Although they are essentially different, as foaming materials, they share some basic characteristics:
Porous and lightweight structure: Both contain a large number of bubbles inside, so they have a low density and are very light in weight. Shock absorption and buffering: The cell structure can effectively absorb and disperse impact energy, providing excellent protection.
Thermal insulation and sound insulation: The air enclosed in the cells is a good insulator of heat and sound, so both have certain heat preservation and noise reduction functions.
Flexibility and processability: Both possess a certain degree of flexibility and can be processed into various shapes through secondary processing such as cutting, stamping, and engraving.
Chemical resistance: Both have good resistance to common chemical substances such as dilute acids and dilute alkalis.
Their huge differences are rooted in their completely different "chemical natures", which leads to a world of difference in performance.
1. Chemical nature and temperature stability: This is the most fundamental and important distinction. The base material of PE foaming is polyethylene, a common hydrocarbon polymer plastic. This structure determines that its temperature resistance is very poor, and it usually can only remain stable in an environment ranging from -50℃ to 80℃. Once the temperature exceeds 80℃, it will start to soften, shrink and even melt. And it is highly flammable. When burning, it will melt and drip, generating flames and black smoke. The base material of silicone foam is silicone rubber, whose molecular main chain is a strong silicon-oxygen (Si-O) bond. This inorganic-organic hybrid structure endows it with extraordinary stability. Its long-term temperature resistance range can reach -60℃ to 250℃, and it can even withstand temperatures above 300℃ for a short period of time without burning. It has the property of self-extinguishing when removed from the fire source and is a naturally high-performance flame-retardant material.
2. Environmental safety and odor: The PE foaming raw material itself is non-toxic, but during the production process, additives may be added or recycled materials may be used, which may cause the product to have a certain plastic odor. Harmful gases will be released when burning. Silicone foam is renowned for its extremely high biocompatibility and chemical inertness. It is non-toxic and odorless, and is very safe even when in direct contact with food or human skin. It can pass the strictest food and medical-grade certifications such as the US FDA and USP Class VI. The residue after its combustion is mainly harmless silicon dioxide (sand).
3. Durability and anti-aging property: The organic carbon chain structure of PE foam is not resistant to ultraviolet (UV) rays and ozone. If used outdoors for a long time, it will age rapidly, become brittle and powderize, losing its performance. Silicone foam has extremely excellent weather resistance, capable of withstanding ultraviolet rays, ozone and oxidation. Even in harsh outdoor environments, it can be used for many years without significant performance degradation, and has an extremely long service life.
4. Cost: One of the greatest advantages of PE foaming is its extremely low cost. The low price of raw materials and the mature production process make it a highly cost-effective general-purpose material. The raw material cost and processing cost of silicone foam are both extremely high, and its price is usually dozens of times or even higher than that of PE foam.