Can you use PTFE to avoid friction in between 2 blocks when running coated material through blocks?

Maybe.
Any lubricant that doesn't react with the surface coating will work between the blocks. Dry lubricants (soaps, graphite, waxes...etc.) or wet lubricants (oil, glycerine, water, soaps...etc.) work well to varying degrees depending on the materials they lubricate and whether the lubricant and the surfaces react adversely under heat and pressure. Consulting a lubrication specialist, (most lubricant manufacturers consult with customers for the best match), for your best results. PTFE can breakdown under high pressure and high temperatures and usually is not great for high speed high temperature operations but works great at low speed and/or low pressure applications, and it does not react adversely with most materials.