Technical Glossary for Flexible Packaging
The VLM Poliplast technical glossary for flexible packaging covers 127 definitions across 11 categories: technical standards and regulations (RecyClass, CEFLEX, ISO, ASTM, EN, EU Regulations), European regulations (PPWR, EPR, CSRD), polymer materials (PE, PP, PET, MDO-PE, BOPE), barrier materials (EVOH, metallised, aluminium), sustainable materials, surface treatments, production processes, packaging types, technical properties, accessories and production defects.
This glossary is built as a decision-making reference for industry specialists: technical managers, process engineers, buyers, quality specialists and R&D teams. Use the search box or the category filters below for quick navigation. For an offline copy, the complete technical guide with all 127 terms is available in the technical resource centre.
Definitions reflect recent methodology updates: RecyClass v3.1 (August 2025), EVOH-in-PE-stream design guidelines (July 2025), retentive inks (March 2026) and EN 18120-1:2026.
RecyClass v3.1
Standardised European methodology for assessing the recyclability of plastic packaging, developed by Plastics Recyclers Europe and updated in August 2025. Applies a 5-grade scoring system, from A to E, based on the base structure and disrupting elements. From 2028 it will be harmonised with the EN 18120 normative framework, adopted into PPWR delegated acts.
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. Over 600 representative samples were analysed in the experimental programme, data later used to develop the PE and PP sections of the EN 18120 series.
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
Series of European CEN standards for design for recycling of plastic packaging. The first part, EN 18120-1:2026, published by CEN, sets out the definitions and classification principles for the compatibility of design elements with real-world recycling processes. In Romania: SR EN 18120 via ASRO. The PE and PP parts were developed with input from the CEFLEX platform and the D4ACE programme.
Note: our two glossary sources currently give two different publication dates for EN 18120-1:2026 - 15 April 2026 in one place and June 2026 in another. We are verifying the exact date directly with CEN-CENELEC and will update this entry once confirmed.
Relationship with PPWR: from 2028, EN 18120 will be incorporated into the delegated acts of Regulation (EU) 2025/40 as the harmonised technical reference for assessing the recyclability grade required from 1 January 2030.
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.
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: general compliance (DoC, PFAS restrictions, packaging minimisation) from 12 August 2026, while the recyclability obligation (banning Non-Recyclable structures, below 70% compatibility) takes effect from 1 January 2030.
Eco-modulated EPR
European system for pricing Extended Producer Responsibility, adjusted according to the packaging's recyclability grade. Bonus for Grade A, standard rate for Grade B, higher rate for Grade C, malus for the Non-Recyclable category.
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.
Polyethylene (PE)
A polymer widely used in flexible packaging, in various grades (LDPE, HDPE, LLDPE) depending on flexibility and sealing requirements.
PE-LD / LLDPE
Low-density polyethylene (920 kg/m³), with high flexibility and low-temperature sealing. Recycling code PE4.
PE-HD
High-density polyethylene (952 kg/m³), stiffer than PE-LD. Used in industrial sacks and coextruded structures. Recycling code PE4.
MDO-PE
Machine Direction Oriented Polyethylene, density 940 kg/m³. A PET replacement in mono-material structures that are recyclable under PPWR 2030.
BOPE
Biaxially Oriented Polyethylene, density 940 kg/m³, with high mechanical strength for PE/PE laminates compliant with PPWR 2030.
Polypropylene (PP)
A polymer used in flexible packaging for its relative stiffness and higher heat resistance compared with polyethylene. Recycling code PP5.
BOPP
Biaxially Oriented Polypropylene, density 910 kg/m³, with high transparency and mechanical strength. Used as a printable outer layer.
CPP
Cast Polypropylene, density 900 kg/m³, non-oriented. Used as a sealant layer in laminated structures due to its low sealing temperature.
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 as a layer in laminated structures (PET/Al/PE, PET/PE) 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.
Polyamide (PA / Nylon)
A polymer used as a functional layer for mechanical strength and gas barrier. Conditionally compatible in the PE stream only for PA 6/66 below 15% with a PE-g-MAH tie-layer.
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.
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: metallised structures lower the recyclability grade towards C or the Non-Recyclable category. For PPWR 2030 compliance, replacement with EVOH under 5 wt% or inorganic SiOx/AlOx coatings, which preserve transparency and NIR compatibility, is recommended.
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.
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 made predominantly of a single type of polymer (≥95%), designed for compatibility with the flexible PE or flexible PP recycling streams.
EcoMonoFilm®
Registered trademark (EUIPO 019103256) for the range of recyclable mono-material PE and PP films made by VLM Poliplast through solventless lamination, flexographic printing and converting films sourced from certified suppliers.
Available structures: BOPP/CPP (mono-material PP), MDO-PE/PE and BOPE/PE (mono-material PE). The structures are designed for compatibility with the PE and PP recycling streams and can reach Grade A/B under the RecyClass v3.1 methodology when correctly engineered. Full technical specifications and product data sheets are available on the dedicated page.
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.
Compostable bioplastics
A category of plastic materials designed for biological breakdown under controlled conditions, such as industrial composting under EN 13432.
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.
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.
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.
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).
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.
Stand-up pouch
A pouch designed to stand upright on the shelf after filling, thanks to its base shape.
Doypack
A type of stand-up pouch with a rounded ("U"-shaped) base, often associated with a premium look and good shelf stability.
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.
Flowpack / HFFS
Automated horizontal packaging from roll stock, used for individual products (bars, bakery items, biscuits).
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.
Retort pouch
A pouch designed to withstand severe thermal processes (sterilisation), for ready-to-eat products or sauces.
Vacuum bag
A multilayer bag used for vacuum packaging, by evacuating the air from inside.
Polybag
A mono-layer or coextruded bag, usually made of PE, used for retail, protection and transport.
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.
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 shelf life of up to 12 months without refrigeration. 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.
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. Typical values for PE film: COF 0.15-0.30. Critical for behaviour on automatic packaging lines: too low a COF causes uncontrolled slippage, too high a COF causes the film to jam.
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. Typical values: 15-35 N/15mm for PE, 20-45 N/15mm for laminated PP.
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 high VFFS/HFFS speeds without jamming, with minimal waste. The reference parameter for film acceptance by customers with automated production.
Shelf-life
The shelf life of the packaged product, determined by the combination of the structure's barrier properties (OTR, WVTR), storage conditions and product characteristics. Shelf-life is the final validation parameter for a packaging-structure choice: a poor barrier choice can cut shelf-life by 50% or more.
Zipper / AMPP
An element sealed inside the pouch to allow reclosing after opening, frequently used on 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.
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).
AMPP
American Molded Plastic Part: a generic term for sealed/joined accessories on injection-moulded plastic pouches.
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.
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