gasfoamed

Gasfoamed is a term used to describe materials that possess a cellular structure formed by the introduction or generation of gas in a liquid or solid precursor. In practice, gasfoamed materials most often refer to polymer foams produced by gas foaming, though the concept also applies to metals and ceramics where porosity is created by gas evolution or gas entrapment during processing.

There are several approaches to creating gasfoamed materials. Physical gas foaming uses a gas, commonly carbon dioxide under high pressure, dissolved in the polymer melt or solution. Upon depressurization or cooling, the dissolved gas exsolves and forms bubbles that create a cellular structure. Techniques include batch foaming and extrusion foaming. Chemical gas foaming employs blowing agents that decompose or react at processing temperatures to release gas in situ, yielding bubbles and foam structure. This method allows foaming without high-pressure gas equipment but requires careful control of cell size and distribution. Gas-assisted foaming in polymers may involve injecting gas into a molten polymer during molding to form hollow or porous sections, which can improve processability and reduce material usage.

Properties and applications: Gasfoamed materials offer reduced density and enhanced energy absorption, thermal insulation, and acoustic damping, with properties varying by cell size, openness, and material matrix. Common applications include packaging foams, thermal insulation panels, automotive components, and cushioning materials.

Environment and safety: The choice of blowing agents and processing conditions affects environmental impact and regulatory compliance. Modern gasfoaming emphasizes low-toxicity, low-VOC blowing agents and recycling options.