Introduction
When it comes to manufacturing, choosing the right cutting technique is crucial for achieving the desired results in your projects. Whether you’re involved in rapid prototyping or full-scale production, the method you select will significantly impact the quality, speed, and cost of your operations. Two of the most popular cutting technologies in the industry are laser cutting and waterjet cutting. Each has its own set of strengths and weaknesses, making them suitable for different applications.
In this article, we’ll explore the fundamental differences between laser cutting and waterjet cutting, analyze their advantages and disadvantages, and help you determine which method is best suited for your specific needs.
How Each Process Works
Laser Cutting
Laser cutting is a subtractive manufacturing process that uses a high-powered laser beam to cut through or engrave materials. The process involves focusing a laser—essentially a concentrated beam of light—onto a small area of the material. The energy from the laser heats the material to the point where it either melts or vaporizes, creating a precise cut.
This technology is incredibly versatile and can be used on a wide range of materials, including metals like stainless steel, aluminum, and mild steel, as well as non-metals such as plastics, glass, and wood. Laser cutting is particularly well-suited for projects requiring high precision, as the laser beam can achieve a cutting slit size as small as 0.006 inches (0.15 mm).
Learn more about Lazer Cutting here: “What Can A Laser Cutter Do? The Basics and What Materials Can Be Cut”
Waterjet Cutting
Waterjet cutting is a process that uses a high-pressure jet of water to cut materials. The water is often mixed with an abrasive material, such as garnet, to enhance its cutting ability. The waterjet is focused through a small nozzle, where it is expelled at pressures as high as 60,000 pounds per square inch (psi). This high-pressure stream of water physically erodes the material along the cut line, effectively slicing through it without generating heat.
Waterjet cutting is known for its versatility in cutting a wide variety of materials, including metals, stone, tile, rubber, foam, and cloth. Because it does not rely on heat, waterjet cutting is ideal for materials that are sensitive to high temperatures, such as plastics and composites. Additionally, it can cut much thicker materials than laser cutting, with optimal thicknesses ranging from 0.4 to 2.0 inches (10 to 50 mm).
Key Comparisons Between Laser Cutting and Waterjet Cutting
Material Capabilities
When deciding between laser cutting and waterjet cutting, one of the most critical factors to consider is the type of material you need to cut.
Laser Cutting
Laser cutting is incredibly versatile when it comes to materials. It is particularly effective on non-metals such as wood, acrylic, glass, and various plastics. However, laser cutting can also be used on metals like stainless steel, aluminum, and mild steel. The primary limitation of laser cutting is its struggle with materials that have different melting points or are reflective. For example, cutting highly reflective materials such as copper can be challenging because the laser beam is reflected away from the material, reducing its effectiveness.
Waterjet Cutting
Waterjet cutting has virtually no material restrictions. It can cut through almost any material, including metals, composites, stone, and even food products. Because it uses mechanical erosion rather than heat, waterjet cutting is ideal for materials that would otherwise be damaged by the high temperatures associated with laser cutting. Additionally, waterjet cutting excels at slicing through thicker materials, making it the preferred choice for projects involving thick metal plates or stone slabs.
Precision and Tolerance
Precision is another critical consideration when choosing between laser cutting and waterjet cutting.
Laser Cutting
Laser cutting offers superior precision, with a minimum cutting slit size of 0.006 inches (0.15 mm) and a processing tolerance of approximately 0.002 inches (0.05 mm). This high level of precision makes laser cutting the go-to choice for intricate designs, detailed engravings, and projects where tight tolerances are essential. The laser’s ability to create fine, clean cuts also means that less post-processing is required, further enhancing its appeal for precision work.
Waterjet Cutting
Waterjet cutting is also precise, but it does not match the fine tolerances of laser cutting. The minimum cutting slit size for waterjet cutting is around 0.02 inches (0.5 mm), and its processing tolerance is about 0.008 inches (0.2 mm). While this level of precision is more than adequate for many applications, it may not be sufficient for projects requiring extremely detailed cuts or tight dimensional tolerances.
