Explore the Precision Laser Cutting Advantages & Disadvantages

“When it comes to speedy, replicable complex designs and cost-effective parts shearing, a laser cut tool greatly contributes to fulfilling these requirements. It can cut down nearly every material, whether plastic or highly rigid metal.”

The process uses highly concentrated light beams to achieve precise results through melting, vaporizing, and ablating materials from focused hotspot shots. This technique offers flexibility in operation by utilizing discrete laser sources like CO2, NdYAG, and liquid crystal devices. Thus, laser cutting advantages allow manufacturers to work with a wide range of applications, from producing highly detailed parts for medical use to aircraft prototype components. The laser cutting field is so widespread and developed because of fabricating sheets, sawing down tubes, engraving complicated design parts, drilling through diamonds, and micro-welding in semiconductor production. Therefore, its uses are very far-reaching from a broad aspect. 

It provides more advantages than conventional cutting techniques. These machines are characterized by the fact that they are considered most accurate. These machines can produce the least material waste and are notably speedy in part machining. Moreover, laser machines can pierce to shape simple designs into complex designs like 2D and 3D. On the side, it also poses a few disadvantages. For instance, its use is limited by the thickness of materials, release of harmful gases and fumes, large energy consumption, and high initial investment requirements. 

Laser machines also provide several benefits to users. However, other methods, like waterjet cutting, CNC machining, and plasma cutting, are also considered effective because of their unique approaches. This article will thoroughly look into laser cutting’s advantages and disadvantages by explaining the working process and exploring the precision types of cutting techniques.

How Lasers Precisely Cut Materials?

Precision laser cutting

The laser cutting process is based on the use of a highly focused energy laser beam that is used to heat and vaporize materials swiftly. This heat is created at an intense rate, forming a small area of high temperature that rapidly melts or evaporates the material as it passes through it in uniform speed around 5 to 15 seconds for small-sized parts depending upon the material being pierced. 

In laser cutting sheet metal processes, gas is directed to the hotspot, which results in melting or vaporizing of intended part material. Gases are used as assistance depending upon the material type being cut. These can be different from plastics to metals. For example, lightweight aluminum is usually prone to oxidation, and nitrogen gas is considered as a convenient option to prevent oxidation causes. On the contrary, for steel, oxygen is notably significant in speeding up the piercing process by locally oxidizing the material and thus facilitating slag removal from parts’ surfaces. 

Laser cutting machines come in diverse designs. The most frequently used type is stationary workpiece and moving laser optics, mirrors, along with X and Y-axes. The other process, normally used, is called the “fixed optic” format. It keeps the laser head still while the workpiece moves during the cutting operation. In addition, other techniques are described as a combination of both aforementioned techniques. The machines could be configured in different ways; however, they all work using computerized or software-controlled functions by following the intricate cutting paths defined in 2D and 2.5D G-code patterns.

Laser Cutting Advantages

Laser cutting offers a multitude of advantages that make it a preferred choice in various industries: Here are some unique aspects of laser cutting includes;

1.High Precision

Prototype 3D laser-tool machining

The laser beam is a precise, and automatic process. Its effective control over energy and materials or laser optics movements results in highly accurate cutting. One of the core benefits is that it enables the execution of complex designs at high feed rates, even on difficult to fragile materials of varying thickness between 0.32 mm to 0.10 mm.

2. Less Material Contamination

In contrast to mechanical cutting techniques that generally require using coolants or lubricants, laser cutting only uses energy and gas. This unique feature avoids a scenario where grinding or cutting coolant may chemically contaminate the material being processed. 

3. High-Speed Process

Laser cutting is known for its high processing speeds, in comparison to various other techniques. According to a real time example, a 40 mm sheet of steel metal could be precisely cut 10 times less from a 12 kW oxygen-assisted laser as compared to standard bandsaw, and also up to 50 -100 times faster than a precision wire-EDM cutting process. 

