouches and films intended for the medical industry.

ISO 14001:2015

International standard for environmental management systems. Requires identification of environmental aspects, setting impact-reduction objectives and integrating environmental considerations into processes. VLM Poliplast holds ISO 14001:2015 certification.

ISO 15105

Standard for determining the gas transmission rate (including oxygen) through plastic films. Part 1: differential pressure method. Part 2: concentration method. European equivalent to ASTM D3985, used in technical specifications for barrier films.

ISO 15106

Standard for determining WVTR through plastic films. Part 1: electrolytic sensor. Part 2: gravimetric method. Part 3: capacitive sensor. European equivalent to ASTM F1249, used to assess the water-vapour barrier of structures intended for moisture-sensitive products.

ISO 15378

Specific requirements for Good Manufacturing Practice (GMP) applied to primary pharmaceutical packaging materials. An extension of ISO 9001 adapted to the pharmaceutical industry, integrating GMP principles from the European Commission and the FDA. Relevant for flexible packaging intended for medicinal products.

ISO 22000:2018

International standard for food safety management systems. Integrates HACCP (Hazard Analysis and Critical Control Points) principles with the ISO 9001 structure. VLM Poliplast holds ISO 22000:2018 certification for the production of food-contact packaging.

ISO 45001:2018

International standard for occupational health and safety management systems. Replaces the former OHSAS 18001 and aligns structurally with ISO 9001 and ISO 14001. Current ISO edition: ISO 45001:2018 (2024 amendment). The European version adopted by CEN is EN ISO 45001:2023, with no content changes. VLM Poliplast holds ISO 45001:2018 certification.

Regulation (EC) 1935/2004

The general European framework for materials and articles intended to come into contact with food (FCM). Establishes the inertness principle (the material must not transfer components in quantities that endanger health), the traceability principle and the obligation to issue a Declaration of Conformity.

→ Who signs the declaration, and when

Regulation (EU) 10/2011

Specific regulation for plastic materials and articles intended to come into contact with food. Contains the positive list of authorised substances (monomers, additives), the overall migration limit (OML = 10 mg/dm²) and specific migration limits (SML). Recently amended by Regulation (EU) 2025/351.

Regulation (EU) 2023/2006

Regulation on Good Manufacturing Practice (GMP) for materials and articles intended to come into contact with food. Complements the 1935/2004 framework with operational requirements: quality systems, traceability, process documentation, supplier qualification. Mandatory for all operators in the FCM supply chain.

PPWR (EU) 2025/40

The European regulation on packaging and packaging waste (Packaging and Packaging Waste Regulation), Regulation (EU) 2025/40. Entered into force on 11 February 2025 and generally applicable from 12 August 2026. Requirements apply in stages: the Declaration of Conformity, PFAS restrictions and packaging minimisation from 12 August 2026; design-for-recycling requirements from 1 January 2030, or 24 months after the delegated acts under Article 6(4) enter into force, whichever is later. From 1 January 2038, packaging must reach at least performance grade B.

→ Regulation (EU) 2025/40 explained in full

Eco-modulated EPR

Differentiation of the contributions paid under extended producer responsibility schemes according to the packaging's recyclability performance, instead of a flat charge by weight. EPR obligations are set in Article 45 of PPWR, and the common European modulation framework is to be established through the delegated acts under Article 6(4). Until it enters into force, member states modulate contributions under national criteria.

→ How fees are modulated by recyclability

CSRD

Corporate Sustainability Reporting Directive, the European directive on corporate sustainability reporting. Applicable to Scope 3 GHG calculations, including the carbon footprint of the packaging component.

Declaration of Conformity (DoC)

Document required by PPWR for packaging placed on the EU market, including information on design recyclability, material composition and compliance with European requirements.

→ Download the editable DoC template

Polyethylene (PE)

A polymer widely used in flexible packaging, in various grades (LDPE, HDPE, LLDPE) depending on flexibility and sealing requirements.