Speed and Efficiency
The speed at which materials can be cut is another key factor that influences the choice between laser cutting and waterjet cutting.
Laser Cutting
Laser cutting is generally faster, especially when working with thinner materials. Cutting speeds can range from 20 to 70 inches per minute, depending on the material and thickness. This speed advantage makes laser cutting particularly well-suited for high-volume production environments where time is of the essence. The quick processing time also means that laser cutting is more efficient in terms of machine utilization, which can translate to lower overall costs for large-scale projects.
Waterjet Cutting
While slower than laser cutting, waterjet cutting offers other advantages that may outweigh its speed limitations. Waterjet cutting speeds typically range from 1 to 20 inches per minute, depending on the material and thickness. While this slower speed might be a drawback in high-volume production settings, it is often acceptable for low-volume, high-mix environments where the ability to cut a wide variety of materials is more important than sheer speed.
Potential Material Damage
The potential for material damage is an important consideration, particularly for projects involving delicate or heat-sensitive materials.
Laser Cutting
Laser cutting can cause burn marks and discoloration on certain materials due to the high temperatures involved in the process. These burn marks can often be removed through post-processing, but this adds an extra step to the manufacturing process. Additionally, the heat generated by the laser can create a heat-affected zone (HAZ) around the cut, which may weaken the material or cause it to deform.
Waterjet Cutting
Waterjet cutting is a cold-cutting process that does not generate any heat. As a result, there is no heat-affected zone, making waterjet cutting ideal for materials that would be damaged or weakened by high temperatures. However, the high-pressure waterjet can apply significant force to the material, which can cause small parts to deform or even fail to cut properly. This is particularly true for thin or delicate materials, where the force of the waterjet may be too much for the material to withstand.
Advantages and Disadvantages
Laser Cutting Advantages
- High Precision and Accuracy: Laser cutting is known for its exceptional precision, making it the preferred choice for projects that require detailed designs and tight tolerances.
- Speed: Laser cutting is much faster than waterjet cutting, especially when working with thinner materials. This makes it ideal for high-volume production environments.
- Minimal Waste and Clean-up: Since laser cutting uses light to cut materials, there is very little physical waste produced, and any dust can be easily vacuumed.
- Engraving Capabilities: Laser cutting can also be used for engraving, allowing for the addition of serial numbers, assembly marks, or aesthetic designs directly onto the material.
Laser Cutting Disadvantages
- Limited Thickness: Laser cutting is generally limited to materials up to 1 inch thick. While it can cut thicker materials, the process becomes less efficient, and the quality of the cut may suffer.
- Potential for Hazardous Fumes: Depending on the material being cut, laser cutting can produce fumes that may be hazardous if not properly ventilated.
- Thermal Stress: The heat generated during laser cutting can cause thermal stress in the material, potentially leading to cracks or warping.
Waterjet Cutting Advantages
- Versatility: Waterjet cutting can be used on a wide range of materials, including those that are difficult or impossible to cut with lasers.
- No Heat-Affected Zone: Because waterjet cutting is a cold process, there is no risk of thermal damage to the material, making it ideal for heat-sensitive materials.
- Ability to Cut Thick Materials: Waterjet cutting excels at cutting thicker materials, with optimal thicknesses ranging from 0.4 to 2.0 inches.
- Clean and Smooth Cuts: Waterjet cutting produces clean, smooth edges that typically do not require additional finishing.
Waterjet Cutting Disadvantages
- Lower Precision: While still precise, waterjet cutting does not offer the same level of accuracy as laser cutting, which may be a drawback for projects requiring very tight tolerances.
- Slower Cutting Speeds: Waterjet cutting is generally slower than laser cutting, which can increase production time and costs.
- High Noise Levels and Clean-up: Waterjet cutting is noisy and requires significant clean-up due to the mixture of water and abrasives used in the process.
Application Scenarios
When to Use Laser Cutting
Laser cutting is the ideal choice for projects that require high precision and intricate designs. It is also the preferred method when speed is a critical factor, such as in high-volume production environments. Additionally, laser cutting is well-suited for applications that require engraving, as it can easily add serial numbers, assembly marks, or decorative elements directly onto the material.
