Chemnitz University of Technology Department of Mechanical Engineering Professorship of Plastics Engineering

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Chemnitz University of Technology Department of Mechanical Engineering Professorship of Plastics Engineering – Prof. Michael Gehde

speaker: M.Sc. Karoline Hofmann1

co-author: Prof. Dr.-Ing. Michael Gehde1

1 Professorship of Plastics Engineering, Chemnitz University of Technology, Germany

PPS Dresden ∙ 29th June 2017 ∙ M.Sc. Karoline Hofmann www.kt-chemnitz.de JOINING POLYCARBONATE – MANUFACTURING AND EVALUATION OF TRANSPARENT JOINTS USING AN INNOVATIVE OBJECTIVE TEST METHOD

PPS Dresden ∙ 29th June 2017 ∙ M.Sc. Karoline Hofmann 1 www.kt-chemnitz.de contents

1.introduction 2.methodology 2.1 material 2.2 joining process 2.3 test methods 3. results

4. conclusion

powerpoint [1] [1] PPS Dresden ∙ 29th June 2017 ∙ M.Sc. Karoline Hofmann 2 www.kt-chemnitz.de motivation

characteristics applications problem solution

Optical media 100 % Medical 100 % devices Building and 80 % Construction

Electronic 80 %

Automotive 75 % [3] Vetrotech Domestic Appliances 65 %

Leisure and 60 % Safety Other 50 %

Packaging 15 %

bisphenolA unique non unique [4] Motorradland GmbH [5] Nexi [2] [2] PPS Dresden ∙ 29th June 2017 ∙ M.Sc. Karoline Hofmann 3 www.kt-chemnitz.de motivation

characteristics applications problem solution

problem: • large - scale laminated safety glass • dimensional limitation of the

extrusion process [7] research aim: • joining PC sheets • good optical and mechanical properties • restoring the transparency

• „invisible“ connections GmbH

• finding a suitable test method [6] Silatec

[6] [6,7] [6,7]

PPS Dresden ∙ 29th June 2017 ∙ M.Sc. Karoline Hofmann 4 www.kt-chemnitz.de methodology

• basic material tests (K.-F.-Titration, DSC, tensile-/bending test ) material

• variation of heating time welding process

• mechanical and optical testing test

• mechanical results results • optical results

PPS Dresden ∙ 29th June 2017 ∙ M.Sc. Karoline Hofmann 5 www.kt-chemnitz.de welding process

radiator joining radiation drying time heating distance pressure power 80°C time [s]

2 mm 4 mm 30 – 60 s 12 mm

[8] R. Dietz

welding base material test results process

PPS Dresden ∙ 29th June 2017 ∙ M.Sc. Karoline Hofmann 6 www.kt-chemnitz.de mechanical results PC 2 mm

bending stress [MPa] tensile stress [MPa] base material bending stress [MPa] base material tensile stress [MPa] 160

140

120

100

stress [MPa] stress 60

0 40 45 50 55 60 heating time [s]

welding base material test results process

PPS Dresden ∙ 29th June 2017 ∙ M.Sc. Karoline Hofmann 7 www.kt-chemnitz.de sample preparation

saw removal [10] grinding and finishing polishing

• removing the • removal of the • stick the • finishing specimen out welding seam specimens to a surface using of the center of • forming a flat cylindrical a diamond the welded and even sample holder suspension plates surface • grinding and polishing in several steps • repeat on other side

welding base material test results

process [10] Struers [10]

PPS Dresden ∙ 29th June 2017 ∙ M.Sc. Karoline Hofmann 8 www.kt-chemnitz.de optical tests – utilized devices

photography photoelasticity using a polariscope microscopy

[10] Sony [11] Olympus

welding base material test results process

PPS Dresden ∙ 29th June 2017 ∙ M.Sc. Karoline Hofmann 9 www.kt-chemnitz.de light intensity measurement

5 3 1. laser 6 2. specimen 2 3. sample holder 1 4. micrometer 4 5. aperture 6. photoelectric cell

• new innovative test method M • enables qualitative and objective evaluation • comparability of all samples B • detection of defects, joining dimensions and structural changes

welding base material test results process

PPS Dresden ∙ 29th June 2017 ∙ M.Sc. Karoline Hofmann 10 www.kt-chemnitz.de results light intensity measurement PC