4. Unlimited 2D & 3D Complexity

3D laser cut-design prototype part

The nature of laser cutting, controlled by g-code movement, is considered more convenient for producing intricate designs with minimal force applied to the material. This allows cutting the features that are very closely related to the main body. The process only affects materials property, and could lead to unsatisfactory consequences because the cutting process itself is more accurate, and automatically shapes 3d to 2d configurations

5. Versatility in Materials

Laser cutting technology is a very versatile machine that effectively cuts down a variety of materials, such as acrylic, stainless steel, mild steel, titanium, hastelloy, and tungsten. The latest technology, like dual-frequency lasers, is introduced, extending the range of materials that can be handled with ease and precision. Examples include carbon fiber reinforced composites.  

Limitations of Laser Cutting

Laser cutting, despite its many advantages, also comes with some notable disadvantages. Let’s figure out some limited aspects of the process.

1. Limitation on Material Thicknes

The most common laser cutting machines are usually ranges in <6 kW power. This noticeable factor restricts their use in cutting depth in metal thickness to approximately 12 mm, and even at this depth, the process usually results rather slowly. However, going deeper means the need for more powerful and larger machines which normally costs higher. In this respect, the main disadvantages of laser machining are the same as those for other traditional cutting techniques, such as waterjet and wire EDM erosion, though the latter may be faster.

2. Harmful Gases and Fume

Although some materials, especially metals, are not so harmful during laser cutting, others like polymers can lead to emission of toxic gases and fumes when exposed to high temperatures conditions. For instance, fluoropolymers and PTFE thermoplastic can produce phosgene, which can be negatively dangerous to human health. The use of specialized controlled atmosphere processing is crucial to counter such dangers or harmful emissions. 

3. High Energy Consumption

Laser machines are amongst the precision tools that generally consume more energy than other cutting tools. As an example, a 3-axis CNC machine can pierce down a 40 mm steel plate blanks, and consumes a lower power than a standard laser-tool machine, utilized for the same purpose. Nevertheless, the overall or combined power usage can change depending on the processing time among other factors. In conditions where laser beam cutting is faster, the net power consumption may still be in favor of the laser machine, although the comparison of these differences is quite complicated.  

Upfront Cost Required To Install Laser Cutting Machine

Initial investment costs for laser machining tools can vary significantly, depending on factors such as power utilization. Here are some cost-detrimental scenarios discussed below; 

• The small-sized machine shops usually use low-power lasers in the 1–3 kW range which costs at around $2,000. These machines are usually designated for light duties, and able to cut to shape up to 10 mm steel sheets, and provide modest output. 
• For applications requiring more power and better capabilities, machines with the power output of 6-10 kW are available in the market. These machines offer much more cut depth and faster processing leads than the previous small-sized machine. Their price range starts at around $10,000 and reaches up to $150,000 for the popular brands and high-capacity models. 
• To sum up, the initial investment for laser machines is usually not much higher than that for 3-axis or 5-axis CNC machining centers. The total cost of ownership is often lower because of reduced maintenance and faster production times. The entry-level CNC machining centers usually start at $8,000, and the higher-grade ones can go from $24,000 to $260,000 for the top brands of laser machines.

7 Common Laser Cutting Techniques?

Although laser cutting applications are so widespread, it’s notably a versatile technique, known for its exceptional capacity to create parts in high dimensional frequency. There are seven effective techniques of laser cutting;

Melt Cutting (Laser Fusion Cutting)

Laser fusion cutting, also known as melt cutting, is primarily a high-powered laser beam. It usually works on a small region of the intended workpiece to produce intense heat that melts the metal. 

Once the metal reaches a molten state, an inert gas such as nitrogen, helium, or argon blows away the melted material. The machine can appropriately shear alloys of aluminum, steel, copper, titanium, and nickel. In operation, the beam is focused on a particular spot until the melting is achieved. The shielding gas made of inert gas is the one that keeps the metal from being oxidized by the surrounding oxygen and the jet of gas softens the metal and is cut through by the slicing action.

