Which materials are permitted for mortar construction in fireworks displays?

The correct choice highlights the permitted materials for mortar construction in fireworks displays as paper, high-density polyethylene (HDPE), and fiberglass. These materials are chosen for their lightweight properties, resistance to shattering, and ability to withstand the pressures generated during the firing of aerial shells.

Paper can be utilized for certain types of mortar tubes since it is capable of handling the required structural loads while being easily manufactured and disposed of. HDPE is favored because it is durable, resistant to chemicals, and has a good strength-to-weight ratio, making it suitable for repeated use in mortar construction. Fiberglass is viable as well due to its strong, corrosion-resistant properties, which can enhance both performance and safety when used in the correct structural context.

Other candidate materials such as wood and plastic may not meet the structural integrity or safety requirements necessary for mortar tubes, as they can degrade under the harsh conditions of a fireworks display. Metal, while strong, could lead to additional hazards if not designed properly to mitigate the risk of explosion or failure. Glass is typically avoided in this context due to its fragility and propensity to shatter under stress, which poses significant safety risks. Thus, the combination of paper, HDPE, and fiberglass represents materials that align with safety and performance standards