PET is one of the most widely used resins because of its transparency, flexibility and memory (i.e. the ability to return to its original shape following deformation), and good compatibility with most cosmetic ingredients.

The good durability of PET is ideal for transparent bottles of shampoos and conditioners that may often slip from the hands and fall to the ground. The bottle will dent, without cracking, unlike other transparent resins. With the addition of pigments, PET bottles or pots become coloured, transparent or translucent. They can also be completely white by the addition of titanium dioxide or pearlescent by adding mica-based pearl luster pigments such as Iriodin®. The addition of sunscreen to the resin confers protection from light to the inner product without the loss of packaging transparency.

Source: Cosmetic Formulation Principles and Practice - Heather A.E. Benson, Michael S. Roberts, Vânia Rodrigues Leite-Silva, Kenneth A. Walters

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