Laser Sublimation Cutting

Laser sublimation cutting, also named vaporization laser cutting. It is a non-metal cutting process that is performed by focusing the laser beam on one spot until the work material heats up and vaporizes. It involves using a jet of inert gas to uniformly blow-off the vaporized particles. Its primary function is to remove the material rather than preventing oxidation. The thicker the material, the more heat and longer exposure time are needed to vaporize it and eventually it causes material loss, and increases lead times. Laser vaporization can be used for low-melting point metals, like tin, and magnesium alloys.

Remote Control Laser Cutting

The remote laser cutting vaporizes the job part by sublimation without a gas jet. Unlike older techniques, remote cutting machines don’t depend on a gas jet for material removal. This, in turn, impedes them to deal with thick sheets of metal because of the lack of assistance for material removal.

Oxygen Laser Cutting

Oxygen flame cutting

Oxygen laser cutting, also known as LASOX (Laser Assisted Oxygen Cutting). It facilitates cutting materials in-depth, and speeds of standard laser cutters. Although the conventional melt laser cutting is restricted to certain thicknesses. As an example, LASOX allows standard 2kW laser cutters to process thicker materials of 2 to 4 inches (50mm to 100mm). This result is achieved by displacing the inert gases that are normally used in laser tools with the oxygen. It serves as the fuel that ignites the laser’s heat at the focal point and thus the temperature rises to extreme levels. The higher temperature not only helps to cut down high thickness materials but also makes the cutting speed faster.

Flame Laser Cutting

In addition, an oxy-fuel laser cutter combines the jet of oxygen fuel mixture with the heating and vaporization of the laser cutter. The most widely used fuels such as propane, natural gas, and acetylene are used, that produce a strong flame resulting in cutting of material much easier. 

In contrast to LASOX that is solely based on oxygen, flame cutting provides flexibility that can be used with different fuel mixtures. The composition of the gas mixture influences the power of the flame. For example, an oxygen and acetylene mixture can lead to a very hot flame that has the same cutting power as a plasma cutting torch. Flame cutting has the capacity to cut materials with a maximum thickness of 10 inches (270mm). 

Zero Width Laser Cutting

The thermal stress laser cutting (TSLC) or a zero width laser cutting (ZWLC) is the process of a fiber laser in controlled bursts with the help of a jet of either water or coolant. The joint action of these two factors results in the formation of internal thermal stresses within the material, which in turn cause the formation of micro-cracks along the scribe line, without any material waste.  These micro-cracks are created by the controlled cracking process, based on the different expansion rates of the material.

ZWLC heats the materials such as glass to their critical points for starting the sudden expansion of the thermal process. The cooling jet, is applied after the hot jet, that creates a thermal gradient inside the material, thus generating high internal thermal tensile stresses. In contrast, laser melt cutting which vaporizes material equal to the laser spot diameter is usually used to make precise cuts and no material is lost in the process. It is, therefore, suitable for projects that require extremely high precision tolerances.

Controlled Fractures Laser Cutting Machines

Laser cutting achines with controlled fracture are made by inducing thermal stresses in brittle materials, which result in the initiation of cracks without the use of a coolant. Sometimes, a mechanical shock can be used in order to separate out the two sides of the material. These machines usually use CO2 lasers to vaporise the material and make it expand, thus creating compressive stress. When the material is cooled it contracts, under tensile stress. 

For other options CO2 and fiber lasers are combined. The fiber lasers produce highly powerful and focused beams which can easily penetrate through the tough materials, while the CO2 lasers provide a gentler heating that initiates the process without damaging the workpiece.

Alternative Techniques To Plasma Cutting

Here are three prominant alternative techniques to plasma cutting including;

CNC Plasma Cutting

CNC plasma cutting

Plasma cutting uses an electrode on a superheated gas plasma stream to direct an arc and erode material, similar to the process of electrical discharge machining (EDM). It’s highly powerful, even powerful enough to cut hard steel parts. Normally, it is used for heavy metal and coarse processing jobs, such as preparing steel components for ships and architectural projects.

