Invention and History of the Hot Melt Glue Gun
The hot-glue gun, also known as hot-melt glue gun or hot glue device, is an indispensable tool for industry and hobbyists alike. Loved by some, loathed by others, it will nevertheless sooner or later be used by everyone. But who actually created this useful invention and how did it come about?
Polygun
George Schultz is described in an obituary in the Boston Globe as “the inventor of the first industrial hot-glue gun.” According to the Globe, he founded the company Industrial Shoe Machinery in Boston in 1954, which he sold to 3M in1973. Somewhere along the way, he invented the Polygun, the “first industrial hot-glue gun.” 3M manufactured hot-glue guns under the name „Polygun“ until they changed the name to „Scotch-Weld“ in 2006.
The earliest related patent that can be found for George Schultz was for a device for dispensing thermoplastic material. It was issued on 2nd June 1971. The diagram shows a trigger hot-glue gun, but the adhesive is held in an internal reservoir rather than being delivered by sticks. Although Mr Schultz was certainly the inventor of a hot-glue gun, he was hardly the inventor of the hot-glue gun.
Plastic extrusion gun
Perhaps the earliest prototype hot-glue gun was this plastic extrusion gun, which was created in 1949 by William R. Myers and Albert S. Tennant. The device was designed to melt and apply plastic to fishing hooks to make flies for fishing. The plastic was fed into the device in the form of ribbons rather than sticks, and no thermoplastic adhesive was used. However, many parts and components of a modern hot-glue gun existed, and later inventors often referred to the Myers and Tennant plastic extrusion gun in their patents.
As with any invention, it is perhaps pointless to attribute its invention to a single person. The hot-glue gun is based on a number of parts and components, such as the development of thermoplastics, the evolution of plastic extrusion guns, and society’s need for a portable device that achieves all of this. The hot-glue gun we all know and love includes a variety of features and improvements that were not present in the earlier versions.
In 1975, Heinz Bühnen made a trip across the “big pond” to America. In the USA, the tech-savvy son of the company’s founder Heinrich Bühnen was fascinated by something completely new: The so-called Glue Colt –a hot-melt glue gun for glue sticks. In Germany, the “Klebe-Colt” is considered the forefather of all hot-glue guns.
In 1976, he was the first to introduce this stick glue gun to the German market – an absolute innovation in Germany back then!Many years later, the practical devices have become not only an indispensable part of industry and trade, but also the DIY market. The glue guns have “grown up”. There are now devices that, compared to the beginning, can process large quantities and glue sticks with a diameter of up to 18mm.
How does a hot glue gun work?
The hot melt adhesive is pressed into the melting chamber through the rear stick feed. By pulling the trigger, the stick is pushed over the transport carriage into the heated melting chamber to be melted.
The melting chamber is heated by the adjacent heating cartridge. When the trigger is activated, the teeth of the transport carriage grab into the stick, push it further towards the nozzle and at the same time prevent it from slipping back.
The seal on the melting chamber ensures that the melted adhesive does not run back down the stick and into the device. The feeding movement of the cold stick increases the pressure in the melting chamber so that the integrated ball-spring system of the nozzle clears the way for the hot glue.
When the pressure decreases, the ball closes the nozzle again, preventing the hot melt adhesive from dripping out.