An estimated $250 billion is expected to pass the global footwear market by 2020 by $300 billion in 2017. Over 80% of global footwear requirements are manufactured and exported by China and India. The world footwear market accounts for about 70% of shoes.
The growth driver for the shoe industry is a growing health awareness, which creates a higher demand for sports shoes and leads to demand for formal shoes with changing lifelines and increasing numbers of employees. The rapid growth is also caused by the large population shift to urban industrial and service-orientated societies from rural agriculture.
Historical evidence of shoes is from around 8,000 years ago in the Copper Age. Shoes were initially made from animal skin or plant-based material and hand-stitched. The mechanized shoemaker industry developed at the beginning of the 19th century, with leather, wood, or linen shoes. There are now more shoes made of rubber, plastics, and other polymers.
The selection of raw materials and the shoemaking process, therefore, depends upon its use as a product designed to protect and comfort the foot of the individual and to ensure its esthetic use as a fashion item. The style, complexity, and cost of the shoes vary considerably according to the weather in the region.
It is composed of approximately 15 to 17 components according to the size and design of the show, from the exterior sole of the bottom to the shoelace on the top part, depending on the type of show and the intended use. There are some shoes with straps, zippers, elastic, and velcro or buttons used to tighten up the upper foot. Most shoes, however, are designed or made in a complex top with colorful or designed shoestrings. In this way, they look attractive. The esthetic appeal is enhanced by various laceration methods. Cross-lacing and lace knotting are most common.
Shoestrings are usually used to secure human feet for shoes. The strings or strings, one for each shoe, consist of one. Leather, hemp, cotton, or jute were the traditional shoestrings. The shoelaces are currently made of synthetic fibers, such as nylon, polyester, and polypropylene. Shoestring is therefore the only textile fiber component used in the entire process of shoemaking.
The shoestring color depends on the shoe color, which in the event of formal wear are predominantly Black or Brawn. However, colored strings that match or contrast with the color of shoes are used for improving the fashion look in the case of casual or sports shoes. Depending on the textile fiber, the material is therefore dyed.
The dimensions and shape of the shoestring are also different; the most common is the flat cross-section, and a circular ribbon type is followed.
Hydrophobic and waterproof are the main functional requirements of shoestrings. Rain or wet soil or grass can damp the slides and the humidity springs in the socks, so the wearer is uncomfortable in its inner part. At the same time, the anti-dirt and anti-dirt features of the shoestrings must be provided. In order to provide the desired effects such as softness or rigidity, slip-resistant, anti-microbial, stain repellant, and waterproofing, it is necessary to use suitable finishing chemicals.
The most desired effect on shoestrings is waterproofing. The aim is to reduce the critical textile component surface tension below the water surface tension. This improves the internal cohesive power of water over the textile’s external attraction. The coating or finishing of such surfaces prevents shoestring moistening.
For differentiating the extent and longevity of water repellency, different finishing chemicals are used. Waxes, polyacrylates, polysiloxanes, fluoro-polymers, and dendrimers are some of the commonly used chemicals for this effect.
The oldest and cheapest way to convey water repellence is to coat shoestrings with paraffin wax. It is, however, water repellent, which implies that it resists only water and water expansion on the surface but permits its penetration to prolonged contact. It does not comply with the desired waterproofing requirement, which even under proceeded contact does not allow water permeation. In addition to water repellence, polysiloxanes give a soft, shiny feel and have increased durability compared to wax coating but also moderate water insulation.
Fluoropolymers are regarded as the most suitable for waterproofing and durability, but to this end, they are also the most expensive chemicals. The cost of these substances depends on the production process such as oligomerization, electroporation, and telomerization as well as the length of the carbon chain associated with them, such as C8-Octane and C6-Exane. But these chemicals have concerns with the toxicity, even if they are not directly in contact with the skin and therefore can not be a major problem on shoestrings for a longer period of time.
In order to achieve sustainable, eco-friendly, economical waterproofing of slats, a new and patented dendrimer-based technology known as a Bionic finish is under evaluation. Dendrimers are highly branched oligomers with non-polar chains that form a structure of the star brush that prevents a molecule of water to remain on the textile surface. It also gives high resistance to abrasion, wash, and soft handle durability. At room temperature, the shoestrings are sunk or passed through the chemical bath. The excess chemical will be squeezed off the area and then dried at approximately 110-120 C and cured at 170-180 C. This product is then removed.