page_title: 3D printing speed
section_title: Improved SLA processes
hierarchical_section_title: 3D printing speed / Research / Improved SLA processes
caption_attribution_description: English: Fast 3D printing by integrating construction kit building blocks
context_page_description: 3D printing speed measures the amount of manufactured material over a given time period, where the unit of time is measured in hours, and the unit of manufactured material is typically measured in units of either kg, mm or cm³, depending on the type of additive manufacturing technique.
  The following table compares the speeds of commercially relevant 3D printing technologies.
  3D printing speed refers to only the build stage, a subcomponent of the entire 3D printing process. However, the entire process spans from pre-processing to post-processing stages. The time required for printing a completed part from a data file is calculated as the sum of time for the following stages:
  The pre-processing stage, which spans the preparation process of both part and printer. This is required before the actual printing starts. It is calculated as the sum of the time required for the following processes:
  Positioning and orienting of the part to be printed
  Entering the parameters within the printer's software
  Generation of the support structure
  Generation of slices
  Generation of the tool path plan by the software
  Warming up and loading of support and build materials
context_section_description: The speed of SLA processes is limited by:
  Adhesion of cured material to the projection window
  Disturbance of the resin surface
  Rapid continuous additive manufacturing by inhibition patterning
  Due to the mentioned effects, the printing speed with SLA methods is limited to a few millimeters to several centimeters per hour. To address this problem a system of two light sources is used, one for polymerization and one for inhibiting the polymerization to avoid adhesion and as a result print faster. This method allows us to speed up the process up to 200 cm/hr. Moreover, by controlling the intensity of each pixel in the setup  topographical patterning can be created in a single exposure with no stage translation.
  A mixture of photo initiators and photo inhibitors is used in the setup. The absorbance spectra of two material is orthogonal this allows to control the process with the two orthogonal light sources. As the material is generated layer by layer the tray is gradually lifted and the photo inhibitors will not allow adhesion near the window.
  Rapid, large-volume, thermally controlled 3D printing, using a mobile liquid interface
  Another way to address the adhesion problem is to create a dead layer which prohibits the curing process. One method to create this dead layer is to use fluorinated oil flow. This liquid is omniphobic which means that it repels all the materials and will not stick to anything. The reason to use a flow instead of a static layer is to create a larger force against the adhesion force and also help with the cooling of the cured layer (curing generates heat).
caption: During the design the object is converted into smaller blocks to be printed faster. Only the part that needs to be iterated on will be printed with high resolution (red area).