ClearweldR Products and the Laser Welding Process
ClearweldR allows the near infrared (NIR) and infrared (IR) laser welding of clear IR and NIR transparent plastics. ClearweldR can be coated onto parts or used as an additive compounded into resins. While there are many established methods to weld plastics, each with its own advantages and disadvantages, ClearweldR offers a dynamic, plastic welding technology to provide you with greater design, engineering and manufacturing flexibility. The image to the right shows how a ClearweldR solution can be coated and laser welded using ClearweldR solutions. The ClearweldR is coated, leaving a green layer on the surface of the part. A second top part that is IR transparent is placed above the coated part and pressure is applied. The laser welds the two parts together, and when performed correctly, the ClearweldR coating is both transparent and colorless.
Our Products
ClearweldR Coatings
ClearweldR coatings offer a simple approach to laser welding NIR transparent plastic parts. The ClearweldR 100 and 900 series are applied to the part as a coating. Typical application methods are: ultrasonic sprayer system, precision fluid dispenser, inkjet printing or any method that would commonly deposit solvent-based solutions. See our Distributers and Equipment page for more information.
ClearweldR Resins
When ClearweldR resin is used, the additive material is compounded into the resin using loadings between 0.015 and 0.1 weight % depending on part thickness, part geometry and type of resin. The ClearweldR additive efficiently converts laser energy to heat. The user has the flexibility to compound ClearweldR into nearly all thermoplastic resin materials. Clearweld resin, when laser welded, will not lose color. We recommended use of the lowest loading that reliably welds.
ClearweldR and the Laser Welding Process
The parts to be welded are placed in a clamping system that allows for pressurized contact. Many laser welding systems come with the feature already built in, as seen in Leister’s Maxi Laser welding system for Large Components. A laser ranging from 900nm to 1100nm used with a ClearweldR product produces melting at the interface between the two parts. The laser welding is complete in seconds. However, allow the part to cool before removing from the clamping system. Cooling systems can be used to expedite the cooling process.
Laser Welding Parameters
Laser welding occurs at the interface between two parts. The two parts melt due to the laser heat generated. As the parts cool, they fuse creating a bond that is as strong as the base material itself. The heat generated during the weld is determined by the energy density of the laser and the amount of ClearweldR deposited. Energy density is determined by laser power, scan speed and the spot size of the laser. For example, to increase weld speed use a more powerful laser or use a larger amount of ClearweldR. It is important to use a laser welding system to weld plastic. While laser welding using a laser engraving system is possible, we do not recommend this practice due to the smaller spot size of these systems. When using a laser welding machine, make sure to follow the manufacturer’s suggested parameters.
Energy density is determined by laser power, scan speed and the spot size of the laser. For example, to increase weld speed you can use a more powerful laser or use a larger amount of ClearweldTM. When using a laser welding machine, make sure to follow the manufacturer’s suggested parameters.
ClearweldR Compatible Resin
ClearweldR can be used to weld most thermoplastics. Thermoplastic compatibility is based on a number of factors, including melt temperatures and the polymer chemistry. Typically welding like materials will weld successfully. It is also possible to weld dissimilar materials. ClearweldR has provided a polymer compatibility chart below to assist with determining the weld strength of different polymer types. If you do not see your specific polymer on the chart, please Contact Us to set up a welding trial.
