Polymer mixing is defined as a process of upgrading a polymer or polymer system by melt mixing. The compounding process ranges from the addition of a single additive to a wide variety of additive treatments, polymer alloys, and reactive mixing. It is estimated that one-third of the U.S. production of polymers will be compounded. Blends can be tailored to the performance requirements of the final application. Blended products have miscellaneous properties such as high gloss and excellent impact strength, or precision moldability and good stiffness.
The well-mixed polymer is usually pelletized for further processing. However, it is increasingly interesting in the industry to combine compounding with the next process, such as profile extrusion, to avoid reheating the polymer.
Folding mix
Various types of melt mixing equipment are used, from roll and batch mixers to single screw and twin screw extruders. Continuous compounding (extruder) is the most commonly used equipment because he can provide consistent quality products and reduce operating costs. There are two types of mixing: distributed mixes can be evenly distributed in a mix without using high shear stress. This kind of mixture is called extended mixing or laminar mixing.
Decentralized mixing is also known as intensive mixing, where high shear stress is applied to break up cohesive solids. For example, when the additive package is broken, the actual particle size becomes smaller.
Mixing operations often require two types of mixing in one process.