Dual Planetary Roller Extruder for Thermally Vulcanizable Adhesive Degassing
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Solution Overview
Problem
Current methods for producing thermally crosslinkable polymers in planetary roller extruders face challenges in achieving sufficient degassing, especially for highly viscous materials, which limits their use in producing reactive adhesives that can be crosslinked later, and existing degassing processes are not effective in reducing gas content to very low levels.
Innovation Solution
A method involving a first planetary roller extruder for compounding and a second degassing planetary roller extruder, where thermal crosslinkers are added and dispersed, followed by degassing in the second extruder to produce a thermally vulcanizable, meltable pressure-sensitive adhesive, allowing for efficient gas removal and processing within a temperature range of 130 °C to 230 °C.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a single planetary roller extruder is used for compounding thermally crosslinkable polymers, then the process is simple and continuous, but sufficient degassing cannot be achieved especially for highly viscous materials
Solution Approach 1:
The extrusion process is divided into two separate planetary roller extruders: the first for compounding and the second for degassing. This segmentation allows each unit to be optimized for its specific function, with the second extruder operating under vacuum to effectively remove gases from highly viscous thermally crosslinkable polymers without compromising process continuity.
Solution Approach 2:
The first planetary roller extruder acts as an intermediary that prepares the polymer compound before it enters the second degassing extruder. By performing compounding first and degassing second, the system mediates between the need for continuous processing and the need for effective gas removal, ensuring the polymer is properly mixed before vacuum treatment.
2Loss of substance
If existing degassing processes are used, then some gas removal is achieved, but gas content cannot be reduced to very low levels
Solution Approach 1:
The second planetary roller extruder operates under vacuum conditions, creating an inert environment that enables thorough degassing. This vacuum environment allows gases to be removed from the highly viscous polymer melt more effectively than atmospheric degassing processes, reducing gas content to very low levels required for high-quality adhesive production.
3Adaptability or versatility
If thermal crosslinkers are added in the first extruder, then crosslinking can occur later at 130-230°C, but gas content increases requiring effective degassing
Solution Approach 1:
Thermal crosslinkers are added and dispersed in the first planetary roller extruder before the degassing stage. This preliminary action ensures the crosslinking agents are uniformly distributed in the polymer matrix before vacuum treatment, allowing subsequent controlled crosslinking at 130-230°C while the second extruder removes the gases generated during this pre-mixing stage.
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 method enables the production of a thermally vulcanizable adhesive with adjustable adhesive strengths, suitable for automotive applications, by effectively reducing gas content and ensuring proper crosslinking, thus overcoming the limitations of existing degassing processes.
Implementation Method 1
plasticization refers to the transformation of powdered or granular plastics through temperature and pressure, thus reducing the viscosity of the material
Implementation Method 2
the energy introduced through friction can be dissipated quickly and effectively
Implementation Method 3
the second vented planetary roller extruder consists of a vent zone of at least one roller cylinder... the mixture of plasticized polymers and solids is degassed in the vented planetary roller extruder
Implementation Method 4
the solids contain at least thermal crosslinkers, which can crosslink the plasticized polymers for the purpose of increasing the molecular weight of the polymers
Implementation Method 5
a method for producing a particularly thermally vulcanizable, meltable, preferably pressure-sensitive adhesive
Data Source
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AI summary
The invention relates to a method for producing a preferably adhesive glue using a first planetary roller extruder and a second degassing planetary roller extruder arranged downstream, wherein the first planetary roller extruder consists of an atmospherically operated filling and dispersing zone consisting of at least one roller cylinder, to which filling and dispersing zone the polymers forming the thermally vulcanisable meltable glue are supplied in a plasticized state, same are fed within the first third of the at least one roller cylinder; furthermore, downstream of the addition of the plasticized polymers, via an opening of the at least one roller cylinder, solid substances are added which are dispersed in the plasticized polymers in the filling and dispersing zone, wherein the solid substances contain at least thermal cross-linkers, and the flow temperatures of the central spindle and of the at least one roller cylinder are configured such that no gelling occurs, then the mixture of plasticized polymers and solid substances is supplied to a second degassing planetary roller extruder, which consists of a degassing zone consisting of at least one roller cylinder, and is degassed there, and the degassed mixture is then guided to a coating assembly.