Jan 20, 2022 · 0.79. +0.01. +1.28%. - Increase - Decrease - No Change. The chart indicates the daily price movements of US Plastic Prices for HDPE - Blow Molding. Open price indicates the starting price or the closing price of HDPE - Blow Molding for the previous day. The close price is the price when the trade had ended for the day for HDPE - Blow Molding.