Tego film is an adhesive sheet used in the manufacture of waterproof plywood. It is applied dry and cured by heat, which allows for high-quality laminates that are free from internal voids and warping. Tego film plywood products were used in aircraft manufacture in Germany during World War II, and the loss of the plant during a 1943 bombing raid was a serious blow to several aircraft projects. Tego film was an invention of the Essen, Germany, firm of Th. Goldschmidt AG later Evonik Industries ) .
Tego film was developed as a glue for waterproof plywood. It comprised a paper sheet impregnated with a resole phenolic resin. [1] heated, assembled between wood veneers and then compressed, a strong and waterproof laminated plywood was formed. Most plywood at this time used other adhesives, such as casein. These adhesives were generally applied as aqueous solutions, which caused warping of thin veneers and made achieving a solid laminate without risk of voids difficult. As Tego film was used dry, it gave a high-integrity result, solid, and without risk of hidden weaknesses. [2] This became an important factor in time, when it was applied to use in aircraft construction.
This adhesive was manufactured by Th. Goldschmidt AG Essen at their Wuppertal subsidiary. By 1932, it was being exported worldwide. [1]
The de Havilland Albatross airliner of 1936 had a fuselage of wooden sandwich construction; wafers of birch plywood were spaced apart by a balsa sheet and glued by a casein adhesive. This same construction, but with Aerolite, a urea-formaldehyde adhesive, achieved fame with its wartime use in the DH.98 Mosquito fast bomber. As well as being a construction of light weight and high performance, it also avoided the use of aluminium, a strategic material during wartime, and could use the skills of woodworkers, rather than those of specialised aircraft metalworkers.
When Germany attempted to emulate this aircraft with the Ta 154 Moskito, it used Tego film. [3] Flight testing and development of the first Tego film-bonded prototypes from summer 1943 to 1944 was highly successful, but RAF bombing of Wuppertal in February 1943 (incidentally one of the first Oboe-equipped Pathfinder squadron bombing raids) [4] had already destroyed the only Th. Goldschmidt AG factory producing Tego film. RAF squadron records show a second raid of 719 aircraft on the night of 29/30th May 1943 on Wuppertal with the primary objective being the Goldschmidt Tego film plant.
For the production aircraft, an ersatz cold adhesive was used, produced by Dynamit AG of Leverkusen. [5] During a test flight on 28 June 1944, [3] one of the two aircraft broke up in flight. Investigation showed that the glue left an acidic residue after curing, that in turn damaged the structure of the timber. [3] Mass production of the aircraft never took place after this.
Another case of an aircraft design whose existence was threatened by the acidic replacement adhesive was the largely wood-structured Heinkel He 162 Spatz, the winner of Nazi Germany's last significant aircraft design competition, for a Volksjäger, or "people's fighter" single-engined, jet-powered fighter-interceptor as part of the Jägernotprogramm in the concluding months of the war.
Today, four factories produce Tego film: Surfactor in Germany, AICA in Japan, Kotkamills Imprex in Finland, and Dongwha in South Korea. Dongwha has bought Kotkamills Imprex. [6] The bonding material is exported to plywood manufacturers all over the world.
Plywood is a composite material manufactured from thin layers, or "plies", of wood veneer that are glued together with adjacent layers, having both glued with each other at right angle or at 90 degrees angle. It is an engineered wood from the family of manufactured boards, which include plywood, medium-density fibreboard (MDF), oriented strand board (OSB), and particle board.
The Focke-Wulf Ta 154 Moskito was a fast twin-engined German night fighter aircraft designed by Kurt Tank and produced by Focke-Wulf during late World War II. Only a few were produced, proving to have less impressive performance than the prototypes.
Engineered wood, also called mass timber, composite wood, human-made wood, or manufactured board, includes a range of derivative wood products which are manufactured by binding or fixing the strands, particles, fibres, or veneers or boards of wood, together with adhesives, or other methods of fixation to form composite material. The panels vary in size but can range upwards of 64 by 8 feet and in the case of cross-laminated timber (CLT) can be of any thickness from a few inches to 16 inches (410 mm) or more. These products are engineered to precise design specifications, which are tested to meet national or international standards and provide uniformity and predictability in their structural performance. Engineered wood products are used in a variety of applications, from home construction to commercial buildings to industrial products. The products can be used for joists and beams that replace steel in many building projects. The term mass timber describes a group of building materials that can replace concrete assemblies.
Lamination is the technique/process of manufacturing a material in multiple layers, so that the composite material achieves improved strength, stability, sound insulation, appearance, or other properties from the use of the differing materials, such as plastic. A laminate is a layered object or material assembled using heat, pressure, welding, or adhesives. Various coating machines, machine presses and calendering equipment are used.
Papier-mâché, frequently written as paper mache, is a composite material consisting of paper pieces or pulp, sometimes reinforced with textiles, and bound with an adhesive, such as glue, starch, or wallpaper paste.
Glued laminated timber, commonly referred to as glulam, is a type of structural engineered wood product constituted by layers of dimensional lumber bonded together with durable, moisture-resistant structural adhesives so that all of the grain runs parallel to the longitudinal axis. In North America, the material providing the laminations is termed laminating stock or lamstock.
Pressed wood, also known as presswood, is any engineered wood building and furniture construction material made from wood veneers, wood shavings and particles, sawdust or wood fibers bonded together with an adhesive under heat and pressure.
Particle board, also known as particleboard, chipboard, and low-density fiberboard, is an engineered wood product manufactured from wood chips and a synthetic resin or other suitable binder, which is pressed and extruded. Particle board is often confused with oriented strand board, a different type of fiberboard that uses machined wood flakes and offers more strength.
