Chemical packaging starts from a different question than most other applications: not how strong does this film need to be, but what is actually inside it. A film that is structurally perfect but chemically incompatible with its contents will degrade, swell, or fail from the inside out, often without obvious warning until a leak has already happened. Resin selection and structure design for this category begin with the specific chemical or chemical family the film will contact.
Drum liners and secondary containment film carry the added burden of being a backup system: they exist specifically because a primary container might fail, so the liner itself failing is not an acceptable outcome. We design these structures around the actual chemical exposure, concentration, and duration the application involves, rather than assuming a single liner spec covers every chemical equally.
Strength and puncture resistance still matter once chemical compatibility is established, since a liner that is chemically resistant but tears during installation or handling never gets the chance to do its job. We treat compatibility as the gating decision and build the rest of the structure, gauge, and toughness around it.