Single-screw extrusion

Work package (WP1): Single-screw extrusion

Objectives:
Presenting the impact of structural modifications in a single-screw plasticizing system on the homogeneity and effectiveness of plasticizing, and on the mechanical properties of extrudates obtained from thermoplastic composites with a filler and powdered nanofiller – at training courses and a seminar.
The training course will focus on:
- the impact of the length of the plasticizing system on plasticizing time,
- the impact of the design of the feed opening zone on the homogeneity and effectiveness of plasticizing,
- how the intensification of the blending process in a plasticizing system by means of introducing a rotational barrel segment into the plasticizing system design impacts the effectiveness of composite blending and plasticizing,
- how the heat generation method in the plasticizing system impacts the properties of extrudates.
During a training course, the technological parameters of single-screw extrusion will be analysed, verified and optimized, and an evaluation of composite properties will be carried out taking into account the impact of changes in:
- the plasticizing time by changing the rotational speed of the screw,
- the temperature in the particular zones of the plasticizing system,
- the depth and number of grooves in the active grooved feed zone of the plasticizing system,
- the torsional angle and torsional direction of the grooves in the active grooved feed zone of the plasticizing system,
- the rotational speed and rotation direction of the plasticizing system segment.
All activities will be discussed in detail during the seminar organized at the LUT.

Description of work:
1. Training on the design of a single-screw plasticizing system and on the technological aspects of single-screw extrusion with special attention paid to new technological and innovative solutions in the structure of the active grooved feed zone and the kinematic activation of the plasticizing system.
2. Preparation of composite blends of various composition to study the process of their extrusion. Preparation of composite blends on the basis of thermoplastics from the polyolefin group: polyethylene and polypropylene with various fillers and nanofillers, such as talc, chalk, glass microgranules, short-cut glass fibres and montmorillonite. The blends with various chemical composition will be prepared at the University of Lviv.
3. Conducting laboratory research on the modernization of a single-screw extruder aimed at determining the influence of introducing structural changes on technological problems of plasticizing effectiveness and extrudate properties. The laboratory research will allow us to assess the correctness of the adopted structural assumptions and their influence on extrusion effectiveness and the quality of the obtained extrudates for the given technological parameters.
4. Conducting research on particular properties of the types and quantities of the fillers used for specific high performance engineering materials in order to determine the optimal technological conditions for the given structure of the plasticizing system. Assessment of the influence of technological conditions and composite and nanocomposite composition on single-screw extrusion processing. Preparation of samples from the obtained extrudates for further activities related to Work Package 4.