This is a very complex industrial using plastic pipe elbow injection mould what Asiaa Billion made at 2020 years. it is much more complex then the water pipe elbow. it have snak moving slider and other 2 direction slider too. let us know freely,if we can help you for this type mould project too.
https://www.asia-billion-moulds.com/mould-die/commodity-plastic-injection-mold/plastic-pipe-elbow-injection-mould.html