Waterjet Cutting

High Precision water jet cutting 

The Waterjet cutting process uses a small portable machine to cut and shape a wide range of materials precisely using garnet abrasive material as a cutting tool. Although it’s quite efficient for the majority of materials, the only difficulties can be a surface when dealing with especially hard workpieces. Waterjet cutting is characterized by its precision cutting, but it’s relatively slower than laser machining, especially when it comes to thicker and harder materials. 

CNC Machining

Precision CNC machining 

A traditional method, CNC machining, is a process that extracts parts from flat material stock with high precision, reliability, and repeatability, just like laser machining methods. CNC machining, in addition, requires more setup and processing times and involves a higher level of manual interventions. However, CNC has some cost considerations, but it can be a good tool to accommodate the 3D designs and perform partial depth cuts, while there is a possibility of local heating due to rotating cutting tools.

Precision Cutting Services at Prolean

Prolean provides customers’ with on-demand manufacturing solutions from a wider perspective. Our faculty of skilled professionals helps you from a suitable selection of material to process. Whether you need prototypes designs to mass produced components, our in-house machining set-up is equipped with high precision latest machines to fulfil your project needs. If you want to make an initial assessment of your design, just send us your DFM, our engineers help you create a complete analysis by suggesting appropriate process, and material options to ensure to save your costs on manufacturing projects. Send us your design, and get an instant free engineering quote from us!

Summing Up

The invention of laser machining brings changes in the manufacturing industries, with limitless benefits. The rapid processing of various materials reduces the time spent and cuts down operation costs. The scope of its application is wide.  It can be used in the aerospace and automotive industries. The benefit and drawback of laser machining help you make the right choice for your projects. If you need top quality laser cutting services contact prolean, one of the leading manufacturers in china for on-demand manufacturing. 

FAQ’s

Q1. What are the capabilities of laser cutting?

Laser cutting is a popular tool for the production of different industry-use products, including the manufacture of automotive and aircraft interior parts and medical disposable or one-time-use parts fabrication. The utensil can slice even exotic metals, flexible plastics, etc.

Q2. What are the common laser cutting defects in the process?

The process often yields burrs and variations or rough edges on parts being laser cut. Moreover, material decoloration, and fluctuations in gas pressure during operation are also linked as common laser cutting defects. 

Q3. Is it expensive to use laser cutting?

While laser part fabrication may appear to be a costly startup, in fact, it’s an investment in precision and fidelity required for projects or applications. Indeed, the machines are relatively priced high according to the type of material to be cut and laser power requirements, but the high productivity, and accurate results makes it a worthy investment for parts creation. 

Q4. Can manufacturers employ laser machining for mass production?

Laser cutting is considered a perfect and economical choice for large volumes due to its incomparable accuracy and uniformity. These prominent factors in turn, contribute to time and cost savings.

Q5. Mention some advantages & disadvantages of laser beam machining?

Laser beam machining technology has a lot of benefits, but it also has a few minor drawbacks. It’s advantageous to cut through a variety of materials, from high-strength metals to plastics.  Additionally, tooling needs are quite minimal, which tends to incur low costs in the process. The surface integrity of the part being laser cut is maintained along with the accuracy and dimensional stability of the part. Nevertheless, in terms of drawbacks, it usually requires skilled professionals and high maintenance. Furthermore, the gas and fume emissions during the plastic melting process can be hazardous for the persons in charge and the environment.

Q6. Can a standard laser machine cut engineered-grade plastics?

Yes, a standard laser machine is designed to cut down engineered-grade thermoplastics with high performance and dimensional accuracy. Typically, from medical grade Delrin to rigid acrylic, it can precisely pierce materials into intended form or shape.