The haze of polypropylene is directly related to the size of spherulites – large spherulites increase the haze and lower the clarity.
The benefit of a clarifying additive compared to a nucleating agent is to achieve an even smaller size of spherulites. This is obtained through a very different physical mechanism and results in a significant improvement in clarity, haze and gloss.
The use of a clarifier has also a positive impact on mechanical and processing properties.
Clarified polypropylene is widely used in consumer goods and mass market applications such as microwave-able and sterilized food packaging, hot filled bottles, food boxes, cosmetic jars, medical packaging.....
These applications require the use of plastic additives that do not degrade during processing and secondary operations, nor migrate from the packaging.
Therefore, clarifying agents are typically classified according to their total performance. These include optical properties (haze, gloss), organoleptics (taste, odor), heat stability and efficiency (recommended concentration).
| | Recommended concentration (ppm) | Clarity improvement | Taste and odor | Heat stability |
| IRGACLEAR® DM | 1800 | 4-5 | 1 | 3 |
| IRGACLEAR® XT 386 | 150 | 5 | 5 | 5 |
NEW GENERATION CLARIFIER
Ciba has developed the latest generation clarifier IRGACLEAR® XT 386 to answer to the most challenging needs. This product provides:
- A high thermal stability over the entire processing window of polypropylene
- Consistent performance in regrind
- Excellent clarity and strong haze reduction at very low concentration
- Ultra-Low migration and low risk for plate-out on processing equipment
- Neutral organoleptic properties
IRGACLEAR® XT 386 is suitable for any converting technology. When combined with Ciba® pigments, it allows to color transparent polypropylene packaging with a high see-through effect and long term light stability.
More information about clarity and transparency
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