Ultrahigh temperature, low scorch method of making crosslinkable compound compositions
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Solution Overview
Problem
The existing method for making crosslinkable polyolefin compositions involves soaking organic peroxide into polyolefin granulates in soaking towers, which is time-consuming, leads to non-homogeneous distribution, and increases production costs, while also causing premature crosslinking.
Innovation Solution
A method involving ultrahigh temperature mixing in a melt compounding device to rapidly create a homogeneous mixture of thermoplastic polyolefin, antioxidants, and curative additives, eliminating soaking towers and reducing scorching, using a process that includes feeding materials into an extruder, mixing at high temperatures, and injecting curative additives directly into the melt.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If organic peroxide is soaked into polyolefin granulates in soaking towers, then the peroxide is incorporated into the granulates, but the process is time-consuming (6 to 12 hours soaking time) and leads to non-homogeneous distribution with concentration gradients
Solution Approach 1:
The patent changes the temperature parameter from conventional low-temperature soaking (50-80°C) to ultrahigh temperature processing (above melting temperature of polyolefin). This parameter change enables rapid homogeneous mixing by melt compounding, eliminating the time-consuming soaking process and concentration gradients while achieving complete peroxide incorporation in minutes rather than hours
Solution Approach 2:
The patent utilizes phase transition of polyolefin from solid granulates to molten state during melt compounding. By heating above the melting temperature, the polyolefin transitions to a liquid phase where peroxide and crosslinking coagents can be thoroughly mixed and homogenized, then cooled to form uniform granulates with consistent peroxide distribution
2Reliability
If organic peroxide is soaked into solid granulates at low temperature, then premature crosslinking is prevented, but the soaking process takes 6 to 12 hours and increases production costs by 35% to 50%
Solution Approach 1:
The patent implements continuous melt compounding processing where polyolefin, peroxide, and crosslinking coagents are continuously fed, melted, mixed, and extruded in an integrated process. This eliminates the discontinuous soaking process and its associated time losses, achieving continuous production without premature crosslinking through controlled residence time in the extruder
Solution Approach 2:
The patent extracts and eliminates the soaking towers from the production process entirely. By using direct melt compounding, the process removes the separate soaking step that caused time delays and cost increases, integrating peroxide incorporation directly into the extrusion process
3Ease of manufacture
If organic peroxide is soaked into granulates, then crosslinkable composition is formed, but soaking towers add 35% to 50% additional expense to production line cost
Solution Approach 1:
The patent merges the peroxide incorporation step with the existing extrusion process. By injecting peroxide and crosslinking coagents directly into the melt compounding extruder, the process combines mixing, heating, melting, and peroxide incorporation into a single integrated operation, eliminating the need for separate soaking towers and reducing equipment complexity
Solution Approach 2:
The patent makes the extruder perform multiple functions: melting polyolefin, mixing additives, incorporating peroxide, and forming uniform granulates. This multi-functional approach eliminates dedicated soaking equipment and reduces overall production line complexity while maintaining crosslinkable composition formation
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 results in a fully crosslinkable, homogeneous compound composition with minimal scorching, reducing production time and costs, and enabling efficient production of extruded articles like coatings, films, and cables with improved curability.
Implementation Method 1
ultrahigh temperature mixing in a melt compounding device to rapidly create a homogeneous mixture
Implementation Method 2
a temperature that is well below the —O—O— bond cleavage temperature of the organic peroxide
Data Source
AI summary
An ultrahigh temperature, low scorch method of rapidly making a crosslinkable compound composition comprising a homogeneous mixture of a thermoplastic polyolefin, antioxidant, and curative additives comprising one or more organic peroxides and one or more multialkenyl crosslinking coagents. The method avoids soaking towers and lengthy soaking times, and yet makes a fully crosslinkable, homogeneous compound composition with minimal or no premature crosslinking of the thermoplastic polyolefin(s).