KENT supplies insulated box liners in foam and metallized bubble constructions for shipping cartons. Fitted inside an outer box, they add an insulation layer between the contents and the surrounding environment. Selection starts with carton dimensions, payload volume, coolant layout and top-closure space.
Key Buying Points
Foam liners come in 2D and 3D formats; bubble liners offer bottom-gusset or four-side heat-sealed designs.
Size around the carton's usable internal length, width and height, allowing for insulation, contents, coolant and closure.
Confirm the material, thickness, closure and bulk-order requirements against the selected design and approved sample.
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Insulated Box Liner Options for Your Cartons
Start with the liner format, then review its material construction. The terms 2D and 3D describe the shape, while foam and bubble describe the insulation structure.
The 2D foam liner uses a flat format positioned and folded according to its design. The 3D version has a formed bag shape, with length, width and height checked against the carton interior.
Try the selected format in your existing carton. Check the base, side coverage, top overlap and access for loading your contents.
Bottom-Gusset and Four-Side Heat-Sealed Bubble Liners
Bubble liners are available in bottom-gusset or four-side heat-sealed designs. A bottom gusset provides room to open the base; a four-side heat-sealed design needs its finished dimensions and seam allowances checked against the drawing.
Dimension conventions and fitting methods can differ. Include both your carton measurements and the required liner design when requesting a quotation.
Materials and Insulation Structures
Insulation Cores with MPET or PE Facing Films
Foam box liners combine an insulation core with facing films. The 2D options are MPET/foam/MPET or PE film/foam/PE film. The 3D options are MPET/foam/PE film or MPET/foam/MPET.
Confirm the core material, facing combination and thickness for your order. If your specification requires EPE, PU or another named material, include that requirement in your enquiry.
MPET refers here to metallized film. If your specification calls for “foil box liners,” clarify whether you require metallized film or actual aluminum foil so the material can be matched correctly.
Bubble liners combine metallized film with single- or double-bubble-layer constructions. The bubble layer also provides some cushioning during contact and handling; assess the required protection with your actual packing arrangement.
This range includes peel-and-seal flaps. Load the contents, fold the flap according to the selected design, remove the release liner and press the adhesive closed before sealing the outer carton. Confirm foam-liner closures separately.
Sizes, Thickness and Usable Packing Space
Foam Liner Specifications
Item | 2D Foam Liner | 3D Foam Liner |
|---|
Format | Flat format positioned according to the design | Formed bag shape with length, width and height checked |
Material options | MPET/foam/MPET; PE film/foam/PE film | MPET/foam/PE film; MPET/foam/MPET |
Catalog thickness references | 25 mm; 35 mm | 25 mm; 35 mm |
Custom thickness | Confirm for the selected construction and requirements | Confirm for the selected construction and requirements |
Sizing | Flat dimensions, carton fit and top-fold allowance | Formed liner length, width, height, carton fit and top allowance |
Top closure | Confirm for the specific design | Confirm for the specific design |
Thickness note: The catalog lists 25 mm and 35 mm as reference options. Confirm the core, inclusion of facing films, measurement state and tolerance during quotation and sampling.
Bubble Liner Specifications
Item | Metallized Bubble Liner |
|---|
Material options | MPET/bubble; MPET/bubble/MPET; MPET/bubble/bubble/MPET; MPET/bubble/bubble |
Format | Bottom gusset or four-side heat sealing |
Closure | Peel-and-seal flap, confirmed for the selected configuration |
Bubble and film specifications | Confirm bubble size, film gauge and finished thickness for the construction |
Sizing | Finished dimensions, gusset or seam allowances and top-flap space |
Carton fit | Confirm against usable internal length, width and height |
Carton Internal Dimensions, Payload and Coolant Allowances
Provide your carton's usable internal length × width × height, with units, plus the packed product dimensions, weight and coolant arrangement. Outer carton measurements cannot substitute for usable internal dimensions.
Insulation, seams, base construction and top folds all take up space. Trial-pack the actual contents and planned coolant to check that the carton closes properly without excessive compression.
How to Fit and Pack Insulated Box Liners
Fit the Liner, Load the Contents and Close the Pack
Position the liner: Fit it inside the carton according to the design. Open the base and sides, checking corners and top allowance.
Load the contents and suitable coolant: Follow the packing layout, with appropriate separation where the contents should avoid direct coolant contact.
Close the liner: Cover or fold the foam version as specified. For a peel-and-seal bubble liner, fold the flap and press the adhesive closed.
