Lean Manufacturing: new approaches to production process
An analysis of the benefits and advantages that companies sensitive to Lean Thinking encounter, as...
Properties of plastic materials
Plastics, highly versatile and resistant, are organic or semi-organic materials to which various additives are added.
They have unique properties such as high thermal and acoustic insulating power, lightness and good tensile strength.
They have a fair amount of chemical resistance and can be easily shaped, thanks to their plasticity.
Compared to other materials, they have a low production cost, are light, both flexible and rigid, malleable and insulating.
In addition to their adaptability, however, they have a fairly low use temperature, are not biodegradable and are then subject to deterioration.
Plastics are obtained from the combination of polymers, additives and sometimes fillers.
Types of polymers
Polymers are formed by monomers, in particular by the repetition of simple chemical units, and are classified into three groups by processability.
- Thermoplastic polymers
- Thermosetting polymers
- Elastomeric polymers
Thermoplastic polymers are polymers that, during processing, are not affected by chemical alteration.
A transformation defined as "reversible", possible precisely because thermoplastic polymers retain their plasticity when hot.
They are very versatile because they can be melted, shaped, heated and cooled without losing their plastic characteristics.
Thermoplastic polymers are produced and shaped following the required shape of the final product.
The techniques used are melting, pressing, injection molding, however if exposed to very low temperatures it could break, as if it were glass.
Examples of thermoplastic polymers are polystyrene, polyethylene, nylon and polypropylene.
On the contrary, thermosetting polymers, once shaped, cannot be further worked, as they undergo chemical degradation.
In an initial phase they have a certain plasticity, but subsequently, due to cross-linking, the products become rigid and no longer fusible.
In the initial state, the material for the production of thermosetting polymers is in liquid form, and then modeled for the required shape.
Examples of materials can be polyurethane, polyester and some specific types of resins.
Another type of polymeric materials are elastomers or rubbers, widely versatile and durable, which are well suited to various applications.
They are natural or synthetic polymers that have properties similar to those of rubber and are resistant to wear, heat and abrasion.
During the processing phase, a low permanent deformation was recorded, so much so that they are considered among the most flexible materials available.
This type of material is subject to vulcanization, which allows the rubber to acquire elastic characteristics, increasing resistance.
New evolving trends
Thanks to their affordability, versatility and durability, plastic materials are considered irreplaceable in many applications.
In addition to making our lives cheaper and safer, in many industrial productions they are essential materials to maintain the integrity of some products.
Due to this widespread and excessive use, a phase of great success is followed by a phase of progressive replacement, considering the volume of waste produced.
The no longer negligible impact on the environment has led the EU to launch protection programs for the safeguard of environmental resources.
In addition, many initiatives have been launched to introduce and replace traditional resources with materials from renewable sources or recycling technologies.
Efforts to make the plastics industry circular are attributed to Europe and the United States, and concern both recycling and bioplastic technologies.
A new category of materials with different properties and application possibilities.
A material is defined as “bioplastic” if it is bio-based or biodegradable, but it still has very high costs, in fact, its production is very limited.
In addition, there are many recycling operations, which are “recovery operations that process waste materials into products for the original or secondary purpose”.
Some recycling technologies include mechanical recycling, dissolution, and chemical or molecular recycling, used for material recovery and valorization in the most sustainable way.
Although the production of bioplastics is still very limited, it is assumed that the sector will experience rapid growth and represent an important lever for decarbonization in the future.