| Recorded: |
February 7, 2011 |
| Presented by: |
Dr. Rick Cox & Art Hamfeldt, DeltaNu  |
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Join DeltaNu as they discuss how Raman Spectroscopy can be applied to quality control in medical plastics. Raman spectroscopy is a rapid and non-destructive inspection method employed in the lab and the warehouse. Timely inspection of incoming raw materials and outbound finished products is a critical step in ensuring a rigorous QA/QC process, to avoid potential brand damage, liability issues, and recall. This webinar describes the fundamentals of Raman spectroscopy and case studies using benchtop and handheld Raman systems to solve various quality control issues. Issues covered include contamination, physical failures, known and unknown material identification, and other product liabilities. DeltaNu is a business unit of Intevac Photonics.
Questions and Answers
Why would I choose to use Raman verses FTIR for my raw material identification?
Raman benefits:
- Sampling
- Raman can sample though containers and bags.
- Raman is non destructive and no sample preparation is required.
- Fundamentals
- Raman is good for distinguishing materials such as:
i. TiO2 (anatase and rutile).
ii. CC double bonds are strong.
iii. CN: plastics with acrylonitrile (ABS, SAN), are easy to distinguish.
iv. Some heavily filled SiO2 polymer composites (i.e. glass, clay, silica) can be easier with Raman than FTIR.
v. Some additives may interfere with FTIR identification, and Raman may not be as sensitive to small variations in additive.
- Many times the spectra are less complex, i.e. less overtone and combination bands.
- Size and Costs
The size and costs have lowered significantly over the past several years. Handheld Raman systems may be purchased for less than USD 20,000.
Are there any materials, polymers, inorganics, etc which respond BETTER with Raman vs. FTIR? Are any
classes of material NOT responding to Raman as well as FTIR?
See above for fundamental differences.
What wavelength laser is in the handheld device or can you choose what will work best for your application?
Handheld units are only available with 785 excitation laser. Other wavelength options are available for laboratory based systems, and we do have a new portable 1030 nm based system.
I have a PP part in a PET/PP film thin gage flow wrap bag. Can I reliably shoot the part?
Yes, as long as the flow wrap is translucent, you should be able to reliably measure the part behind the bag.
How do I build the database for the additives or are they already available?
It is more than likely that you will have to append your additive to the library, but this is a simple process. If you are measuring trace levels of additives in a finished product, Raman is not as sensitive. This will be a difficult application if the additive is less than 1%.
Can the method distinguish between different vendor's resins that are in the same basic plastic family (e.g. two different ABS resins)?
This depends upon what makes the resins different. Please contact us at sales@deltanu.com to determine if this is possible. Please include many samples so we can determine if there is a difference in the materials Raman can detect.
Can we use Raman for identify plastics blend...like ABS+PC or PPO+PS...? and can we use it to identify % of Glass fiber in polymer..?
Blends can be added to the library and be identified going forward. Quantification with Raman is application dependant and would require a study to provide a definitive answer as sample homogeneity and fiber filament size would preclude a definitive answer.
Is this limited to thermoplastics? Is there a library for thermosets?
The Pharma•ID is not limited to thermoplastics; a library of thermosets can be created and added to an existing library.
Is it possible to determine whether oxidation or contamination has occurred by analyzing different parts of a product, such as yellowed zones on a handle?
Yes, this is a good application for Raman.
Can you detect polymer (molecular weight) degradation?
There are some examples in the literature of using Raman spectroscopy for molecular weight degradation of medical plastics such as ultra high molecular weight PE in orthopedic implants. So yes, this is possible.
Can we measure the content of antioxidants before and after processing (injection molding)?
Raman may be able to measure and determine the presence of antioxidants before and after processing; success would be dependent on the antioxidant and its concentration.
Is it possible to know if a plasticizer has been changed on a PVC tube? Or the amount of plasticizer used with this equipment?
This depends upon what the differences are in the plasticizer. Please contact us at sales@deltanu.com to determine if this is possible. Please include many samples so we can determine if there is a difference in the materials Raman can detect.
Is there a option with Raman to determine difference PP with glass fiber and no glass fibers, also PP or PA 6 with some others additives?
Yes, the glass fiber is a good application for Raman. PP with other additives will depend upon concentrations.
What are the lowest levels of UV and antioxidant levels that can be detected in plastics?
The lowest level would be application dependant, but typically additives less than 1% cannot be detected.
Will you be at NPE in Orlando in April?
DeltaNu will not be attending NPE in 2012.
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