What Is Lock-Seal PET/PE Lidding Film?
Lock-seal PET/PE lidding film is a laminated tray-sealing film designed to create a strong, non-easy-peel closure on compatible food trays and containers. The PET or BOPET outer layer provides tensile strength, dimensional stability, clarity, puncture resistance, and a printable surface. The PE-based inner layer provides heat sealing to a compatible PE sealing surface.
A lock seal, also called a weld seal or permanent seal, prioritizes package security, tamper evidence, liquid containment, and distribution strength. It is different from an easy-peel film, which is formulated to open with a lower and more controlled consumer peel force.
HSQY supplies nominal thicknesses from 0.052mm to 0.09mm, roll widths from 150mm to 900mm, and standard 500m rolls with custom conversion available. The standard grade on this page is not automatically high barrier, freezer safe, microwaveable, or ovenable. These functions require a separately specified structure and completed-package testing.
Why Use a Lock-Seal Lidding Film?
Strong permanent closure: Provides a high-strength seal for packages that are not intended for easy consumer peeling.
Tamper evidence: Opening may visibly tear the film or damage the tray flange, indicating interference with the package.
Liquid containment: A correctly validated weld seal can support products containing sauces, marinades, purge, or other liquids.
Distribution security: Higher seal strength can help packages withstand handling, stacking, vibration, and transport.
Clear product presentation: Transparent PET/PE structures can provide visibility and gloss.
Custom printing: The PET surface supports branding, preparation instructions, barcodes, and traceability.
Anti-fog option: A suitable anti-fog grade can improve visibility for chilled, moisture-rich foods.
Custom roll conversion: Width, length, core, winding direction, roll weight, and outer diameter can be matched to the tray sealer.
Lock Seal vs. Easy Peel
| Seal Type |
Opening Behaviour |
Typical Use |
| Lock Seal / Weld Seal |
Forms a strong permanent bond; opening may tear the film or distort the tray flange. |
Liquid foods, tamper-evident packs, transport-sensitive products, and food-service packaging. |
| Hard Peel |
Peelable but requires relatively high opening force. |
Products requiring stronger distribution security with manual opening. |
| Easy Peel |
Opens with controlled force and reduced film shredding or sealant residue. |
Retail convenience foods, dairy, desserts, salads, and consumer-ready meals. |
The standard product on this page is positioned as a lock-seal grade. It should not be described as clean peel or easy opening unless a separate peelable sealant structure is supplied and validated.
How the BOPET/PE Laminate Works
| Layer |
Primary Function |
Buyer Consideration |
| PET / BOPET Outer Layer |
Provides clarity, stiffness, tensile strength, dimensional stability, puncture resistance, and printability. |
Confirm gauge, haze, gloss, surface treatment, shrinkage, and printing requirements. |
| Printing Layer |
Carries logos, product information, preparation instructions, barcodes, and traceability. |
Confirm surface or reverse printing, ink system, colors, print repeat, and eye-mark position. |
| Laminating Adhesive |
Bonds the PET outer layer to the PE sealing layer or additional functional layers. |
Confirm cure time, bond strength, migration, odor, and thermal or chilled-storage requirements. |
| Optional Barrier Layer |
Reduces oxygen, moisture, or aroma transmission when standard PET/PE is insufficient. |
Specify OTR, WVTR, MAP gas mixture, food type, storage temperature, and shelf-life target. |
| PE-Based Sealant Layer |
Creates the heat seal to a compatible PE sealing surface and controls lock-seal strength. |
Must be matched to the tray flange, sealing window, contamination level, and required seal strength. |
Lock-Seal PET/PE Lidding Film Specifications
The specifications below retain the current commercial values while separating standard performance from optional functional grades. Final guaranteed properties should be documented in the approved technical data sheet, sample approval, and purchase order.
