With the growing popularity of online shopping, people are increasingly ordering goods through internet platforms. Upon receiving orders, they may arrive either in cardboard boxes or in special plastic bags. Although some services have started using brown bags, most still deliver goods in white plastic bags. Often, it is observed that these white bags have a black inner layer. This article explains why this happens.
These packaging materials used for online goods delivery are known as courier bags or polymailers. Technically, they are called 'co-extruded polyethylene bags.' Their quality differs from ordinary bags and is considered higher.
There are several reasons why the inside of these plastic bags might be black. One of the main reasons is related to ensuring confidentiality. The black color makes the bag completely opaque, preventing the contents of the order from being seen from the outside, thereby maintaining the buyer's privacy.
Another important factor is protection from sunlight. Some products, such as cosmetics, medicines, or specific chemicals, can spoil under the influence of bright light or direct sunlight. The inner black layer blocks ultraviolet radiation, protecting the product.
Special black inner layers are used in some milk packaging for sun protection, which helps the milk stay fresh longer. These bags consist of several layers of plastic, and the inner black film increases their strength, preventing tears during transportation.
The black color can also be a result of using recycled plastic. When producing such polymers, materials like LDPE/LLDPE containing secondary raw materials are often mixed with virgin plastic. Since it is difficult to achieve a uniform and attractive color when mixing various old plastics, black is the simplest solution. Furthermore, recycled plastic may have traces of old colors, prints, or minor contamination, which are easily masked by the black color.
