Final answer:
Welding plastics requires lower temperatures than metals, causes less material deformation, and generates minimal smoke. Therefore, the correct answer is D. Lower, less, smoke.
Step-by-step explanation:
Compared to metals, welding plastics requires lower temperatures, results in much less deformation or changes to the material properties, and produces little to no smoke. The correct answer is D. Lower, less, smoke.
When welding plastics, lower temperatures are used because plastics melt at much lower temperatures than metals. Additionally, the process of plastic welding typically results in less deformation to the materials, maintaining more of their original properties compared to metal welding.
In terms of emissions, plastic welding generates much less smoke as opposed to metal welding, where the higher temperatures and the nature of the materials often result in more fumes or smoke.
Compared to metals, welding plastics requires lower temperatures, results in much less deformation or changes to the material properties, and produces little to no smoke.