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plastic |
production process |
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Intraplás renders its customers know-how and
service excellence that evolved not only from experience but also from our
capacity to integrate a production process that includes
extrusion, printing and
thermoforming. These three
technologies comprising Intraplás' production process are briefly described below.
EXTRUSION
Extrusion is the most common plastic manufacturing process, if determined by annual polymer consumption by each thermo-plastic manufacturing method.
Extrusion consists in running the pressurised material through an orifice, with different degrees of complexity, to give the material the same transversal gauge as the orifice.
The extrusion of thermoplastics is not that simple. During processing the polymer is melted in a cylinder and later cooled in a calender. This process is normally continuous and used to produce strips, plastic film, plastic sheeting, etc..
THERMOFORMING
 Thermoforming consists
in heating a sheet of thermo-plastic above Tg (for amorphous polymers) or near the melting point (for semi-crystalline polymers), and then forcing it against mould walls. In contact with the mould that is cooled by a circulating fluid (normally water), the material cools down and retains the mould's shape. Lastly, the mould is opened and the part is removed.
Thermoforming of plastics is currently very common in
food packaging.
PRINTING
Printing is a finishing technology that can be performed in various ways using very different techniques. The
dry offset printing process is used at Intraplás.
Dry Offset
The dry offset process consists of reproducing images and text on the surface of plastic parts to make them more attractive to the consumer.
The process starts by preparing the metal negative plates with a photopolymer relief of the motif to be printed, made from an image.
The image is broken down into its constituent colours, and one plate is produced for each of the image's colours (our machines allow up to 8 different direct colours to be used).
After the image has been broken down according to colour, the plates are produced. Each plate contains the relief of the part of the image corresponding to the respective colour. Each plate is, therefore, associated with a specific
colour.
After each plate has been prepared, it is mounted in the machine's respective plate-holder drum. As the drums rotate each plate touches the inkpad containing the ink colour of the image section on the respective plate. After having passed over the inkpads, the plates in the plate-holder drums transmit their ink to a rubber pad on another drum which also rotates and tangentially touches all the plate-holder drums. This pad, after having received the ink from all the plates comprising the image to be printed, touches the package's surface and deposits all the collected ink, thereby producing the printed image.
Packages are then sent to an area where they are exposed to UV light bulbs that dry the ink.
This process is used to print on packages, cups and lids produced by thermo-shaping.
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