| Property |
Standard or Available Option |
Selection Note |
| Product Type |
Lock-seal / weld-seal tray lidding film |
Rollstock for tray-sealing equipment |
| Material Structure |
BOPET/PE laminate |
Exact PET, adhesive, PE, and optional barrier layers depend on the application |
| Primary Tray Application |
Compatible PET/PE trays and other PE sealing surfaces |
Send the tray grade, drawing, or physical sample |
| Thickness |
0.052–0.09mm, custom |
Confirm nominal gauge and manufacturing tolerance |
| Standard Widths |
180mm, 320mm, 400mm, and 640mm |
The broader custom width range is 150–900mm |
| Roll Length |
500m, customizable |
Depends on thickness, width, core, roll weight, and maximum outer diameter |
| Appearance |
Clear or custom printed |
Confirm haze, gloss, colors, print coverage, transparent windows, and eye marks |
| Seal Type |
Lock seal / weld seal |
Easy-peel requires a different sealant grade |
| Anti-Fog |
Optional, custom |
Recommended for chilled and high-moisture foods |
| Standard Barrier |
General product protection |
Do not claim high oxygen barrier without OTR data |
| High Barrier |
Optional EVOH or other barrier structure |
Specify OTR, WVTR, gas mixture, and target shelf life |
| Microwave / Oven Use |
No for the current standard grade |
Use a separately qualified thermal grade when required |
| Freezer Use |
No for the current standard grade |
A low-temperature grade requires separate testing |
| Reference Density |
Approximately 1.36g/cm³ for the listed laminate |
Finished density varies with layer ratio and functional layers |
| Printing |
Flexographic or gravure printing by project |
Confirm artwork, color count, print repeat, eye mark, and annual volume |
| MOQ |
1000kg |
Trial quantity depends on stock, width, printing, and specification |
| Payment Terms |
30% deposit and 70% balance before shipment |
Confirm in the commercial quotation |
| Delivery Terms |
FOB, CIF, EXW; other terms may be discussed |
Subject to destination and shipment size |
| Lead Time |
10–15 days after deposit and specification approval |
Printed, barrier, or specialty grades may require more time |
Which Trays Can PET/PE Lock-Seal Film Seal?
| Tray Material |
Compatibility Guidance |
Recommended Approach |
| PET/PE Tray |
Primary application when the tray flange presents a compatible PE sealing surface. |
Confirm PE grade, flange geometry, contamination tolerance, and seal strength. |
| PET/EVOH/PE Tray |
Often compatible when the outer sealing surface remains PE. |
Validate the complete barrier package, seal integrity, and MAP gas retention. |
| PE or PE-Coated Tray |
May be compatible when the PE grade matches the lidding sealant. |
Test seal initiation temperature, weld strength, and package distortion. |
| Plain APET / RPET Tray |
A plain PET flange may not seal reliably to a standard PE sealant. |
Use a PET-compatible or universal sealing layer after testing. |
| CPET Tray |
Standard PET/PE lock-seal film should not automatically be treated as CPET-compatible or ovenable. |
Use a dedicated CPET sealing and thermal grade. |
| PP / PP-EVOH-PP Tray |
A polypropylene sealing surface generally requires a PP-compatible sealant. |
Use BOPET/CPP, EVOH/PP, or another qualified PP sealing structure. |
| Aluminium or Coated Paperboard |
Requires substrate-specific sealing chemistry. |
Send samples and develop a dedicated lock-seal grade. |
Standard PET/PE vs. High-Barrier PET/EVOH/PE
| Structure |
Typical Performance |
When to Select It |
| Standard BOPET/PE |
Mechanical strength, clarity, general moisture and aroma protection, and PE lock sealing. |
Shorter shelf-life products where a validated high oxygen barrier is not required. |
| PET/EVOH/PE High Barrier |
Adds a defined oxygen-barrier layer for MAP and oxidation-sensitive foods. |
Meat, poultry, seafood, cheese, and prepared foods requiring target OTR performance. |
| Anti-Fog PET/PE |
Adds condensation control for improved product visibility. |
Chilled produce, salads, meat, dairy, bakery, and ready meals. |
| Easy-Peel PET/PE |
Uses a modified sealant layer for controlled consumer opening. |
Retail convenience foods that require a clean, peelable lid rather than a weld seal. |
A standard BOPET/PE laminate should not be promoted as high barrier solely because it contains PET. High-barrier claims require a defined functional layer and measured OTR and WVTR values.
Seal Integrity and Leak Prevention
A strong film does not automatically create a leak-free package. Seal integrity depends on the tray flange, film sealant, tooling flatness, temperature, pressure, dwell time, web tension, filling process, and contamination on the sealing surface.
| Potential Failure |
Common Cause |
Corrective Action |
| Incomplete Seal |
Low temperature, insufficient dwell time or pressure, uneven tooling, or tray deformation. |
Establish a validated sealing window and inspect every cavity. |
| Channel Leak |
Wrinkles, trapped food particles, damaged tray rim, or non-uniform pressure. |
Improve flange cleaning, film tracking, tray handling, and tooling maintenance. |
| Seal Too Weak |
Incompatible PE grades, low seal temperature, or insufficient contact. |
Test the actual tray and select the correct sealant formulation. |
| Film or Tray Distortion |
Excessive heat, long dwell time, high tension, or unsuitable tray stiffness. |
Reduce thermal load and optimize film tension and tooling. |
| Delamination |
Insufficient adhesive cure, excessive thermal stress, or incompatible laminate components. |
Verify bond strength, cure time, storage, and application conditions. |
Contamination Tolerance
Food residue on the tray flange can reduce seal strength and create leak paths. Projects involving sauce, oil, moisture, powder, meat purge, or particles should include contaminated-seal testing at the planned commercial line speed.
