---
title: "Vapor Smoothing Evonik TPA Parts | AMT PostPro"
description: "PostPro vapor smoothing on Evonik TPA (HP MJF 4200): lower roughness, better tear strength and compression set, minimal dimensional change."
canonical: https://amtechnologies.com/resources/whitepapers/improving-evonik-tpa-part-properties-with-postpro-vapor-smoothing/
updated: 2026-10-06
type: whitepaper
---
Whitepaper · Evonik TPA (polyamide elastomer)

# Evonik TPA: improving part properties with vapor smoothing

This study tests PostPro vapor smoothing on Evonik and HP’s co-branded TPA powder, a flexible polyamide elastomer, printed on an HP MJF 4200, for surface quality, mechanical properties and dimensional stability.

[Read the whitepaper (PDF, opens in a new tab)](https://6983077.fs1.hubspotusercontent-na1.net/hubfs/6983077/Website/Whitepapers/AMT_WP_TPA_EVONIK%20TPA.pdf?ver=2) [Test your parts](https://amtechnologies.com/test-your-parts/)

Published Nov 7, 2022 Free download, no form

![Cover of the whitepaper “Evonik TPA: improving part properties with vapor smoothing”](https://amtechnologies.com/img/resources/wp-evonik-tpa-720.webp)

- **With**: Evonik
- **Material**: Evonik TPA (polyamide elastomer)
- **Printing**: HP Multi Jet Fusion 4200
- **Published**: Nov 7, 2022

Source: [Evonik whitepaper, amtechnologies.com](https://amtechnologies.com/resources/whitepapers/improving-evonik-tpa-part-properties-with-postpro-vapor-smoothing/) [PDF (opens in a new tab)](https://6983077.fs1.hubspotusercontent-na1.net/hubfs/6983077/Website/Whitepapers/AMT_WP_TPA_EVONIK%20TPA.pdf?ver=2) published Nov 7, 2022

## The material

TPA is a flexible polyamide elastomer with low density, high extensibility, energy return and good processing characteristics. Its rebound resilience and elongation at break suit functional 3D-printed parts in automotive and equipment manufacturing.

## The process

PostPro uses a patented physico-chemical process: controlled mobility and rearrangement of the top layer of surface material gives a sealed, smooth finish without compromising the part’s mechanical properties.

## Key findings

- Surface roughness significantly reduced
- Mechanical properties such as tear strength and compression set improved
- Minimal dimensional variation, so geometries and tolerances are kept
- Better color retention and resistance to UV-induced degradation than untreated samples[PDF](https://6983077.fs1.hubspotusercontent-na1.net/hubfs/6983077/Website/Whitepapers/AMT_WP_TPA_EVONIK%20TPA.pdf?ver=2)

Key finding

Better tear strength and compression set; better color retention under UV[PDF](https://6983077.fs1.hubspotusercontent-na1.net/hubfs/6983077/Website/Whitepapers/AMT_WP_TPA_EVONIK%20TPA.pdf?ver=2)

Full whitepaper

Method, data and charts in the PDF. Free, no form to fill in.

[Download the PDF (opens in a new tab)](https://6983077.fs1.hubspotusercontent-na1.net/hubfs/6983077/Website/Whitepapers/AMT_WP_TPA_EVONIK%20TPA.pdf?ver=2)

Related

- [Compatible materials lists](https://amtechnologies.com/resources/documents/)
- [What is vapor smoothing?](https://amtechnologies.com/learn/what-is-vapor-smoothing/)
- [All whitepapers](https://amtechnologies.com/resources/whitepapers/)

Test your parts

## Send us a part. See it smoothed.

We vapor smooth your own parts and send them back with the results. No cost to evaluate · Parts returned · Typical turnaround 2–3 weeks[1]

[Test your parts](https://amtechnologies.com/test-your-parts/) [See the systems](https://amtechnologies.com/products/vapor-smoothing/)

## Sources

1. [PostPro benchmarking: send us your 3D printed parts](https://benchmarking.amtechnologies.com/) · AMT · read Oct 6, 2026