Determining the best way to mark your part will require some knowledge about your part and what type of mark your part will require. Although both lasers and pad printers can mark on metal, glass, plastic, wood, fabric, and other substrates, there are some key differences in these marking technologies. Below you will learn more about these marking techniques which will allow you to determine which is best for your organization. Many companies see the benefit of both technologies and use both in their secondary or part printing decoration area. In general they can be summarized in the below chart but read on for more information.
Laser marking uses concentrated beams of light filtered through different mediums inside the laser to produce varying wavelengths that burn an image onto a part. The most common forms of laser types that are found in the marketplace today are CO2, UV, fiber, and green. These laser types operate on different frequencies. Some substrates respond to different frequencies in different ways. For example a UV laser can easily mark glass, but a fiber laser beam will pass right through it. For this reason, we offer free sample marking of your part to determine which laser source will work on your part.
Since energy is used to burn the substrate surface, the part can be lightly marked with this energy or burned enough to “etch” the product, which is a mark that can usually be felt through touch. Lasers are considered permanent forms of marking as the substrate needs to be destroyed to remove the mark.
Common substrates for lasers to mark are plastics, glass, metals, paper products, and even organic materials like food and cotton. Lasers do not require operating supplies and require very little energy to mark substrates. Because they are software driven, lasers can be programmed to mark both moving and stationary parts. This software also allows lasers to dynamically mark objects, which means the mark can change while marking items that are moving underneath it. This makes a laser a perfect solution to mark changing serial numbers or even barcodes like data matrix codes and serial bar codes on items that are on conveyor belts or even extruded materials like plastic or metal piping.
Lasers typically mark parts in shades of grey (white to black) but with certain metals, colors can be extracted by marking the parts by varying frequencies inside the software that comes with the system. Lasers find themselves built for automation and can be used in part marking single use prototypes up to thousands of parts per hour. Laser lifespans are typically under 10 years in 24×7 use upon which time the source will need to be replaced which typically costs about half of the initial investment. Lasers work well on flat parts but can also print round parts using special focusing lenses and software, called 3-D laser marking. This can also work in conjunction with rotational fixtures which allow full 360 degree printing.
Lasers are powered by software so the image can quickly change on-the-fly.
The software allows for quick image loading. Typically lasers can mark parts quickly in just seconds from the moment being turned from off to on. Laser prices have come down over the years but typical lasers still are in the tens of thousands of dollars for good reliable machinery producing excellent beam quality with reliable and easy-to-use software, support, and warranties.
Laser light can be hazardous to eyes and skin, so it is important to consider how a laser is implemented inside an operation. For more about laser safety, click here.
Pad printing uses ink which is picked up from a recessed area on a printing plate and deposited on the part. The plates are created one at a time, so the image does not lend itself to changing, rather it is important to know the majority of pad printing jobs require multiple parts to be marked. The ink is dry-to-touch in seconds. This ink can be built up in a series of colors on the part which can then reflect a multiple series of colors on parts; think of combining yellow and blue to make green. They can also print multiple separate colors onto one part.
Pad printing machines excel in part decorating shapes that are two or three dimensional, like a coffee cup or a part that has recessions. Pad printing can mark almost any substrate but it is important to select ink that has been chemically engineered to adhere to the parts. There are multiple ink types. To learn more about ink, click here. Ink from pad printing is not considered permanent but there are inks that are formulated to be extremely durable, being UV and chemical resistant. Once printed onto a part, most people would confuse them with being permanent.
Because ink is being deposited onto a part with a pad, the part must be stationary. Common output times range from 120 parts per hour with manual machines, to 500 parts per hour using a 1-color automatic machine, to thousands of parts per hour using multi-color machinery with automation. The part being decorated is usually being produced identically in the hundreds or thousands as the image is stationary, meaning that it cannot change dynamically like a laser. The fact the same image can repeatedly be reproduced accurately in color time and again, leads pad printing to be a dominant marking type in the decoration world. Everything from cosmetics cases to garments are pad printed today. Pad printing starts at a few thousand dollars to buy excellent entry level equipment. Pad printing machinery pricing is a direct correlation to the quality of image and life of the equipment. Find out why using cheap pad printing machinery is a huge mistake here.