how to get the ID of pipe smooth

[eagle4620]

We just took are die apart down to the basket cleaned and burned all plastic out of basket, Started line and inside of pipe has waves not smooth any ideas out there to help solve this problem. we are making 26" pipe

[Skip]

First, what is the "basket"---a screen pack?? No need for screen packs in PVC pipe extrusion.

Assume you use a twin screw (almost all pipe made on twin screws). If so, your exit melt temp should be in the 380F-390F (180C) range, with screw oil temp and metering zone temp the same to get a smooth melt flow into the adapter,spider and die.
A wavy glossy ID could mean material is too hot----a dull rough ID to cold. A smooth semi-gloss is just right.
If using twin screw, use a "reverse" barrel temp. profile, hotter in the rear----like Z1-180C,Z2-170C, Z3-160C, Z4150C Screw oil-150C. Adapter-170, Spider-180, Die-190-195C.
This works best with "flood feeding"---material should be cheesy,semi fused at vent so a good vacuum can be pulled.
If material is fused and wrapped around screw at the vent, it is too hot---decrease Z1 &Z2.
Hopefully your lube system is balanced for your extruder.

[haf]

In order to help you, Please what kind of material are you extruding, PE, pvc.. . I imagine the basket you mean by lattice basket die. Isn't it.
Haf