Most commonly used thermoplastics can be welded with the exception of fluoropolymers.
Both could be clear or both could be pigmented or just the bottom part can be pigmented.
It is not required when using the 2-micron laser.
To date, we have welded parts up to 700mm diameter. There are really no limitations as each system is custom designed based on the customer’s requirements.
Yes and Dukane will advise you for the optimum joint design. In many cases flat-on-flat surfaces are acceptable. A good fit between mating surfaces is critical.
This depends on the material properties and thickness of the upper part.
Moderate curvature is possible without any special tooling.
Yes, in fact the laser welding systems are flexible and the systems are easy to automate.
Our laser work cell enclosures are Class 1 CDRH certified with laser-safe glass viewing window.
Not necessarily. Some parts can be clamped using metal (aluminum or stainless steel).
No, due to the 2-micron laser beam is absorbed by the polymer itself.
Fumes or smoke are an indication of thermal decomposition of the thermoplastic material. So process optimization is critical.
Yes, in many cases an annual calibration is sufficient, but calibration frequency is guided by your quality control requirements.
Check top status bar on HMI to find out why it is not ready for cycle.
See operation manual section 11. Main items listed below:
Yes, the industrial HMI can be shut down at any time. It will not hurt the function of the machine or HMI.
This is the way you Zero the weight of the tool and the table. Allow you to know that the force you are developing is what you are putting on the part during weld. In some machines you enter the tool weight directly and the machine knows the weight of the table and subtracts both from the pressure in the system. The more accurate way to do this is called “Float the Table”. In this case you load the tooling and run a process of increasing pressure until the table moves. That is where the force to lift is zero. Then this pressure is subtracted from the force of the system.
The oil should be changed out every 10,000 hours or when it is discolored.
The bolts in all spring and lamination carriers must be used. The upper moving tool develops up to 208g’s. This means a 100 pound tool will dynamically produce 20,000 pounds + of dynamic load. Electrically we can see one bolt missing and the head to begin to run not in a desired mode. Multiple bolts missing will damage the machine and void a warranty.
An un-balanced tool will not run linearly. It will start to move in a orbit form. This stresses the lamination carriers and the Coils. A balanced tool is the single most important thing you can do to make the machine last longer.
Tool ID in a Dukane machine is simple binary input to the machine through the tooling connector. By wiring 24 volts to the correct pins it is possible to give a tool a unique tool ID. In using this each time you plug in the tool the program associated with the tool will be pulled up in the PLC/HMI. So there is no chance to get the wrong weld parameters for a given application and no reason to set up parameters when you load the tooling.
Check the weld time of the machine. It is very probable that you have exceeded the maximum weld time. You will need to add more time or increase clamp pressure or amplitude to make distance in desired amount of time.
If possible, it is usually better to weld in melt down distance. This is the only closed loop welding method. You can change pressure, amplitude, and even surface area of weld part to part and still make the same distance giving you consistent welds.
You need to calculate all the surface area of the top of the weld beads. Then multiply this area by 250 lbs / square inches of area. This is a good starting point it can vary by a lot based on application.
Hold pressure should not exceed weld pressure. In fact it is nice to reduce hold pressure by 10% or so. When a welder goes into hold mode you get “post weld collapse” and this is a thinning of the heat affected zone. This thinning is a reduction in weld strength. You need hold pressure but excessive pressure can yield a cold weld.
In general the marks are from the part moving in the nest (could be upper or lower nest or both). You need to increase weld pressure so the parts lock up in the nest better. This usually solves the problem. If not finding a way to lock the part on the tool may be required. The use of locators and return flanges in your part usually will work fine.
Yes you can use the Dukane Material compatibility chart available on the website to determine what materials are weldable to each other. Then you need to answer two more questions:
We need to be thinking pressure and amplitude. If you have a weld in an area where you do not want a weld you need to remove the pressure or remove the amplitude. Usually this means you need to clear the supporting nest in this area relieving any chance that pressure is applied to the area of unwanted weld. Only in rare occasions is it possible to reduce or eliminate the amplitude.
Auto tune is the matching of the natural resonance of the head to the digital drive. When this matching of the frequency occurs, you get lowest possible power draw from the power supply. A small deviation of even 1Hz can mean a lot of lost power. This excess power will show up in your coils of the vibration head causing excessive heat which over time can damage the coils and or lamination carriers. An auto tune can and should be done at every change in tooling. It also can be done in between tooling changes. Dukane machines can be autotuned on a set number of cycles.
A melt map is usually done at 0.5mm or half the desired weld depth. By welding the part at minimum weld depth tearing the part and looking at all weld beads you will find areas of no weld. You would add shims to the tooling until you get around 80% of all areas welded. Then weld the part at full melt depth and check to see if you are making all critical characteristics of the part that are required.
What you need to think of are pressure and amplitude.
Hold time, is a period of time after weld is completed where the head rings back down to center position and then part stays clamped in the nest until the molten plastic part solidifies. Generally accepted rule is if the parts welds in “X” seconds you need “1/2X” amount of hold time. If you are not cycle time constrained just make hold time equal to weld time.
Yes, we weld parts all the time that hold significant pressure without leaking. Example of some of these applications are Tail lamps, Intake Manifolds, Electronic modules, Toilet tanks, and many others