1.Types of sheeting
There are two kinds of sheeting methods applied to leather fabrics: through sheeting and edge sheeting.
(1)Through piece
The process of chipping the whole parts is called through-sheet, through-sheet has two kinds of flat blade cutting and round blade cutting. Flat blade cutting is generally applicable to hard and thick leather, such as the fat side of the camera bag, wall parts, etc.. Round blade cutting is generally applicable to handle fabric, package buckle leather, package edge leather, inlay leather, rolled edge leather and other components.
(2) Piece edge
The edge of the parts according to the product process quality requirements, piece into a slope stubble-like process called the edge of the piece. Such as leather cases, leather bags, ticket holders and other parts of the folding edge, stubble, stitching and other parts.
Sheet operation is mainly applied to thicker fabrics, such as cowhide fabrics, and for sheepskin and other thinner fabrics generally do not need or only take a light piece.
2. Application of sheet material
(1) For folding parts of the edge of the piece
In the production process of luggage products, in general, the obvious exposed edges of parts need to be folded. For example, the upper part of the bag needs to do light edge processing. In order to obtain a better appearance, the edge should be sheet thin processing.
The width, thickness and thinness of the edge of the piece should be determined according to the process requirements of the folded edge. Different leather, there are different requirements. Cowhide: leather thick and solid texture, so the slice should be wide, should be slightly deeper.
Sheepskin: leather is thin and soft, so the piece of cutting should be shallow, should be narrow.
(2) For stubble parts of the piece edge
Parts and parts overlap each other called stubble. When stubble is pressed, the parts are divided into upper and lower pressed parts, both upper and lower pressed parts need a piece of edge, the purpose is to make the product as a whole after sewing or gluing the edge potential flat and beautiful. Due to the different positions of the parts on the product, the requirements of the edge of the piece are also different. Generally speaking, the width of the upper pressed parts can be equal to the overlap amount, and the width of the lower pressed parts can be slightly smaller than the overlap amount, if it is larger than the overlap amount, it will cause the stubble to be exposed and affect the beauty of the product.
(3) The edge of the piece used for sewing parts
Since the thickness of the sewn part increases after the leather fabric is sewn, which makes gluing difficult and causes uneven defects in the appearance, the sewn part of the part needs to be hemmed in order to make the sewn edge uniform and flat. In the case of reverse stitching, both parts are sliced at the edge of the seam, and both sides of the seam have the same thickness and are of equal width. If the two parts need to be inlaid in the middle when overlapping, such as the inlay of the tooth skin, then when slicing the edges, the thickness of the slicing should be slightly deeper and the width of the slicing also slightly wider.
3. Slicing method
There are two methods of slicing: one is manual slicing, the other is machine slicing.
(1) Manual slicing
Manual slicing is very important in the production process of leather products, which requires the operator to have a certain foundation of knife work and familiar with the process. Manual slicing includes two types: - one is the edge of the parts of the direct slicing, the other is the edge of the parts of the indirect slicing. There are three types of slicing applications: the first is slicing the edge of the folded edge, the second is slicing the edge of the inlay, and the third is slicing the edge of the seam. When slicing folded edges, the mesh layer is sliced and the grain surface layer is retained. When slicing, the mesh layer is facing upward and the grain layer is pressed on the surface of the sliced tile, so that the slope of the sliced edge is slightly flat, thus making the folded edge flat. When slicing the edges of the joint, the upper pressing material slices the mesh layer, and the lower pressing material needs to slice the grain surface layer; when slicing the seam part, both parts slice the mesh layer.
There are three types of flake cutting applications: the first is flake cutting of folded edges, the second is flake cutting of inlaid edges, and the third is flake cutting of stitched edges. When slicing folded edges, the mesh layer is sliced and the grain layer is retained. When slicing, the mesh layer is facing upward and the grain layer is pressed on the surface of the sliced tile, so that the slope of the sliced edge is slightly flat, thus making the folded edge flat. When slicing the edges of the joint, the upper pressing material slices the mesh layer, and the lower pressing material needs to slice the grain surface layer; when slicing the seam part, both parts slice the mesh layer.
①Direct chipping: Direct chipping is the method of chipping directly by hand until it meets the process requirements.
Slice operation method is as follows:
a. Sharpening: Sharpening the knife.
b. Slicing: lay the material, the edge of the piece on the left side of the operator, the right hand holds the knife tip forward, the thumb's finger surface pinch in the side of the 80 ° knife angle, the knife angle in the drawing of the line forward, the knife forward when pushing the force to be soft in the strength, knife, knife edge and leather into 15 ° ~ 20 ° angle, the knife surface and the material surface angle should be constantly changing with the formation of the slope of slicing.
② Indirect slicing: indirect slicing is the edge of the sliced parts on the slicing machine for "re-knife" trimming. If the slope of the parts sliced by the machine slice is not straight, it will cause unevenness of the surface of the mosaic in the parts and parts, thus forming product defects. Therefore, the quality of the flake must be corrected by manual second flake.
(2) Machine chipping
In the luggage processing process, according to the technical data requirements, the leather will be thin or edge parts into slope 253 surface. Machine slicing production efficiency, workers labor intensity is small, suitable for industrial mass production.
Before operation, first adjust the distance between the presser foot and the circular knife, so that the thickness of the leather meets the requirements, then use the right hand thumb to pinch the corner or - end of the part, the part will be sent between the presser foot and the circular knife, with the rotation of the feeding stick to pull out the good part, while the left hand will gradually send the unsliced part to the leather slicing machine until it is completed. When operating, make sure that the leather to be sliced part of the feed is flat and wrinkle-free, so as not to block or damage the surface of the leather, the speed of the sliced leather should be based on the speed of the feeding stick as a criterion, both hands only play a basic auxiliary role, not to force pulling, so as not to appear uneven thickness of the sliced leather or even the phenomenon of sliced leakage.
