Duramold
Encyclopedia
Duramold is a composite material process developed by Virginius E. Clark
. Birch plies are impregnated with phenolic resin, such as Haskelite and laminated together in a mould under heat (280°F) and pressure for use as a lightweight structural material. Similar to plywood
, Duramold and other lightweight composite materials were considered critical during periods of material shortage in World War II
, replacing scarce materials like aluminum alloys and steel.
The material has some advantages over metal in strength, construction technique, and weight. A cylinder made of duramold is 80% stronger than a cylinder made of aluminum. There are over 17 varieties of Duramold, using various quantities of birch or poplar wood, with as many as seven plies. The Duramold process has also been used to make radomes for aircraft as well as missile bodies.
The Fairchild Aircraft Corporation patented the process, designing and constructing the AT-21, (NX/NC19131) as the first aircraft made using the Duramold process. Several aircraft used Duramold in parts of their structure but the largest aircraft manufactured with the process is the Hughes H-4 Hercules
, which was almost completely built with Duramold in very large sections. Hughes purchased rights to the process for this use.
Virginius E. Clark
Virginius Evans Clark was an American World War I engineer. Clark designed the 1922 Clark Y airfoil used by many early aircraft.-Biography:...
. Birch plies are impregnated with phenolic resin, such as Haskelite and laminated together in a mould under heat (280°F) and pressure for use as a lightweight structural material. Similar to plywood
Plywood
Plywood is a type of manufactured timber made from thin sheets of wood veneer. It is one of the most widely used wood products. It is flexible, inexpensive, workable, re-usable, and can usually be locally manufactured...
, Duramold and other lightweight composite materials were considered critical during periods of material shortage in World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
, replacing scarce materials like aluminum alloys and steel.
The material has some advantages over metal in strength, construction technique, and weight. A cylinder made of duramold is 80% stronger than a cylinder made of aluminum. There are over 17 varieties of Duramold, using various quantities of birch or poplar wood, with as many as seven plies. The Duramold process has also been used to make radomes for aircraft as well as missile bodies.
The Fairchild Aircraft Corporation patented the process, designing and constructing the AT-21, (NX/NC19131) as the first aircraft made using the Duramold process. Several aircraft used Duramold in parts of their structure but the largest aircraft manufactured with the process is the Hughes H-4 Hercules
Hughes H-4 Hercules
The Hughes H-4 Hercules is a prototype heavy transport aircraft designed and built by the Hughes Aircraft company. The aircraft made its only flight on November 2, 1947 and the project was never advanced beyond the single example produced...
, which was almost completely built with Duramold in very large sections. Hughes purchased rights to the process for this use.