Pressure Forming

1
Understand Pressure Forming with Simple Science

• This is a technology that is used by almost all
  the industries very frequently and hence, there
  lies several ways to explain same. As learnt
  above, the easiest definition is when heat and
  pressure are both used together to melt plastic
  and help it gain a new shape of a new product.
  But if you consider a complex definition of
  Pressure Forming then you will learn that
  thermoforming is a type of pressure forming only
  but except for the procedures that mechanically
  bend or give a shape to a material. All in one,
  pressure forming is a procedure that is run over
  the stiff forming temperatures of the sheet,
  which are tough to mold. In this procedure, air
  pressure is released on the free side of the
  plastic sheet and with the help of the vacuum and
  the mold the plastic is given the desired shape.
  
• In short, you can also understand it the way that
  Thermo Forming is similar to pressure forming.
  This generic term has been given to all the
  forming technologies that are used over plastic
  material. It falls within the oldest methods that
  are used to form two or more pieces of plastic.
  Of course, it is a bit different from the modern
  pressure forming methods, which have been filled
  in with more innovation and newer strategies
  today.
• Thermoforming came into existence during the
  1870's in the USA. The brains behind this
  innovation were of John Wesley Hyatt, the father
  of modern plastic processing and Charles
  Burroughs. They once folded the thin skived
  sheets of celluloid plastic into tubes and
  inserted those into steel molds and heated them
  with steam under pressure. They noticed that
  under the effect of steam, the celluloid sheeting
  got soft. They then eventually forced the sheets
  to take some mold shape, which when were removed
  and allowed to cool in water to harden the
  plastic resulted into newer shaped plastic.
• This procedure is generally a two-step procedure.
  In the first step, the plastic sheet is drawn
  against the mold surface and all the air from the
  mold cavity is pulled by the vacuum. In the
  second step, with the help of a metal box (called
  the pressure box), a seal is created between the
  sheet and the mold service. Then, the air
  pressure is put into it to force the plastic
  sheet into the mold, copying the entire surface
  and shape. Once the part has cooled, the air is
  released and the pressure box is unclamped from
  the sheet to remove the part. , and the part is
  removed.