Quality Manual-Receiving Inspection-Leather and PU

It's very important to make quality inspection of all kind of in-house material.

Let's Proceed to Receiving Procedure.

Purpose: 

To establish and maintain documented procedures for receiving inspection in order to verify that the specified requirements for the product are met.

Scope:

This section applies to all the materials used for producing shoes in your factory are quality checked.

Raw material plays a very important role in making a quality product. Even the most outstanding manufacturing methods cannot compensate for defective materials. In line with that the raw material and accessories in housed are inspected before adding on the stock.

Leather:

• Leather is checked with the approved swatch (color, shade, thickness, texture etc). If it doesn’t match, is returned. Then the leather is selected in three different grades on the basis of usability avoiding defects.
• Grade A – usability 90 – 100%
• Grade B – Usability 80 – 89%
• Grade C – Usability 70 – 79%

After making this grading, it has been reported to the Top Management for his decision. Normally Grade C is returned.

Sometimes Grade B is sending back for correction to improve the usability or negotiated with the supplier for reduction to a reasonable extent.

Possible defects in the leathers are:

Flow Chart Of Leather Store

• Scratches or blemishes in the grain.
• Brand marks in the butt.
• Growth marks in the neck.
• Warble and tick marks.
• Loose grain.
• Holes in the butt.
• Loose flank-bigger flanks.
• Stain marks in the reverse side.
• Poor trimming.
• Coarse finish break.
• Butcher cuts etc.

Leather Inspection Report should like this

Leather Inspection Report

 Fabric/ PU Store:

Fabric/PU comes on roll form. While receiving rolls are counted and matched with the purchase order and the approved swatch and also get it approved by the sample dept. Quantity written on the roll is recorded.  Length is checked while making lay during use in the cutting dept. and accordingly communicated to the supplier for necessary settlement.

Flow Chart of Fabric or PU Store.

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Glossary of I K L

Glossary of I:
Inseam- the hidden seam of a welted shoe holding together the welt, upper, lining and insole.

Instep- top part of the arch of a foot over the metatarsal bones from back of the toes to the ankle. Also the corresponding part of a shoe last.

Iron- term used for measuring the thickness of sole leather. One iron equals 1/48 in. (0.0283 in.). Three iron thickness is 1/16 in. and 12 iron is 1/4 in.

Isocyante resins- Most application for this resin are based on its combination with polyols (e.g. polyesters, polythers, etc). During this reaction, the reactants are joined through the formation of the urethane linkage.

Glossary of K:

Kid- originally referred to leathers made from the skins of immature goats, term is now used rather loosely to apply to glove and shoe leathers made from goat skins.


Glossary of L:

 Lap seam- the simplest form of seam used in sewing. Made by lapping one part slightly over the other and sewing through both. One or both of the parts so joined is usually skived along the edge to reduce the thickness.

Shoe Last

Last- form over which the shoe is made and which determines its shape. Although there are numerous types of lasts in common use, the basic differences are guided by the type of shoe construction. Lasts may be made of wood but are usually plastic.

Lasting- one of the most important operations of shoe making. Requires the shaping of the upper tightly o\to each contour of the last, the pulling and stretching of the upper so that there will be no wrinkled outer or lining parts and no crooked seams.

Lockstitch- a double thread stitch that locks the thread together within the material. It is distinguished in service by the fact that breaking one stitch does not permit the seam to be ravelled out.

Louis heel- high heels with a gracefully curved back, with a lip extending part way under shank resulting in a curved breast. Usually 16/18 to 24/8 in height, sometimes called French heel.

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Basic of Shoes- Bottom Parts

Last part of the Basic of shoes series. Here is the first three parts
1. Basic of Shoes
2. Basic of Shoes- Leather Upper
3. Basic of shoes- Synthetic and Others

• Rubber: Rubber is used for the upper when the sole is made of the same material.
• Bottoms: The types of materials commonly used in shoe bottoms are:
• Leather
• Rubber
• Plastic

• Leather: The larger and thicker leather skins are used for bottoms. The insoles are cut from the bellies and the outsoles from the skin cut along the backbone where the leather has the greatest abrasion resistance. The properties of leather of bottoms are:
• Great abrasion resistance
• Expensive: Leather is generally more expensive then most rubbers or plastic. That is why it is mainly used in high quality footwear.
• Less durable than most other materials: Leather is chosen for its attractive appearance rather than durability, which is lower compared with most other materials.

