Stationary Sensor in Carder Web Guide for Contamination-Resistant Detection
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Solution Overview
Problem
Existing carding machines face issues with the detection of disruptive particles such as trash, neps, and foreign matter in carded fiber webs, leading to contamination of sensors, reduced service life, and production downtime due to complex and movable sensor arrangements.
Innovation Solution
A carding machine with a stationary sensor system in the web guide element, positioned to detect fiber webs on the doffer, uses a translucent element and polarization filter to minimize contamination and enhance accuracy, while fixed sensors with parallel data processing improve detection efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the sensor is arranged in a web guide profile with a concave surface facing the doctor roller, then the sensor can detect the fiber web, but the web guide profile becomes rapidly contaminated, reducing measurement accuracy and service life
Solution Approach 1:
The patent inverts the conventional arrangement by positioning the sensor on the convex outer surface of the web guide profile rather than the concave inner surface. This inversion allows the sensor to detect the fiber web through the profile wall while the convex surface faces away from the fiber flow, preventing contamination. The sensor beams penetrate the profile wall to detect neps and disruptive particles in the fiber web without the sensor housing being exposed to contaminating fibers and dust.
Solution Approach 2:
The patent introduces the profile wall as an intermediary element through which sensor beams pass to detect the fiber web. The translucent or transparent profile wall allows optical detection while physically separating the sensor from the contaminating fiber environment. This intermediary structure enables measurement functionality while protecting the sensor system from harmful contamination.
2Measurement precision
If the web guide profile is cleaned frequently to maintain detection accuracy, then measurement precision is improved, but production downtime increases due to complete card shutdown
Solution Approach 1:
By inverting the web guide profile orientation so the convex surface faces outward, the patent eliminates the need for frequent cleaning operations. The sensor is positioned such that the detection surface is not exposed to fiber contamination, maintaining measurement accuracy throughout the service life without requiring production interruptions for maintenance.
Solution Approach 2:
The patent implements a self-cleaning mechanism where the fiber web flow itself continuously cleans the convex outer surface of the web guide profile. As fibers pass by the profile, they naturally remove any accumulated dust or contaminants from the external surface, eliminating the need for manual cleaning interventions and associated production downtime.
3Adaptability or versatility
If a movable sensor arrangement is used in the web guide profile, then detection flexibility is improved, but device complexity increases and reliability decreases due to dragged cables
Solution Approach 1:
The patent merges the sensor system with the stationary web guide profile structure, integrating the sensor housing directly into the profile. This combination eliminates the need for separate movable sensor assemblies and dragged cables, creating a fixed, reliable installation that maintains detection capability through the profile wall while removing failure-prone moving components.
Solution Approach 2:
The patent replaces the mechanical movable sensor system with an optical detection system. Instead of physically moving sensors to detect different positions, the stationary sensor uses optical beams that can detect the entire fiber web width through the transparent profile wall, substituting mechanical movement with optical field coverage.
4Object-affected harmful factors
If the sensor detects the fiber web on the doffer teeth, then contamination of the sensor area is reduced, but the gap between the web guide element and doffer must be very narrow
Solution Approach 1:
By inverting the web guide profile orientation and positioning the sensor on the external convex surface, the patent allows the sensor to detect fibers on the doffer teeth through the profile wall while maintaining a normal gap between the profile and doffer. The detection surface is protected from contamination while the optical beams penetrate the profile to monitor the fiber web in the doffer tooth area.
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 system provides longer service life, reduced contamination, and faster detection of disruptive particles, enabling real-time optimization of carding processes and improved fiber quality.
Implementation Method 1
the concave surface of the web guide profile, which is arranged towards the doctor roller, has an at least partially transparent wall through which the fibers are detected by a sensor
Implementation Method 2
A polarization filter is arranged on the translucent element within the fleece guide element. The polarization filter is designed for circular polarization, so that the sensor beams reflected by the doffer's clothing are blocked
Data Source
Figure 1
Figure 2~2a
Figure 3
AI summary
The invention relates to a carder (100) with a device for recognising undesired particles, in particular articles of trash, neps, shell neps, thickened points and/or foreign articles in a carded fiber web (16), wherein the device comprises at least one sensor (30) which is arranged in a stationary manner in a web guiding element (20) which is arranged in the transition from a doffer (5) to a stripper roller (6), wherein the at least one sensor (30) detects the fiber web (16) on the doffer (5).