Barrier properties to protect the product
- To prevent the penetration of ultraviolet (UV) light into the interior of the container where it may damage the product’s properties. Typical configuration consists of 3 layers, with a black middle layer. Used for dairy product bottles which require an extended shelf life.
- To avoid the penetration of oxygen into the packaging where it may cause oxidation of the product, 6 layers are typically needed, as the barrier layer requires adjacent layers with adhesive properties(salsas, mayonnaise, juices, ketchup, some dairy products with added vitamins).
- To prevent the product properties from exiting the packaging (chemical products, etc.), two layers are utilized.
Use of recycling
- To take advantage of post-consumer recycled materials. Three layer configurations, with the recycled layer being located in the interior.
- To minimize the quantity of “Masterbatch”, in cases in which its cost is high. The “Masterbatch” is added to the external layer which is thinner than the internal layer.
- To manufacture multi-layer containers it is necessary to install coextrusion systems, whereby the different extruders simultaneously feed the Head.
- It is extremely important that the layers maintain both longitudinal and radial consistency in order to minimize the barrier material quantity.
- In the case of Urola’s rotary machinery, because there is only one head, regardless of the number of moulds, the multi-layer configuration is considerably simplified while at the same time, the required consistency is guaranteed.
- For this, the highest quality multi-layer heads in the industry are used.