→ LDPE and LLDPE in flexible packaging

PE-LD / LLDPE

Low-density polyethylene (920 kg/m³), with high flexibility and low-temperature sealing. Recycling code 04 under Decision 97/129/EC.

→ Polyethylene film for automated lines

PE-HD

High-density polyethylene (952 kg/m³), stiffer than PE-LD. Used in industrial sacks and coextruded structures. Recycling code 02 under Decision 97/129/EC.

MDO-PE

Machine Direction Oriented Polyethylene, density 940 kg/m³. A PET replacement in mono-material structures that are recyclable under PPWR 2030.

→ Where MDO-PE sits in an all-PE structure

BOPE

Biaxially Oriented Polyethylene, density 940 kg/m³, with high mechanical strength for single-family polyethylene laminates compliant with PPWR 2030.

→ What biaxial orientation does to polyethylene

Polypropylene (PP)

A polymer used in flexible packaging for its relative stiffness and higher heat resistance compared with polyethylene. Recycling code 05 under Decision 97/129/EC.

→ Polypropylene and why tacticity matters

BOPP

Biaxially Oriented Polypropylene, density 910 kg/m³, with high transparency and mechanical strength. Used as a printable outer layer.

→ BOPP film in gloss and matt

CPP

Cast Polypropylene, density 900 kg/m³, non-oriented. Used as a sealant layer in laminated structures due to its low sealing temperature.

→ What the chill roll decides in cast polypropylene

PET

Polyethylene terephthalate, density 1390 kg/m³. A polymer used for mechanical strength, dimensional stability and print support. Outer layer in traditional laminates.

Relationship with PPWR: flexible PET used as a layer in traditional multi-material laminates is not compatible with RecyClass Grade A or B. For PPWR 2030 compliance, flexible PET is being replaced with MDO-PE or BOPP in mono-material structures.

→ PET film and what orientation changes

Polyamide (PA / Nylon)

A polymer used as a functional layer for mechanical strength and gas barrier. Above the 5%-by-weight threshold set in the RecyClass criteria for the PE stream, polyamide makes the structure incompatible with that stream. The CEFLEX D4ACE methodology treats PA in PE structures separately, with its own thresholds and requirements for PE-g-MAH tie layers.

→ PA 6 and BOPA, puncture resistance explained

EVA

Ethylene-vinyl acetate, an ethylene-based copolymer used as a sealing layer or auxiliary component. Compatible with the PE recycling stream.

PS

Polystyrene, a polymer with limited use in flexible packaging, mainly for transparent films and shrink applications.

PVC

Polyvinyl chloride, a polymer historically used in flexible packaging, especially for cling and shrink films. Not recommended in the PPWR transition.

EVOH

Ethylene vinyl alcohol, a copolymer used as an oxygen barrier layer. Fully compatible with the PE stream up to 5 wt% of packaging weight (RecyClass, July 2025), provided the tie-layer ratio is optimal.

→ How the oxygen barrier actually works

PVDC

Polyvinylidene chloride, a polymer used as a layer or coating providing an oxygen and water-vapour barrier, applied to polymeric films or in multilayer structures.

Aluminium foil

A metal layer used in laminates to achieve a very high barrier to gases, vapour and light. Incompatible with mono-material PE/PP recycling.

Metallised film

A polymeric film with a metal layer applied by vacuum vapour deposition, used to improve barrier performance. Penalises the RecyClass score because it interferes with NIR sorting.

Relationship with PPWR: in the RecyClass and CEFLEX criteria, a metallised layer above the compatibility threshold is treated as incompatible with the PE and PP streams, and the final grade of a specific structure is established by assessment. Alternatives for high-barrier applications are EVOH under 5 wt% or inorganic SiOx and AlOx coatings, which preserve transparency and NIR compatibility.

→ Why pinholes decide a metallised barrier

Inorganic coatings (SiOx, AlOx)

Inorganic layers deposited on polymeric films using vacuum-based technologies, used to improve oxygen and water-vapour barrier while preserving transparency.

