README file
Data Set Title: “Surface data for non-planar ironed specimens”
Data Set Author and Contact Person: Andrea Montalti (University of Bologna, Department of Industrial Engineering), ORCID ID 0009-0001-9623-1633, andrea.montalti8@unibo.it
Data Set License: This data set is distributed under the Creative Commons Attribution 4.0 International (CC BY 4.0) license. https://creativecommons.org/licenses/by/4.0/
Publication Year: 2025
Data set Contents
The data set consists of:
•	one spreadsheet in .csv format 
raw_roughness_data_20251215.csv
•	one spreadsheet in .csv format
roughness_data_20251215.csv
•	one spreadsheet in .csv format
curvature_data_20251215.csv
•	one readme file in .rtf format
ironing_non_planar_data_README_20251215.rtf
Data set Documentation
Abstract
This data set contains surface roughness measurements of specimens manufactured via material extrusion additive manufacturing (MEX) and post-processed using a non-planar ironing process.
Specimens produced with different post-processing techniques were analyzed, including:
•	non-planar deposition;
•	non-planar ironing;
•	chemical smoothing.
Several materials were investigated:
•	Polylactic acid (PLA);
•	Acrylonitrile Butadiene Styrene (ABS);
•	IGUS Iglidur I151-PF;
•	Polymaker Polysmooth.
The dataset contains the following files: 
•	“raw_roughness_data_20251215.csv”, that includes experimental roughness measurements;
•	“roughness_data_20251215.csv”, that includes average roughness related to the measurements; 
•	“curvature_data_20251215.csv”, that includes curvature data.
Content of the files
•	The file “raw_roughness_data_20251215.csv” includes experimental roughness measurements. Ten roughness measurements were performed for each specimen and direction, from which mean values were calculated. Specimens analyzed: A, B, C, D, G, H, I, J.
•	The file “roughness_data_20251215.csv” includes average roughness related to the measurements. Processed data providing a direct comparison between specimens, including details on manufacturing parameters and post-processing techniques. Specimens analyzed: A, B, C, D, G, H, I, J.
•	The file “curvature_data_20251215.csv” includes curvature data. Data obtained from curvature analysis of the specimens through 3D scanning. Specimens analyzed: 0, A, B, C, D, G, H.
File specifications
.csv files were created using the following specifications:
•	Character set: Western Europe (Windows 1252-WinLatin 1)
•	Field delimiter: semicolon (;)
Methodology
The specimens consist in a flat cylinder with diameter of 50mm and 5mm height with on top a portion of a sphere with a radius of 120 mm, manufactured using Fused Filament Fabrication (FDM). An ironing process was applied to the top surface to improve surface finish.
A single ironing tip was used, featuring a fillet radius of 4.5 mm, operating within a temperature range of 200–230 °C. The reported temperatures refer respectively to non-planar deposition and non-planar ironing.
The measurement direction corresponds to the ironing direction. Prior to measurement, the surface was manually sanded using abrasive paper.

Surface roughness measurements were performed using a Mitutoyo SJ-210 roughness tester, with the following parameters:
•	ISO 1997
•	Sampling length (λc): 0.8 mm
•	Sampling count (Nc): 5

According to the instrument settings, the total evaluation length (Lt) is calculated as: 
Lt = (Nc + 1) × λc

For each specimen:
•	Ten measurements were taken in each principal direction.
•	Measurements were performed in both parallel and perpendicular directions.
For specimens without ironing, the measurement directions refer to the infill direction of the last deposited layer. For ironed specimens, the directions refer to the final ironing pass direction.
When the last pass direction was no longer identifiable, measurements were taken along random directions.

For each measurement, the following surface roughness parameters were recorded:

For each specimen, the mean values of Ra, Rq, Rz, and Rp were calculated for both directions. 
Finally:
•	The average between perpendicular and parallel measurements is reported in the “Ra_avg” column.
•	The relative roughness with respect to the specimen without ironing was calculated.

To conduct a comprehensive assessment of the surface condition, 3D surface scans were performed using the Shining 3D PRO EU scanner, which provides a precision of 0.02 mm. These scans were acquired with a point cloud resolution of 0.1 mm, providing detailed topological data of the surface and enabling the identification of any deviations or flaws that may have occurred during the process.
The 3D scan was used to analyse the overall curvature of the surface in order to evaluate the influence of the ironing process on the final result, in comparison with a CAD model of the component.
List of variables
Analyzed specimens:
Code	Name of the specimens	
0	Planar-printed specimens (PLA) without non-planar deposition, non-planar ironing, or post-processing treatments	
A	Planar-printed specimens (PLA) with non-planar ironing	
B	Planar-printed specimens (PLA) with non-planar deposition using PLA	
C	Planar-printed specimens (PLA) with non-planar deposition using Polysmooth	
D	Planar-printed specimens (PLA) with non-planar deposition using Polysmooth and chemical surface smoothing	
G	Planar-printed specimens (PLA) with non-planar deposition using Polysmooth, followed by sanding and chemical surface smoothing	
H	Planar-printed specimens printed entirely in Polysmooth (planar), without non-planar deposition or ironing, followed by chemical surface smoothing	
I	Planar-printed specimens (PLA) with non-planar deposition using Iglidur® 151	
J	Planar-printed specimens (PLA) with non-planar deposition using ABS	

File: raw_roughness_data_20251215.csv
Name of the variable	Description	Values / Units	
Code	Specimen identifier	A, B, C, D, G, H, I, J	
Direction	Measurement direction	Perpendicular to ironing; 
Parallel to ironing; 
Random	
n°	Replicate index of roughness measurement	1–10	
Ra	Arithmetic mean roughness	µm	
Rq	Root mean square roughness	µm	
Rz	Average maximum height of the profile	µm	
Rp	Maximum profile peak height	µm	
v	Measurement speed	0.5 mm/s	
Lambda_c	Sampling length	0.8 mm	
Nc	Sampling count	5 (–)	
Note: in the original file, lambda_c and Nc may appear in auxiliary columns/rows due to formatting; in this documentation they are defined explicitly to avoid ambiguity.

File: roughness_data_20251215.csv
Name of the variable	Description	Values / Units	
Code	Specimen identifier	A, B, C, D, G, H, I, J	
Direction	Measurement direction	Perpendicular; 
Parallel; 
Random	
Planar	Planar material	PLA or Polysmooth	
Non planar deposition	Presence of non-planar deposition	Yes / No (material specified if Yes)	
Non planar ironing	Presence of non-planar ironing	Yes / No	
Other treatment	Additional post-processing	No; 
Chemical smoothing; 
Sanding + chemical smoothing	
T	Deposition and ironing temperatures	°C	
Lube	Lubricant use during ironing	Yes or No	
Ra	Mean arithmetic roughness	µm	
Rq	Mean root mean square roughness	µm	
Rz	Mean average maximum height of profile	µm	
Rp	Mean maximum profile peak height	µm	
Ra_avg	Average Ra roughness measured parallel and perpendicular to the ironing direction	µm	

File: curvature_data_20251215.csv
Name of the variable	Description	Units	
Code	Specimen identifier	0, A, B, C, D, G, H (I and J not present)	
Min.	Minimum deviation from nominal geometry	mm	
Max.	Maximum deviation from nominal geometry	mm	
Average	Mean deviation from nominal geometry	mm	
RMS	Root mean square of deviations	mm	
Standard Dev.	Standard deviation of deviations	mm