Plymax is a

composite Composite or compositing may refer to: Materials * Composite material, a material that is made from several different substances ** Metal matrix composite, composed of metal and other parts ** Cermet, a composite of ceramic and metallic material ...

material. It consists of a thin sheet of metal, such as

aluminium Aluminium (or aluminum in North American English) is a chemical element; it has chemical symbol, symbol Al and atomic number 13. It has a density lower than that of other common metals, about one-third that of steel. Aluminium has ...

copper Copper is a chemical element; it has symbol Cu (from Latin ) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkish-orang ...

, or

duralumin Duralumin (also called duraluminum, duraluminium, duralum, dural(l)ium, or dural) is a trade name for one of the earliest types of age hardening, age-hardenable aluminium–copper alloys. The term is a combination of ''Düren'' and ''aluminium'' ...

, that is bonded to a thicker sheet of

plywood Plywood is a composite material manufactured from thin layers, or "plies", of wood veneer that have been stacked and glued together. It is an engineered wood from the family of manufactured boards, which include plywood, medium-density fibreboa ...

, giving it strength and rigidity at a relatively low weight. Plymax was introduced during the 1920s, quickly spreading throughout Europe and the world by the 1930s. The material has been extensively used in the

aviation Aviation includes the activities surrounding mechanical flight and the aircraft industry. ''Aircraft'' include fixed-wing and rotary-wing types, morphable wings, wing-less lifting bodies, as well as lighter-than-air aircraft such as h ...

industry; various military aircraft throughout the 1930s and 1940s made use of the material. Plymax was also adopted by the automotive industry, being used on the bodies of several cars, such as the 1931 Triumph Super 9 and the articulated body of the Trojan Tasker. It has also found use within the construction industry for various large fixtures, typically partitions and doors, as well as by furniture manufacturers for various home furnishings.

History

Plymax first emerged during the early 1920s, one of the first compositions was a

-faced plywood, manufactured by Luterma. The term 'Plymax' was a registered

trademark A trademark (also written trade mark or trade-mark) is a form of intellectual property that consists of a word, phrase, symbol, design, or a combination that identifies a Good (economics and accounting), product or Service (economics), service f ...

of Venesta, which introduced the material to the British market. During the 1930s, the material was being extensively used within the architectural and construction sectors, where items such as partitions, doors, cubicals, counters, and stalls were constructed and installed throughout large buildings such as schools, hospitals, offices, and factories. According to Venesta, the typical metals used in Plymax are

steel Steel is an alloy of iron and carbon that demonstrates improved mechanical properties compared to the pure form of iron. Due to steel's high Young's modulus, elastic modulus, Yield (engineering), yield strength, Fracture, fracture strength a ...

and

; however, alternatives have included

bronze Bronze is an alloy consisting primarily of copper, commonly with about 12–12.5% tin and often with the addition of other metals (including aluminium, manganese, nickel, or zinc) and sometimes non-metals (such as phosphorus) or metalloid ...

stainless steel Stainless steel, also known as inox, corrosion-resistant steel (CRES), or rustless steel, is an iron-based alloy that contains chromium, making it resistant to rust and corrosion. Stainless steel's resistance to corrosion comes from its chromi ...

and others. Key qualities of the material are its rigidity and relatively light weight. By itself, each metal sheet lacks stiffness, when paired to the plywood to become a

, it becomes far more rigid, being similar in principle to that of a steel

girder A girder () is a Beam (structure), beam used in construction. It is the main horizontal support of a structure which supports smaller beams. Girders often have an I-beam cross section composed of two load-bearing ''flanges'' separated by a sta ...

in that the vertical web contributes little to the overall strength in comparison to the flanges set at the top and bottom, but plays a critical role in the rigidity. Due to its high strength-to-weight ratio, the material attracted the attention of various aircraft manufacturers. One notable example of its use was on the Morane-Saulnier M.S.406, a

Second World War World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...

-era fighter aircraft that was extensively used by the

French Air Force The French Air and Space Force (, , ) is the air force, air and space force of the French Armed Forces. Formed in 1909 as the ("Aeronautical Service"), a service arm of the French Army, it became an independent military branch in 1934 as the Fr ...

. Various aircraft would adopt the material for portions of their design; in one case, the interior floor of the

Handley Page Halifax The Handley Page Halifax is a British Royal Air Force (RAF) four-engined heavy bomber of the Second World War. It was developed by Handley Page to the same specification as the contemporary twin-engine Avro Manchester. The Halifax has its or ...

was composed of Plymax. Plymax was reportedly once a popular material for furniture use, although its use has somewhat diminished following the arrival of new types of processed woods.

References

{{reflist

External links

Plywood: Material of the Modern World

From cockpit to domestic interior: the Great War and the architecture of Wells Coates
Composite materials