→ Transparent barrier film for sensitive products

Tie-layer

A functional adhesive layer between incompatible polymers (e.g. PE and EVOH). For EVOH in a PE stream, the EVOH-to-PE-g-MAH tie ratio is critical to reaching RecyClass Grade A.

Mono-material packaging

Flexible packaging built predominantly on a single polymer family, PE or PP, without combining it with incompatible polymers, designed for compatibility with the flexible PE or flexible PP recycling stream.

→ Single-family film in PE and PP

EcoMonoFilm®

Registered trademark (EUIPO 019103256) for the range of recyclable mono-material PE and PP films made by VLM Poliplast through flexographic printing, solventless lamination and converting.

Available in single-family polypropylene structures and in single-family polyethylene structures. The structures are designed to align with the RecyClass v3.1 criteria for the PE and PP recycling streams. Full technical specifications and product data sheets are available on the dedicated page.

→ The EcoMonoFilm® range and its data sheets

rPE / rPP (recycled content)

Plastic materials obtained from post-consumer waste (PCR, Post-Consumer Recycled), used as a partial raw material in manufacturing new flexible packaging.

→ Recycled content under Article 7

Compostable bioplastics

A category of plastic materials designed for biological breakdown under controlled conditions, such as industrial composting under EN 13432.

→ Compostable or recyclable, which one applies

PLA

Polylactic acid, a bioplastic derived from renewable sources, used in flexible packaging that is compostable under industrial conditions.

PHA

Polyhydroxyalkanoates, a family of biodegradable biopolymers produced through biological processes, used to a limited extent in flexible packaging.

PBS

Polybutylene succinate, a biodegradable polyester used in compostable flexible packaging, often blended with other biopolymers.

Lamination adhesives

Adhesive systems used to bond layers together in a multilayer package. Solventless adhesives (acrylic, solvent-free polyurethane) are preferred for RecyClass compliance.

Printing inks

Formulations used for printing on polymeric films, adapted for adhesion to non-porous surfaces.

Retentive inks

RecyClass-certified inks that remain attached to the polymeric material during the recycling process. Previously called "non-bleeding inks". Not penalised below 5 wt% of packaging weight.

UV-LED inks

Inks cured by exposure to ultraviolet light generated by LED sources. A modern printing technology for flexible films, with lower energy consumption and minimal VOC emissions compared with solvent-based inks. Compatible with RecyClass requirements for mono-material packaging.

NIR (Near-Infrared sorting)

Automated plastic-waste sorting technology based on near-infrared spectrometry. Metallisation and opaque inks interfere with NIR sorting.

→ Designing a pack the sorter can read

Slip agent

A polymeric additive added to film formulations to reduce the surface coefficient of friction (COF). Ensures controlled film sliding on automatic VFFS/HFFS packaging lines and on slitting machines. Common types: erucamide, oleamide.

Antistatic

An additive that reduces the electrostatic charge of polymeric films. Critical for packaging intended for the electronics industry (ESD bags), powdered products (flour, powdered sugar) or fine chemical products, to prevent powder adhesion and electrostatic discharge.

Corona treatment

A surface-activation process for films (especially PE and PP) to improve the adhesion of inks and adhesives.

Anti-fog coatings

Treatments applied to the inner surface of packaging to reduce condensation and maintain transparency.

Delamination

A defect where layers separate in a laminated package, caused by incompatibilities or incorrect process parameters.

Extrusion (blown / cast film)

A process for forming polymeric films by melting and shaping into a continuous sheet. Blown film for flexibility, cast film for transparency.

Coextrusion (COEX)

The simultaneous extrusion of multiple layers to produce a multilayer film with different functions (barrier, sealing, strength) in a single process.

Lamination

A process combining two or more films with adhesive or heat to produce a multilayer structure.

→ Duplex and triplex laminated film

Solventless lamination

A lamination technology that does not use organic solvents, using reactive adhesives instead. Preferred for RecyClass compliance and reduced VOC emissions. Progressively adopted across European industry as a replacement for classic solvent-based lamination.

