Applying for a job, I woud love to find someone for checking my english cover letter, could you?

I am writing in response to your job advertisement for a Packaging Technologist as seen on the careerjet.com website.

I am a recent PhD polymer sciences graduate with special expertise in nanocomposites within packaging applications. As a young project manager, I have five years of hands-on experience with the analysis, characterization, formulation and processing of plastic materials. Where did you work?  Was this hands-on experience part of your PhD program, or was it a job working at a company?  Where did you get your PhD?  

As part of my PhD, in collaboration with ParisTech and Grenoble INP, I was required to manage an entire project, starting with the valorisation of the biomass, the formulation of nanocomposites based on PLA, and finishing with the study and understanding of their mechanical and barrier properties. This project was developed with the goal of offering innovative bio-based and biodegradable materials for the food packaging industry. Then, I feel able to translate costumer needs into laboratory research and up-scale production.  (I am not sure what you mean here.  Did you actually translate customer needs into laboratory research and production as part of your PhD program, or would you just have been ready to do so if it were required?)

I am looking now for a challenging position in R&D for proposing new solutions for the design and the quality assurance of materials according to the requirements of the actual society. My commitment for to innovation and my interest in working in a multidisciplinary environment are also factors that particularly take my attention for reasons why I would like to join joining your company.

My professional experience has been also completed by the supervision of engineering projects.  (I do not understand what you mean here.  Were you a supervisor?  Or did other people supervise your engineering projects?) My global vision and communication abilities have been enriched with scientific and technological networks derived from international conferences Which conferences did you go to?. My dynamic and curious nature allowed me to be part of several internships in laboratories around the world, in which not only my scientific knowledge was enriched but also my cultural sensitivity and ability to work in a team context. What internships?  Where?  What did you do during your internships?  Your letter would be stronger if you explained where the internships were and what you did.

I am confident that I am a good candidate for the position you are offering, so I am looking forward to an opportunity to further discuss this job with you.

Yours sincerely,

Your letter is very good.  The two red parts are the only parts where I did not understand what you meant.  The questions in blue are ideas for you to think about in terms of details you could add in to give more information to potential employers.