Material pair

Polypropylene (PP) to Polypropylene (PP)

Best bet

Plastic bonding system (primer + CA)

The activator primes PP's waxy surface so the adhesive can grip — the one common product made for this.

Preparation

Prep each side differently

Polypropylene (PP)

Wash and dry — then stop: no amount of scuffing makes ordinary glue stick to PP.

Polypropylene (PP)

Wash and dry — then stop: no amount of scuffing makes ordinary glue stick to PP.

Conditions

When the answer changes

Keep the repair indoors and snug-fitting — the system cures brittle and its data sheet rules out exterior use and gaps. A bin that flexes in use wants a plastic weld (a soldering iron) or a replacement instead.