The 3D printing technology that mainly uses sheet materials as raw materials is introduced as follows:
The 3D printing technology that mainly uses sheet materials as raw materials is LOM.
The sample is ground into a transparent sheet with a thickness of about 30 μm. Mainly used for petrographic analysis of natural rocks and inorganic non-metallic materials. For fragile or more porous samples, they need to be soaked in resin glue before grinding; for inorganic materials with fine crystals, they must be ground thinner to facilitate observation and analysis under a polarizing microscope.
The LOM process is called laminated solid manufacturing. The full English name is: Laminated Object Manufacturing. Also known as SSM (slicing solid manufacturing) in our country, this technology was patented by Michael Feygin of the American Helisys Company in 1985 and successfully developed in 1986.
At present, the company has launched two models of forming machines, LOM-1050 and LOM-2030. LOM rapid prototyping technology was first developed by the American Helisys company. This technology stacks thin sheets of material, such as paper, plastic film, etc., one on top of another. The laser beam only needs to scan and cut the edges of each layer, instead of scanning the entire surface layer like SL technology.
The working principle of LOM:
The surface of the sheet is coated with a layer of hot-melt adhesive in advance. During processing, the hot-pressing roller heat-presses the sheet to make it fit with the formed surface below. Workpiece bonding; under computer control, the CO2 laser cuts out the cross-sectional profile of the part and the outer frame of the workpiece on the newly bonded new layer, and cuts a grid aligned up and down in the excess area between the cross-sectional profile and the outer frame.
After the laser cutting is completed, the workbench drives the formed workpiece down and separates from the strip sheet; the feeding mechanism rotates the rewinding shaft and the feeding shaft to drive the material belt to move, so that the new layer moves to Processing area; the workbench rises to the processing plane; the hot-pressing roller heat-presses, the number of layers of the workpiece increases by one layer, and the height increases by one material thickness; and then the cross-sectional profile is cut on the new layer. This is repeated until all sections of the part are bonded and cut, thereby obtaining a solid part manufactured in layers.
The LOM process uses thin sheet materials (such as paper, plastic film or composite materials) as raw materials, and uses a laser cutting system to cut the paper with hot melt adhesive on the back according to the cross-sectional contour data extracted by the computer. The laser cuts the inner and outer contours of the workpiece. After cutting one layer, the feeding mechanism superimposes a new layer of paper on top, uses a hot bonding device to bond the cut layers together, and then cuts again. In this way, layer by layer is cut and bonded, and finally becomes a three-dimensional workpiece. .
On this rapid prototyping machine, the cross-sectional profile is cut and stacked to form a product as shown in the figure. Among them, the required workpiece is surrounded by small squares of scrap material. After removing these small squares, the three-dimensional workpiece can be obtained.