No, it starts with material shortages-the various chemicals need to be reacted with each to make the plastic. Some does come from China, but a lot is made state side, too. When everybody shut down last year, some material manufacturers did to. When things started moving in 3rd quarter, it created a supply issue, since manufacturers were shipping from inventory and not replenishing anything. So, demand outpaced supply and the plants take a while to get up to speed-not just a flip off switch. Between hurricanes and the Southern Freeze, it was a perfect storm.
