How to prevent condensation of food packaging

For almost 50 years, our partner CONSTAB (part of the Kafrit group) has been producing additive masterbatches. For the plastics industry, antifog masterbatches are used in food packaging. Antifog masterbatches prevent the formation of condensation on the inside of the packaging. This keeps the contents of the packed product visible; the visible quality of the product is not affected and remains attractive to the potential buyer.

Two types

Are available for polyethene film:

Based on a new generation of additives, the product AF 00260 LD has recently been developed for PE films with cold fog properties at temperatures of 0.5°C and higher. This product can also be used in combinations of PE and PP. The antifog effect lasts up to about six months. Both products are approved for contact with food. AF 00260 LD can also be used for a laminated film. Laminating will have an impact on the antifog properties.

For polypropylene film, CONSTAB delivers AF 00262 PPR, which functions for at least six months. This product is suitable for hot fog (60°C) as well as cold fog (0.5°C). The product is approved for food applications, taking into account the dosage and structure of the (multi-layer)film. The final antifog effect depends partly on the structure of the (multi-layer)film and the polymers and additives used, etc. It is therefore recommended that we cooperate with the supplier and/or manufacturer when developing this type of film.

For the agricultural film, CONSTAB provides a series of antifog/anti drip masterbatches that have been operating for more than 18 or 24 months (depending on the type of masterbatch and the film structure).

Nucleators

To understand nucleators, we need to distinguish between different types.

We have clarifiers, and these are additives that are soluble in the polymer matrix. They form germs at the intersections of the chains. These products give a very clear PP-H or PP-R (better transparency from HDPE is also accessible). These products also affect the stiffness of a product.
We have clarifiers, and these are additives that are soluble in the polymer matrix. They form germs at the intersections of the chains. These products give a very clear PP-H or PP-R (better transparency from HDPE is also accessible). These products also affect the stiffness of a product.
These products are not to be confused with foam nucleators. These are also solid particles, which are used to control the foaming process. These nucleators have nothing to do with the above two types.

For injection moulding types of polypropylene, CONSTAB has developed a nucleating agent masterbatch and a clarifier masterbatch that affects the solidifying characteristics of the polymer in such a way that it is more easily workable and has better end properties. What both products do is create germs for the crystals. As a result, the Tc is about 10 degrees higher.

Demoulded

This means that a product is more shape-solid when cooled and could, therefore, be demoulded earlier (shorter cycle time). Moreover, these products create many small crystals, which makes the finished products more transparent and stiffer, without sacrificing too much impact. These products generally cause a little more shrinkage, but a more uniform shrinkage (machine and transverse direction almost identical). The influence of colour pigments on processing is virtually nullified. Warping is prevented because of the more uniform shrinkage. Not every PP can be nucleated. This needs to be tested.
It can be done quite easily by adding the desired Masterbatch to the maximum dosage. There should be an effect almost immediately (brighter product). Is there no effect to see that the pp used does not nucleate? If there is an effect to be seen, the testing can continue. Dosage down to determine where the optimum lies between cost and impact.