Heinz Gross

Director

Speaker Biography:

Heinz Gross received a PhD in mechanical engineering at RWTH Aachen.

He has over 39 years’ experience in research and development of extrusion processes and of extruded products. He owns several worldwide granted patents for advantageous extruded products and for novel extrusion downstream equipment. Among others, he has invented membrane dies, flex ring heads, and mixing spider heads. In 2014 he received the James Lindsey White Innovation Award granted by the Polymer Processing Society (PPS) for an outstanding innovative development in the field of polymer processing technology.

His employment history is as follows:

Röhm GmbH, Darmstadt, Germany, 1983 to 1993

Head of Research development and application engineering of the business unit for technical products.

Dr. Groß Kunststoff-Verfahrenstechnik, Roßdorf, Germany, 1993 to 2018,

Director

Development of improved downstream equipment and of novel extrusion dies

Presentation Description:

Dynamically shaping the wall thickness of the parison around its circumference is the solution to reduce objectionable wall thickness differences in blow molded parts and to reduce material and energy consumption. Since centuries the PWDS system was the only available solution to modify the thickness of the parison over its circumference while it is discharged. But the PWDS system suffers from many limitations which prevent to alter the wall thickness of the parison in a way which is tailored to the needs of the article that has to be blow molded. The problem with the PWDS system is the fact that a steel ring has to be deformed. That is why its use is limited to die diameters of 50 mm or wider. Only four actuators can be used, that have to be arranged in an angle of minimum 90 degrees. The deformation of the die is limited and it has to follow the natural bending curve of the steel ring. Furthermore the PWDS system is a rather complex solution that has to be maintained regularly that might fail during production and that is rather expensive. As in the past no better system was available blow molders have accepted these deficiencies. Now the innovative patented GWDS system has overcome all the enumerated drawbacks. It is extremely cost efficient as it needs no special actuators. It uses a solid die and a solid pin which must not to be maintained and which cannot fail during its use. Over centuries blow molders have also accepted that small blow molded articles have more or less thickness variations in the region of the weld line. This because no solution was available for small blow molded articles to dynamically shape the wall thickness of the parison over its circumference. Now this can also be easily avoided when using a GWDS die. The universal GWDS solution is a convincing, innovative, easy solution to tailor the wall thickness of the parison in a way as it is afforded to further reduce objectionable wall thickness differences in blow molded articles.

In the meantime artificial intelligence is used everywhere but nearly all blow molders accept that it is still state of the art that blow molding machines must be adjusted manually. Innovative autarkic dies negotiate even that problem. They enable a very sensitive goal-oriented adjusting of the relative position between the pin. The adjustment is initiated from the control cabinet of the machine. The once found optimal situation in every individual die can be stored in the computer of the machine and can be exactly reproduced at any time. 

The possibilities to fabricate metal parts have been broadened in the last centuries by inventing generatively fabrication methods. The borders of realizing advantageous complex geometries have been shifted by far. Blow molders can profit in a great deal from the advanced scope of design which are opened up by the generative selective laser melting (SLM) fabrication method. Innovative novel head deigns for blow molding can be realized which open up improved processing possibilities.

The innovative solutions will be explained in detail and results which have been achieved will be presented.