First, the bag composed of symmetrical fan surface
The basic feature of the bag composed of symmetrical fan is that the combination line of front and rear fan is in the midline position of the side of the bag body, and the front and rear fan can be changed in different forms according to different shapes. If the structure is completely symmetrical and the two fan parts are identical, the production process is often based on the backstitching method.
1. The design of the package body composed of simple front and back fan
(1) Smaller volume, no pleating at the bottom of the fan
The bag made up of simple front and back fan, the fan surface is generally rectangular or trapezoidal, and the process uses the backstitching method or adds ridge strips to support the shape of the bag body. Because the bag body is flat and thin, so often designed in the front sector with three-dimensional patch pocket, both to increase the capacity of the bag, but also visually increased the sense of thickness. And the bag shape and fan profile is similar, unified and harmonious.
By the simple front and back of the fan surface composition of the bag in the shape of the change is also often designed for dual-use bag, one is in the bag body side height of 2 / 3 with a strap, the upper part of the bag body when the shoulder naturally drops, showing
Natural; the other is designed at the mouth of the bag to pull the belt, hand-carried look casual and generous. The sewing method of this bag is similar to the flat tote bag with three-dimensional patch bag, first the strap is installed, and then the production of lining and fabric, respectively, after forming the bag upper mouth folded edge, and according to the design requirements of the handle fixed in the corresponding position, and finally the bag upper mouth, the face is assembled neatly.
In addition, this structure of the bag can also make some changes to the bottom to form a new image of appearance, such as the bottom of the fan at right angles or sharp angles, when the width of the bottom of the bag increases, the capacity increases, the entire body of the bag also presents a different shape. When sewing this kind of bag, the front and back of the fan are sewn together by backstitching, thus forming two sharp corners on the bottom side of the bag, and then the sharp corners are folded upward along the side seam line, sewn and fixed according to the designed bottom width, forming the bottom of the widened bag. The width of the bottom can be large or small, varying with the width of the seam allowance.
(2) Pleated bottom of the fan
In the bottom of the fan surface to make a cut angle to form a pleat, so that the width of the bottom of the package increases, the volume of the package increases, and the fan surface forms a curved shape. This structure is mostly designed with the cut angle, length and position changes in the fan surface, and the package body shape varies with the size, length and position of the cut angle. The larger the cutting angle at the bottom of the fan, the more obvious the formation of the bulge, the greater the width of the bottom of the package; the longer the cutting angle, the longer the fold formed, the flatter the bottom of the package. Cutting angle according to the need for general design in the bottom two corners of the fan and the middle of the bottom of the package, so that the formation of the effect of the bulge along the entire edge of the package body more uniform; if only in the two bottom corners of the fan to do cutting angle, the package body on both sides of the bulge is more obvious, while the middle of the package body is naturally curved state. The impact of the size, position and length of the fan cut corners on the body shape needs to be carefully compared and appreciated, and the law of structural changes on the shape can only be applied. When sewing, first the fan on the pleated seam well, pay attention to the ends of the pleated seam to be fixed firmly, especially in the internal end of the fan must be sealed thread, and then the zipper parts sewn together, after the gouge part of the molding, and finally the front and back of the fan sewn together -.
(3) The bottom of the fan face is made shrink pleated package
The bottom of the fan side to do shrink pleats and do pleating the same purpose, but present a different visual effect. Shrink pleats can increase the internal volume of the bag, and the appearance of the effect is lively and vivid, with a certain sense of fashion. Shrink pleats caused by the amount of the appearance of the effect of a large difference, the larger the amount of shrink pleats, the greater the volume of the bag, the stronger the sense of feminine trim. This bag in sewing, especially to pay attention to the uniformity of the bottom of the bag pleats, it is necessary to use a large needle code to pinch the shrinkage pleats first, and then the front and back of the fan sewing operation.
2. bag body consisting of the front and back of the large sector containing the plug and the bottom of the bag
( 1) Bottom and plug are retracted into the bag body
This structure bottom and plug are indented into the bag to a certain depth, the middle of the bag body with a partition fan, the upper part of the partition fan is set up with the inner skin, the partition fan with the inner parts of the material cover made, suitable for women's backpacks, handbags, etc., because the plug and the bottom are indented into the bag, so the volume is smaller, often designed for two or three compartments structure. According to the bag body fan, plug and vertical direction whether there is an angle, the production method is different.
(2) The front and back of the fan to do different forms of changes in the body of the package
This structure in the design of the focus on the front and rear fan on the mutual extension of change, the parts in the drawing has been in accordance with the principle of residual shortage of the rear (front) fan to the front fan extension in the front (rear) fan in order to ensure that the package body shape remains unchanged. In the production process, the extension part is still considered as one with the original fan surface, the production procedure is the same as the general geometric fan surface, except that when sewing the extension part, we should pay full attention to the external shape of the extension part, especially the connection between the front part of the extension part and the other fan surface, we must ensure that the stitching is smooth and smooth.
Second, the package body composed of asymmetric fan
Asymmetric sector constitutes the package is based on the basic structure of the symmetrical sector, after the displacement of the structure line, before and after the sector of the plane and surface changes and derived from the new package. This kind of bag structure is novel, rich in changes, suitable for individualized young women. Among the bags designed by the displacement of the structural line is the sector, plug and the bottom profile contour line according to the modeling and structural needs of the position of the change, the change follows the principle of residual shortage, that is, a part to other parts of the extension and increase the part, need to be extended in the parts subtracted to ensure that the overall form remains unchanged. However, no matter how the structure line is transferred, as long as the principle and law of change is mastered, it can be applied flexibly. The sewing method is similar to the one consisting of symmetrical scallops.
