Analytical Odor Control in the Recycling Sector

Recycled materials, which are raw materials from the selection of waste, in their various states of life (loose, bales, ground, granules), o the final product, created through recycling processes, can bring with them gradients and types of odors that can be more or less unpleasant to operators or end customers.

The sensation of acceptance or not of smell is entirely subjective and depends on an infinite series of sensory evaluations: what for me could be an acceptable smell, for the customer could be an unbearable home.

The human nose is sensitive, but different between person and person in intercepting odors and, above all, it is not able to accurately catalog an equal level of odorous compounds, nor the repetition of the intensity of the odors it intercepts. 

What a company produces, in terms of smell on a product , whether it is raw material or a finished element, must be cataloged in a completely analytical way, without approximation, to determine standards that can accepted by both the producer and the customer, so that all subsequent productions can fall within the established ranges.

Defining and being able to replicate a range of odors accepted by the parties is not only an increase in the qualitative service of the product itself and of the company, but also a guarantee towards the end customer who can reasonably know that the odor intensity can be cataloged and managed exactly.

Let's see some examples where an "electronic nose" can make the difference:

• Producers of PET trays, receiving the recycled granule or ground, can analytically evaluate the odor intensity of the raw material and give the producer himself standards not to be exceeded to avoid problems on the trays in the distribution chain.

• Manufacturers of beverages in PET bottles can establish with certainty not only the maximum odor levels accepted on the raw material, but they can establish whether the product contained in the bottles can undergo transfers by the plastic bottle of odorous substances that can affect the quality of their product.

• Producers of raw materials can establish with their customers the maximum odor ranges acceptable to both, through an analytical analysis of the material first sold in order to ensure a reliable product quality.

• The manufacturers of bottles for detergents , for care, for perfumed liquids need to purchase recycled raw material in HDPE that has an odor content coming from the surfactants such that they do not interact negatively with the final packaging on the shelves of the shops or can alter the fragrance of the liquids or powders contained.

• Furniture or packaging manufacturers for industrial logistics who use PP, HDPE and LDPE from post consumption, they must be able to establish with certainty the incidence of the odors of the raw materials they buy, in order to establish limits that cannot negatively affect the final product they distribute.

• We could continue to cite other examples in which the lack of a certain classification of odors can often lead to the dispute of the materials, with considerable costs and degeneration of customer-supplier relationships.

Through the use of an odorous substance analyzer , a laboratory machine that uses samples of raw materials or pieces of final products , therefore in the form of granules, ground, liquids, etc ..., which are heated, creating volatile substances inside the test tube, which are then chemically analyzed and compared, through an analysis program, this creates a precise picture of the types and intensities.

The machine allows you to compare also standard samples and therefore accepted by the parties, with the various production samples in order to intercept the deviations and immediately evaluate production corrections. 

The results of the analyzes return a precise photograph, not only of the odor intensity, but also of the types of chemical compounds present in the samples that produce the mix of odors, so as to be able to intervene in a precise and timely manner. 

The tool that analytically analyzes the smells or fragrances of the volatile substances contained in the products is also used in the food sector to unmask food sophistications such as, for example, those of olive oil, to verify the compositions of coffee, to evaluate the freshness of food or the transfer of substances contained in the packaging to food.

Automatic translation. We apologize for any inaccuracies. Original article in Italian.