Flat Refillable Ice Pack | Slim Cooling Block

BONBON Capsule Cooling Surprise | Mini Ice Pack + Real Reward Concept

A slim reusable refillable ice pack concept designed for cooler bags, lunch boxes, camping, travel, outdoor family use, and simple DIY summer cooling setups.

BONBON contest concept

This entry is designed as a capsule surprise idea with two versions:

• a mini capsule-size version that fits inside the BONBON capsule as the surprise item
• a larger real-size version that can be used as a practical reusable ice pack

The mini version represents the small capsule surprise, while the larger version shows the real functional cooling product that the surprise can unlock, represent, or be redeemed for.

Important Capsule Fit Note

This model is designed for the BONBON 2.7-inch capsule contest.
https://makerworld.com/uk/models/2566374-bonbon-2-7-inch-capsule-content-checker

The capsule checker shown in the photos was taken from the contest host/creator’s MakerWorld profile and used to test the model size.
The model was checked inside the contest-size checker to confirm the fit.

How to use

Fill it partly with water, leave enough empty space for ice expansion, freeze it, and use it as a flat cooling block.

The slim rounded shape makes it easy to place inside a cooler bag, lunch bag, backpack pocket, or near small DIY cooling setups where a flatter ice pack is more convenient than a bulky block.

This design uses a recessed filling area and a separate cap, helping keep the overall shape compact and easy to handle.

The ice pack uses an internal honeycomb-style structure to help divide the water volume into smaller sections and support the flat walls during freezing. This helps reduce deformation and stress from ice expansion while keeping the model slim and lightweight.

Important

Do not fill completely. Water expands when frozen. Always leave empty space inside before freezing.

The internal structure does not mean the model can be filled completely. It only helps support the shape and divide the water volume.

This is a 3D printed container, so always test for leaks before using it near electronics, food, bags, or temperature-sensitive items.

Leak / material preparation note

Possible leaks are not automatically caused by the model design. This is a functional 3D printed container, so water-tightness depends heavily on the material, printer condition, slicer settings, and calibration.

Before using the ice pack, make sure your filament is properly dried, especially PETG, and that your printer is calibrated for that exact material. Incorrect flow, too high or too low temperature, poor layer bonding, wet filament, under-extrusion, weak walls, dirty nozzle, or modified print settings can all cause leaks.

For better sealing, print slowly, use enough walls and top/bottom layers, check extrusion and flow calibration, and make sure the cap and filling area are printed cleanly.

Always perform a leak test before freezing or using the model in a bag, near electronics, near food, or near temperature-sensitive items.

Recommended print settings

PETG or PLA Tough Plus recommended
0.2 mm layer height
4–5 walls recommended for freezer use
25–40% infill
5–6 top/bottom layers
Print slowly for better layer bonding
Dry filament before printing, especially PETG
Calibrate flow/extrusion for your material
Use a clean build plate
Make sure the cap and filling area are printed cleanly before use
Leak test before freezing or daily use

Use ideas

Cooler bags
Lunch bags
Camping
Travel
Outdoor summer use
Picnics
Road trips
DIY fan cooling setups
Small cooling box setups

Safety note

This is a 3D printed functional prototype, not a certified food-contact or medical cooling product.

Do not use it directly with unpackaged food.
Do not use it for medical cooling.
Do not use it near electronics or important items without leak testing first.
Always test carefully before real use.

Refillable Freezer Ice Pack|Portable Cooling Block

https://makerworld.com/uk/models/2983090-refillable-freezer-ice-pack-portable-cooling-block

Slim Ice Stick Tray + Fan Mount

https://makerworld.com/uk/models/2986837-ice-tray-fan-cooling-mount-for-diy-cooling

More of my print-in-place designs: 👇