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Read all about Tosaf groundbreaking installations during NPE 2018 Show

We are super exited to be featured on "Plastics Today " Magazine coverage of the five top must see of the NPE 2018

For those who couldn’t make it to the NPE 2018 show, Orlando,  Plastics Today Magazine”  

covers the highlights from the NPE.

For more details Click on the link below and enjoy: https://www.plasticstoday.com/packaging/npe2018-watch-literally-and-4-more-cool-things-show/205502927458850/page/0/4

 

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Tosaf New Anti-Fog Masterbatch

Tosaf is launching a newly-developed anti-fog masterbatch: AF7380PE

Tosaf is proud to announce the launch of AF7380PE, a newly-developed anti-fog

When packaged goods are stored in a refrigerator, water droplets tend to appear on the surface of the packaging film, obscuring the contents from view and seriously degrading overall product quality.

To avoid this unwanted result, the surface properties of the film must be altered. The most common way of doing this is through the use of migrating additives.

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In over 30 years of working closely with its customers, Tosaf has developed an innovative range of anti-fog masterbatches that help reduce the harmful effects of water drops on packaging film. A wide range of solutions have been developed to suit different applications, for example refrigerated and hot meals packaging, greenhouse films and industrial packaging. Anti-fog additives for plain polyethylene (PE) films are well known and widely used. However, as film structure becomes more complex and film producers require the same anti-fog masterbatch for a variety of production processes, demand has grown for new solutions and more sophisticated formulations.

Tosaf is proud to present its novel 3rd generation anti-fog masterbatch for polyethylene films, AF7380PE. This masterbatch combines the company’s broad experience working with the most sophisticated anti-fog materials with its profound understanding of the market’s needs. According to Tosaf’s Film Additives R&D Manager, Dr. Evgeni Zelikman, the unique benefits of AF7380PE lie in its combination of excellent anti-fog activity and superb optical properties.

AF7380PE is suitable for a wide range of production processes, from laminated polyethylene films, multi-layer co-ex barrier films produced by blown and cast extrusion, and oriented films produced by double- and triple-bubble production technology.

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THE IMPORTANCE OF UV CAP-LAYER ON PC SHEETS

Many questions are addressed to us regarding the UV absorbing layer (“cap layer”). In this and in upcoming newsletters, various aspects of the UV cap layer will be discussed. The importance of UV protection for polycarbonate sheets is well known to all PC sheet producers and their customers.

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When production of polycarbonate sheets started over 30 years ago, producers were not aware of the necessity of a protection system against ultraviolet light from solar radiation. Later, customers began to complain about this failure after only a short service life.

In order to protect the sheets, producers first employed a protection system based on an acrylic lacquer layer enriched with UV-absorbers.
The acrylic layer was sprayed on the sheet during the process or applied by a special roller system. The lacquer provided very good resistance to solar radiation and, in terms of UV protection, gave better performance when compared to the co-extrusion of a UV layer.

On the other hand, the reliability of the lacquer layer was very poor. In many cases, the layer was easily peeled off from the sheet, especially when the sheet was subject to high-stress circumstances. High stress could develop, for example, from extreme weather conditions or when the sheet was installed in a curved shape.

Bayer (today Covestro) was the first to develop the innovative idea of protecting the sheet with a thin polycarbonate layer enriched with UV absorbers and applied on the sheet by co-extrusion technology. This was a breakthrough in the production of polycarbonate sheets (solid and multi-wall) with extended service life.

Originally, co-extrusion of an additional polycarbonate layer on top of the UV protective layer was required due to the high level of plate-out of the UV absorber at the die exit prior to the calibration stage. Later, high molecular weight UV absorbers were developed (e.g. Tinuvin 360) that minimized evaporation/migration levels on the calibrator inserts.

Sheet producers discovered that optimal UV layer thickness should be in the range of 30 to 40 microns (Fig.1). The UV absorber concentration in this layer should be at least 5% or 6%, though higher UV absorber levels resulted in better UV protection performance.

Fig. 1 – Most sheet producers monitor and adjust the thickness of the UV layer with the aid of an optical microscope equipped with a UV lamp that emphasizes the co-extruded layer. Thickness measurements need to be conducted across the sheet’s width to guarantee complete protection.

The rheological properties of the UV layer should match the base layer in order to achieve uniform layer distribution.

Nevertheless, rheology isn’t the only factor which affects the layer distribution. The feed block design also has a very important effect. Use of a poor quality or a poorly designed feed block can result in uneven UV layer distribution (Fig.2). As a result, there is a reduction in the efficiency of the UV layer and the process becomes less economical.

 

Fig.2 – Layer distribution of a 2.1-meter width multi-wall sheet. Blue line: original distribution. Orange line: after feed-block modification. Inefficient distribution of the UV compound can lead to an increase in consumption of UV cap layer compound by 20% or more. It is good for the UV compounders…but very costly for sheet producers.   

Finally, the plate-out properties of the UV compound should be as low as possible to enable smooth production without interruptions for cleaning the calibrators. Few companies offer compounded UV polycarbonate for sheet protection. The main suppliers are the polycarbonate resin producers although several independent compounders offer these compounds as well. However, quality must be tested carefully before the material can be approved.

In short, the UV layer is the Insurance Certificate of the polycarbonate sheet. Therefore, sheet producers must pay careful attention to sourcing the UV cap layer from a reliable supplier. Not less important is implementing the compound in a reliable process that gives a uniform thickness across the entire sheet width.

As always, thank you for your interest and comments.  If there is a particular topic that you would like to see discussed in a future newsletter, please be in touch and let us know!

 

Gabi Bar

Polycarbonate Product Manager | Tosaf Compounds
Tel: +972 (0)4 6068 000 Fax: Cell: +972 (0) 54 5663319
gabib@tosaf.com  www.tosaf.com

 

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