Laminated veneer lumber (LVL) is an engineered wood product that uses multiple layers of thin wood assembled with adhesives. It is typically used for headers, beams, rimboard, and edge-forming material. LVL offers several advantages over typical milled lumber: Made in a factory under controlled specifications, it is stronger, straighter, and more uniform. Due to its composite nature, it is much less likely than conventional lumber to warp, twist, bow, or shrink. LVL is a type of structural composite lumber, comparable to glued laminated timber (glulam) but with a higher allowable stress. A high performance more sustainable alternative to lumber, Laminated Veneer Lumber (LVL) beams, headers and columns are used in structural applications to carry heavy loads with minimum weight.
In woodworking, veneer refers to thin slices of wood and sometimes bark that typically are glued onto core panels to produce flat panels such as doors, tops and panels for cabinets, parquet floors and parts of furniture. They are also used in marquetry. Plywood consists of three or more layers of veneer. Normally, each is glued with its grain at right angles to adjacent layers for strength. Veneer beading is a thin layer of decorative edging placed around objects, such as jewelry boxes. Veneer is also used to replace decorative papers in wood veneer HPL.
Wood glue is an adhesive used to tightly bond pieces of wood together. Many substances have been used as glues. Traditionally animal proteins like casein from milk or collagen from animal hides and bones were boiled down to make early glues. They worked by solidifying as they dried. Later, glues were made from plant starches like flour or potato starch. When combined with water and heated, the starch gelatinizes and forms a sticky paste as it dries. Plant-based glues were common for books and paper products, though they can break down more easily over time compared to animal-based glues. Examples of modern wood glues include polyvinyl acetate (PVA) and epoxy resins. Some resins used in producing composite wood products may contain formaldehyde. As of 2021, “the wood panel industry uses almost 95% of synthetic petroleum-derived thermosetting adhesives, mainly based on urea, phenol, and melamine, among others”.
Fiberboard or fibreboard is a type of engineered wood product that is made out of wood fibers. Types of fiberboard include particle board or low-density fiberboard (LDF), medium-density fiberboard (MDF), and hardboard or high-density fiberboard (HDF).
During the Second World War, the city of Wuppertal suffered numerous Allied air raids, primarily nighttime attacks from the Royal Air Force's Bomber Command during its Battle of the Ruhr bomber offensive. The largest raids were on the night of 29-30 May 1943, heavy enough to cause a firestorm, and on 24-25 June. The wartime-era German Feuerwehr fire brigades were ill-equipped to fight the fires. The RAF's airstrikes destroyed areas of Wuppertal's north-eastern Barmen, central Elberfeld and south-eastern Ronsdorf communities, mainly through incendiary area bombing, resulting in destructive firestorms. Other Allied aircraft also carried out numerous smaller air raids on Wuppertal. Overall, more than 6,500 people lost their lives during World War II in Wuppertal from such raids; 38 percent of the built-up urban area was destroyed.
Wood flooring is any product manufactured from timber that is designed for use as flooring, either structural or aesthetic. Wood is a common choice as a flooring material and can come in various styles, colors, cuts, and species. Bamboo flooring is often considered a form of wood flooring, although it is made from bamboo rather than timber.
Aerolite is a urea-formaldehyde gap filling adhesive which is water- and heat-resistant. It is used in large quantities by the chipboard industry and also by wooden boat builders for its high strength and durability. It is also used in joinery, veneering and general woodwork assembly. Aerolite has also been used for wooden aircraft construction, and a properly made Aerolite joint is said to be three times stronger than spruce wood.
Norman Adrian de Bruyne FRS was born in Punta Arenas Chile on 8 November 1904, and baptised on 19 March 1905 at the Anglican St. James Church, by the Rev. Edwin Aspinall. His father was Dutch and his mother English. He grew up in England, studied science at the University of Cambridge and became a physics researcher. Around 1930, he became interested in aviation. de Bruyne was the first student of the new flying school which Arthur Marshall established in Cambridge in 1931.
APA – The Engineered Wood Association is a nonprofit trade association of the United States and Canadian engineered wood products industry. They represent engineered wood manufacturers and mandate things such as quality testing, product research, and market development. APA's corporate headquarters are in Tacoma, Washington. The headquarters campus includes an office building and a 42,000-square-foot Research Center. A regional quality testing laboratory is located in Atlanta, Georgia.
Duramold is a composite material process developed by Virginius E. Clark. Birch or poplar plies are impregnated with phenolic resin and laminated together in a mold under heat and pressure for use as a lightweight structural material. Similar to plywood, Duramold and other lightweight composite materials like the similar Haskelite were considered critical during periods of material shortage in World War II, replacing scarce materials such as aluminum alloys and steel.
Molded plywood is the term for two- or three-dimensionally shaped products from multiple veneer layers that are glued together through heat and pressure in a pressing tool. The veneer layers are arranged crosswise at an angle of 90 degrees. Molded wood is used for flat furniture components such as seats, backrests and seat shells. When the veneer layers are arranged in the same direction, it is called laminated wood. It is used for armrests and chair frames. After pressing, the blanks are processed mechanically. A particular feature is the ability to produce different variations of shapes from the blanks. Due to its immense strength and low weight, molded wood is particularly suitable for interior decoration, seating furniture, bed slats, skateboards and vehicle construction.
Haskelite is the brand name of a plywood, once made by the Michigan-based Haskelite Manufacturing Corporation. It was made from waterproof glue developed by Henry L. Haskell. The moldable plywood was originally called Ser-O-Ply. It was used in the construction of various vehicles including military tanks, boats, airplanes, buses, trucks, and automobiles. The plywood was manufactured with different characteristics depending on particular needs and then given a brand name.