Test clean and intentionally contaminated tray flanges.
Measure seal strength on all tray sides, corners, and compartments.
Use an agreed vacuum, pressure-decay, dye, or bubble leak-test method.
Confirm the seal remains acceptable after chilled storage and transport simulation.
Define acceptable leak rate and visual seal criteria before production.
Anti-Fog and Custom Printing Options
Anti-fog treatment can be added for chilled products where condensation may obscure the food. Specify the anti-fog side, sealing side, winding direction, storage temperature, food moisture, and target display life.
Custom printing can include branding, ingredients, instructions, barcodes, QR codes, batch-code areas, and transparent product windows. Confirm the print method, color standard, print repeat, eye-mark position, registration tolerance, and whether the print is surface or reverse printed.
Recyclability Considerations
A PET/PE laminate contains more than one polymer family and should not automatically be described as recyclable in every market. Recyclability depends on the complete structure, layer percentages, adhesive, ink, coatings, tray material, local collection rules, and recycling infrastructure.
Where recyclability is a primary requirement, compare the conventional PET/PE laminate with a qualified PE-dominant lidding structure and verify compatibility with the selected tray and local design-for-recycling guidance.
Tray-Sealer and Roll Compatibility
Provide the tray-sealer brand and model, film width, core inside diameter, maximum outer diameter, roll weight, winding direction, seal-side orientation, eye-mark sensor, tooling layout, operating speed, temperature, pressure, and dwell time.
Line trials should evaluate web tracking, tension, cutting, seal continuity, weld strength, burst performance, leakage, contamination tolerance, print registration, anti-fog performance, tray distortion, and performance after the intended storage period.
Quality-Control Requirements
Thickness profile: Influences stiffness, roll build, tracking, sealing response, and puncture performance.
Lamination bond strength: Confirms PET and PE layers remain securely bonded.
Seal strength: Must be measured using an agreed method and the actual tray.
Seal initiation temperature: Establishes the lower limit of the operating window.
Coefficient of friction: Affects unwinding, web transport, and high-speed machinability.
Optical quality: Includes haze, gloss, gels, scratches, black spots, and contamination.
Roll quality: Includes edge alignment, telescoping, wrinkles, joints, core condition, and winding direction.
Barrier data: OTR and WVTR should be supplied when shelf-life or MAP performance is claimed.
Typical Applications
PET/PE ready-meal and prepared-food trays
Fresh meat, poultry, and seafood packs using an appropriate barrier structure
Cheese, dairy, deli, and processed-food trays
Fresh produce and salad packs with optional anti-fog
Liquid-containing foods requiring a strong permanent seal
Tamper-evident food-service and contract-packing applications
Custom printed retail food packaging
PET/EVOH/PE MAP trays using a compatible high-barrier lid
Explore HSQY's PET/PE tray range and PET/PE tray sealing film category for related packaging solutions.
Information Required for an Accurate Quotation
Tray material, layer structure, supplier, product code, drawing, or physical sample
Tray dimensions, flange width, compartments, and fill weight
Required lock-seal strength and acceptable film or tray failure mode
Food type, oil, moisture, sauce, powder, and flange-contamination risks
Filling temperature, storage temperature, distribution conditions, and target shelf life
Need for standard barrier, high barrier, MAP, anti-fog, printing, or easy peel
Tray-sealing machine brand, model, tooling layout, and commercial line speed
Film thickness, width, length, core ID, maximum outer diameter, roll weight, and winding direction
OTR, WVTR, gas mixture, residual-oxygen, leak-rate, or burst requirements when applicable
Artwork, number of colors, print repeat, eye-mark position, and registration tolerance
Required food-contact, migration, quality, and destination-market documentation
Trial quantity, annual volume, delivery destination, and requested launch date
Request Lock-Seal Film Samples and Pricing
Customization Services
Custom 0.052–0.09mm thickness and tolerance
Custom 150–900mm roll widths
Custom roll length, core, roll weight, maximum outer diameter, and winding direction
Lock-seal, hard-peel, and separately developed easy-peel structures
Anti-fog, high-barrier, MAP, low-temperature, and thermal-grade development
Flexographic or gravure printing for branding and traceability
Custom eye marks, print repeats, transparent windows, coding areas, perforation, and venting
Tray compatibility review, seal-window trials, contamination tests, and leak testing
Custom cartons, roll labels, pallet marks, and international delivery
Quality and Compliance Documentation
HSQY can provide available quality-management, inspection, and material documentation for the approved grade. Buyers should request the technical data sheet, certificate of analysis, food-contact declaration, migration or compliance reports, seal-strength method, barrier data when applicable, and roll inspection criteria.
