Marking Painted Zinc Component

Zinc die-cast components are commonly used in the manufacture of consumer and industrial products, especially in automotive applications. Many of the components used in automobiles, power and hand tools, and household hardware, like sink faucets, are zinc die-cast. Die-cast zinc parts have excellent dimensional tolerances, a very good surface finish, and have proven to be very durable. In particular, zinc components retain their strength even though they can be cast with the thinnest walls. Because of their high-quality surface finish, die-cast parts are easily plated or painted with a minimum of prep work.

For this application, we were asked to mark the outlet port on this painted zinc die-cast air regulator body. The marking setup consisted of an FH Flyer marking head and a 25 W laser controlled by our WinMark Pro laser marking software. The Flyer head was equipped with a 125 mm focal length lens that provided a 180 um (0.007”) spot size. This small spot size creates a high enough power density to efficiently vaporize the paint away while also achieving excellent mark detail.

The mark file consisted of 13 mm (0.5”) high TrueType text that was bolded and filled (Text Bold and Text Fill properties set to Yes) with a Filled Font Resolution of 450 lines per inch. the mark velocity was setto a speed of 508 millimeters per second (20 inches/sec) and the Power (duty cycle percentage) was set to correspond to 25 watts. The resulting mark, completed in a cycle-time of 5.42 seconds, exposed the zinc regulator body underneath creating a high-contrast mark against the surrounding painted surface.

Laser Marking Guidelines on Wood Products

In mass-production lumber processing operations, there is often a requirement for marking simple guide lines on wood products like plywood or particle board sheeting. Depending on the end application, these guide lines might show where a sheet needs to be trimmed further on in the production process, like paneling or exterior sheeting that needs to be cut to specific custom lengths, or the line could be for a simple visual aid to indicate a nailing line on exterior siding or to show the on-center position of framing behind the sheeting.

Traditionally these guide lines are done using ink-jet printers; however, ink-jet consumables are costly and in some cases, must be disposed of as hazardous waste. Laser marking eliminates these expenses while providing a consistent permanent mark in the wood. For this type of application, laser implementation can be fairly inexpensive as it can require as little as 10 to 30 watts of laser power, depending on line speed requirements, and beam delivery can be a simple fixed optic mounted above the product conveyor.

For this specific application request, we were asked to mark a visible line across a large particle board sheet. To simulate this type of operation in our Applications Lab, we used our Flyer marking head to move the beam across the sheet because we could not physically move such a large sheet underneath the laser. The demonstration setup consisted of a Synrad 10 W CO₂ laser and an FH Flyer marking head, equipped with a 370 mm focal length lens that produced a 540 um (0.021”) spot size on the wood surface. This large diffuse spot size greatly increases the visibility of the mark line as there is more surface burn compared to smaller focused spot sizes with greater power densities that waste energy by vaporizing the wood, which creates minimal mark contrast.

Using 10 watts of power, the particle board samples were marked at line speeds of 15.2 meters per minute (50 ft/min) resulting in a clearly visible, dark nailing line. In situations where higher line speeds are necessary, laser power can be scaled from 10 watts all the way up to 400 watts.

Introducing the New Synrad Laser Processing Calculator

The new Synrad Laser Processing Calculator not only allows you to evaluate the feasibility of laser cutting applications (with better predictive algorithms and visual feedback for various material types), but it now includes the ability to evaluate simple laser marking applications.

An improved web-based user interface guides you through the process. Simply select a material type, enter a few application parameters, and then select a laser power to see how quickly the process can be completed. The results include a description of the cutting or marking operation along with speed and/or cycle time information and a photograph showing results of actual laser processing on the selected material. Try it out