<?xml version="1.0" encoding="utf-8"?>
<export-example>
  <doc>
    <id>819</id>
    <completedYear/>
    <publishedYear>2021</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>8</pageFirst>
    <pageLast>13</pageLast>
    <pageNumber/>
    <edition/>
    <issue>1</issue>
    <volume>Vol. 16</volume>
    <type>article</type>
    <publisherName>Japan Laser Processing Society</publisherName>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>2021-01-25</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Online pyrometry for weld seam localization in absorber-free laser transmission welding of transparent polymers</title>
    <abstract language="eng">Production of optical and medical devices makes high demands on cleanliness, precision, visual appearance and reliability. Advantages  of laser transmission welding – contactless input of energy, high  precision, no adhesives and no particle formation – can be fully  exploited for this use. For absorber-free welding, lasers emitting in the polymers’ intrinsic absorption spectrum between 1.6 μm and 2 μm are used. Focusing the laser beam with high NA provides large intensity gradients inside the specimen and enables selective fusing of the joining zone without affecting the surface. Since a molten  upper surface leads to visible and palpable irregularities and  causes warpage, the verticalexpansion of the weld seam is crucial. To meet the high quality and reliability required in the medical and optical  industry, online monitoring of the seam is necessary. The aim of  this  work is the localization and evaluation of the weld seam using pyrometry. First, the emitted thermal radiation is computed, enabling signal analysis regarding origin and spectrum. Thus, assessment of measurement spectrum and forecast of the signal in dependence on seam  shape and position is possible. Finally, welding tests with Topas 8007-04 are performed at 200 mm/s feed rate and monitored with 100 kHz. The comparison of tracked data with thin-cuts demonstrates that weld seam localization by pyrometry is possible, enabling online assessment of the process.</abstract>
    <parentTitle language="eng">Journal of Laser Micro/Nanoengineering</parentTitle>
    <identifier type="doi">10.2961/jlmn.2021.01.2002</identifier>
    <identifier type="issn">1880-0688</identifier>
    <enrichment key="BegutachtungStatus">peer-reviewed</enrichment>
    <author>Frederik Maiwald</author>
    <author>Stephan Englmaier</author>
    <author>Stefan Hierl</author>
    <subject>
      <language>deu</language>
      <type>swd</type>
      <value>Laserdurchstrahlschweissen</value>
    </subject>
    <subject>
      <language>deu</language>
      <type>swd</type>
      <value>Kunststoff</value>
    </subject>
    <subject>
      <language>deu</language>
      <type>swd</type>
      <value>Transparenz</value>
    </subject>
    <subject>
      <language>deu</language>
      <type>swd</type>
      <value>Schweißnaht</value>
    </subject>
    <subject>
      <language>deu</language>
      <type>swd</type>
      <value>Wärmestrahlung</value>
    </subject>
    <subject>
      <language>deu</language>
      <type>swd</type>
      <value>Pyrometrie</value>
    </subject>
    <subject>
      <language>deu</language>
      <type>swd</type>
      <value>Prozessüberwachung</value>
    </subject>
    <collection role="ddc" number="670">Industrielle Fertigung</collection>
    <collection role="institutes" number="FAKMB">Fakultät Maschinenbau</collection>
    <collection role="oaweg" number="">Gold Open Access- Erstveröffentlichung in einem/als Open-Access-Medium</collection>
    <collection role="othforschungsschwerpunkt" number="16316">Produktion und Systeme</collection>
    <collection role="institutes" number="TCParsberg">Technologie-Campus Parsberg-Lupburg</collection>
    <collection role="institutes" number="">Labor Laser-Materialbearbeitung (LMP)</collection>
  </doc>
  <doc>
    <id>827</id>
    <completedYear/>
    <publishedYear>2020</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst/>
    <pageLast/>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume/>
    <type>conferenceobject</type>
    <publisherName>Japan Laser Processing Society</publisherName>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>2021-01-25</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Online pyrometry for weld seam localization in absorber-free laser transmission welding of transparent polymers</title>
    <abstract language="eng">Optical and medical devices made of transparent polymers are gaining popularity because of its cost advantages. The manufacturing technology must be able to meet the high demands of these applications. Advantages of laser transmission welding – contactless input of energy, precision, no adhesives and no particle formation – can be exploited here. For absorber-free welding, lasers emitting in the polymers‘ intrinsic absorption spectrum are used. Focusing the laser beam with high NA enables selective fusing of the joining zone. Since a molten upper surface leads to visible and palpable irregularities, the lateral expansion of the weld seam is monitored in this work. Welding tests with 1 mm thick plates of COC are performed and monitored by pyrometry. Distances between seam and surface measured in thin cuts and are compared with the pyrometer signal. This shows that the localization of the weld seam is possible and proper and faulty parts can be distinguished by pyrometry.</abstract>
