{"id":1521,"date":"2020-06-23T16:04:53","date_gmt":"2020-06-23T14:04:53","guid":{"rendered":"https:\/\/www.2milasrl.it\/tecnologie-estrusione-soffiaggio\/"},"modified":"2021-03-17T16:49:21","modified_gmt":"2021-03-17T15:49:21","slug":"conversion-technologies-extrusion-blow-molding","status":"publish","type":"post","link":"https:\/\/www.2milasrl.it\/en\/conversion-technologies-extrusion-blow-molding\/","title":{"rendered":"CONVERSION TECHNOLOGIES FOR PLASTICS – 4: EXTRUSION-BLOW MOLDING"},"content":{"rendered":"

Today we shall talk about the Extrusion – Blow Molding technology.<\/em><\/strong><\/span><\/p>\n

We have arrived at the fourth processing technique within the context of this general information section.
\nIn this article we shall talk about extrusion-blow molding, a technique that is only apparently simple and certainly not trivial.<\/span><\/p>\n

As in the case of extrusion, the plasticizer apparatus (extruder) has a limited variety of adjustments, which requires the use of dedicated and selected materials, for their rheology in the “melt” (melted) phase and constant quality.
\nIt is a processing technique system that can be continuous or cyclical.<\/p>\n

Through an extrusion process (plasticizing screw-heating cylinder), the material is conveyed to an annular extrusion head, which produces a tubular profile called “parison”.<\/span><\/p>\n

The parison, which always has a diameter functional to the size of the final object, comes out of the head (downward) at a specific speed until it reaches the necessary length, after which it is intercepted and stapled (closed above and below) by the two halves of the mold.<\/span><\/p>\n

At that point, once the sealing of the two ends has been obtained, air under pressure is blown through a nozzle inside the parison. Thanks to the calibrated air pressure, the tube, consisting of the still hot polymeric material, by swelling and stretching adheres to the walls of the mold, assuming the final designed shape.<\/span><\/p>\n

The hot material, in contact with the mold walls thermally conditioned by the circulation of a refrigerant fluid, is cooled\u00a0 <\/span>down to extraction temperature. <\/span><\/p>\n

Once sufficient rigidity is reached, the mold opens and the part is pulled out. <\/span><\/p>\n

The top and bottom “scraps” are removed and are usually immediately re-grinded and added in a certain percentage to the virgin material directly in the extruder hopper.<\/span><\/p>\n

 <\/p>\n

The main configurations of extrusion-blow molding plants are:<\/span><\/h3>\n