CUTTING

A. INCOMING MATERIAL INSPECTION
All materials from warehouse must be checked and ensure that warehouse department sends the right materials, and cutting department has to check that there is “released” sticker on materials.
If there are any color grouping, cutting dept. has to inform other dept (stitching, assembly, and packing)

B. CUTTING PREPARATION

Leather Storage
Materials from warehouse should be prepared and stored according to the standard for each type of materials.
1. Leather need to be protected from the sunlight, otherwise the leather will be yellowing.
2. The temperature can’t be too high, otherwise the chemical in material will come out.
3. It is better hanging the leather than rolling leather in the leather storage , so wrinkles or creases can be avoided.

Cutting Dies Inspection
In order to make the cutter have high performance the cutting template the most important preparation process before cutting. It can help the cutter avoid the defective.
Cutting Dies Inspection :
· Check the size of the cutting die to see whether it is fit with the pattern.
· Check the horizontality the cutting die on the cutting board or glass.
· Inspect the cutting dies quality through both sound and vision.

Machines Adjustment
1. The optimal distance between cutting die and cutting board is 8 – 10 mm
2. Always set the pressure to zero after every shift finishing and when every shift starting need to reset the pressure in order to avoid any cutting board and any cutting dies damages.

MATERIAL TYPE :

v Leather
Checking with the leather before cutting is necessary to the cutter. Cutter must check quality cutting area with correct stretch, without defective and loose grain. Each type of leather have to be stored separately. Leather normally stretches by arrow, but some special parts are soft and can stretch four directions. So cutter must try to pull leather in order to know leather stretching before cutting.

v PU, Textile, Foam
Every roll from warehouse should be prepared according to the standard number of layer for each type of material, example :
Ø Super tuff : 4 Layer
Ø Cosmo : 6 Layer
Ø Meriskin : 2 Layer
Ø Foam 4.30 : 4 Layer
Ø Foam 8.50 : 2 Layer
Ø Canvas 6oz : 4 Layer
Ø H. Nylex : 4 Layer
Ø Nylon : 5 Layer
Ø LS : 2 Layer
Ø Bontex : 3 Layer





C. LEATHER QUALITY
Leather can be divided into 6 parts, each part has different quality level with each area of the whole leather due to different structure.
v Back
Firm structure, high quality
This area is the most valuable part with the best fiber structure and very view elasticity.

v Shoulder
Worse than the back part because of natural construction.

v Neck
Similar with the leg position, has a little soft, multi-wrinkle.

v Belly
The muscular fiber is longer than the other parts, so the skin is soft, extensible, easy getting loose grain. This position often causes by movement and has some special structure.

v Leg
Similar with the belly material, not has a great value, used for less quality-required components.

v Flank
Soft, multi-wrinkle at armpit and hamstring position. Very soft, serious wrinkle, loose grain. Normally, we cannot cut any components from this area.


D. DEFECT ON LEATHER
Natural defect
v Warble damage holes on scars caused by the grub of warble fly
v Scratchy scars caused by wide, and fighting
v Disease produce a rough are on the skin
v Growth marks, lines in the neck and shoulder areas, more pronounced in older animals
Processing
v Flay cuts caused during of flesh leave the skin weakened
v Brand mark

E. CUTTING TECHNIQUE
v Machine adjustment
v Make sure the Cutting dies in a good condition .
v For the hole skin start on the left shank, cut trough to the butt and to the right s hank.
v Side start back layer to the direction of shank and belly. ( This would result to wastes incurring on interior quality parts of leather).
v Cutting dies have to be placed as close as possible to avoid excessive waste.
v Sample of the shoes should be placed as close as possible to avoid excessive waste
v Cut the large sizes from the largest skin.
v Save skins with many defects for small sizes
v Lift the cutting dies, do not drag them across the leather as they could scratch it.
v Ensure that suede’s patterned and shaded leather is match up.
v Place cut components on the bench so as to avoid damage and put knives on the flesh side of stacked component
v Operator should be felt the stretch direction before cutting

F. CUTTING RULES FOR LEATHER
v Extensibility
Ø The Upper must not stretch in longitudinal direction
Ø Bearing in mind the function of the skin on the body of animal helps the cutter to know the direction of stretch in the various parts of the skin.
v Quality
Ø The best part of the leather must be used for the forefoot are (vamp, toecap, which is referred to as the face of the shoes.
Ø The left & right shoe have to be in the same conformity quality and appearance
Ø Part cut “ the wrong way” always appear rougher on the shoe and darker in color
v Surface utilization
Ø Since leather is generally the most expensive material used for an upper, the surface are need to be used optimally, in order to achieve purpose
Ø Before cutting we must know the stretching direction

Basic rules of cutting
v In the case of a whole skin, the cutter begins on the left shank, working his way over the butt to the right shank. The second layer goes in the reverse direction
v Cow leather almost always comes in sides. In this case the cutter always begins at the back line and works his way systematically.

G. CUTTING RULES FOR TEXTILES AND SYNTHETICS
v Textiles
Ø All textiles components, whether the upper or lining, must have the least stretch in the longitudinal direction of the foot
Ø Placement of the cutting dies thus depends on the direction of warp and weft in the material.
Ø To avoid a possible formation of wrinkles a diagonal stretch is often necessary when working with foxing and lining parts.

v Textile-based synthetic materials
Ø For coated textile, the same basic rules apply as for textiles without coating
Ø Upper parts are cut, under compliance with wrap and weft. When working with printed textiles. The direction of the print also needs to be considered.
Ø However, if the material is used for foxing, the parts are cut out of the material in diagonal direction, in order to avoid folds when lasting.

v Non-woven synthetic material
Ø Non-woven synthetic upper materials are available today with and without a woven backing, in various different thickness and in all required survase finish.
Ø The least stretch should be in the longitudinal direction of the upper.


H. EDGE INKING
If color on the edges of the leathers are not the same (not dyed trough) after being cut, then the edge of these materials must be sprayed with correct and matching ink. Edge inking will be done for visible edge on the shoes.

I. SKIVING
To make the edge of components thinner because of the layering component, we have to skive the edge of component to avoid x-ray (example : PU Foam 8 mm for collar padding)

J. BUFFING
Buffing is the process to remove the surface of leather, making better absorption of primer and cement to the leather. The purpose of having initial buffing process in cutting department is to make the buffing process in assembly easier and faster. For some models, we also need to buff PU Foam to avoid x-ray (example: PU foam 8 mm for collar padding)

K. SCREEN PRINTING AND EMBOSSING
Ø Screen Printing
Usually used for brand name or adidas logo, we have to use the correct and matching ink.

Ø Embossing
HF embossing is another ornamental operation. The precise temperature, pressure and time needed for successful embossing very according to the type, substance and moisture content of the upper material being embossed.

L. EMBROIDERY
During embroidery care has to be taken to ensure that sufficient stitches are programmed in order to achieve an uniformed appearance especially on the edges. The use of the correct thread type and thickness as well as correct needle size is very important for the stitching result. The color of the embroidery used must correspond with the stipulated color specification. Thread ends must be cut or flamed correctly.