Bubble cloth is a fabric formed by interweaving stripes of meridional corrugated concave and convex bubble parts and plain ground parts. This type of fabric is realized by the tension of the warp yarns in the corrugated state being relaxed compared to the tension in the plain weave state. During the normal weaving process, the ground warp yarns are placed on the upper warp beam for let-off, and the foamed warp yarns are placed on the lower warp beam with a positive let-off device. What plays a leading role in the foaming effect of bubble cloth is the tension of the upper and lower axis ground warp yarns and bubble warp yarns. In addition, the opening time of the loom, the positive let-off timing, the positive let-off amount, and the height of the drop frame play an auxiliary adjustment role.
1. Loom ground warp and bubble warp tension
The setting of the upper and lower axis warp tension is related to the total number of warp threads. During the weaving process, the upper and lower axis tension is increased or decreased according to the foaming effect of the bubble cloth. If you increase the tension of the ground warp yarn and reduce the tension of the bubble warp yarn, the fabric will easily blister. The lower the tension of the bubble warp yarn, the better the foaming effect of the fabric will be. However, if the tension of the bubble warp yarn is too low, the drop pieces on the bubble warp yarn will fall and contact the drop bar, causing The situation of accidental stop. Therefore, the tension setting should be comprehensively measured based on the foaming effect and the droop balance of the drop pieces. The lower limit of the bubble warp yarn tension is limited to the fact that the drop pieces do not droop during the weaving process. The setting range of the ground warp tension of the upper shaft of current air-jet double beam looms is generally 1000-1300 N, and the setting range of the bubble warp tension of the lower shaft is generally 600-1000 N.
2. Loom opening time
In the bubble weaving process, the opening time of the loom is generally adjusted to 310°~350°. The larger the opening time value, the stronger the foaming effect and the greater the foaming ratio. The larger the shedding time value is, the smaller the warp filling tension is, the greater the relative buckling degree is, the fluffier the yarn is, and the greater the friction between the weft yarn and the steel reed that pushes the weft yarn to the cloth fell, and the higher the warp filling tension is at the cloth fell. Smaller, better foaming effect. Therefore, if you need a bubble-heavy effect, the opening time can be adjusted to 350°.
3. Loom active let-off timing
The adjustment of the positive let-off timing of the loom is set relative to the shedding time, and is generally achieved by changing the mechanical eccentricity. The greater the positive let-off timing is in advance of the opening time, the better the foaming effect will be. Relative to the opening time, the maximum set positive let-off timing is 90° ahead of the opening time.
4. Loom active warp let-off
The active warp let-off amount of the loom has a great relationship with the formation of bubbles. By mechanically adjusting the back beam let-off joint, the buckling degree of the warp bubbles can be further controlled. This process is relatively cumbersome in actual operation. Current looms have three let-off amounts, namely 13.2 mm, 6.8 mm, and 4.5 mm. The larger the warp let-off amount is, the more obvious the fabric foaming effect will be.