    <parentTitle language="deu">21st International Symposium on Laser Precision Microfabrication: Dresden, 26.06.2020</parentTitle>
    <identifier type="url">http://www.jlps.gr.jp/en/proc/lpm/20/073.pdf</identifier>
    <enrichment key="opus.source">publish</enrichment>
    <author>Frederik Maiwald</author>
    <author>Stephan Englmaier</author>
    <author>Stefan Hierl</author>
    <subject>
      <language>deu</language>
      <type>swd</type>
      <value>Laserdurchstrahlschweissen</value>
    </subject>
    <subject>
      <language>deu</language>
      <type>swd</type>
      <value>Kunststoff</value>
    </subject>
    <subject>
      <language>deu</language>
      <type>swd</type>
      <value>Transparenz</value>
    </subject>
    <subject>
      <language>deu</language>
      <type>swd</type>
      <value>Schweißnaht</value>
    </subject>
    <subject>
      <language>deu</language>
      <type>swd</type>
      <value>Wärmestrahlung</value>
    </subject>
    <subject>
      <language>deu</language>
      <type>swd</type>
      <value>Pyrometrie</value>
    </subject>
    <subject>
      <language>deu</language>
      <type>swd</type>
      <value>Prozessüberwachung</value>
    </subject>
    <collection role="institutes" number="FAKMB">Fakultät Maschinenbau</collection>
    <collection role="othforschungsschwerpunkt" number="16316">Produktion und Systeme</collection>
    <collection role="institutes" number="TCParsberg">Technologie-Campus Parsberg-Lupburg</collection>
    <collection role="institutes" number="">Labor Laser-Materialbearbeitung (LMP)</collection>
  </doc>
  <doc>
    <id>892</id>
    <completedYear/>
    <publishedYear>2020</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>686</pageFirst>
    <pageLast>690</pageLast>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume>94</volume>
    <type>conferenceobject</type>
    <publisherName>Elsevier</publisherName>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>2021-01-28</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Absorber-free Laser Transmission Welding of Transparent Polymers using Fixed Focus Optics and 3D Laser Scanner</title>
    <abstract language="eng">Laser transmission welding is a well-known joining technology for thermoplastics, providing reliable and hermetical sealing without adhesives or particle formation. The main advantages of laser-based energy input - high precision, no additional adhesive and no particle emission - are essential for medical and optical applications. To obtain sufficient absorption in visually transparent polymers, thulium fibre lasers emitting in the polymers’ intrinsic absorption spectrum are used. Optics with high numerical aperture provide large intensity gradients inside the specimen, enabling selective fusing in the joining zone. Although the basic feasibility has already been demonstrated, the welding process lacks stability and productivity.&#13;
&#13;
Aim of this work is the determination of optimized settings for a fast and reliable welding process. Thus, the interplay of process parameters as well as their impact on the seam are analysed by thermal simulations. Calculated settings are verified by welding tests with COC, PA6 and PETG, using a fixed-focus optics and a 3D laser scanner with up to 200 mm/s feed rate.</abstract>
    <parentTitle language="eng">Procedia CIRP</parentTitle>
    <identifier type="doi">10.1016/j.procir.2020.09.117</identifier>
    <enrichment key="BegutachtungStatus">peer-reviewed</enrichment>
    <enrichment key="ConferenceStatement">11th CIRP Conference on Photonic Technologies [LANE 2020] on September 7-10, 2020</enrichment>
    <licence>Creative Commons - CC BY-NC-ND - Namensnennung - Nicht kommerziell - Keine Bearbeitungen 4.0 International</licence>
    <author>Frederik Maiwald</author>
    <author>Stephan Englmaier</author>
    <author>Stefan Hierl</author>
    <collection role="ddc" number="670">Industrielle Fertigung</collection>
    <collection role="institutes" number="FAKMB">Fakultät Maschinenbau</collection>
    <collection role="oaweg" number="">Gold Open Access- Erstveröffentlichung in einem/als Open-Access-Medium</collection>
    <collection role="othforschungsschwerpunkt" number="16316">Produktion und Systeme</collection>
    <collection role="institutes" number="TCParsberg">Technologie-Campus Parsberg-Lupburg</collection>
    <collection role="institutes" number="">Labor Laser-Materialbearbeitung (LMP)</collection>
  </doc>
</export-example>
