Plastics do not always leave the petrochemical or recycler with the properties required for a particular application, but to solve this problem there are additives (sometimes called "modifiers"). The additives can modify impact strength, improve surface finish, increase or reduce hardness and etc., can also serve only to reduce the cost of the material.
But ... since nothing is perfect when the subject is plastic, other intrinsic properties of the material can go into space with the use of certain additives, such as some flame retardants that generate a loss of mechanical resistance in most polymers where Are used.
In the market there is an immense variety of expensive products that promise to perform miracles in plastics, but to achieve certain effects, it is often enough to use only the active principle of these additives, which came out much more.
Here you will find everything you need to know about additives, fillers and reinforcements: