Cutting thick acrylic sheets (plexiglass) is not the same as cutting thin panels. Once thickness goes beyond 50mm, the process becomes much more demanding.

At this level, the main challenge is heat buildup caused by friction. If not controlled properly, it can lead to melting, deformation, or internal stress.

Table of Contents

What Is Considered Thick Acrylic Sheet?

In real production, thick acrylic sheet usually refers to:

50mm acrylic sheet
80mm acrylic sheet
100mm+ acrylic block
ultra-thick acrylic up to 400mm

As thickness increases, cutting becomes slower and more sensitive to heat and tool stability.

Method 1: Cutting Thick Acrylic with a Panel Saw

A panel saw (acrylic cutting machine) is commonly used for straight cuts.

Suitable Thickness Range

Standard machines: up to 80mm

Above 80mm: requires heavy-duty or customized saws

Why Cooling Is Necessary

When cutting thick acrylic sheets, the contact area between the blade and material is large. This creates strong friction, which generates a significant amount of heat.

Water cooling is used only to remove this heat

It helps to:

prevent the acrylic from softening
avoid edge melting
maintain cutting stability

There are no other purposes—cooling is purely for heat control.

Method 2: CNC Machining for Thick Acrylic Blocks

For thickness above 80mm, panel saw cutting becomes less efficient and less stable. In these cases, CNC machining is a better solution.

Step-by-Step Cutting Strategy

Thick acrylic is never cut in one pass.

Example:

For a 200mm thick acrylic sheet
First, machine 100mm depth from one side
Then flip the sheet
Machine the remaining 100mm from the other side

This approach reduces cutting resistance and improves precision.

Tool Selection and Cutting Control

When machining thick acrylic blocks, tool setup is critical:

choose the right cutting tool (end mill for acrylic)
control cutting depth per pass
adjust spindle speed and feed rate

Too aggressive cutting will increase friction and heat.

Too slow will reduce efficiency.

The goal is to keep cutting stable while minimizing heat buildup.

Common Problems When Cutting Thick Acrylic

Most issues come from poor heat control and improper setup:

overheating caused by friction
melted or rough edges
internal stress (can lead to cracks later)
uneven cutting lines
tool marks

These problems are not caused by the material itself, but by incorrect processing.

Practical Tips from Production
always control heat during cutting
use water cooling when using saws on thick sheets
avoid cutting full thickness in one pass
ensure stable clamping
keep tools sharp and suitable for acrylic

For thick plexiglass sheets, stability and heat control matter more than speed.

When to Use Each Method

Use panel saw when:

thickness ≤ 80mm
straight cutting is required
high efficiency is needed

Use CNC machining when:

thickness > 80mm
high precision is required
working with large or thick acrylic blocks (100–400mm)

Final Thoughts

Cutting thick acrylic sheets is a controlled industrial process.

Thin sheets can be cut easily
Thick sheets require proper machines, step cutting, and heat control

The most important factor is simple:

👉 Friction generates heat, and heat must be controlled

With the right method, even 200mm–400mm acrylic blocks can be cut cleanly and precisely.

How to Cut Thick Acrylic Sheets (50-400mm)