→ How the layers of a laminate work together

Metallisation

Deposition of a very thin metal layer onto a polymeric film by vacuum vapour deposition, to improve barrier and light protection.

Slitting & rewinding

Cutting jumbo rolls into narrower rolls and rewinding for conversion or use on automatic packaging machines.

Die-cutting

Punching / cutting special shapes (handles, windows, euro-holes) using a die.

Laser perforation

A controlled laser-perforation process used for micro-holes and regulating gas exchange (e.g. fruit and vegetable packaging).

→ Perforated film for fresh produce

Thermoforming

Forming heated film into cavities (trays, blisters), sometimes followed by filling and sealing.

Flexo / rotogravure / digital printing

Industrial processes for transferring inks onto polymeric films. Flexo for medium volumes, rotogravure for large volumes, digital for short, customised runs.

Hot-fill

A filling process in which the product (liquid or semi-liquid) is filled at high temperature (85-95°C) for thermal sterilisation and preservation. Used for sauces, juices, jams. Requires packaging structures with compatible heat resistance and barrier properties (BOPP, CPP, mono-material PP).

Pouch

Flexible packaging formed from a structure sealed at the edges, used for food and non-food products.

→ The full pouch range, made to order

Stand-up pouch

A pouch designed to stand upright on the shelf after filling, thanks to its base shape.

→ Stand up pouches with zip and valve

Doypack

A type of stand-up pouch with a rounded ("U"-shaped) base, often associated with a premium look and good shelf stability.

→ Doypacks with a folded gusset base

K-Seal

A type of stand-up pouch with a base formed by angled seals, used for heavier weights.

Plow Bottom

A type of stand-up pouch with a folded base, designed for stability and greater volume.

Quadseal

A pouch sealed on four sides, used for coffee, pet food and other high-volume products.

→ Quad seal bags with side gussets

Flowpack / HFFS

Automated horizontal packaging from roll stock, used for individual products (bars, bakery items, biscuits).

→ Flow wrap and pillow packs

VFFS

Vertical Form-Fill-Seal, automated vertical packaging from roll stock, frequently used for pillow bags and bulk products.

Pillow pouch

Packaging formed from roll-stock film, sealed longitudinally and transversally, commonly used on VFFS/HFFS lines.

Rollstock

Film supplied in roll form for automatic packaging machines, for forming, filling and sealing.

→ Film on the reel, slit to your line width

Retort pouch

A pouch designed to withstand severe thermal processes (sterilisation), for ready-to-eat products or sauces.

→ Pouches sterilised after sealing

Vacuum bag

A multilayer bag used for vacuum packaging, by evacuating the air from inside.

→ How a multilayer structure is built

Polybag

A mono-layer or coextruded bag, usually made of PE, used for retail, protection and transport.

→ Poly bags, clear or printed

Bag-in-Box

A packaging system with an inner bag and an outer cardboard box, used for liquids or dosable products.

Stretch film

Elastic film (usually LLDPE) used for pallet wrapping through stretching and self-adhesion.

Shrink film

Film that contracts under heat, used for grouping, protection and stabilisation.

MAP

Modified Atmosphere Packaging, a packaging technology in which the gas composition inside is controlled to extend shelf life.

→ Modified atmosphere, and when vacuum is better

Aseptic packaging

A packaging system in which the product and the packaging are sterilised separately, with filling then carried out in clean-room conditions. Enables a long shelf life without refrigeration, set for each product by the food manufacturer. Used for UHT products (milk, juices), medical products and liquid pharmaceuticals.

Density

Mass per unit volume of the polymer, expressed in kg/m³ or g/cm³. Ranges between 900 kg/m³ (CPP) and 1390 kg/m³ (PET) for common polymers.

Grammage

The film's mass relative to its area, expressed in g/m². Used as the primary technical specification for comparing structures.

Micron (μm)

A unit of measurement for the thickness of flexible films. 1 μm = 0.001 mm. Typical thicknesses: 12-200 μm.

