Foaming Agent
There are two chemical blowing agents are frequently used in PVC foaming: azodicarbonamide and sodium bicarbonate.
Azodicarbonamide(exothermic blowing agent): It gives relatively fast foaming at a more narrow temperature range.
Sodium bicarbonate (the endothermic blowing agent): It gives longer foaming times and has a broader range of decomposition temperature.
The main use of azodicarbonamide is in the production of foamed plastics as a blowing agent. Thermal decomposition of azodicarbonamide results in the formation of nitrogen, carbon monoxide, carbon dioxide and ammonia gases, which are trapped as bubbles within the polymer to form a foamed article.
Sodium Bicarbonates are based on inorganic chemicals and generate CO2 gas. This produces foams with a much smaller cell structure, resulting in improved appearance and better physical properties.
Endothermic chemical foaming agents contain no hazardous materials so they are environmentally friendly, safe to process.
Foaming Agent is widely used in PVC board and panel, sheet and frame, PVC wood composite, shoes, artificial leather, rubber. It is commonly used for the expansion of PVC.
Foaming agents are also expected to reduce the usage of major raw materials such as plastics and rubber.