• Rubber: Rubber can be:
• Natural
• Synthetic(SBR)

          The properties of rubber for bottoms are:

• Hard wearing
• Flexible
• Waterproof
• Easier and less expensive to produce than leather

               Today, most types of rubber are likely to be based on the general-purpose synthetic rubber denoted S.B.R., rather than the traditional natural rubber obtained from rubber trees. Soles made from these two types of rubber are vulcanized (except crepe) and have similar properties. Vulcanized soles are sometimes referred to as "Composition rubbers" because they are made up of a number of ingredients added to the basic rubber to control the properties. Some black compounds may have a tendency to mark floors depending on the quantity of carbon black in the mix. The soles are used in a wide variety of footwear from heavy-duty to general purpose.

• Rubber bottoms vary in type, including:
• Translucent rubber-vulcanized: Translucent rubber is a high-quality vulcanized rubber, either natural or synthetic. It contain silica and it is usually available in "natural" colors ranging from off-white to light brown.
• Resin rubber-vulcanized: Resin rubber was developed in the early 1950s to simulate leather. It is a firm type of vulcanized rubber based on a synthetic SNR-rubber, reinforced with a high styrene resin.
• Microcellular rubber-vulcanized: Microcellular rubber is basically a resin rubber with a cellular structure. During vulcanization the rubber is expanded by a blowing agent which forms numerous small, non-interconnection cells.
• Sponger rubber-vulcanized: Sponge rubber is used for sole for felt or cloth slippers. It has a spongy, cellular structure and it is covered with a thin, solid skin. it is vulcanized directly to the upper.
• Crepe-not vulcanized: Crepe is obtained directly from the rubber latex, the milky liquid from rubber trees, by coagulation the rubber particles and milling them into sheets. It is lightweight, flexible, hard-wearing and comfortable to wear. The downside of crepe is that it will deteriorate if contaminated by oil, petrol or chemicals. If subjected to heat, sole will discolor and become soft and tacky. It is frequently used for soles of stitchdown shoes and sandals.

• Plastic: Polyvinyl chloride (PVC) is cement lasted as a molded unit or directly injected to the upper. PVC is the main synthetic used for shoe soling. The PVC polymer is hard, but when used for soling it is softened by the addition of plasticisers. It can be either used as "direct injection" to the upper or as a stuck-on unit, "Cement lasted." The Properties of PVC bottoms are:

• Hard wearing
• Flexible
• Soft
• Can slip when cold

• Thermoplastic Rubber (TPR) is directly injected to the upper. TPR can be injection molded. It was originally developed for soling to simulate crepe and soft vulcanized rubbers. The properties of TPR of bottoms are:
• Looks and feels rubbery
• Lighter than vulcanized rubber or PVC
• Good traction
• Excellent cold track resistance
• Low cost

• Ethylene Vinyl Acetate (EVA) is used in an expanded form. Normally used in expanded form either on its own or blended with S.B.R. It is used fro outsole in lightweight footwear and midsoles in trainers. The properties of EVA for bottoms are:
• Much lighter than conventional SBRs microcellular rubbers but with the same durability.
• Flexible and resilient
• Good ground insulation
• Used as outsoles in lightweight footwear
• Used as midsoles in trainers.

• Polyurethane(PU) can be blended to be solid, cellular, flexible or rigid. Normally for shoe the blend is a flexible cellular structure. For top-pieces the solid, rigid from is used. PU is a very hard wearing polymer resistant to most chemicals. Used frequently as a two-part sole material with a thin solid PU-polymer and a blown PU-material for most of the sole making. It is frequently used for safety footwear. The properties of PU for bottoms are:
• Light in weight, flexible and resilient 
• Good ground insulation
• Most durable of the cellular soling.

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What is shoe and shoe last

leather moccasin shoes

Shoe: A shoe is a footwear which is not a luxury, but is one of the essential commodities which has got a great bearing on personal and public health.

It protects one of the most marvelous and the most abused parts of the human anatomy foot (having  a  complex and delicate arrangement of bone, muscle, tendon, ligament, arches, nerves and blood vessels) from external environmental hazards.

Shoe Last: The last is a reproduction of the approximate shape of the human foot.

shoe last

It is the form around which a shoe is made.  As a result , lasts are fundamental to shoe manufacturing because they dictate the exact shape, size, and fit of the shoe made on them.

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