The selection of lining material for thermal bags should take into account heat insulation performance, safety, cost and environmental protection. Common materials can be divided into the following categories. Analyze their characteristics and application scenarios from a technical perspective:
I. Mainstream Inner Tank Materials and Characteristics
(aluminum-coated film
Structure: Generally composed of PET (polyester film) + aluminum foil +PE (polyethylene), forming a multi-layer reflective structure.
Heat insulation: aluminum foil has a smooth surface that reflects over 95% of infrared radiation. Combining with the air layer in the middle to block heat conduction, the dual heat insulation mechanism of ``reflection + blocking"is formed.
Strengths:
Excellent heat insulation performance. At normal temperatures, the internal temperature may fluctuate up to 5°C within 24 hours (for example, in a six-hour a 6-hour heat preservation test, the aluminum foil lining can maintain the temperature over 80% of the initial value).
It's lightweight approximately 2.7g/cm3, only athird of foam) and easy to carry around.
Waterproof and moisture-resistant, with direct access to food, it meets FDA food-grade standards.
Application scenarios: Takeout thermal bags, portable picnic bags.
2.EPE Pearl Cotton
Structure: Closed-cell foaming structure with individual bubbles.
heat insulation: The thermal conductivity of the air inside a bubble is extremely low, and heat insulation is achieved by blocking heat conduction.
Strengths:
It has excellent buffering performance, absorbs impact and protects fragile items such as medicines in glass bottles.
Its low cost (raw materials cost about a third of the price of aluminum foil) makes it suitable for mass production.
It has the characteristics of recyclability and good environmental protection.
Application scenarios: Fresh Food Cold Chain Packaging, Electronics transport boxes, Industrial Parts Shielding.
3.XPE cross-linked polyethylene foam
Structure: Chemical crosslinking modified Closed-cell foaming material with high bubble density.
Thermal insulation: Similar to EPE, but with crosslinked structures that improve the material's strength and temperature resistance (-40°C to 100°C).
Strengths:
heat insulation performance is superior to EPE (thermal conductivity of approximately 0.032 W/(m. K)). 0.038 W/(m.K)).
Wear and puncture resistant, suitable for reuse scenarios.
It can be processed into complex shapes to meet customized requirements.
Application scenarios: High-end cold chain logistics boxes, medical vaccine transportation boxes, outdoor insulation bags.
4.AirPods (air cushioning material)
Structure: Independent air columns is made of multi-layer co-extruded films and expands to form a buffer layer.
Heat insulation: The air layer inside the column blocks blocks heat conduction, while the layers reflect some of the radiant heat.
Strengths:
It has extremely strong buffering performance (it can withstand more than 100kg of impact) and is suitable for transport of precision instruments.
It is small and, when not inflated, less expensive to transport.
Customizable design (such as density and thickness of column arrangement).
Application scenarios: Wine Cold Chain Packaging, semiconductor equipment Transportation, Art protection boxes.
