Plastic parts with black main layer absorb light and UV radiation and thus protect the filling goods. 

This black layer keeps the contents fresh and extends the shelf life of the products without the need for additional preservatives.

Because the three layers are made of the same materials, these hollow bodies are 100% single-variety recyclable.

A functional layer, which in this case consists of EVOH, does not necessarily have to serve as a barrier layer.

It can also be used for optical purposes, as in this example. The EVOH layer is applied to the outside and gives the bottle a particularly classy and high-quality depth effect.

This effect is particularly popular in the cosmetics industry and for personal care products.

Commonly, CoEx4 technology is used for agrochemical products or for fresh juices.

The CoEx5 technology is used for cosmetic packaging and for food packaging. It is used when a regrind layer is not permitted (unlike CoEx 6 applications) but a barrier layer is required. The virgin inner layer prevents the contents from coming into contact with the barrier layer, which is essential for some goods.

Special colors and effects like glitter are very expensive. If you use them in a CoEx application, you save a lot of masterbatch and therefore costs. In this case, the thicker inner layer is made of natural material, while only a thin outer layer needs to be colored.

Please refer to the chart for information about the materials used and the layer configurations.

The CoEx6 technology is mainly used in the automotive sector, but it is also used in cosmetics packaging and for food packaging (most prominent example: ketchup bottles). The virgin inner layer prevents the contents from coming into contact with the barrier layer, which is essential for some goods.

If the EVOH barrier layer has a proportion below 6% of the total weight, the plastic part is 100% recyclable in the EU and can be returned to the recyclable material cycle.

In our sample, the proportion of EVOH barrier is 5% (3% in the barrier layer and 2% in the main layer by adding regrind). For the vast majority of applications it is possible to keep the percentage below 6%. The perfect all-round distribution of the W. MÜLLER extrusion heads ensures a stable and consistent quality of the functional layer, even in the low percentage range.