Seeing your requirement I will suggest 2 thermoplastic polymers which can be used to make your product with limited resources:

1. Casted Nylon which can be used for Maximum Service Temperature = 170 deg C. This comes in block, sheet and rod form which you can then machine it as per your requirement.

Kindly go through the below link for detailed specification:

https://www.matweb.com/search/datasheet_print.aspx?matguid=bf1a334c8b1b4da6bbc86da935d8f423

2. Polytetrafluoroethylene (PTFE) or teflon material. This material comes in powder form which can be transformed into Rods, Bushes & Plates by cold compression moulding / sintering process.

PTFE Resin is cold compressed / compacted in mould at around 300-320 kg/cm² and due to the waxy nature of the PTFE powder it get mechanically bind to form a product like rod, sheet and blocks. The product is then ejected from mould & sintered in oven at about 350-370°C and this is where the fusion of PTFE particles happens and we get a solid product.

This is also available in block, sheet and rod form which you can then machine it as per your requirement.

Seeing your requirement I will suggest some other thermoplastic polymers if you are thinking of mass production with less cost.

1. Glass filled nylon or glass filled Polybutylene Terephthalate - which can be processed via Injection moulding. However, you have not provided dimensions to your product, if it will be very thick then this option will be challenging due to shrinkage.

We can't make hollow cylindrical shell inside a outer shell wall. you have to make product open from one side - may be from bottom.

Also increase the thickness from 1mm to 1.8-2.5mm. As your product have 65mm high Otherwise it will flex.