In the production of recycled plastic polymers, the scarce use of plastic protectants can generate poor finished products

The concept that a recycled polymer it must be cheap and, therefore, of low quality, is still quite rooted in the minds of plastic material producers who, unfortunately, can face unpleasant disputes on the material supplied to make the finished products.

The principle of absolute cost-effectiveness of recycled polymers does not match the current needs of the use of plastic waste that society has, and therefore, it is necessary to adequately qualify the recycled polymers with appropriate treatments in the recycling and in the production of new granules.

As we know, the number one enemy of plastic is aging caused by atmospheric agents, which reduce its durability, characteristics mechanical and physical, creating major economic problems for the production and distribution chain.

But let's see what is the aging mechanism of plastic products

Plastic products can undergo various aging mechanisms over time due to several factors, including exposure to sunlight, heat, oxygen, humidity and chemicals.

These aging mechanisms can affect the physical and chemical properties of the plastic, leading to a loss of strength, flexibility, color and other desirable characteristics.

One of the most common aging mechanisms is oxidation.

When plastic is exposed to oxygen in the air, chemical reactions can occur that lead to the formation of hydroxyl groups in the structure of the plastic. These hydroxyl groups can adversely affect the mechanical properties, making it more brittle and susceptible to breakage.

Sunlight, especially ultraviolet (UV) radiation, is another factor that can cause aging of plastic products .

UV radiation can degrade the chemical structure of plastic, causing the fragmentation of molecular chains and the formation of free radicals. This can lead to a decrease in mechanical strength and the appearance of cracks and discolorations on the plastic surface.

Heat is another important factor in the aging of plastic products.

Prolonged exposure to high temperatures can cause a diffusion of the chemicals present in the plastic, leading to a loss of flexibility and an increase in fragility. Heat can also speed up chemical reactions within the plastic, contributing to its degradation.

Humidity is a factor that can contribute to the aging of plastics, especially those sensitive to water.

The absorption of moisture can cause the formation of hydrogen bonds in the structure of the plastic, leading to a decrease in its mechanical properties.

What are the consequences of oxidation processes

Plastic oxidation can have several unintended consequences, including:

Loss of mechanical strength: Oxidation can reduce the mechanical strength of plastic, making it more brittle and susceptible to breakage.

Change in physical properties: Oxidation can alter the physical properties of the plastic, such as flexibility, hardness or transparency.

Colour change: Oxidation can cause the appearance of spots or discolorations on the surface of the plastic, changing its aesthetic appearance.

Loss of durability: Oxidation can accelerate the aging of the plastic, reducing its durability and affecting the its longevity.

To mitigate the aging effects of plastic products, different additives are used during the manufacturing process.

Additives such as UV stabilizers, antioxidants and anti-degrading agents can help protect plastics from the harmful effects of aging . Additionally, low-temperature storage conditions and insulation from sunlight can help preserve the properties of plastics over time.

How to protect plastic products from aging

To protect plastic products from aging, various preventive measures can be taken.

Use of additives during the manufacturing process among which we can mention:

UV stabilizers, for example, help prevent degradation caused by sunlight.

Antioxidants and anti-degrading agents can help protect plastics from oxidation and chemical degradation.

Protective varnishes: when the plastic product has been made it is possible to apply specific UV protective varnishes.

The choice between using protective varnishes or additives in the production mix depends on several factors, including the specific application, the type of plastic and the manufacturer preferences.

Both options can offer protection against UV rays, but have different approaches and specific advantages.

Protective paints

Protective varnishes, as we have said, can be applied to the surface of the plastic to create a protective layer that blocks UV rays.

This approach offers flexibility because paints can be applied after the finished plastic product is manufactured. Paints can also provide greater customization in terms of aesthetic appearance and finish.

However, they require an additional application step and may require periodic maintenance to maintain the effectiveness of the UV protection.

Additives in the production mix

Protection additives can be incorporated directly into the plastic body during the manufacturing process.

These additives act as UV stabilizers, protecting the plastic from aging caused by UV radiation.

The use of anti-UV additives during production has the advantage of offering uniform protection throughout the mass of the plastic product , without requiring further application phases or specific maintenance.

Furthermore, the incorporation of additives into the body allows greater resistance to UV degradation than a simple external varnish.

The choice between protective varnishes and additives in the body will also depend on the specific needs of the plastic product and the preferences of the manufacturer.

In some applications, such as in the building sector, the use of anti-UV additives in the production mix may be preferable to ensure long-term protection without the need for external applications.

However, there may be instances where the use of protective varnishes is more suitable, such as when a custom finish is desired or when additional layers are to be added surface protection.

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