Ph.D. Student at IT Sligo - Department of Mechanical and Manufacturing Engineering

Research Topic

“Laser Transmission Welding of Semi-crystalline Polymers and its Composites”

PEM would like to introduce you to Ms. Foram Dave, one of our PhD Student Researcher’s, Foram tells us about herself, her studies and her research topic “Laser Transmission Welding of Semi-crystalline Polymers and its Composites”, in this ‘Meet the Team’ showcase;   


Foram believes that the biggest prerequisite for brilliance is the inclination to learn. Only intensive and comprehensive research work in her field of interest will put her on the right track, to gain in-depth knowledge of advanced technology, and to achieve higher academic standards.


Polymer Science is a multidisciplinary area in which physics, biology, chemistry, and engineering are blended with an aim to improve the quality of human life. It also improves the technological advancements in many fields. It was this that made Foram take the Rubber Technology field during her undergraduate studies at L.D. College of Engineering, Ahmedabad, Gujarat, India (2009-2013). Foram’s Bachelor of Engineering thesis was based on the “Development of Pneumatic Rubber Coated Fabric Diaphragm”.


To deepen her knowledge in polymers, she pursued master studies in Polymer Science and Technology from the Indian Institute of Technology, Delhi (2014-2016). Her master thesis was about microbial degradation of the blends, where functionalized poly (lactic acid) was blended with poly (acetic acid). These blends are used for various biomedical applications such as regeneration and repair of bone and cartilage tissue.


Foram is deeply interested in Polymer Science as a lifelong career. She was recruited by Robert Bosch Engineering and Business Solutions Pvt. Ltd. in the automotive electronics department as a Senior Engineer (2016-2018). Dealing with sealants, thermal interface material, conformal coatings, and potting of an electronic control unit in the automobile sector. Gradually, she developed a strong ability to perform as an independent researcher as well as a team player.


Foram started her PhD at IT Sligo (Department of Mechanical and Manufacturing Engineering) in September 2018 under Dr David Tormey (Engineering) and Dr Richard Sherlock (Science). Her research topic is “Laser Transmission Welding of Semi-crystalline Polymers and its Composites”. It is an industrial based project along with Abbott diagnostics.

Laser Transmission welding (LTW) of polymers is a technique that is used to join polymeric components of varying thickness and configuration using laser sources such as a diode, Nd: YAG, CO2, etc. They are widely used in industries like automotive, microelectronics, aerospace, medical, packaging, optoelectronics, microsystems, etc. This technique requires one part to be transmissive to a laser beam and the other part to be absorptive to the beam as shown in Figure 1. The two parts are put under pressure while the laser beam moves along the joining line with defined parameters such as power, scanning speed, spot diameter, etc. resulting in diffusion of the two melted surfaces. The key advantages of LTW considering the industrial prospective are the reproducibility of the process due to no wear and tear of the tool and increase in productivity with better quality. It is a non-contact, flexible, and easily controllable process with almost no contaminations. Through laser, a localized and narrow heat zone can be created. However, there are various investigations still going on in this field

Figure 1. Schematic diagram of Laser Transmission Welding (LTW) of plastic


The specific objectives of the present work are the systematic study on the effect of Carbon Black(CB) and laser welding parameters on the thermal, morphological, mechanical, and optical properties of the welded polymer samples during diode laser transmission welding of poly(propylene) (PP). Various polymer characterising techniques (DSC, TGA, FT-IR, SEM, XRD, UTM, etc.) will be utilised for the pre- and post-welded samples of PP composites.


Other objectives are:

  • Understand the phenomenon of inter-diffusion and melting of the semi-crystalline polymers 

  • Determine whether the processing conditions of injection moulded samples significantly influence the key properties of the laser-welded samples of PP and its composites

  • Optimising the laser parameters (laser power, scanning speed, and clamping pressure) and dosage of CB for good weld quality 

  • Analysis of variance (ANOVA) method will be utilised to find the statistical significance of the laser operating parameter(s) and CB. 

  • The present work aims to eliminate the issues faced by the industry during the laser welding process and improve productivity by scrap rate reduction and improving the weld quality. 

LTW opens novel product layouts with assured weld quality. When tool cost, consumable cost, and expenses with respect to wear and tear are considered, LTW scores to be an economical technique of joining parts which are compatible with automation. The project-specific cost seems to be one third lower due to a high degree of system flexibility and integrated process control. The parts are joined within seconds without the application of any joining agent. Moreover, it does not involve post-processing like curing, finishing, etc. which saves time, workforce, and post-processing equipment expenditure. This allows designers and manufacturers to recommend LTW as an emerging technology for joining complex geometries.

To understand and learn about laser processing and become familiar with polymer characterisation techniques, initial trials were carried out using a CO2 laser on poly (lactic acid) (PLA). A conference paper presented in the 17th International Conference on Manufacturing Research ICMR 2019 based on the “Bulk modification of poly (lactic acid) by CO2 laser radiations” which has been published in Advances in Manufacturing Technology XXXIII (doi:10.3233/ATDE190065). Foram also received an opportunity to present her work on “Laser Transmission Welding of Polymers & its Composites” in IMC:36-Irish Manufacturing Conference at Trinity College, Dublin.

The project is a cross-border collaboration along with ulster university, Jordanstown and NIACE, Advanced Composites and Engineering, Belfast. It is EU INTERREG V funded project with academic partners North West Centre for Advanced Manufacturing (NWCAM).


Eighteen months of Foram’s research has been at IT Sligo. The professors, supervisors, and all the staff members have been extremely helpful and always motivating Foram to grow further and have her own ideas for implementation. Foram feels’ that such encouragement is exceedingly rare. Together with the sound academic foundation and industrial experience, she wishes to achieve her ultimate goal of doing research in Polymers and pursue a PhD degree.