Understanding Mechanical Properties of Thermoplastics

– The key to material selection, part design and performance

Dates: 28 & 29 September 2020
Time: 9:00-16:30 a.m.
Where: Online via MS Teams

Many professionals involved in plastic part design or materials specialists can benefit from improving their understanding of the very complex thermo-mechanical performance of polymeric materials or compounds. This knowledge is often critical considering the frequently complex failure phenomena observed in plastics (creep, impact, environmental stress cracking, plastic yielding, crazing, brittle failure). The subject is both very wide and extremely challenging. The ambition of this seminar is to provide an in depth introduction to the participants, regardless of your background or specific experience.

Two days are too little to go deep into every detail. However, they are more than enough to explore the subject quite deeply and establish a solid knowledge base for all participants. This course will prepare you for more specialized reading or training in your particular field of interest within the area.

Is no hindrance to participate this seminar if you have not attended BIMS I (Understanding Injection Molding of Thermoplastics).

Seminar’s scope
This seminar will focus on the complex mechanical performance of plastics in order to introduce the key behavior of these unique materials (visco-elasticity, non linearity, creep, impact, failure mechanisms).

The seminar is relevant for

  • Design or mechanical engineers working with plastics
  • Moulders interested in part performance
  • Professionals interested in plastic part failure mechanisms
  • FEA specialists
  • Project Managers involved in developing plastic parts
  • Research Engineers interested in polymer performance
  • Material specialists or designers wishing to improve their understanding of mechanical performance of a given class of materials (amorphous, crystalline, filled or unfilled).
  • Students involved in the field of polymers
  • Young, skilled professionals with limited experience in the field
  • Seasoned professionals looking for a fresh view on (or review of) polymer mechanical performance
  • Flow analysis specialists wishing to extend their knowledge to the field of mechanical performance
  • Customer support engineers
  • Scientists

Seminar content
The teaching material (more than 250 slides) provides an in depth introduction to the field of plastic mechanical performance. After attending the seminar, participants will have a fairly good answer to many typical questions that often come up when dealing with plastics. These questions could be:

  • Why does the modulus of plastics change so much with temperature? Why is this change so different from one polymer to another?
  • Why do amorphous polymers generally fail in a brittle way in long term tests or impact? Why do some still perform quite well in these conditions?
  • Why do we have such a thing as a “brittle-ductile” transition in polymers? What is it exactly? Why are some polymers ductile at some test rates and brittle at lower as well as higher strain-rates? Why is the test “timing” so important for plastics?
  • Why does plastic performance change so much with processing conditions, even when unfilled, and even when amorphous?
  • Why do polymers “age”? What does this mean and what are the implications on performance?
  • What are the mechanisms behind rubber reinforcement? Why is the morphology of these blends so critical? Why do we need to tailor the formulations to every specific polymer?
  • What is Yielding? What is plastic flow? Why do some polymers “shear-band” and neck in a tensile experiment, and some don’t?
  • What is the role of crystallinity in mechanical properties of plastics?
  • Why does a polymer, at the same temperature, generally fail at very different times and stress levels in short vs. long term (creep) tests? Is there a way to predict long term performance from shorter terms tests?
  • How can we measure properly the intrinsic mechanical properties of polymers at large strains without artifacts (necking) or premature failure?
  • Why do glass fiber increase modulus and strength but reduce elongation at break? What are the reinforcing mechanisms? How critical is the interfacial strength between matrix and filler? What is the optimum fiber length?
  • Why do we test plastics with and without a “notch”? What is really happening at the notch? Why do some polymers still perform when notched and some don’t?

The list of questions is very long, but the ones listed above give at least a good idea of the general approach of the seminar. The seminar focuses on giving the participants a thorough understanding, so that any new question, new problems, new polymer hopefully can be addressed and examined with the right concepts in mind.

Bring your own materials, examples or stories
Compared to the BIMS seminar on Injection Molding, this training on mechanical properties is more challenging in terms of theoretical content. We count on the attendants’ active participation to bring up examples of plastic part failures, or other mechanical related issues in order to make the session as interactive as possible. We will enrich the presentation with more and more practical examples provided by the participants as we go along. We thank you in advance for your help and material (parts, drawings, pictures, examples, good stories…).

Why attend the seminar?

  • The course is highly interactive
  • Attendance is limited, allowing for questions, group discussions and analysis of attendant problems
  • Parts drawings are welcome for open discussion when possible
  • You will get a thoroughly teaching in aspects of the polymer mechanical properties, in only two days
  • You extend your professional network
  • The teacher of the course, Dr. Vito Leo has been working some 35 years in Polymer Processing and has a well known expertise. This course offers a unique possibility to be updated, guided by Vito Leo.

Past participants have said
“Best course I have ever attended”, Gorm Dannesboe, Electro Acoustic Developer, Oticon
“Best course in a long time’, Peter Gadgaard Tønning, Materials Specialist, VELUX A/S

Further information
Dr. Vito Leo, Sentier de BOMAL 8, 1315 INCOURT – BELGIUM, bims.seminars@gmail.com, tel.: +32 478 449709, fax : +32 2 6125066.


28 September:

  • Introduction. Stress-strain and toughness concept
  • Time-Temperature effects – Ductile/Brittle transition
  • Molecular aspects – Amorphous and Crystalline polymers
  • 3D aspects of stress : the concept of triaxiality
  • The “Failure box” concept
  • Notches, Fracture Mechanics and crack growth aspects

29 September:

  • Crazing and ESCR
  • Fatigue failure in polymers
  • Creep
  • Physical ageing, moisture and UV effects on failure
  • Rubber toughening
  • Flow induced effects on mechanical response
  • Fiber filled materials

Registration fee

 DKK 8,800 +25% VAT  Members of ATV-SEMAPP
 DKK 9,300 +25% VAT  Non-members

Binding registration
Registration is binding, however substitutions are accepted at any time.