Hairspray doesn't spray, only drizzles

I use Nioxin's shampoo and conditioner and mouse and thickening gel. I use the hairspray also. I have used these products for more than 10 years. However, with the hairspray, I have a problem with the product not spraying. In the past, when the hairspray was less than 1/2 full, I would start having a problem with it stopping up and not spraying properly. At that point, I could clean the nozzle and and it could be used. Currently, I have 3 new cans of the hairspray and 2 will not spray at all; another one only drizzles out. What do I do to get it spray? I love the product when it sprays as it should.