OTR

Oxygen Transmission Rate, the rate of oxygen transmission through a film, expressed in cm³/m²/day. Critical for oxidation-sensitive foods.

→ Barrier film for oxygen-sensitive products

WVTR

Water Vapor Transmission Rate, the rate of water-vapour transmission, expressed in g/m²/day. Critical for moisture-sensitive products.

Sealing temperature

The temperature range at which the sealant layer forms a reliable seal. Ranges between 90°C (CPP) and 140°C (PE-HD).

Hot-tack

The ability of the sealant layer to stay bonded immediately after sealing, before it has fully cooled. Critical for high-speed packaging lines.

COF (coefficient of friction)

Coefficient of Friction between the film surface and a reference surface (metal, identical film). Measured as static and dynamic values under ASTM D1894. Critical for behaviour on automatic packaging lines: too low a COF causes uncontrolled slippage, too high a COF jams the film on the forming collar. The value is adjusted through slip additives and confirmed on the structure data sheet.

Seal strength

The mechanical strength of the seal between two film layers, measured in N/15mm under ASTM F88. Determines packaging reliability during transport, storage and handling. The value required depends on product weight and handling, and the value achieved is confirmed on the delivered structure.

Machinability

The film's behaviour on automatic packaging lines. The result of the combination of COF, hot-tack, stiffness, dimensional stability and tensile strength. A film with good machinability runs at the machine rated speed, without jams and with little waste at set-up.

Shelf-life

The shelf life of the packaged product, determined by the structure's barrier properties, storage conditions and product characteristics. The packaging is one of the conditions, not the only one: the shelf life is set by the food manufacturer, through its own testing. When moving from a classic laminate to a mono-material structure, barrier equivalence is verified on the product before the change.

Zipper

An element sealed inside the pouch to allow reclosing after opening, frequently used on pouches.

→ Grip seal and resealable pouches

Slider

A manually operated slider used to close/open the pouch via a zipper.

Spout

A pouring nozzle / valve element for liquid or semi-liquid products in pouches.

Degassing valve (one-way valve)

A one-way valve used on coffee packaging to release accumulated CO₂ while keeping outside oxygen out.

→ Coffee packaging and the CO₂ problem

Euro-hole

A standardised hanging hole on packaging, for retail-shelf display.

Tear-notch

A small cut/notch on the edge of the packaging to make manual opening easier.

Easy-open

A packaging structure designed for quick opening without additional tools.

Peelable / sealable

A structure in which the seal can be peeled apart without tearing the film. Resealable packaging supports repeated reclosing.

Tamper-evident

A packaging feature that indicates whether it has already been opened (e.g. a perforated seal, a label that tears on opening).

Fitment

A generic term for injection-moulded plastic accessories sealed onto a pouch: spouts, valves, caps. In a recyclability assessment the fitment is a separable component, analysed separately from the pouch structure, and its material influences the result for the packaging unit.

Window film

A transparent window in printed packaging, for viewing the product.

Anti-fog-lined laminates

Structures with a matte interior or an absorbent layer, to reduce condensation in meat/fish packaging.

Zip snap button

A "click"-type closure used on pouches to keep them open in shape.

Hang-tab

A hanging feature applied to packaging, separate from the standardised euro-hole.

Resealable

A generic term for any packaging that can be functionally reclosed after first opening (zipper, slider, peelable/sealable).

Fish-eyes

Point defects from extrusion in the form of gels or visible contamination in the film. Caused by non-homogenised polymer, uncontrolled regrind or contamination entering the extruder. Impairs print quality and barrier-structure integrity.

Blocking

The tendency of two film layers to stick together unintentionally on the roll or during storage. Addressed with slip agents and anti-block additives. A critical issue for very clean films (additive-free) intended for premium food contact or medical applications.

Solvent retention

Residual organic solvents left in the laminated structure after a classic lamination process. Can migrate into the packaged food (FCM risk) and cause off-odour. Prevented through solventless lamination, a technology that eliminates the use of organic solvents and ensures compliance with Regulation (EU) 10/2011.