Lamp Black Carbon Black in Polyester Preforms
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Solution Overview
Problem
Conventional reheat additives for polyethylene terephthalate resin preforms, such as carbon blacks and metallic antimony particles, reduce the L* color value and increase haze, making preforms appear darker and cloudier, while also affecting the reheat temperature in the stretch-blow molding process.
Innovation Solution
Incorporating lamp black carbon black with a particle size range of 100 to 160 nanometers as a reheat additive in polyester resin compositions to achieve a faster reheat rate with maintained high L* color value and clarity, improving the stretch-blow molding cycle time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional reheat additives (carbon blacks, metallic antimony particles) are used to improve reheat rate, then the reheat temperature increases and production rate improves, but the L* color value decreases and haze increases making preforms darker and cloudier
Solution Approach 1:
The patent changes the particle size parameter of carbon black from conventional ranges (10-500 nm) to a specific optimized range of 100-160 nm. This parameter change resolves the contradiction by achieving fast reheat rates while maintaining high L* color values and low haze, as the specific particle size range optimizes infrared absorption without excessive light scattering.
Solution Approach 2:
The patent uses lamp black carbon black as a replaceable additive that can be incorporated into the polyester resin at specific concentrations (1.5-3.5 parts per million). This additive provides the necessary infrared absorption for fast reheat while being easily incorporated and distributed in the resin matrix, resolving the contradiction between reheat performance and optical clarity.
2Productivity
If carbon black with smaller particle size (15-30 nm as in Pengilly patents) is used to improve reheat, then reheat rate increases, but the preforms become darker and cloudier
Solution Approach 1:
The patent optimizes the particle size parameter to 100-160 nm, which is larger than the 15-30 nm range in prior art. This parameter change reduces light scattering and absorption that cause darkness and cloudiness, while still providing sufficient infrared absorption for fast reheat rates, thus resolving the contradiction between reheat performance and optical clarity.
Solution Approach 2:
The patent creates a composite system by incorporating lamp black carbon black particles into the polyester resin matrix at optimized concentrations. This composite approach allows the carbon black to provide infrared absorption functionality while the resin matrix maintains optical clarity, resolving the contradiction between reheat rate and visual appearance.
3Object-affected harmful factors
If carbon black with larger particle size (200-500 nm as in Harrison et al.) is used, then haze is reduced, but reheat rate decreases
Solution Approach 1:
The patent optimizes the particle size parameter to 100-160 nm, which is smaller than the 200-500 nm range in Harrison et al. This parameter change increases infrared absorption capacity and surface area for heat transfer, thereby improving reheat rate, while the particles remain small enough to avoid excessive light scattering that would increase haze.
Solution Approach 2:
The patent applies local quality by optimizing carbon black particle size specifically for infrared absorption functionality. The 100-160 nm particle size range provides localized optimization where particles are small enough to minimize haze but large enough to provide sufficient infrared absorption, resolving the contradiction between haze reduction and reheat rate improvement.
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
The use of lamp black carbon black provides a faster reheat rate with excellent L* color and clarity, outperforming furnace and thermal carbon blacks in terms of haze and reheat temperature, optimizing preform production in the stretch-blow molding process.
Implementation Method 1
The use of additives that absorb infrared radiation speed the heating of the preforms allowing for faster production rates
Data Source
AI summary
Provided is a polyester or co-polyester resin used in the manufacture of preforms suitable for making bottles and containers containing a carbon black, particularly lamp black carbon black, with a primary particle size in a range of from 100 to 160 nanometers.