Cleanability and water-resistance of food packaging

There is so much you can achieve with coated surfaces. They add value to products, making them more competitive. Through a series of cases based on the needs of different sectors, Sirris will give you an idea about their potential. This blog post will look in more detail at the possibilities for food packaging materials.  

In addition to the manufacturing industry another particularly large sector also benefits greatly from the use of advanced surface functionalities: the food processing industry and producers of packaging for this sector. Easy-to-clean surfaces are of primary importance in the food processing industry. Keeping equipment clean during the production process is a constant challenge. In addition, the provision of sustainable packaging is becoming increasingly important. 

Control of all sources of contamination requires a major effort to ensure food quality and safety. Mineral products such as CaCO3, organic soils and microbiological contaminants are harmful to equipment and can often only be removed when the production is interrupted. Cleaning accounts for 15 percent of the total production time in the dairy industry. Coatings or surface treatments that facilitate cleanability can be a valuable part of a hygiene plan in a food factory. 

A second major challenge faced by these sectors is the need to make packaging more sustainable, with the avoidance of food wastage due to food remaining in packaging and reusability being important issues. Just like in the production process, being able to clean easily is essential here.  

Both these requirements mean that hydrophobic functionality must be achieved on plastics by creating textures during injection moulding of packaging materials and by applying easy-to-clean coatings. 

Packaging for the food industry 

Millions of packagings are made each year for the food industry, ranging from disposable single use packaging to high-quality food containers that last for years. Both types are manufactured by injection moulding. During injection moulding, hot plastic is pressed into a mould and thus takes on its shape as it solidifies. It is also a cost-effective method of transferring complex surface structures to a mass-produced component, with the ultimate aim of adding additional functionality to the piece. This can be achieved by structuring the mould with a negative geometry of the desired surface structure. In particular, water resistance (i.e. the wetting behaviour of the plastic surface with water) is important. 

However, the best results can be achieved when texture is combined with a coating. This results in super-hydrophobic surfaces with excellent water resistance. Two recently developed technologies are, for example, SLIPS and Liquid Pattern surfaces, in which a textured surface is finished with a coating by means of impregnation. They ensure that liquids can run over structured surfaces while these remain smooth and clean. 

In the casebook on functional surfaces that we are composing for you, we give a number of examples of coatings and their applicability, and we also show how the combination of coatings and textures can contribute to better hygiene and less waste.  

In a next blog we will have a look at the possibilities for the production process in the food industry. Would you like to stay up-to-date with our series about functional surfaces? Register here!