Carbon Footprint of a Tennis Shoe

1.0 Introduction

In today’s highly technological world, online shopping has made purchasing of goods an extremely uncomplicated task. Anything from books, computers, food, clothing, shoes amongst many other items can simple “show up” at someone’s front door after only a couple of clicks. Many websites will track their customer’s purchase history so that fitting offers will pop up while their customers browse through their website. Some products, like a perfume for example, may be offered based on a time spam. Let’s say that a customer bought a 200ml bottle of a certain perfume. Once the website calculates that there has been enough time for that perfume bottle to be over, it may kindly remind the customer that s/he “needs” to buy that product again. How nice, right?!

Interesting enough, even though our consumer habits are being somewhat tracked by various companies and websites through their loyalty programs, there is still a huge lack in understanding how our consumer habits truly affect the environment. The consumption of products drives a series of activities such as extraction, manufacturing, processing, transportation and disposal operations that we, as consumers, sometimes are unware of (it is also possible to say that some companies are also unaware of their environmental impact).

Even though people may not be aware of the exact carbon footprint of the products they buy, it seems clear that they are becoming more concerned about adopting a more sustainable lifestyle (from food, to clothes to transportation choice). In addition to public pressure, corporate values, market requirements as well as top management commitment has brought technological advancements that have helped products shift to a more sustainable spectrum. However, there are still a lot to be understood about the environmental impacts of the objects that we use daily, such as for example, a pair of tennis shoes.

2.0 Findings

2.1 Design of a tennis shoe

The basic features of a shoes tend to be a sole, insole, outsole, midsole, heel and vamp (upper). Other parts such as shoe lining, tongues, toe box, laces, etc is determined by the design of the shoe itself. Usually, the design phase will incorporate the consumer’s demands as well as decision on the materials to be used throughout the manufacturing process so that profitability can be maximized (refer to figure 1 to find typical materials found in shoes) [2].

Evolving tennis shoes design has made it become lighter, more durable, more comfortable and better looking. The design process should also consider the sustainability of the product. As a matter of fact, it might be the most important and convenient step to consider sustainable measures as this is when materials that will be used throughout the manufacturing process are chosen. A smarter design could mean that less material will remain at the end of the product life-cycle. The choice of a better fabric could mean fewer heavy metals in the dyes or fewer solvents throughout the whole manufacturing process. Some companies are already incorporating sustainability into their core values as their consumers pressure for brand new technologies that will decrease the environmental impact of the products they buy and use. If you visit Nike’s website, for example, you will find out that the company takes sustainability as an opportunity to innovate. In fact, it has created the Flyknit technology which the company claims to reduce 60% of waste if compared to traditional cut and sew shoe manufacturing [1].

2.2 Manufacturing process

Some say that a tennis shoe is a 3D puzzle of plastic, fabric, rubber and leather along other materials. Even the simplest tennis shoe can have numerous different materials which need to fit together under the correct design and proportion. From natural cotton and wool, synthetic rubbers, leathers, nylon, polyesters and EVA foams can all be possible materials utilized in manufacturing a tennis shoe according to the wanted design. The simplified shoe production process chart can be seen in figure 2 [4]. As possible to conclude from the picture, the manufacturing process is very labor intensive specially the cutting and stitching steps of the process.

The very first step of the manufacturing process is to have the Last, which is a wood, plastic or metal form that will give the shoe its final shape. Afterwards, a shell pattern, which is the shoe pattern that fits the surface of the last, will be manufactured. Usually, die machines will be used to stamp the shoe shapes [6]. This is followed by the cutting process. Giant cookie cutters, computer controlled knives, laser and hand cutting are all methods used.

After all the parts have been cut, they are stitched together. The stitcher puts together