most willingly used materials in additive techniques. It is sold in a very wide range of colours. This work was intended to answer the question of how the type of pigment affects the mechanical and thermal properties of products obtained from PLA. The correlation between the material properties and the structure of the material as well as the macroscopic structure of the product has also been investigated. The paper analyses the mechanical and thermal properties of products made of PLA filaments in 12 basic colours obtained from one supplier. Bending, impact strength, HDT and Vicat softening point tests were carried out. The percentage content of residues after calcination the samples was determined. Additional analysis (DSC) was performed to interpret the obtained tests results. They indicate that the mechanical properties differ significantly between different types of PLA with differences of up to 45%. Vicat softening point tests indicate differences of 5°C between the extreme values of these parameters. The DSC interpretive study did not clearly show the reasons for these differences in the properties of the filaments.

(Owens–Wendt–Rabel–Kaelble) method, and determination of its polar and dispersive components. Depending on the chemical treatment applied, the highest values of the polar constant for DC04 and Al6061 sheets were 26.4 and 39.2 mJ/m2, respectively, the highest values of the dispersion constant were 55.6 and 53.5 mJ/m2, respectively, for DC04 and Al6061 sheets. In the case of the surfaces of sheets made of the Al6061 alloy, the increase in the polar component value was most favorably influenced by the etching with 15% NaOH solution for 5 minutes, and the increase in the dispersive component – by the etching with 15% NaOH solution with the addition of thiourea for 2 minutes. In the case of the surface of DC04 sheets, the increase of the polar component was most favorably influenced by chemical cleaning for 10 minutes (in a solution with the composition: Na2CO3 50 g/mol, Na3PO4 × 12 H2O 50 g/mol, NaOH 50 g/mol). The highest value of the dispersive component of the surface DC04 sheets was obtained after etching with 15% HCl solution with the addition of thiourea for 5 minutes.

swobodnej energii powierzchniowej (SEP) metodą OWRK (Owens-WendtRabel i Kaelble) oraz jej składowych polarnej i dyspersyjnej. W zależności od zastosowanej obróbki chemicznej największe wartości składowej polarnej SEP blach wykonanych ze stali DC04 oraz stopu Al6061 wyniosły, odpowiednio, 26,4 oraz 39,2 mJ/m2, natomiast największe wartości składowej dyspersyjnej, odpowiednio, 55,6 oraz 53,5 mJ/m2. W wypadku powierzchni blach ze stopu Al6061 na zwiększenie wartości stałej polarnej najkorzystniej wpłynęło trawienie 15% roztworem NaOH przez 5 minut, natomiast na zwiększenie stałej dyspersyjnej – trawienie 15% roztworem NaOH z dodatkiem tiomocznika przez 2 minuty. W wypadku powierzchni blach wykonanych ze stali DC04 na zwiększenie stałej polarnej najwyraźniej wpłynęło oczyszczanie chemiczne przez 10 minut (w roztworze o składzie: Na2CO3 50 g/mol, Na3PO4 × 12 H2O 50 g/mol, NaOH 50 g/mol). Największą wartość stałej dyspersyjnej powierzchni blach ze stali DC04 uzyskano po trawieniu 15% roztworem HCl z dodatkiem tiomocznika przez 5 minut.