How a laser machine cuts acrylic

At first glance it is difficult to find differences between acrylic and glass. The material is difficult to excellent without touching it, although they differ not only in physical, but also in chemical properties. Acrylic is 5 times stronger than glass and weighs 2.5 times less. Acrylic has 92% light transmission and is often used as a substitute for glass. Acrylic is much easier to cut than glass.

❗Acrylic can be cut into any shape or size.

You see acrylic products everywhere: advertising, in-store price tags, packaging, lighting fixtures with 3D effects.

We will tell you how a laser machine cuts acrylic, what kinds of acrylic there are, which one to choose for laser cutting.

How does a laser cut acrylic?

The laser cuts through acrylic with a focused beam. Special CO2 CNC acrylic laser machines are used for this purpose.

Why is a laser machine for cutting acrylic called a CO2 laser machine?

At the heart of an acrylic laser cutting machine is a carbon dioxide laser - a multi-layer glass bulb filled with a mixture of gases, the main one being carbon dioxide. These gases serve as an active medium that, under the influence of an electric charge, forms a laser beam to perform laser cutting of acrylic.

What CNC stands for

CNC is an abbreviation for Numerical Control. It is a way of controlling all the moving parts of the laser machine and starting the laser at the necessary moment to the necessary power for laser cutting acrylic.

The working principle of the acrylic laser machine:

Before starting acrylic laser cutting, the workpiece is placed on the working field of the machine. The laser tube of the machine is usually located in the back of the case under a closed cover, away from other parts of the laser machine.

The laser beam is directed to the desired point on the working field and performs the laser cutting of the acrylic, thanks to a system of moving mirrors. The first mirror is located at the laser transmitter and directs the laser beam to the second mirror, which is on the gantry and moves along the Y-axis with it. From the second mirror, the beam is reflected to the third mirror, which is fixed to the laser head and moves along the X axis along the portal. The final third mirror directs the laser beam perpendicular to the working field through the focusing lens onto the workpiece.

How does the laser cut acrylic?

The diameter of the focused laser beam for cutting acrylic is 0.03 mm, and along with the small diameter, the laser has high power. Due to this, a high impact force is achieved on the workpiece.

So that the laser beam can burn through the material, the acrylic laser machine feeds a stream of air into the cutting zone. It not only burns through the material but also blows out combustion products such as soot and acrylic fumes.

❗ It is important to note that blowing during laser cutting of acrylic is a necessary precondition for safety. Without blowing, material fumes will accumulate under the cover of the laser machine and catch fire or even explode.

Advantages of laser cutting acrylic :

• High quality of cut. The laser provides a transparent, clean and even cut of the workpiece;
• Productivity. The speed of laser cutting acrylic is much faster than traditional methods;
• Accuracy. Laser cutting of acrylic provides accuracy up to 0.03 mm: this reduces overspending of material, it is possible to perform work with high tolerance requirements;
• CNC. CNC laser machine provides repeatability and accuracy, cuts complex patterns;
• Non-contact. Laser does not damage the acrylic, as it does not need to be fixed, and mechanical action is excluded;
• Durability. Laser tube life is 10,000 hours;
• Cleanliness. The laser neatly and cleanly melts the material without dust or chips;
• Quietness. The laser cuts acrylic without noise.
• Ease of use. The basic principles of working with a laser machine can be mastered in a few hours;
• Versatility. Not only cuts, but also engraves.
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What do you laser cut out of acrylic?

• Interior and exterior details;
• Souvenirs;
• Outdoor advertising details;
• POS-products;
• Architectural elements;
• Lighting fixtures;
• Cases, panels, dials and other elements of devices;
• Storage jars;
• Aquariums and terrariums;

Types of acrylics

By color, acrylic is divided into:

• transparent;
• colored;
• mirror;
• translucent.

Acrylic is produced in two ways: by extrusion and injection molding. Each type has its own distinctive features.

Extrusion acrylic.

The acrylic mass is passed through an extruder under pressure. The slit of the extruder, and therefore the thickness of the material, can be from 1 to 24 mm.

Advantages:

• Flow rate by sheet thickness (up to 5%);
• The length of the sheet up to 4 meters;
• Requires less power when cutting;
• Cheaper than injection molding;
• Better suited for vacuum forming;
• Easier to make complex shaped products.

Disadvantages:

• Thickness of 1 to 24 mm;
• Residual stress and weak molecular bonds;
• Fragile material;
• The engraving on the workpiece turns gray;
• Not suitable for vacuum forming.

Cast Acrylic

Acrylic is poured under pressure between two sheets of glass.

Advantages:

• Virtually any thickness;
• Strong molecular bonds, no residual stress;
• Higher impact strength than extruded acrylic;
• Higher light transmission than extrusion acrylic;
• White engraving;
• There is the possibility of vacuum unforming.

Disadvantages:

• Limited dimensions in length and width;
• Higher cost;
• Making prefabricated elements is more difficult because the divergence in sheet thickness is up to 30%;
• More effort required for vacuum forming.

❗Bending machines are used to give the desired shape after laser cutting.

Cast acrylic is better for laser cutting because extrusion acrylic cracks due to residual stress.

How thick will a laser cut acrylic?

How thick will a laser cut a sheet of acrylic? Our customers often ask this question. The laser machine will cut 20 mm of acrylic leaving a clean and straight cut.

It will cut 25 mm thick acrylic, but the speed will be slower and it will not cut a conical cut.

Acrylic Engraving

Laser machines have an undeniable bonus over other acrylic cutting methods - engraving.

Acrylic engraving expands the possibilities in manufacturing. An acrylic laser machine allows you to cut out products and immediately apply graphic information to them.

Wattsan Acrylic Laser Machines

Wattsan machines have the following features for long and quality work:

1. Reinforced frame frame. Maintains the accuracy of the machine, smoothes vibrations;
2. 2.9 mm thick body;
3. Durable gantry. Keeps the laser machine functioning without errors. Wattsan machines have an aluminum gantry with a thickness of 7 mm at the corners;
4. Three-phase stepper motors. Superior pitch accuracy and resolution compared to biphasic motors;
5. Correct motor placement. The Y-axis motor is located in the center of the shaft, this solution has a favorable effect on the accuracy;
6. Gear motors. Increase the quality of engraving, lengthening the life of the motor. Wattsan laser machines on acrylic have a gear ratio of 1 to 6;
7. 3M belts;
8. Inductive end sensors. Better than mechanical ones because they are unaffected by dust, dirt, resins and other byproducts of laser cutting acrylic;
9. Optics and mirror system. The lens coating is polycrystalline zinc selenide, the mirrors are made of molybdenum;
10. Laser tube mounts with adjustment wheels. Laser tube positioning is easy to adjust;
11. Nozzle optimization. For laser cutting acrylic, a truncated nozzle is installed to improve cut-through. For engraving, an extended nozzle is installed; it reduces fouling around the edges of the engraving;
12. Blower hoses handle loads up to 8 atm;
13. Anodized lamellae. Eliminates opalescence and blowback on the back side of the material;
14. Garbage collection compartment;
15. Chain mechanism for lifting table. Holds up to 80 kg;
16. Safety. The laser machine's electrics and water cooling system are in different parts of the machine;
17. Potentiometer. It is possible to manually set the desired power.

Almost every Wattsan acrylic laser machine has these features. Machines with the abbreviation ST in the name have a static table, and LT has an elevating table. The main parameters when choosing a machine are the size of the working field and the power of the laser tube.

The Wattsan 2030 FlatBed is the best choice for laser cutting large size acrylic without pre-cutting.