Kynar® Polymer Processing Aids for Polyolefins and other Polymers
Highly efficient additives to improve the extrusion efficiency of thermoplastic resins.
Kynar® PPA PVDF additives are designed to aid in the extrusion processes of thermoplastic resins by eliminating surface defects and increasing output.
Kynar® PPA additives are used in such processes as blown film, cast film, blow molding, injection molding, wire and cable jacketing, pipe and tube extrusion, and extruded fiber processing. Significant benefits are demonstrated when used at very low levels of 100 – 1,500 ppm. Kynar® PPA additives provide many benefits to a wide range of resins, particularly, but not exclusively LLDPE, mLLDPE, LDPE, HDPE, and PP. Kynar® PPA additives have Kosher, Halal, and FDA food contact approval for polyolefins under conditions of use A-H.
While Kynar® PPA additives can improve the processing of your current products, it can also allow you to process tougher low melt-strength polymers at increased rates and with a quality that would not be possible without a processing aid.
Final Product Benefits
- Elimination of melt-fracture (sharkskin)
- Improvement of film transparency
- Improvement of smoothness and surface aspect
- Improvement of product appearance
- Improvement of mechanical properties
- Improved gauge control
- Reduction of gels
- Maintenance time reduction
- Reduction of die build-up
- Consistency of production
- Smoother extrusion conditions
- Lower energy consumption
- Reduction of cycle times and quicker transitions
- Reduced die pressure
- Increased output
Today neither poor appearance...
...nor reduced output is acceptable...
...but both problems can be easily solved!
Select from several grades of Kynar® PPA to match process requirements
Best PPA additive selection is based on:
- Temperature of the extrusion or molding process and the resulting polymer melt temperature
- Melt index of the polyolefin that requires the use of a PPA
- Shear rate of the process
- Use of other additives and fillers in the polyolefin extrusion causing a need for a synergist containing product
Consult with your Arkema technical representative to choose from the above grades of Kynar® PPA (Grades are available as either pellet or powder depending on the preference of the masterbatch producer.)
How to use Kynar® PPA Additives
The two main requirements to get the best out of Kynar® PPA additives are:
- a good dispersion
- a uniform dosing at the typical low concentration level needed with Kynar® PPA additive
For a converter, this is achieved by using:
- either a resin that already contains Kynar® PPA additives; (many resin producers propose polyolefin grades which contain Kynar® PPA additives with appropriate and uniform dosage and good dispersion)
- or a masterbatch:
- containing typically from 1% to 5% of Kynar® PPA additive
- which can be diluted into their standard resin;
(many masterbatch manufacturers propose PPA masterbatches based on Kynar® PPA additives)
Conditions of Use
Kynar® PPA additives are mainly used at 100 - 1,500 ppm levels to overcome the processing problems typically encountered with polyolefins. For such low level of content, it is highly recommended to use Kynar® PPA additives in the form of a masterbatch for an accurate and uniform dosing. Most Kynar® PPA additives are safe for applications involving contact with food articles and meet Kosher, Halal, USA FDA and European food contact regulations - see your Arkema representative for details.
Recommendations for Masterbatch Preparation
Masterbatches should not have a Kynar® PPA additive content above 5% since this can lead to poor dispersion. A level around 2% is usually desirable. The table below can be used to determine the percentage of masteratch to be included in the final mixture to obtain the required level (in ppm) of Kynar® PPA additive.
|Kynar® resin ppm targeted in final mixture||Use of masterbatch at...|
|200||Add 2%||Add 1%||Add 0.67%||Add 0.5%||Add 0.4%|
|400||Add 4%||Add 2%||Add 1.33%||Add 1%||Add 0.8%|
|600||Add 6%||Add 3%||Add 2%||Add 1.5%||Add 1.2%|
|800||Add 8%||Add 4%||Add 2.67%||Add 2%||Add 1.6%|
|1000||Add 10%||Add 5%||Add 3.33%||Add 2.5%||Add 2%|
Technical and sales support for Kynar® PPA
From process improvements to product visuals, Arkema has dedicated equipment and field personnel for technical assistance to achieve complete solutions to challenging issues.
Listed are some articles published on polymer processing aids.
- V. Vora, J. Gingras, “Increasing Throughput, Reducing downtime”, Modern Plastics & Polymers, pp. 190-192 (January 2012)
- V. Vora, F. Beaume, “For Best-in-Class Performance”, Modern Plastics & Polymers, pp.71-72 (September 2012)
- V. Firdous, PP. Tong. “Sharkskin Melt Fracture: Effect on LLDPE Film, Properties”, Journal of Plastic Film & Sheeting, Vol 8 – October 1992 pp 333 – 340
- J. Gingras, F. Beaume, P. Elmerch, J. Laffargue, “Polyvinylidene Fluoride Based Polymer Processing Aids, Their Evaluation and Conditioning Procedures,” Tappi Proceedings, Indianapolis, IN; September 2004