PETG vs. PLA: Differences and Comparison

Model strength and resilience are considerably higher for PETG. The cosmetic quality of model surfaces, however, is generally better for PLA.

PETG vs. PLA: Applications Comparison

PETG is better for strength, wear resistance, and chemical resistance. Stressed components and moving parts are better when made in PETG. Model parts in motion and contact against other components will be more resilient in PETG. Parts that will experience either water, sunlight, or heat exposure will also be better in PETG. PLA is better suited to low-stress, cosmetic applications, and components that require a better finish quality.

PETG vs. PLA: Part Accuracy Comparison

PLA is better suited to maintaining part precision. This is because of its better printability and lower warping. It should be noted, however, that under steady load, PLA tends to creep. For smaller features, PETG bonds better, as it is more viscous in the melt state and achieves better intra-layer coupling.

PETG vs. PLA: Speed Comparison

PETG is more sensitive to print speed than PLA. Newly extruded material may not stick to the layer below or the last strands if the print speed is high. PLA is more sticky, due to its lower viscosity. This results in PETG model build speeds being lower than those of PLA.

PETG vs. PLA: Surface Comparison

Both materials produce similar surface finish quality. Although in many cases, PLA models appear smoother because of the lower melt viscosity.

PETG vs. PLA: Heat Resistance Comparison

PETG has a considerably higher melting point than PLA (180 °C for PETG, 165 °C for PLA).

PETG vs. PLA: Biodegradability Comparison

PETG is derived from crude oil and is environmentally stable. Its life in landfills is measured in centuries. It does experience some degree of UV degradation, shortening the breakdown. PLA is a fragile polymer, and its environmental resistance is so short that it can influence the shelf life of the packaged product.

PETG vs. PLA: Toxicity Comparison

PETG and PLA meet the GRAS (Generally Recognized As Safe) standard and are food safe. Two considerations may influence the application of FDM/FFF parts in food safety terms:

1. Depolymerization occurs when plastics are overheated, producing non-food-safe results. This is more likely to occur in the case of PLA, as the polymer chains are more prone to scorching during extrusion.
2. Coloring agents used in the polymers are likely to NOT be food-safe – and PLA may allow these dye agents to leak.

These factors do NOT imply that printed parts are not food safe. But care should be taken to minimize the use of FDM and FFF parts in food contact.

PETG vs. PLA: Cost Comparison

PETG has a typical cost range of $20 to $25 per kg. This depends on the material class, supplier, and volume purchased. Standard PLA, on the other hand, costs around $15 to $20 per kg.