ISO 9001 is a quality-management-system certification and should not be presented as product-specific proof of food-contact safety. SGS or food-contact claims should identify the exact report, laminate structure, food type, temperature, duration, and intended conditions of use.
![Lock-seal PET PE lidding film quality documentation]()
HSQY International Exhibitions
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2024 Mexico Exhibition
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2025 Philippines Exhibition
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2024 Paris Exhibition
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2023 Saudi Exhibition
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2024 American Exhibition
![HSQY at the 2017 Shanghai exhibition]( "2017 Shanghai Exhibition")
2017 Shanghai Exhibition
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2018 Shanghai Exhibition
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2023 American Exhibition
Production and Packing
Packaging and Delivery
Sample Packaging: Small rolls are protected in PE bags and cartons against dust, moisture, creasing, and edge damage.
Roll Packaging: Commercial rolls are wrapped in PE film and packed in cartons or another suitable export format.
Pallet Packaging: Approximately 500–2000kg per plywood pallet may be used according to roll dimensions and transport conditions.
Roll Identification: Labels can show grade, structure, thickness, width, length, lot number, seal side, winding direction, and production date.
Container Loading: Loading plans are optimized according to roll dimensions, pallet configuration, and container type.
Delivery Terms: FOB, CIF, and EXW are listed options; other terms may be discussed.
Lead Time: Generally 10–15 days after deposit and final specification approval, subject to printing, structure, quantity, and production schedule.
Frequently Asked Questions
What is lock-seal PET/PE lidding film?
It is a BOPET/PE laminate designed to create a strong permanent seal to a compatible PE sealing surface on a tray or container.
What does lock seal mean?
Lock seal means a weld-type seal that is not intended to peel open easily. Opening may tear the film or visibly damage the tray flange.
Which trays can PET/PE lock-seal film seal?
The standard PE sealant is primarily intended for PET/PE, PET/EVOH/PE, PE, or PE-coated trays with a compatible PE sealing surface.
Can it seal plain APET, CPET, or PP trays?
Not automatically. Plain PET, CPET, and PP surfaces often require different sealant chemistry. Test the actual tray before ordering.
Is lock-seal PET/PE film easy peel?
No. A lock-seal grade prioritizes permanent closure. Easy peel requires a separately formulated sealant layer.
Is standard BOPET/PE film high barrier?
Not necessarily. A defined high-barrier structure, such as PET/EVOH/PE, and measured OTR and WVTR values are required for high-barrier claims.
Can the film prevent every leak?
No film can guarantee zero leakage by itself. Seal integrity also depends on tray quality, flange contamination, tooling, temperature, pressure, dwell time, and handling.
Is anti-fog available?
Yes. An anti-fog grade can be developed for chilled foods where condensation may reduce visibility.
Is the standard grade freezer, microwave, or oven safe?
No. The current standard grade is listed as non-freezer, non-microwave, and non-ovenable. Special grades require separate testing.
Can the film be custom printed?
Yes. Printing can include logos, ingredients, instructions, barcodes, QR codes, date-code areas, and transparent product windows.
Is PET/PE lidding film recyclable?
It should not be assumed to be recyclable everywhere because it combines different polymer families. Recyclability depends on the complete structure and local collection systems.
What sizes are available?
The page lists standard widths of 180mm, 320mm, 400mm, and 640mm, a custom range of 150–900mm, thicknesses of 0.052–0.09mm, and a standard roll length of 500m.
What causes a weak weld seal?
Common causes include an incompatible tray surface, flange contamination, insufficient temperature, pressure or dwell time, uneven tooling, or poor film tension.
What is the minimum order quantity?
The current stated MOQ is 1000kg. Sample and trial quantities depend on stock, width, printing, barrier, and seal requirements.
Can I request samples before bulk production?
Yes, subject to material availability and specification. Send the tray sample, machine details, food application, film dimensions, and required seal strength.
About HSQY Plastic Group
HSQY Plastic Group supplies lock-seal PET/PE lidding films, PET/PE trays, PET/EVOH/PE high-barrier trays and films, anti-fog films, easy-peel films, plastic sheets, and related packaging products for international B2B customers.
The team can support tray compatibility, seal-strength development, film-structure selection, roll conversion, printing, anti-fog and barrier selection, samples, production-line trials, quality documentation, export packing, and international delivery.
Contact HSQY for Lock-Seal PET/PE Film
