1. Lower wall sub
Lower wall sub refers to all kinds of wall sub around the fan surface constituting the bottom and side of the bag, such as the upper wide and lower narrow type, upper narrow and lower wide type, rectangular, multi-fold type, two-piece wall sub, etc.
(1). Upper wide and lower narrow type wall sub
The package body in the closed state, the upper wide down narrow type wall sub towards the package folded into a trapezoidal structure, and open the package body when the wall sub is inverted trapezoidal, its purpose is to increase the volume of the package, more soft or semi-hard structure, reflecting the natural, casual effect.
The key to this structure is the production of the upper part of the wall and the corner part of the fan. In the parts mapping, according to different designs of different sewing process requirements, after the processing allowance is put on the parts and marked with the corresponding alignment mark point. Since the length of the arc of the corner part of the fan is increased by adding the allowance, and the length of the straight line of the wall does not change, to make their marking points strictly aligned when sewing, it is necessary to make a cut in the corresponding part of the wall sample, so that the length of the cut can be increased due to the opening of the cut, to supplement the difference in size of the two parts. This is very important in the actual production. When making the cutout, the cutout should be evenly beaten and the length should not exceed 2/3 of the sewing allowance to avoid the defects in the appearance of the finished package due to the exposed cutout.
At the same time, when making the upper part of the wall, because the middle of the upper part generally has a certain arc-like projection due to the need to make up the angle, when making, pay attention to the symmetry of the arc and round smooth, when making the upper part of the arc of the fold, the excess amount to do the fine pleat tightening, the fine pleat should be as small as possible and evenly distributed.
If the fan surface is rectangular, in the production, in order to ensure the smooth coincidence of the fan surface and the wall, and to get a rectangular cross-sectional shape in line with the requirements of the shape, it is necessary to make a cut of about 5mm at the partition between the side of the wall and the bottom of the package. The general number of incisions is one, so as to ensure the margin requirements of the turning part, so that the turning corner of the package body square, regular, so as to ensure the appearance of the package body molding requirements.
(2) Upper narrow and lower wide wall
Narrow upper and wide wall type constitute the package body, simple structure, package body angular, curved full, smooth and natural lines, the use of a larger proportion. The package body can be soft, hard or semi-rigid structure. Although there are many variations in style, but the production process is relatively simple, in the lower corner of the package body is the same as the treatment of the upper wide and narrow type wall sub package, but because of this wall sub upper no corners need to be supplemented, the shape of the horizontal straight line, the wall sub upper mouth along the net folded edge line can be folded net, the requirements of the folded edge straight symmetrical. If the upper mouth has a zipper, then the upper mouth of the fan, the upper end of the wall sub and zipper sewn together to complete the bag production.
(3)Rectangular wall
Rectangular wall sub, free form, simple structure, depending on the presence or absence of intermediate parts and the style varies. The identification of the alignment mark point and the production method is the same as the previous method, here will not be detailed.
Rectangular wall of the bag body because of the shape and lines smooth, simple, so mostly used in the "day" type backpack, business bags, student bags and travel bags, women's bags are also more common, but the design focus is on the change in the shape of the fan or the innovation of the external secondary components.
(4) Multi-fold wall sub
Multi-fold walls are often used in briefcases, of which double and triple pleated walls are more common, the purpose is to use the partition fan
The purpose is to completely divide the body of the bag into several spaces in order to contain various items and documents. The production method of multi-fold walls is similar to that of multi-fold plugs. However, in the case of a bag made up of pleated plugs, the partitions are only sewn to the plugs and are not fixed to the bottom of the bag. The multi-fold wall can be sewn with the partition and the bottom of the bag, so that the bag is completely divided into a number of spaces that are not accessible in the middle, so in the production of multi-fold wall bag. Therefore, it is necessary to focus on the sewing operation of the wall and the partition. Of course, due to the sewing of the partition, the width of the partition needs to be added to the structure of the wall parts, which means that the processing allowance required for sewing the partition needs to be taken into account, so as to ensure that the dimensions of all parts of the package are in line with the standards after sewing. Generally speaking, the partition fan in the bottom of the bag body is only sewn in the middle of the straight part, in the bottom of the bag body and the side of the corner part to leave a certain not sewn position, on the one hand, conducive to sewing, on the other hand is convenient for the use of the bag.
2. Upper wall
The bag body composed of the upper wall is mostly zipper as a way to open and close, the wall is divided into two parts or in the middle to make a zipper cut, the front and rear fan is often designed as a whole large fan. Since the upper wall subs are sewn around the fan, the upper mouth line of the fan is mostly designed with rounded corners for easy production. The shape of the fan of this kind of package body is mostly trapezoid, semicircle and fan with rounded corners on the upper bottom. When the package body adopts the reverse seam, the edge is more ridge strip (side bone), which plays the role of supporting the shape.
The width of the wall in the design is based on the designer's intention and the use of the package, and the length of the wall is determined by the circumference of the large fan. From the fan system surface and the upper wall to form the body of the package production method and the lower wall similar, but because the upper wall also has its own characteristics, so often can be derived from new structures and shapes. The following two common styles are introduced.
(1) the upper wall embedded in the package body
The role of the embedded strip is to make the upper wall embedded in the fan surface. Its shape and size overlap with the outer edge of the large fan and can be sampled directly from the large fan. Since the whole edge of the large fan is long, it is often divided at the corner of the insert and the corresponding processing allowance is added. When sewing, the upper part of the wall is firstly embedded in the package body view. The upper part of the wall is sewn with the inlay on the opposite side, and then sewn with the front of the big fan.
(2) Wall projecting outward to the fan
The wall projection to the outside of the fan is a three-dimensional effect formed by the curvature and convexity of the wall with the help of the structural line change. In the production, we must pay attention to the specific production procedure of the curvature and convexity change of the structure line, especially to the accurate alignment of each mark point, otherwise it will affect the appearance effect of the finished package.
3. Ring-shaped wall sub
Ring wall refers to the wall around the fan surface a week, including the opening and closing tone of the bag mouth parts.
The way of opening and closing is mostly the way of zipper. In the production process, first of all, the lining of the inner pocket, trademark production is completed, after the zipper and the wall sub according to the requirements of sewing together; if there are teeth decorated, you need to pre-sew the teeth and the fan, pay attention to the corner parts of the length of the fan and the length of the teeth with the teeth, shall not appear too tight teeth short, resulting in the four corners of the fan inward buckle shrinkage, the four corners are not brace and cause the appearance of the package body does not stretch. Then, sew the fan face and the wall together, when sewing, pay attention to the alignment mark, strictly in accordance with the alignment mark operation, so as not to cause the fan face on both sides of the wall alignment position is not correct, resulting in the package body crooked screw incorrect, affecting the product appearance. Finally, the stitching part of the fan face and the wall sub is hemmed to beautify the inside of the package and increase the usability of the package at the same time.