• interpretation of the results from the light intensity measurement • reference (air) = 150,986 Ω ≙ 0,0331 A

0,035

0,03

0,025

[A] 0,02

0,015 current 0,01

0,005

0 0 1,5 3 4,5 6 7,5 9 10,5 12 13,5 15 M - measuring distance [mm]

reference (air) t2_50h= 50s t2_55h= 55s t2_60h= 60s

welding base material test results process

PPS Dresden ∙ 29th June 2017 ∙ M.Sc. Karoline Hofmann 11 www.kt-chemnitz.de results light intensity measurement PC 2mm

reference (air) t2_50h= 50s t2_55h= 55s 2_60th= 60s 0,035

0,03

0,025

[A] 0,02 th=50s ≙ 4,92 mm

0,015 current 0,01

0,005 A1 A1 A2 A2 00 03 4 5 6 7 8 9 10 11 12 13 th=55s ≙ 6,44 mm measuring distance [mm]

A1 A2 퐴1퐴2≙ th= 50 s ≙ 5,1 mm B 6,63 mm 퐴1퐴2≙ th= 55 s ≙ 6,4 mm

welding base material test results process th=60s ≙ 6,63 mm

PPS Dresden ∙ 29th June 2017 ∙ M.Sc. Karoline Hofmann 12 www.kt-chemnitz.de conclusion

• mechanical results comparable to the basic material strength • the higher the tested heating times, the better the results • restoring the initial transparence is possible • production of transparent connections is possible • evaluating the transparency using a new and innovative test method • correlation between the test methods

welding base material test results conclusion process

PPS Dresden ∙ 29th June 2017 ∙ M.Sc. Karoline Hofmann 13 www.kt-chemnitz.de further investigations

cooling conditions joining radiator pressure power

heating affected residual time areas stresses

• validation of the new test method • further parameter studies • concepts for more efficient surface finishing

welding base material test results conclusion process

PPS Dresden ∙ 29th June 2017 ∙ M.Sc. Karoline Hofmann 14 www.kt-chemnitz.de sources:

[1] http://www.quickslide-powerpoint.com/de

[2] http://www.bisphenol-a-europe.org/en_gb/polycarbonate-a-major-contributor-to-europe-s-economy-and-quality-of-life

[3] https://www.ais-online.de/firma/vetrotech-saint-gobain/produktinformation/sicherheitsglaeser-protect-vetrogard-und- polygard/17054205/1/

[4] http://www.ebay.de/itm/Visier-HJC-HJ20M-fur-Helm-FG-17-IS-17-stark-getont-HJ-20-M-dark-tinted-/282331272338?

[5] https://www.amazon.de/Nexi-Fahrradbrille-verschiedenen-Gestellfarben-modellabh%C3%A4ngig/dp/B016WB6Z54

[6] https://www.silatec-securityglass.com/references/villa/

[7] http://www.raumprobe.de/material/silatec-sicherheits-und-laminatglastechnik-gmbh/silatec-sicherheitsglas-b1eh1/datenblatt/

[8] Dietz, R. Aufbau der Infrarotschweißanlage, TU Chemnitz, 2016

[9] http://www.spectrographic.co.uk/shop/refurbished/recent-sales-refurbished/struers-tegrapol-21/

[10] http://www.chip.de/artikel/Sony-a77_II-Alpha-77-II-DSLR-Test_70313035.html

[11] N. N.: Digitalkamera-Mikroskop / Polarisation / für AnalyseBX51, 2016. http://www.olympus-ims.com/de/microscope/bx51p/, abgerufen am: 01.10.2016

PPS Dresden ∙ 29th June 2017 ∙ M.Sc. Karoline Hofmann 15 www.kt-chemnitz.de Thank you for your attention

contact details: Chemnitz University of Technology M.Sc. Karoline Hofmann Mail: [email protected] Phone: +49 (0) 371-531 33783 Web: www.kt-chemnitz.de

PPS Dresden ∙ 29th June 2017 ∙ M.Sc. Karoline Hofmann 16 www.kt-chemnitz.de