Semicrystalline Polymer Crystallization Reactor Mixing
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Solution Overview
Problem
Existing methods for crystallizing thermoplastic polymers, such as polyethylene terephthalate (PET), face challenges in ensuring thorough mixing of amorphous and partially crystalline granules, leading to lump formation and increased processing time and costs, due to inadequate mixing in the crystallization reactor.
Innovation Solution
The solution involves pre-mixing partially crystalline or semi-crystalline polymer material with untreated amorphous raw material outside the crystallization reactor, using a transfer section that connects to the reactor below the material level, allowing for intensive mixing before entering the reactor, thereby preventing lumping and maintaining flowability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If amorphous granules are directly mixed in the crystallization reactor, then crystallization can proceed, but thorough mixing is not ensured and lumps of sticky granules are formed
Solution Approach 1:
The patent applies preliminary action by pre-mixing the partially crystalline granules with the amorphous raw material in a feed hopper before introducing them to the crystallization reactor. This preliminary mixing ensures homogeneous distribution of anti-sticking agents throughout the granule mass, preventing lump formation during subsequent crystallization while maintaining stable composition throughout the process.
2Object-generated harmful factors
If coating agents or swelling agents are used to reduce stickiness, then the tendency to lump together is reduced, but processing time increases and costs increase
Solution Approach 1:
The patent discards the conventional approach of using coating agents or swelling agents that require additional processing steps. Instead, it recovers and reuses partially crystalline granules from the crystallization reactor, grinding them and reintroducing them to the feed hopper. This creates a self-sustaining cycle that reduces stickiness without additional processing time or cost.
Solution Approach 2:
The system performs self-service by using its own output (partially crystalline granules) to solve its own problem (stickiness of amorphous granules). The ground partially crystalline granules act as natural anti-sticking agents, eliminating the need for external coating agents or swelling agents and their associated processing time and costs.
3Ease of operation
If a large volume of partially crystalline material is added to prevent lumping, then flowability is maintained, but the volume of material required increases
Solution Approach 1:
The patent applies preliminary action by thoroughly mixing the ground partially crystalline granules with the amorphous raw material in the feed hopper before introduction to the reactor. This preliminary, intensive mixing ensures homogeneous distribution of the anti-sticking granules throughout the entire granule mass, maximizing their effectiveness. Consequently, only a small volume of partially crystalline material is needed to achieve and maintain flowability throughout the crystallization process.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach ensures effective and homogeneous crystallization, reduces the volume of partially crystalline material needed, shortens reactor dwell time, and decreases energy requirements by preventing lump formation and ensuring thorough mixing before the material enters the reactor.
Implementation Method 1
the transfer section ends in the add-on socket... the mixture is only subsequently conveyed into the crystallization reactor
Implementation Method 2
During the crystallization of thermoplastic polymers, there is a partial alignment of molecular chains in the polymer. Starting from the crystal nuclei, the molecular chains fold together and initially form lamellar structures which then form larger structures such as spherulites.
Data Source
AI summary
The present invention relates to a method for producing semicrystalline polymer material, wherein the predominantly amorphous raw polymer material, in particular granules, to be treated is introduced into a crystallization reactor (1) and is partially crystallized there by being heated, but without melting, and subsequently the semicrystalline polymer material obtained in such a way is removed from the crystallization reactor (1) and at least part of said semicrystalline polymer material is diverted and mixed back into the crystallization reactor (1) in order to reduce the adhesive tendency of the polymer material. According to the invention, the diverted semicrystalline polymer material is combined and mixed with the raw polymer material before being mixed back into the crystallization reactor (1), and the mixture is then introduced into the crystallization reactor (1).