How To Laser Engrave Soft and Hard Materials

Laser engraving as a marking technique is suitable for various products from different materials. However, to engrave soft and hard materials, there is a catch. Many people are not familiar with laser engraving, both types of materials.

Generally, the mystery about engraving on hard materials is not as confusing as that of soft materials. Consequently, many marking enthusiasts worry more about marking soft materials than hard ones. Nevertheless, to help you mark either type, this article will introduce both materials and show you the general steps to mark them. It will then introduce several factors you should consider for quality marking without sacrificing productivity.

Soft vs. Hard Materials

Before we go on, we have no doubt you can distinguish between hard and soft materials with ease. However, if you cannot differentiate, below are our definitions of the two types of materials.

· Soft Materials

Our classification of soft materials is majorly for plastic materials such as ABS, Nylon, and Polyethylene. These materials have unique properties, such as thermolabile, and therefore, they are not suitable for some types of laser marking machines.

However, enthusiasts have noted that these materials are compatible with laser engraving machines when denser. Generally, marking soft materials is tough as the laser marking machine emits heat which can damage the product.

· Hard Materials

Hard materials are metals and non-metals such as stones, glass, and ceramics. They are denser and are compatible with selected types of laser engraving. Consequently, knowing the perfect way to laser engrave both types of materials is very important.

How to Engrave on Soft and Hard Products

Before you decide on engraving any material, whether soft or hard, the first thing you should know is the type of laser marking machine you will use. This section will show you this and other things you need to worry about on engraving.

Step 1: Choose the Laser Marking Technology

There are four common types of laser marking technology used in laser engraving. Each type has unique attributes making them suitable for different materials. Below are the four laser technologies and their compatibility with soft or hard materials.

· Fiber Laser Engraving

A fiber laser engraving machine is known for its high wavelength (up to 10000nm) and is suitable for engraving any hard material. The long wavelength means more laser power and lower light absorption, creating deep and permanent markings. Consequently, fiber laser markers are common in the automotive, jewelry, medical, and electronic industries.

Fiber laser engravers are unsuitable for soft materials due to the higher wavelength, as the heat generated can destroy the soft material. However, some enthusiasts recommend it for rush-marking of soft products made from materials such as PVC, PE, and ABS, although the quality is not guaranteed.

· CO2 Laser Engraving

CO2 laser marking machines are the oldest laser markers suitable for non-metallic hard materials such as wood, glass, quartz, and ceramics. They have a long wavelength (sometimes up to 10,600nm). Unlike other laser systems, CO2 laser engraving is unsuitable for marking metals and soft products.

· Green Laser Engraving

Green laser engraving machines run on the cold laser technology, which emits lesser heat than the Fiber and CO2 laser system. Consequently, they are suitable for hard and soft materials, although more compatible with products with reflective surfaces.

They have a low wavelength (about 532nm), promoting absorptivity and low thermal transfer. Consequently, they are an ideal soft product laser engraver.

· UV Laser Engraving

Ultraviolet (UV) laser engraving machines also run on cold laser technology with low wavelength and lower thermal transfer. Consequently, they are also suitable for engraving on soft materials.

They are also fairly accurate due to the high-quality beam. Therefore, they are suitable in the electronic industry (micro-marking circuit boards) and the medical industry (marking measuring cylinders and syringes). There are many types of a UV laser engraver, and you need to understand their properties before knowing how to choose them

· Soft Products: Choosing Between Green Laser Marking vs. UV Laser Marking

You can work with a green or a UV laser marking machine for soft product markings. Both machines have similar properties and are suitable for marking, but you should consider a few things. Before you decide.

UV laser marking machines have focused wavelengths with high beam intensity and minuscule spot size. Consequently, they are precise and suitable for marking up to the micro-level on soft materials.

Green laser marking machines can also produce a clean and readable mark. However, they are better than UV laser engravers since they mark way faster. This is due to their higher wavelength, which grants them more power even though it does not affect the material.

Step 2: Handheld Laser Engraver vs. Traditional Laser Engraver

Although this is not directly linked to soft or hard materials, choosing between a traditional and handheld marking machine can affect your marking productivity.

We would recommend a laser engraving machine with industrial capability yet portable. A handheld laser engraving machine will allow for an easy maneuver, which aids in marking products with complex designs and large sizes. You can check out our laser engraving machines for the perfect one for your product.

Step 3: Choose the Laser Engraving Machine  

After choosing the laser marking technology, you want to ensure an effective and efficient engraving process. Below are the factors you need to consider and how they relate to marking soft and hard products.

· Laser Wavelength

The laser wavelength is the amount of energy of a laser beam measured in nanometers. Every laser engraver has its unique wavelength. The shorter it is, the more concentrated the energy, the more light absorbed by the product, and the better the quality of the markings.

Choose a laser marking machine with short wavelengths for soft materials and machines with long wavelengths for hard materials. Using a long-wavelength machine for soft materials can lead to the burning of the product since the energy is not absorbed while using a short wavelength machine for hard materials won’t be effective and efficient.

Shortest Wavelength	180 – 400 nm	Ultraviolet (UV) Light
Moderate Wavelength	400 – 740 nm	Visible (VIS) Light
Longest Wavelength	700 nm – 1 mm	Infrared (IR) Light

· Laser Wattage

To check against productivity, you also need to consider the laser wattage or the laser is power output, as it is a key determinant of the machine’s speed.

Depending on the laser marking technology you are using, you might have different laser wattage. For example, some fiber laser marking machines have 10W to 100W of output power, and consequently, they are very fast and produce deep, permanent marks. Others, such as the green laser engravers, have about 4W to 6W of power output, and consequently, they have slower speeds and shallower marks.

· Repeatability

Another factor you should consider when getting a laser engraving machine is repeatability. This is important if you will be dealing with batch coding, and the machine must support batch coding. Consequently, it would be best to consider machines that fell in the laser coding class.

Step 3: Engrave Your Product

After selecting the laser marking machine for engraving either product, you can proceed with the engraving process. The marking procedure depends on the marking machine, product size, design complexity, and other factors.

While it might be suitable to engrave the materials yourself, most people have found it better to outsource to laser marking services. You can check several marking procedures and machines we provide to our customers.

Final Thought

Engraving either a soft or hard product can be demanding, especially for soft products. Therefore, this article introduced how you can engrave on both types of materials, and it showed the different marking technology you can use and other things you should consider. Below are some take-home points regarding laser engraving soft and hard materials:

• To mark hard materials, use a laser engraving machine with a longer wavelength. For example, fiber laser marking machines are the most common for such scenarios.
• Use a laser marking machine with a shorter wavelength for soft materials to avoid product damage or readability issues
• UV laser marking machine ensures better precision for soft materials due to the shorter wavelength. On the other hand, the green laser marking machine has a better power output marking it more efficient. Both options can create quality marks on soft products

Do you have a problem deciding on the right marking machine? Or peradventure, the process still looks gray to you; why not contact us at HeatSign. You can use our expert services and get the best marking services for hard and soft materials.