Question

powder bed fusion technologies (sls)
use the information below to answer the question.
selective laser sintering (sls) is part of the powder bed fusion process. similar to the sla process, sls uses a powder bed area, heats up the powder, and uses a build plate. most sls applications will use a thermoplastic, polymer powder, that is similar to the type of material used in the fused filament fabrication technology. the build plate will have a thin layer of the polymer powder laid on it, and then a heat source will sinter or melt the layers together.
mirrors located within the xy axis will focus a laser to selectively connect and fuse the polymer powder together. once the laser has fused the first layer, it will move down and a fresh layer of polymer powder will be laid on the created layer that has already been sintered.
the laser will fuse the next layer to the previous layer, and it will continue to recoat and sinter until the entire form is created. it stays in the vat of powder.
with selective laser sintering, you have to wait for the vat to cool down before the forms are removed. the forms will be covered with powder, which is cleaned off with high - pressure air, and then they are ready for post - production processes.
advantages
one advantage is that structure to support the form is no longer needed and the powder will support it to the next layer. also, the powder remains in the vat and 10% of the powder can be reused in the next process. it also allows for the full capacity of the vat to be used for production possible.
in the sls process, what is used to sinter the layers together?
options:
an adhesive
a light source
a heat source
a resin

Explanation:

To answer the question, we refer to the text: "the build plate will have a thin layer of the polymer powder laid on it, and then a heat source will sinter or melt the layers together." This directly tells us that a heat source is used to sinter the layers in the SLS process. The other options (an adhesive, a light source, a resin) are not mentioned as the sintering agent in the provided text about SLS.

Answer:

a heat source