**2.4 Quality inspection and testing**

**Quality inspection**: Industrial activities which ensure that manufactured products, individual components, and multicomponent systems are adequate for their intended purpose. Whereas *inspection* is the activity of examining the product or its components to determine if they meet the design standards, *testing* is a procedure in which the item is observed during operation in order to determine

**Figure 1.** *Process control.*

## *Significance of "Quality Control" in Leather Goods and Garment Production DOI: http://dx.doi.org/10.5772/intechopen.104494*

whether it functions properly for a reasonable period of time under given stress conditions. Inspection and testing are performed before, during, and after manufacturing to ensure that the quality level of the product is within acceptable design standards.

There are also various types of inspections. The following categories are used in leather goods and garment production:


International standards are preferred to be used for testing leather products, especially in the garment industry. **Table 1** shows this standard.


#### **Table 1.**

*Standards related to leather garments industry and related items.*

## **3. Results and analysis**

#### **3.1 Leather goods common quality parameters**

In addition to the eight quality parameters of any product like durability, feature, performance, conformity, esthetics, serviceability, perceived quality, and reliability, there are also other leather goods-specific quality parameters.

#### **3.2 Most commonly used types of testing**

**Leather testing:** it includes wet rub fastness, dry rub fastness, tool test, stress strain test, and plaster test fastness.

**Leather goods and garments testing:** it encompasses handbags and small luggage, wherein the strength – say – of strap fastenings is an important consideration in the quality assessment of handbags and luggage. A large number of companies in Ethiopia are able to carry out all strength tests utilizing state-of-the-art equipment to assess the risk of strap failures, whether at fastenings (e.g. buckles) or where the strap is attached to the body of the item itself. The other one is the leather belt testing**,** from an assessment of the components of a belt for labeling purposes. Also, specialty companies can perform further tests in order to satisfy all clients' requirements such as the color fastness (wet and dry rub fastness test) to tarnishing of buckles and metal components, to ensure the products are fit for the purpose they are intended for.

A few examples of tests used in leather products manufacturing firms are as follows:

**Smell test:** the smell test is an important part of every inspection. To avoid illegal toxins, the most reliable way to check it is to perform chemical tests as per ASTM D1296 in an accredited Leather Industry Development Institute (LIDI) laboratory.

**Function test:** the objective is to check if the product works as designed or anticipated. In the case of the leather bag, an inspector will wear it and test the zippers' direction and strength.

**Color fastness check on leather**: excessive dye may be rubbed off during a color fastness check. On leather, this is a frequent problem. The test may be repeated 10 times with a dry cloth and 10 times with a wet cloth.

**Abuse and fatigue tests**: pulling on straps and zippers with stronger-than-usual force helps to understand the manufacturing quality of leather bags.

**Seam strength test for leather bags**: this test is similar to the abuse test but focuses on the seams. It uses a tension gauge to check seam strength.

**Load test:** the inspector loads the leather bag with weights (depending on the model between 2 and 20 kg for backpacks (bag type) most of the time. Then the bag is lifted at least 20 times and is hanged on a hook for 4 h. This is an internal company policy similar to that of color fastness check.

**Zipper twisting test:** this type of test is used to check both the strength of the zipper and the seams holding it in the open middle and closed position. The QC pulls the zipper sideways for 10 s in each direction. Low-quality zippers tend to open and bend beyond repair. Extensive laboratory equipment test products (e.g. opening and closing zippers 5000 times) could be used also. However, most of small and medium leather products manufacturing companies use the manual test.

**Carton humidity check:** This test is performed in order to assess the behavior of the product in rainy conditions, while avoiding the buildup of mold or fungus, aiming at maintaining a humidity level below 12%. In particular, during the rainy season, the inspector should check the humidity of the export cartons with a humidity tester. As such, it ought to be ensured that sufficient desiccant (calcium oxide absorb water) is placed in the right spots.

## **3.3 Factors that influence the quality of leather goods and garments**

Factors that influence quality aspects make bags and garments good and/or cheap. The following aspects are commonly experienced in leather products manufacture:
