Roving Piecing via Air Vortex Twist and Suction
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Solution Overview
Problem
Existing roving machines face difficulties in quickly and reliably piecing a fiber structure due to the limited draftability and strength of the roving, especially when reversing the roving through the spinning position, which complicates the processing and transportation of the fiber structure.
Innovation Solution
The roving machine incorporates piecing nozzles aligned to generate an air flow that extends into the inlet opening of the spindle, creating a suction effect and imparting a protective twist to the fiber structure, allowing it to be introduced into the spindle in the spinning direction and providing sufficient strength for handling, thus enabling 'forward piecing' without reversing the already produced roving.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the fiber bundle is introduced into the vortex chamber against the spinning direction (as in conventional yarn production), then the fiber bundle can be processed through the spinning unit, but the roving lacks sufficient strength and draftability for reliable handling and transportation
Solution Approach 1:
The patent inverts the conventional spinning direction by introducing the fiber bundle into the vortex chamber in the spinning direction (from inlet opening through vortex chamber to take-off channel) rather than against it. This inversion allows the air vortex to impart protective twist to the fiber bundle during forward motion, creating roving with sufficient strength and draftability for reliable handling while maintaining ease of processing through the spinning unit
2Ease of manufacture
If the roving is reversed through the spinning position for piecing, then the fiber structure can be joined, but the limited strength and draftability of the roving complicate the processing and transportation
Solution Approach 1:
The patent applies preliminary action by imparting protective twist to the fiber bundle during the forward spinning process through the air vortex, before the piecing operation is needed. This preliminary strengthening of the roving enables subsequent piecing operations to be performed more easily and reliably, as the roving already possesses sufficient strength and draftability, thereby reducing the complexity of processing and transportation during piecing
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 approach allows for fast and reliable piecing of the fiber structure, enhancing its strength and enabling it to be gripped and fed to further processes without the need to reverse the roving through the spinning direction, improving the overall efficiency and ease of handling during the spinning process.
Implementation Method 1
guide a fiber bundle through a vortex chamber in which an air vortex is generated
Implementation Method 2
their delivery speed is limited due to centrifugal forces
Implementation Method 3
an airflow extending from the inlet opening into the discharge duct can be generated during the spin-starting process. This airflow creates a suction effect in the area of the vortex chamber's inlet opening
Data Source
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AI summary
The invention relates to a preparatory spinning machine for producing a roving (1) from a fibre sliver (2), wherein the preparatory spinning machine comprises at least one spinning station (3), which comprises a vortex chamber (4) with an inlet opening (5) for the fibre sliver (2) and a roving-forming element in the form of a spindle (6) having an inlet port (10) and extending at least partially into the vortex chamber (4). The vortex chamber (4) has spinning jets (19) associated therewith, via which air can be conducted into the vortex chamber (4) in order to impart a producer twist to the fibre sliver (2) after a piecing process in the region of the inlet port (10). The spindle (6) has a draw-off channel (9), via which the roving (1) provided with the producer twist can be drawn out of the vortex chamber (4). According to the invention the vortex chamber (4) additionally has piecing nozzles (8) associated therewith, wherein the piecing nozzles (8) each have a flow direction that is oriented in the direction of the inlet port (10) of the spindle (6). The invention further relates to a method for piecing a fibre sliver (2) on a preparatory spinning machine serving to produce a roving (1), which method is characterised in that during the piecing process the fibre sliver (2) is moved in a linear movement into the draw-off channel (9) with the aid of the air flow generated by the piecing nozzles (8), and in addition to the linear movement a producer twist is imparted to the fibre sliver (2) with the aid of the air flow.