ThermoBreathe™ – Precision Air-Permeable Laminate for Heat Packs & Hand Warmers

Kae Hwa’s ThermoBreathe™, the thermal-focused tier of the FunPack series, is a highly engineered air-permeable laminate designed specifically for exothermic heat packs, medical heating patches, and pocket warmers. By acting as a precise “oxygen valve,” ThermoBreathe™ dictates the exact heating profile of the product while providing the extreme mechanical toughness required to safely contain abrasive iron powder during active use.

Lightweight
Breathable
Waterproof
Functional Breathable Heating Pack Material

ThermoBreathe™

Controlled Breathable Material for Heat-Generating Packs

ThermoBreathe breathable material for hand warmers, heating patches and steam eye masks

ThermoBreathe™ is a functional breathable laminate developed for disposable hand warmers, heating patches, steam eye masks, and other self-heating products requiring controlled environmental exchange.

Its engineered microporous structure regulates the amount of air reaching the reactive material inside the pack. By controlling this exchange, ThermoBreathe™ helps manufacturers manage activation speed, heat output, and heating duration more consistently.

The laminate also provides mechanical strength, powder containment, sealing stability, and a soft external surface suitable for converting into consumer heating products.

Controlled Air Intake Stable Heat Release Powder Containment

Engineered to Control the Heating Reaction

Air-activated heating products depend on a carefully controlled reaction between the internal heating formulation and the surrounding environment. If too much air enters the package, the reaction may accelerate and the heating duration can become shorter. If too little air enters, activation may become slow or heat output may be insufficient. ThermoBreathe™ provides engineered permeability to help balance activation speed, temperature stability, and heating duration.

Controlled Air Permeability

Regulates the environmental air entering the pack to support a predictable heating reaction.

Stable Heat Profile

Uniform membrane performance helps manufacturers maintain more consistent heat generation across the finished product.

Powder Containment

The laminate helps keep iron powder and other internal reactive materials securely contained throughout use.

Reliable Sealing

Designed for clean converting and compatibility with thermal or ultrasonic sealing processes.

Core Advantages

Controlled Low Permeability Engineered microporous pathways regulate air intake instead of allowing unrestricted environmental exposure.
Consistent Heating Performance Uniform membrane structure helps support controlled activation, temperature development, and heating duration.
Heat & Puncture Resistance The laminate is designed to withstand handling, internal particle movement, and the thermal conditions generated during activation.
Soft Consumer-Facing Surface Nonwoven surfaces provide a textile-like touch suitable for warming products used close to the body.

How ThermoBreathe™ Works

ThermoBreathe™ acts as a controlled interface between ambient air and the reactive heating formulation inside the pack.

1

Ambient Air Reaches the Pack

When the heating product is exposed to the environment, air contacts the breathable outer surface.

2

Controlled Air Passes Through

The microporous membrane regulates the rate at which air reaches the reactive heating formulation.

3

Controlled Heating Begins

The internal formulation reacts with the incoming air, generating heat while the laminate continues to regulate environmental exchange.

ThermoBreathe™ Functional Principle

“Control the air entering the pack to help control activation, temperature, and heating duration.”

Application Fit

Hand Warmers Breathable packaging materials for disposable pocket warmers and hand-warming products requiring controlled activation.
Steam Eye Masks Soft functional laminate solutions for warming eye masks designed to provide gentle and consistent thermal comfort.
Body Heating Patches Breathable materials for waist, abdominal, shoulder, back, and other body-warming patch formats.
Foot & Insole Warmers Controlled-permeability materials for compact heating products used inside footwear or attached to socks and insoles.
Additional Applications
  • Disposable pocket warmers
  • Adhesive body heat patches
  • Waist warming patches
  • Menstrual comfort heating patches
  • Foot warmers
  • Clothing-attached heating pads
  • Personal wellness warming products

Material Construction

Outer Layer

Heat-Resistant / Soft Nonwoven

Provides mechanical strength, puncture resistance, surface softness, printability, and converting support.
Functional Layer

Controlled-Permeability Microporous Membrane

Regulates environmental air intake to help control the heating reaction while keeping internal powder contained.
Optional Functional Layer

Customized Nonwoven / Film / Treatment

Additional structures can be developed according to softness, heat resistance, sealability, mechanical strength, and target heating behavior.