Laser cutting is particularly effective for materials less than 1 inch thick, such as thin sheet metal, acrylics, and other non-metals. It is also the best option when you need to achieve a polished edge, such as when cutting acrylic for display cases or signage.
When to Use Waterjet Cutting
Waterjet cutting is the better choice for projects involving thick materials or a variety of material types. It is especially useful for cutting materials that are sensitive to heat, such as composites, plastics, and certain metals. Because waterjet cutting does not generate heat, there is no risk of thermal damage, making it the preferred method for materials that could be weakened or deformed by high temperatures.
Waterjet cutting is also ideal for projects where versatility is important. If you need to cut a wide range of materials, from metal to stone to rubber, waterjet cutting offers the flexibility to handle them all with ease.
Cost Considerations
Operating Costs
When evaluating the cost of laser cutting versus waterjet cutting, it’s important to consider both the initial investment and the ongoing operating costs.
Laser Cutting
Laser cutting typically involves a higher initial investment, particularly for fiber laser systems, which are more expensive than their CO2 counterparts. However, laser cutting is generally cheaper to operate, with costs ranging from $2 to $3 per hour. This lower operating cost is due to the minimal consumables required—primarily electricity and occasional replacement of the laser optics.
Waterjet Cutting
Waterjet cutting, on the other hand, has higher operating costs, typically ranging from $50 to $75 per hour. This is due to the need for abrasive materials, such as garnet, and the maintenance required for the high-pressure pumps. While the initial investment in a waterjet system may be lower, the ongoing costs can add up, particularly for high-volume operations.
Maintenance and Training
Laser Cutting
Laser cutting systems, particularly modern fiber lasers, require skilled operators to achieve optimal performance. However, advancements in technology have made these systems easier to manage, with intuitive interfaces and automated settings that reduce the need for constant operator intervention. Maintenance for laser systems is relatively low, primarily involving the cleaning or replacement of optics and regular system checks.
Waterjet Cutting
Waterjet cutting systems are generally easier to operate, requiring less specialized training. The maintenance, however, is more frequent and involves tasks such as rebuilding the high-pressure pumps and replacing worn nozzles. While these tasks are straightforward, they need to be performed regularly to keep the system running efficiently.
Technological Advancements and Trends
Laser Cutting Advancements
Recent advancements in laser cutting technology have significantly expanded its capabilities. Higher-wattage fiber lasers, such as those offered by Amada’s ENSIS and VENTIS systems, now allow for the cutting of thicker materials, including aluminum up to 1 inch thick. These advancements have made laser cutting increasingly competitive with waterjet cutting for a broader range of applications.
In addition to power increases, modern laser systems feature beam shaping technologies that enhance cutting quality and speed. For example, the VENTIS system uses a dynamic beam that moves within the nozzle, allowing for smooth cuts and reduced striations on thicker materials.
Waterjet Cutting Innovations
Waterjet cutting has also seen significant innovations, particularly in the development of minijet and microjet technologies. These advancements allow for high-precision cutting, making waterjet systems more suitable for intricate applications that were previously the domain of laser cutting.
Another trend in waterjet cutting is the creation of extensive material libraries, allowing operators to easily switch between different materials with just a few clicks. This flexibility is particularly valuable in industries that work with a wide range of materials, such as aerospace or automotive manufacturing.
Conclusion
In the debate between laser cutting and waterjet cutting, the right choice depends on the specific needs of your project. Laser cutting excels in precision, speed, and the ability to engrave, making it ideal for detailed work on thinner materials. Waterjet cutting, on the other hand, offers unmatched versatility in material selection and thickness, making it the better option for projects involving a wide range of materials or thick sheets.
For many businesses, the best approach is to use both technologies in a complementary fashion. By leveraging the strengths of each method, you can maximize your production capabilities, bid on a wider variety of projects, and ensure that you always have the right tool for the job.
Additional Resources
For more information on laser cutting and waterjet cutting, consider checking out our services and videos on social media. If you’re ready to start your project, visit our website to learn more or to request a free laser cutting or waterjet cutting quote.
