Development of thin sheet is the part of sheet metal lamination and it is one of the 7 additive manufacturing processes and is a process for creating 3D objects by compiling and laminating thin sheets of material.
What is sheet metal lamination?
The technique of making 3D printing with laminated coating (SL) which is also known as making laminated object (LOM) is by coating several layers of film material to create an object. Each foil is cut with a knife or laser to fit into a cross-section of the object.
This additive manufacturing technique was first developed by Helisys Inc. and later became popular with Solido in Israel. Solid 3D printers are based on LOM technology and manufacture parts made from a combination of PVC (PolyVinyl Chloride) and the adhesive itself, resulting in a model that is robust but inexpensive.
Later, Irish-based Mcor Technologies Ltd invented the paper-based sheet lamination technique. Recent developments in SL have made it possible to use carbon fiber panels and various composite materials, techniques mastered by EnvisionTEC and the introduction of Impossible Objects. These techniques are still being improved by the manufacturer and are not yet widely used.
The lamination process can be gluing, ultrasonic welding or soldering, while the final shape is achieved by laser cutting or CNC machining.
Of all the 7 types of AM technology, sheet metal laminates produce the parts with the lowest additive resolution. Because of their lower costs and faster production times, product designers are able to create low-precision prototypes from standard, readily available materials that are inexpensive.
Type of sheet metal lamination
Sheet metal cladding can be divided into groups based on the construction material used, such as paper, plastic, metal or woven fiber composite material or the molding process used, such as CNC milling, laser cutting or aqua structure. They can also be further categorized based on the lamination technique used to join the sheets, such as: B. Gluing, thermal gluing and ultrasonic welding. There are also differences in when they were formed. In some cases, they are formed as computer-aided manufacture of laminated engineering materials (CAM-LEM) and then bonded or bonded and formed as an ultrasonic additive process (UAM).
Shapes, then Glue – Sheet material is cut first and then glued to a previous base or layer to create 3D geometry.
Gluing and Shaping Process – This process, as the name suggests, brings together all the layers of the sheet material before cutting it into the shape you want.
classification of sheet laminates
In view of all the above variations, sheet laminates can be classified into the following 7 types;
- Manufacture of laminated articles (LOM)
- Composite object selective lamination production (SLCOM)
- Plastic sheet lamination (PSL)
- Computer manufacturing of laminated technical materials (CAM-LEM)
- Selective Stratification (SDL)
- Composite Additive Manufacturing (CBAM)
- Ultrasonic Additive Manufacturing (UAM)
- This is how sheet metal lamination works
Development of sheet laminate
Each type of sheet metal laminate works a little differently, although the basic principles are the same. A schematic overview is shown in Figure 2 of the original manufacture of laminate objects, which in 1991 was the first commercial technique for the manufacture of additives.
When making laminated paper objects, the paper material is taken from standard photocopy paper. First, the paper passes through a standard 2D inkjet printer for coloring. Then all the color pages needed to create the final section are arranged in a 3D printer, which uses them individually.
In this way, each page is removed from the pile, glued to the previous one, and then cut with a knife. Layer by layer, the details are finished. The remaining paper can be removed by hand. Paper models can be fully colored, have wood-like properties, and can be processed and processed accordingly.
The accuracy of the results depends mainly on the thickness of the coating material used, i.e. B. a sheet of paper. Standard paper has a thickness that varies between 50 and 100 microns.
The pre-build and part customization are the same for all 7 types of additive manufacturing technologies and can be demonstrated in 7 steps how additive manufacturing works: 3D modeling, creating STL files, transferring STL files, setting up machines, Construction, parts moving and subsequent machining.
First, a thin net of material is fed from trusses or placed on a building platform. Depending on the type of sheet metal laminate, the next layer may or may not connect to the previous sheet. SDL and UAM connect the planes to each other and ultimately cut the 3D shapes, while CAM-LEM cuts the planes into shapes and then connects the planes together. This process continues until all layers have finished reaching their full height. The printing block is then removed and unwanted outer edges removed to reveal the 3D printed object.
When laminating films, the coating thickness corresponds to the film thickness of the thin material and determines the final quality. The thickness of the coating also depends on the machine and process used.
Although sheet metal coatings can use a variety of materials such as paper, polymers, ceramics, and metals, each material uses a different method of joining. The most common sheet laminating material is pre-applied adhesive paper, which uses heat and pressure to activate the adhesive layer.
Polymers use heat and pressure without glue because they depend on fusing the sheets together. The sheets are joined by ultrasonic welding, while materials such as fibers and ceramics use the heat energy of the jaws in an oven to hold the layers together.
Application of thin 3D printed sheet
Application sections for creating 3D laminated objects include ergonomics studies, topographic visualizations, and architectural models for paper objects. With thermoplastics and fibers, it is possible to directly produce technical lightweight components that are functional and lightweight for the aerospace and automotive industries at very competitive prices.
Different types of sheet lamination techniques are used for different purposes and are directly related to specific processes. Paper techniques such as LOM and SDL are used for full color printing, while sheet metal lamination is used in hybrid production.
SLCOM can be used to produce high quality composite fiber parts, while the CAM-LEM process can be used to produce ceramic parts.
Advantages and disadvantages of sheet metal lamination
The advantages of sheet metal lamination
- Print times are faster, but more processing is required
- Possibility of integration as a hybrid production system
- Easy material handling
- Ceramic (CAM-LEM) and composite fiber (SLCOM) parts can be produced
- OEM components such as sensors, cables, etc. Can be built into the section during the coating step. It really depends on the sheet metal lamination technique and the materials used
- Relatively low cost as standard material is used
- No support structure required
- The work area is larger than most modern AM technology facilities
- Full color printing – LOM / SDL can print across the full color spectrum
- With some sheet lamination techniques, the state of the material does not change during or after processing
- Possibility of multilayer layers (UAM)
In some cases, the material that is cut can easily be recycled. This can also be a disadvantage if the section is smaller than the bed sheet or the size of the bed
The disadvantages of sheet metal lamination
- The layer height cannot be changed without changing the sheet metal thickness, which means that the resolution of the section is related to the thickness of the sheet metal along the vertical construction axis.
- Layers can vary depending on the paper or plastic, but may require further processing to achieve the desired effect.
- The choice of materials available is limited
- Removing excess material after the lamination phase can take a long time and generate a lot of waste compared to other AM methods.
- Perforated parts (internal cavities and cavities) are difficult to manufacture in some types of sheet metal lamination processes, such as:
- The bond strength depends on the lamination technique used, and in some cases the adhesive bond is not good enough to withstand the long term with the strength and integrity of the product.
- Material waste can also be large if the part being produced is smaller than the production area or sheet metal size