# Polymeric Powders for Powder Bed Fusion: From Chemistry and Powder Characteristics to Process Parameters, Defects and Applications

## TL;DR

This review connects polymer powder properties to printing outcomes in powder bed fusion, emphasizing how chemistry and processing affect defects and applications.

## Contribution

A powder-centred framework is introduced to systematically link polymer chemistry, powder characteristics, and process parameters to defects and application performance.

## Key findings

- Key powder descriptors like crystallinity and particle size distribution influence processing windows and defect mechanisms.
- Environmental factors such as moisture and temperature affect powder behavior during printing.
- Powder qualification and lifecycle effects are critical for achieving consistent and transferable polymer PBF manufacturing.

## Abstract

Polymer powder bed fusion (PBF) is strongly influenced by powder chemistry and powder state, yet many studies discuss the materials and processing conditions in isolation. This review synthesises the literature using a powder-centred framework that connects polymer chemistry and powder production history to measurable powder descriptors, and then links these descriptors to processing windows, defect mechanisms, and application outcomes. Key descriptors include crystallinity and thermal transitions, additive packages, particle size distribution, morphology, and surface texture. Environmental sensitivities are also considered, including moisture uptake, temperature effects, and optical response. These factors are related to powder spreading, energy absorption, and melt solidification or sintering to explain how flowability, packing density, and melt dynamics govern porosity, lack of fusion, distortion, and degradation. Powder qualification is discussed together with lot-to-lot variability and lifecycle effects, including ageing, reuse, and refresh, using the indicators commonly reported in laboratory and production settings and supported by emerging in situ monitoring. Application case studies are consolidated to illustrate how powder state and process control translate into repeatable qualification targets as polymer PBF moves toward a predictable and transferable manufacturing practice.