The laser's areas of application in the plastics industry
Carbonizing
The image shows the basic principle of carbonizing using the laser. The AC-LASER Software and laser machining systems by ACSYS allow the marking of plastic, whereby the plastic surface remains virtually undamaged.
Color alteration and bleaching with the laser
This effect can only be achieved with plastics, certain types of paint and a few technical ceramics. The effect depends on the wave length of the laser beam. The laser beam penetrates into the material and is absorbed by color pigments. When the pigments change chemically, this causes the color of the material to change. Since the laser beam penetrates into the plastic, the surface of the material remains virtually undamaged. The change in color depends on both the pigment and basic material.
Foaming
The image shows the basic principle of foaming using the laser. The AC-LASER Software and laser machining centers by ACSYS allow the selective and slightly raised marking of the plastic surface.
Due to their multi-axis functionality, ACSYS laser systems offer the possibility of marking large-area lengths of plastic in a single working step.
Foaming of plastics with the laser
Certain types of plastics can be marked by means of foaming. Hereby, the laser beam fuses the surface of the plastic.
During this process, gas bubbles are created in the plastic, which are included in the material during the cooling-down phase. Because of the included gas, the volume of the affected material increases and the locations, which have been laser-processed, appear raised.
Plastics engraving
The image shows the basic principle of laser engraving marking. Engraving marking means that the surface of the material is very slightly roughened, thereby creating a visible marking on the workpiece.
Laser marking by means of plastics engraving
The thermal energy of the laser is used for fusing and evaporating material in a very specific location so that a very slightly sunk marking is achieved. The workpiece absorbs virtually no heat during this process, which is an advantage when processing plastics. Laser marking is far more durable compared to painted markings.
Plastic cutting
Laser cutting of plastic materials offers advantages compared to conventional cutting processes, in particular if flexibility and the highest quality are required.
Plastics are cut in the same way as metals - by localized heating of the material above the melting point. The molten material in the focal point of the focused laser beam is removed by a gas, which is directed coaxially to the laser beam, and a cutting joint is created.
The separation edge has a high quality because, unlike the conventional process, no micro cracks are formed. In contrast to the fine-cutting of metals, a galvo head can also be used. Without any mechanical tracking of the axes, the laser beam is guided onto the material that is to be cut only by deflection mirrors. This is possible for thin materials such as foils or thin plastic mats. No gas is required for this process. The laser melts the plastic within a fraction of a second and reliably separates it.
In sectors such as the automotive industry or jewelry industry where aesthetic considerations are very important, the high quality of the laser plastic cutting process offers a great advantage.
High processing speeds due to highly dynamic linear axes in ACSYS laser machining systems ensure very short process times.
Plastic welding
The basic process of laser plastic welding is seam welding. During this process, the laser beam penetrates the workpiece, which is to be joined and is positioned on top, and is then absorbed by the piece, which is positioned at the bottom.
The heat leads to plasticization, which results in the bridging of the gap in the workpiece. As heat is conducted, the workpiece, which is positioned on top, is heated up. This means that the smallest possible gap in the workpiece is a determining factor for the application's success since the gap acts as a heat barrier.
Working principle of laser absorption welding (see illustration):
The laser light penetrates the upper layers and is absorbed by the lower piece that is to be joined (A). As the lower piece heats up (B), heat is conducted to the upper piece (C).
The shared molten area solidifies under pressure that is applied externally, thereby creating a high-quality weld connection (D).
What can be welded?
Success in laser plastic welding depends on a number of factors. One is the choice of material. Normally, plastics of the same composition can be joined to each other. Different plastics can also be joined, provided that they are chemically and physically compatible and that their melting temperature ranges overlap sufficiently.
Using the correct laser source is another important factor. Finally, successful welding also depends on the design of both the part and processing machine, which must exert sufficient pressure on the materials that are to be joined. A trial setup is the quickest way to find out what will work. Please contact us with your queries at any time.
Thermoplasts, duroplasts and elastomers
The successful machining of plastics with the laser depends on a number of different factors.
The first factor is the material. There are countless combinations and admixtures of additives for plastics, which change the properties of the plastic material. These properties include malleability, hardness, elasticity, fracture strength, resistance to temperature, resistance to heat deformation and resistance to chemicals.
Using the correct laser source is another important factor. Each type of plastic responds differently to the varying wavelengths of laser light from a fiber laser, diode-pumped laser source or CO2 laser.
Ultimately, the success of the task will depend on the design of both the part that is to be machined and processing machine. A trial setup is the quickest way to find out what will work.
Please contact us with your queries at any time.