Industry Standards for Passenger Transit, Rail Vehicle Specifications

Composite Panels


Balsa

Balsa is typically used in floor and partition panels. The balsa is stacked in strips of a particular size (varies) and cut across the wood grain to the desired core thickness for the final panel ("end grain balsa"). This core is typically covered with stainless steel for floor panels, or with melamine covered aluminum for interior panels.

Composite panels using Fiberglass Reinforced Plastic or Phenolic composites, are frequently used for lighter weight applications. In these examples the resin is infused, under high vacuum, into a mold containing the balsa core, fully encapsulating the balsa. Panels manufactured using this method are typically more resistant to delaminating under high moisture conditions.

Balsa panels can also be manufactured for higher strength structural applications.

Standard: MIL-S-7998 - Sandwich Construction Core Material, Balsa Wood,
Purpose: This specification covers one grade of balsa wood for use as a core material in the preparation of sandwich panel sheets and shapes. Although this specification is classified as "inactive" by the DOD for new designs, it is still applicable for Sandwich construction using balsa materials.
Criteria: Specify compliance with standard
Usage: Shall comply with applicable requirements of MIL-S-7998