How to Master Thermoforming with PMMA for Precision and Performance

In lighting design, materials need to do more than just look good — they must perform, adapt, and last. At Hexatron, we’ve worked with optical-grade materials for years, and when it comes to thermoformed diffusers, one material stands out: PMMA (Polymethyl Methacrylate).

Why PMMA Is Ideal for Thermoforming

PMMA, also known as acrylic, offers several advantages that make it perfect for thermoforming. It softens at moderate temperatures and allows smooth, controlled shaping without losing its optical properties.

When heated and vacuum-formed into a mold, PMMA maintains excellent surface gloss, diffusion uniformity, and dimensional stability. We use PMMA sheets specifically developed for thermoforming. These sheets feature enhanced thermal stability and uniform optical behavior, which ensures consistency across every batch and project.

Custom Optical Control: From 45% Light Transmittance to Translucent Finishes

Lighting designers and engineers often have different optical goals. To meet these diverse needs, we offer PMMA materials in various light transmittance levels, starting from 45% for high diffusion up to fully translucent grades.

Each diffuser can also be produced in a range of surface finishes:

• Matte or satin surfaces for soft diffusion and uniform illumination.
• Prismatic textures such as honeycomb, hexagon, micro-hexagonal, or pyramidal patterns to control the beam angle and improve UGR (Unified Glare Rating) performance.

Our in-house optical team helps customers select the ideal combination of haze, transmittance, and surface structurefor each application.

Our Thermoforming Process

Over the years, Hexatron has successfully completed several thermoforming projects for both domestic and international lighting manufacturers.

Here’s how it works:

1. Design and CAD Evaluation
2. The customer sends us a CAD drawing. Our engineering team reviews the design, checking curvature, wall thickness, and optical requirements.
3. Mold Development
4. Based on the approved drawing, we create a custom mold ensuring a perfect fit with the customer’s luminaire or aluminum housing.
5. The mold fee is always offered at cost, keeping the project affordable without compromising quality.
6. Sample Production and Testing
7. Once the mold is ready, we produce sample parts using our thermoforming-grade PMMA sheets.
8. These samples are then tested by the customer for fit, light diffusion, and appearance. We deliver a couple of other optical grades for facilitating testing and approval.
9. Customer Approval and Mass Production
10. After approval, we move to mass production, ensuring repeatable quality across every part.
11. Our production lines are equipped for both small-batch and large-volume runs.

What Happens During Thermoforming

It’s important to understand how the material behaves during the thermoforming process. When PMMA is heated and stretched into shape:

• The sheet thickness is reduced, especially in areas of high curvature.
• As the material thins, light transmittance naturally increases, which can make the part slightly brighter.
• Optical uniformity can change slightly depending on geometry, but our formulation ensures smooth diffusion across the surface.

To achieve the right optical balance, our engineers often simulate light performance in advance or make minor adjustments to the base sheet’s diffusion level before production.

Specialized PMMA Grades for Reliable Results

Unlike general-purpose acrylic sheets, our PMMA materials are formulated specifically for thermoforming. They feature:

• Excellent thermal stability to prevent yellowing or surface defects during heating.
• High molecular weight for consistent forming without cracks.

This makes them ideal for lighting diffusers, domes, covers, and decorative lighting.

Packing and Shipping Thermoformed Products

Thermoformed products often have larger volumes and irregular shapes compared to flat sheets. To protect these delicate surfaces during transport, we provide specialized packaging.

We use custom-fit protective frames, soft liners, and reinforced cartons or crates to prevent scratches and deformation during shipping. In some cases, diffusers are stacked using foam separators.

We also optimize the packaging size to minimize shipping costs while ensuring every piece arrives in perfect condition, ready for assembly or direct installation.

Interested in starting your project?

Send us your CAD file or design concept. Our team will help you select the right PMMA grade, create the mold, and deliver professional results from prototype to production. Contact Us.