1. Parts and leather fabric parts of the relationship
Different parts have different requirements for leather material. Because the main parts basically represents the product appearance quality, therefore, its material selection is the most priority; in the secondary parts or inconspicuous position of the secondary parts, the quality of leather fabric requirements are slightly lower, but in the conspicuous parts of the secondary parts still need to choose high-quality fabrics. Therefore, according to the different parts and material parts of the comprehensive consideration, both to ensure the use of the quality of luggage products, appearance quality, but also to maximize the savings of leather fabrics.
The main parts of the travel suitcase are box cover, box bottom in the tendons, cover fat surface, box bottom fat surface, walls, etc., because the box cover, bottom fat surface, wall panels, etc. are in the main parts of the product, therefore, for natural leather as the fabric of the suitcase, these parts should be selected with superior quality leather parts, such as: hips, neck and shoulder parts, etc., can not use the abdominal cortex parts. To ensure that the main parts of the product surface smooth, fat shape full.
For the bag, the front and back fan is the most important part of the bag visually, and its decorative and practical functions are the most important. Almost all of the bag production use the best material of the batch. In the cutting process, good materials are selected and cut in priority. Among them, the requirements of the front sector parts are higher than those of the back sector parts. The decorative meaning of the switch way is basically equivalent to the front fan face, which has very good practical function, so the best material shall be used, and the requirements of the front fan face are basically the same. Side decorative function is second to the front fan and cover, the functional significance is more important, in the choice of materials, focus on the solid and durable quality. The bottom as the bag's weight-bearing Zou bit, the decorative significance of the requirements are not high, in terms of material selection requirements in general. Inside the bag lining, inside the bag, partition fan and other components, its use function is relatively more important, the decorative function is second. Generally speaking, the choice of lining material is mainly related to the fabric material and design intent, can allow the existence of light defects.
Therefore, the principle of the choice of materials for each part of the bag product is: the main parts of the best back part of the leather, to ensure that the product appearance requirements, the rest of the parts of the material selection criteria can be slightly relaxed, can use the abdominal neck, neck, limb parts, in order to rational application of leather and reduce product costs.
2.Parts and leather fiber bundle (wisp) direction of the relationship
In the row of material, in addition to pay attention to the part of the leather, but also pay attention to the leather texture of the horizontal and vertical direction, especially for the front and back of the fan, wall, back belt and other weight-bearing parts, must pay attention to the horizontal and vertical extension of the problem.
Because the natural leather material tissue structure is relatively complex, mainly by the collagen fiber bundle longitudinal and transverse weave. By the longitudinal and transverse fiber weave to form a dense mesh structure, the main fiber bundle direction and the spine cone line parallel, the rest of the parts outward extension, and the spine cone line into - a certain angle. When the direction of the main fiber bundle of leather fibers is the same as the extension direction, the elongation is small and the tensile strength is large. When tilted to a certain angle, the elongation rate gradually increases, and its 90 ° angle of the transverse direction of the elongation rate is the largest.
The main load-bearing parts of the luggage products generally require good strength and small elongation to ensure that the product in the processing process to maintain the appearance of the shape of the same or less change and the actual use of the needs. Therefore, when cutting, the main fiber bundle direction is used, in order to save leather, improve utilization, leather products auxiliary parts can be used lateral, oblique fiber. Should try to avoid the application of transverse direction on the load-bearing parts. Of course, for different leather fabrics should also be treated separately, for example, cattle leather transverse longitudinal elongation difference is relatively small, in the application can relax the angle requirements, and for those transverse longitudinal elongation difference between the leather, it is necessary to fully consider the angle of the problem.
3.The reasonable use of leather residue
In the natural leather fabric there are various kinds of residues, among which there are physiological residues left when the animal body is alive, and there are also processing residues caused in the tanning process. The existence of these injuries reduces the use value of leather, and also brings - certain difficulties to the cutting of products. In order to make better use of leather materials, reduce the loss rate of raw materials and improve the cutting quality, it is necessary to carefully understand the leather fabric's residual condition, so as to make full use of the leather's residual defects, and greatly improve the economic efficiency of the products under the premise of ensuring the appearance quality of leather products.
According to the degree of leather surface injury and available degree, the injury is divided into three categories:
① surface injury: only the surface and not the substance of the injury is called the surface injury, the surface injury only affects the appearance of the product, does not affect the actual use of quality, such as color flowers, whip flowers, scars, etc.. This disability can generally be applied in inconspicuous locations, and requires it to be a relatively small area of disability.
② light injury: the disability area is small or depth of not more than 1/4 of the skin thickness of the disability is called light injury, such as fungal injury, cracked surface, tortoise, etc.. Light injuries include knife wounds and small holes, the appearance of the product and the use of a certain impact, in general, the surface of the product should not appear such injuries, should try to put such injuries can be covered parts, or placed in the sewing of the parts of the balance.
③Serious injuries: injuries that are larger or deeper than 1/4 of the thickness of the skin are called serious injuries, such as gadfly eyes, fractures, heavy wounds, knife marks, etc. Heavy wounds - generally no longer used in the finished product parts, should be cut off when cutting.
Similarly, in the selection of leather, but also to take into account the quality requirements of different parts, try to improve the utilization of leather. For example, the lid of the suitcase, the bottom of the fat side of the middle set in the rib, in the set in the rib below the fat side of the leather surface, allowed to have a disability, in the rib of the two sides of the folding parts can also be allowed to have a disability, after the strip because in the back of the product, can use the skin surface disability.
Therefore, the principle of using to avoid the residue is: the front part of the product, the cover choose the best leather, while the side wall, the back part can use the art part of the residue, those parts of the surface covered with decorative strips, allow the use of the residue, in addition, in the joint, sewing parts also allow the existence of the residue, the residue will be hidden inside the product, does not affect the external beauty.
