Self Transfer at SCL

I am considering booking a flight from EZE to SCL on Latam or Sky and then flying home to US on United. I know I will have to collect luggage and recheck, but will I have to go through passport control and "enter" Chile to do that since it's 2 different airlines or is there a way at that airport to stay in transit? If I have to enter, how much time should I allot for the transfer?