Three fire engines and a pump were at the Brynmenyn Industrial Estate, with officers damping down.
At its height, 65 firefighters tackled the blaze at a mattress recycling unit that broke out at 09:00 BST on Friday.
Cooling jets were also being used on gas cylinders, which weigh up to 47kg (104lb) each, on the site.
Roads on the estate have reopened, except for Aneurin Bevan Avenue which remains closed.
An investigation into the fire is expected to start on Monday.
A fire that burned throughout Friday at a recycling centre was still going on Saturday after a collapsed roof prevented full access to the site.