Close the carton: Check load stability and closure, then seal the outer box.
Keep the packing method consistent with the approved sample, especially coolant placement, top folds and closure.
Shipping Applications and Temperature Requirements
Thermal box liners can form part of a shipping pack for temperature-sensitive goods. For prepacked food, delivery assortments or other contents, select the construction around the required temperature range, transit time, ambient conditions and starting product temperature.
Evaluate insulated shipping box liners together with the payload, coolant, carton and closure. Where a temperature range or hold time is required, test the intended complete packing configuration.
Keep food in suitable primary packaging. Review lining materials and relevant requirements separately if direct food contact is intended. Explore the KENT thermal packaging range for other bag formats.
Custom Sizes, Samples and Bulk Orders
Send requirements for carton fit, liner format, material combination, insulation thickness and closure. Feasible configurations are confirmed for the selected design. Include drawings, current-pack photos or packaging specifications so dimension conventions can be checked.
Sample Fit Checks and Complete-Pack Validation
Use samples to check carton fit, seams, top closure and packing operations. For thermal validation, assess the complete pack using the planned contents or a suitable surrogate, coolant and shipping conditions.
Submit your needs through our packaging sample service. Sample type, charges, freight and preparation time are confirmed for your request.
MOQ, Lead Time and Packing Details
MOQ and lead time depend on dimensions, construction, quantity and customization. Confirm units per carton, outer-carton dimensions, gross and net weights, and delivery destination alongside the quotation to assess purchasing and freight costs.
Have your carton dimensions and target quantity ready? Send your specifications for a bulk quotation.
Frequently Asked Questions
1. What Carton Measurements Do You Need to Size a Liner?
Provide usable internal length, width and height with units, plus packed product dimensions, weight and coolant details. On drawings, identify internal versus external measurements and the dimension order so carton size, liner size and usable packing space can be distinguished.
2. How Do I Choose Between 2D and 3D Liners?
The 2D version uses a flat format, while the 3D version has a formed bag shape. Choose around your carton, payload and packing process. Use samples to check the base fit, top coverage and whether the outer carton closes properly.
3. What Is the Difference Between Foam and Bubble Box Liners?
Foam liners use an insulation core with facing films; bubble liners combine metallized film with bubble layers. Compare space requirements, closure and complete-pack performance. A material name alone does not establish how long a pack will maintain temperature.
4. How Does Liner Thickness Affect Usable Packing Space?
Insulation occupies space at the base and sidewalls, while seams and top folds also affect capacity. Actual space requirements depend on compression and liner design. Check the fit using your carton, contents and coolant before confirming dimensions.
5. How Long Can Insulated Box Liners Maintain Temperature?
Hold time needs to be established for the complete pack. Starting product temperature, payload, coolant, ambient conditions, transit time and closure affect the result. Provide your target temperature range and shipping conditions to guide liner selection and testing.
6. Do Insulated Box Liners Still Need Gel Packs or Other Coolants?
Coolant requirements depend on the contents and shipping conditions. The liner adds insulation, while coolant supplies thermal capacity as required by the packing design. Its type, quantity, conditioning and placement should suit the target temperature range and the contents.
7. Which Liner Options Have a Peel-and-Seal Closure?
The metallized bubble liner range includes peel-and-seal flaps. Top closures for foam liners are confirmed for the specific design. Check adhesive placement, flap allowance and the closing method when agreeing on your specification.
8. Can You Make Liners to Fit Our Existing Cartons?
Send your carton internal dimensions and packing layout for a fit review. Final liner dimensions need to allow for insulation, seams, coolant and top closure. Confirm the proposed size through a drawing and sample before ordering.
9. Can We Check Samples Before Placing a Bulk Order?
You can request samples to check dimensions, material, closure and packing operations. Where temperature targets apply, validate the complete pack as well. Sample type, charges, freight and preparation time are confirmed for the project.
10. How Are MOQ and Lead Time Confirmed?
Send the liner format, dimensions, material requirements, quantity and destination. KENT will confirm MOQ, sampling arrangements and production lead time for that configuration. Custom orders follow the agreed specification and order conditions.
Request a Custom Box Liner Quote
Send your carton internal dimensions, payload size and weight, target temperature range, transit time, coolant plan, quantity and delivery destination. Include current-pack photos or drawings if available so the liner format, materials and sampling requirements can be reviewed.
Request Your Custom Box Liner Quote from KENT
