Bilobal Spinneret Orifice Orientation for Filament Cooling
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Solution Overview
Problem
Existing spinnerets for spunbond and meltblown processes do not efficiently distribute air for uniform cooling and attenuation of bilobal filaments, leading to non-uniform cooling and reduced filament strength.
Innovation Solution
The spinneret features bilobal spinning orifices with a specific orientation, where the longitudinal central axis of each orifice is tilted relative to the air stream direction, improving air circulation and cooling efficiency by adjusting the angle between the orifice axis and the air stream direction within a range of 3° to 15°, preferably 5° to 10°.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional spinnerets with standard orifice orientation are used, then the structure is simple and easy to manufacture, but the cooling and attenuation of bilobal filaments is non-uniform, reducing filament strength
Solution Approach 1:
The patent applies asymmetry by tilting the longitudinal central axis of each bilobal spinning orifice at a specific angle (3° to 15°) relative to the air stream direction. This asymmetric orientation creates non-uniform air flow distribution that enhances cooling efficiency and filament attenuation, directly improving filament strength while maintaining a relatively simple spinneret structure
Solution Approach 2:
The patent changes the orientation parameter of the bilobal orifices from the conventional parallel alignment with air streams to a tilted configuration within a specific angle range (3° to 15°). This parameter modification optimizes the interaction between air flow and filaments, improving cooling uniformity and filament strength without significantly complicating the spinneret manufacturing process
2Temperature
If conventional spinneret orientation is used, then manufacturing is simple, but air circulation around filaments is insufficient, reducing cooling efficiency
Solution Approach 1:
By introducing an asymmetric tilt angle (3° to 15°) between the orifice longitudinal central axis and the air stream direction, the patent enhances air circulation patterns around the filaments. This asymmetric configuration creates more effective air flow distribution that improves cooling efficiency while remaining compatible with standard spinneret manufacturing processes
Solution Approach 2:
The patent applies local quality by specifically orienting the bilobal orifices at a tilted angle in the regions where filaments are formed and cooled. This localized orientation adjustment optimizes air flow interaction precisely where needed for cooling, without requiring complex modifications to the entire spinneret structure
3Productivity
If conventional spinneret design is used, then the structure is simple, but filament attenuation is non-uniform, reducing processing efficiency
Solution Approach 1:
The asymmetric tilting of bilobal orifices (3° to 15° angle) creates optimized air flow patterns that enhance filament attenuation uniformity. This improves processing efficiency by ensuring consistent filament properties, while the relatively simple tilted configuration avoids significant increases in spinneret manufacturing complexity
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 orientation enhances uniform cooling and attenuation of bilobal filaments, resulting in increased filament strength and improved processing efficiency in both spunbond and meltblown processes.
Implementation Method 1
the spun filaments are rapidly cooled by cold air streams that are blown below the spinneret plate (quenching step)
Implementation Method 2
a high volume air flow at a temperature which is typically equal or slightly greater than the melt temperature of the polymer, is used to attenuate the filaments
Data Source
Figure 1
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Figure 5~6
AI summary
The spinneret (140a) is used for manufacturing a web by a spunbond process or meltblown process, and has longitudinal axis (X) that corresponds to the width of the spunbonded or meltblown web. Said spinneret comprises bilobal spinning orifices (141) each having a longitudinal central axis (A). The angle (α) between the longitudinal axis (X) of the spinneret and the longitudinal central axis (A) of one bilobal spinning orifice (141) is between 75° and 87°, in order to improve the cooling and attenuation of the filaments.