Punching of thermoplastics: a finishing operation to cut surfaces of different thickness without burrs.
Punching is a tooling operation that can be applied for two reasons: to impress marks or shapes on the article or to cut surfaces of thermoplastics.
When it is used to impress marks or shapes, punching uses a punch that applies a pressure or percussion on the article to machine, until the desired deformation is obtained.
When it is used as a cutting technique, punching uses a punch and a matrix that reproduces the shape of the cut to obtain. The punch goes down on the surface, which is placed over the matrix. Under the pressure of the punch, the surface bends until it is chopped off where the borders of the matrix are. The portion of surface removed by the action of the punch is the article. Instead in shearing, the portion of surface removed by the punch is the excess material, called shaving/chip.
Punching is a reliable cutting method: both cold and hot punching do not affect the article, neither on the temperature side nor on the chemical side. Besides, it is versatile, since it allows to cut surfaces of different thickness without burrs.
The articles that we can punch can be produced by means of injection moulding, extrusion moulding, compression moulding, thermoforming, blow moulding, suction 2D/3D (2k) and rotational moulding.
Among the articles punched by the customized machines of GS Finishing Machines there are the following, listed as an example: engine clear-air pipes, engine dirty air pipes, ducts for the air-conditioning of the interior compartment, fuel filling pipes, tanks for liquids and various other components of the engine compartment and of the interior compartment.