Shedding mechanism-shed formation and clarity
1. Shed formation
When shedding, the warp yarn is divided into upper and lower layers as the heald frame relaxes, forming a diamond-shaped space, which is the shed. As shown in Figure 1-12, H is the maximum lifting stroke of the warp, which is called the shed height; the horizontal distance from the cloth fell B to the guide rod D of the drop frame is the shed length or shed depth, which can be divided into The length of the front part of the shed is L1 and the length of the rear part is L2; L3 is the heddle eye C1 to The horizontal distance of the yarn holding point E of the back beam. The ratio of L1 and L2 is called the symmetry of the shed, expressed in m. When m is equal to 1, it is called a symmetric shed, and when m is greater than or less than 1, it is called an asymmetric shed. The entire shed is divided into two parts, the front and rear, by the heald frame. The front of the heald frame is the working part, and the weft carrier introduces the weft yarn from here. When the shed is fully open, the angle formed by the upper and lower warp yarns at the cloth fell B is called the shed front angle, and the angle formed at the guide rod D in the drop frame is called the shed back angle.
The polyline BCDE in the figure is the warp position line of the warp, referred to as the warp position line for short. If the two points D and E are located on the extension line of BC, then the meridian position line becomes a straight line and becomes a straight line. The horizontal line drawn through point A is called the breast beam horizontal line, also known as the meridian line. It is the standard for measuring the height of the back beam E. When the back beam is higher than the meridian, that is, when P > 0, it is called a high back beam; when the back beam is lower than the meridian, that is, when P < 0, it is called a low back beam. The warp position line has a significant impact on the warp breakage, tension, elongation and fabric appearance quality during the weaving process, and should be adjusted and controlled. The adjustment of the warp position line in weaving production generally refers to the change of the position of the back beam, and once the positions of other points are determined, they generally do not change.
2. Shed clarity
The degree to which the upper and lower warp yarns in the front of the shed are on the same plane is called the clarity of the shed. If the upper and lower warp yarns in the front of the shed are exactly on the same plane, it is called a clear shed, which is convenient for the passage of the weft carrier. However, in this opening method, the warp yarns are easily entangled, and the rear heald frame has a large movement, which can easily cause the warp yarns to break. head. If the upper and lower warp yarns in the front of the shed are not in the same plane, it is called an unclear shed. If the upper warp yarns in the front shed are not in the same plane and the lower warp yarns are in one plane, it is called a semi-clear shed. In this case Below, the difference in the movement of the heald frame is small, and the movement of the rear heald is smaller than that of the clear shed, which is advantageous, but it is necessary to prevent misweaving and warp breakage caused by the penetration of the weft carrier into the non-clear warp layer.
AAA4353466DG
Extendedreading:https://www.yingjietex.com/product/Imitate-Hemp-In-Disorder-Dobby-Polyester-OXFORD-Fabric.html
Extendedreading:
Extendedreading:
Extendedreading:
Extendedreading:
Extendedreading:
Extendedreading:
Extendedreading:
Extendedreading:
Extendedread
