PPSU
For applications requiring repeated sterilization or very high tenacity values, Friul Filiere is of the opinion that polyphenylsulfone (PPSU), which belongs to the family of amorphous sulfonic polymers, is the most appropriate choice. At an under-load inflexion temperature of 207° this self-extinguishing material can resist to a continuous exposure to heath and to shocks. On the one hand these characteristics make polymer suited for many applications such as in the medical or in the hydrosanitary sectors and in the auto industry, but on the other hand they also render the extrusion process more complicated.
A European transformer aiming to extend their own range of products to PPSU profiles, recently contacted Friul Filiere who developed an ad hoc plant consisting of an extruder with thermoregulated cylinder, with ceramic resistors and a screw with dedicated profile.The line also presents a special distribution of the flows, innovative calibrators thermostated at high temperatures, using diathermic oil for a tight control of the temperatures, and inner cooling to assure walls stabilization.
The constructor’s collaboration with Solvay Advanced Polymers, who developed a polymer able to guarantee reliable performances at high temperatures, in addition to the required chemical and mechanical resistance, has been of fundamental importance.This line allows the extrusion of polyphenylsulfone in spite of the material extreme processing parameters: for example, temperature ranges from 350 to 400°C and fixed Vicat softening point is 230°C; moreover, polymer reaches very high fluidity levels when in the state of plastification and, therefore, becomes difficult to control.