ThermoBreathe™ Applications

ThermoBreathe™ can be engineered for different thermal-product formats, from compact hand warmers to soft steam eye masks and body heating patches.

ThermoBreathe applications including hand warmers, heat eye masks and body heating patches

Hand Warmers

Breathable functional packaging for pocket warmers requiring controlled activation and stable thermal output.

Steam Eye Masks

Soft laminate structures for warming eye masks designed for controlled and comfortable heat delivery.

Body Heat Patches

Functional breathable materials for wearable heating patches used around the waist, abdomen, back, shoulders, and other areas.

Customizable for Your Heating System

ThermoBreathe™ can be engineered according to the heating formulation, target activation rate, desired temperature profile, heating duration, package dimensions, sealing method, and converting process.

Controlled Air Permeability
Target Heating Duration
Customized Basis Weight
Customized Width
Roll or Pre-Cut Format
Surface Printing
Thermal / Ultrasonic Sealing
Tear & Puncture Strength
Softness & Surface Feel

Specification

Brand ThermoBreathe™ (FunPack Series)
Product Form Roll
Material Breathable Film + Soft Nonwoven Fabric
Structure 2-Layer or 3-Layer Microporous Composite
Breathability Mechanism Strictly Controlled Air Permeability (Optimized for heating rates)
Barrier Properties 100% Anti-sifting (Powder block), High Thermal Stability, Extreme Resistance to Kneading and Tearing
Surface Treatment Premium Soft-Touch / Custom Brand Printing
Weight 10 - 100 gsm
Overall Width 80 - 2000 mm (Customizable)
Length 1000 - 6000 M
Application Hand warmers, heat therapy patches, toe warmers
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Redefining the Boundaries of Breathable Technology

Understanding Oxygen Permeability — The Science of Safe Heating

An air-activated heat pack generates warmth when its internal iron-powder formulation reacts with oxygen from the surrounding air, so the packaging material effectively sets the heating profile. If too much air passes through, the reaction accelerates, temperatures can rise too quickly and the heating duration becomes shorter; if too little air passes through, activation is slow and heat output is insufficient. ThermoBreathe™ uses a controlled-permeability microporous membrane to regulate this air intake, helping manufacturers achieve a predictable activation speed, stable temperature and target heating duration, while its tough nonwoven laminate keeps the reactive powder securely contained through rubbing and kneading.

Why Global OEMs Choose Kae Hwa's FunPack Series

With over 60 years of polymer expertise, Kae Hwa Industrial is a trusted partner for global OEMs in the heat pack and functional packaging industries. Operating from ISO 9001 and ISO 14001 certified facilities in Taiwan and Malaysia, we deliver consistent, customizable materials. From tuning air permeability to a target heating duration to optimizing seal strength and puncture resistance, our clean, solvent-free production processes support reliable, consistent heating performance.

About Us
Engineering Reliable Protection Through Precision

FAQ

Heat packs generate warmth through the oxidation of iron powder. Our ThermoBreathe™ laminate features microscopic pores that strictly regulate how fast oxygen can enter the pouch. By customizing the size and density of these pores, we control the speed of the chemical reaction, thereby dictating whether the pack gets very hot quickly or stays warmly consistent for 12 to 24 hours.

No. ThermoBreathe™ is manufactured using thermally stable polymer blends designed specifically to withstand prolonged exposure to exothermic heat. The material retains its structural strength and will not warp, melt, or delaminate during the product's entire heating lifespan.

Absolutely. Consumers naturally rub hand warmers to distribute the heat. We utilize a high-strength lamination process that securely bonds the functional film to a durable nonwoven fabric. This creates a tear-resistant composite that easily withstands aggressive friction without bursting or leaking the abrasive black iron powder inside.