There is no active filter mechanism. Passive filtering is by water currents from agitation circulating lint outside the basket where it (theoretically) is held in the outer tub, not passing back in through the basket perfs which are formed by punching through from the inside (sharp edge protrudes outward).

F&P offers an accessory filter, assuming it's still available, which is a sort of cup with a nylon sock attached that fits inside the agitator barrel. I have one. It's somewhat effective (doesn't do much at the lowest water level), but I don't use it very often. Call F&P customer service, tell them you have a linting problem, ask for the filter. Sorry, I don't recall the part number.