English to Portuguese Tech/Engineering Mechanics / Mech Engineering

"A flexible package with an integral fitment is made from 90 to 100% polyethylene by weight, especially from 95 to 100% by weight allowing the package to be recycled.
BACKGROUND ART
It is known to prepare flexible packages having integral fitments (such as spouts or valves).
The fitments may be installed using an adhesive or using heat sealing.
The amount of heat required to heat seal the flexible film to the fitment is significant, and, as a result, the flexible film typically contains at least one layer of a heat resistant polymer (such as polyamide or polyester) to ensure that the film does not fail during the welding process.
This makes these packages difficult to recycle because it is not possible to easily separate the polyester (or polyamide) layer form the polyethylene in current recycling facilities."

Aqui tem um vídeo mostrando o que é esse "fitment" mas não sei o nome disso em português: https://www.youtube.com/watch?v=sbNK6ME0RT8