SPD Dynamic Tint Film
Suspended particle device film with 30:1 continuous dimming — from ≥ 60% VLT transparent to ≤ 2% VLT deep tint. 90V AC drive, zero power in opaque state.
≥ 60%
VLT (ON)
≤ 2%
VLT (OFF)
30:1
Dimming ratio
90V AC
Drive voltage
Why Continuous Tint Matters
Binary privacy switching solves instant on/off scenarios — meeting rooms, bathrooms, healthcare partitions. But facades, skylights, and automotive applications need gradual light adjustment that tracks solar intensity throughout the day, not a binary toggle between two states.
SPD suspended particle technology provides continuous dimming across a 30:1 range by varying the alignment voltage from 70–110V AC. At lower voltage, particles partially align — intermediate tint. At full voltage, particles form columns — maximum transparency (≥ 60% VLT). With power removed, particles scatter — deep tint (≤ 2% VLT). The result is responsive tint control that adapts to occupancy, solar angle, and occupant preference without the jarring transition of binary switching.
SPD Technology Principle
SPD film uses suspended microscopic particles in a fluid layer between two conductive substrates. In the OFF state (no applied voltage), particles float randomly and absorb or scatter incident light — the film appears deeply tinted at ≤ 2% VLT. When 90V AC is applied, the electric field aligns the particles into orderly columns parallel to the light path, allowing light to pass through — ≥ 60% VLT.
The key advantage: voltage is continuously adjustable from 70–110V AC. At intermediate voltages, particles partially align, producing proportional tint levels. This enables a 30:1 dimming ratio with smooth transitions — OFF→ON in ≤ 1 s, ON→OFF in ≤ 9 s. AC drive prevents particle polarization that would degrade performance over the > 100,000 hour rated lifespan. Power consumption is 3 W/m² in transparent state and 0 W in opaque state.
SPD Model Specifications
Three variants — base (laminated, 0.38 mm), standard (laminated, 0.48 mm), and adhesive type (0.57 mm, dry install).
| Parameter | Base (0.38 mm) | Standard (0.48 mm) | Adhesive (0.57 mm) |
|---|---|---|---|
| Film thickness | 0.38 mm | 0.48 mm | 0.57 mm |
| Max width | 1,500 mm | 1,500 mm | 1,500 mm |
| Voltage | 90V AC, 50/60Hz | 90V AC, 50/60Hz | 90V AC, 50/60Hz |
| Adjustable voltage | 70–110V | 70–110V | 70–110V |
| Power (transparent) | 3 W/m² | 3 W/m² | 3 W/m² |
| Power (opaque) | 0 W | 0 W | 0 W |
| Switch OFF→ON | ≤ 1 s | ≤ 1 s | ≤ 1 s |
| Switch ON→OFF | ≤ 9 s | ≤ 9 s | ≤ 9 s |
| Transmittance ON | ≥ 60% | ≥ 60% | ≥ 60% |
| Transmittance OFF | ≤ 2% | ≤ 2% | ≤ 2% |
| Dimming ratio | 30:1 | 30:1 | 30:1 |
| Haze (ON) | < 1% | < 1% | < 1% |
| CRI | Ra ~ 95 | Ra ~ 95 | Ra ~ 95 |
| UV rejection (ON/OFF) | 82% / 96% | 82% / 96% | 99% / 99% |
| IR rejection (ON/OFF) | 14% / 60% | 14% / 60% | 14% / 60% |
| Operating temp | -20°C to 90°C | -20°C to 90°C | -20°C to 90°C |
| Lifespan | > 100,000 hrs | > 100,000 hrs | > 100,000 hrs |
| Cycles | > 200M | > 200M | > 200M |
| Install method | Laminated | Laminated | Adhesive (dry) |
Technology Comparison — PDLC vs SPD vs Electrochromic
| Attribute | PDLC | SPD | Electrochromic |
|---|---|---|---|
| Switching speed | ≤ 60 ms / ≤ 20 ms PRO | OFF→ON ≤ 1 s / ON→OFF ≤ 9 s | Seconds to minutes |
| Steady-state power | 3.7 W/m² | 3 W/m² transparent / 0 W opaque | Low at steady state |
| Dimming range | Binary clear ↔ frosted | 30:1 continuous dimming | Continuous gradient |
| Installation | Self-adhesive or laminated | Laminated or adhesive | Factory-laminated only, complex integration |
| Best For | Instant privacy | Solar management | Thermal management |
Applications
Facades
SPD film delivers continuous tint control for building facades — clear for views, deeply tinted for solar rejection. OFF state blocks 60% IR and up to 96% UV. Operates from -20°C to 90°C, covering most exterior conditions. Laminated or adhesive installation. BMS integration for scheduled zone control.
- Continuous tint
- 60% IR rejection OFF
- -20°C to 90°C
Skylights
Skylights need gradual dimming rather than binary switching. SPD provides 30:1 continuous dimming from ≥ 60% VLT to ≤ 2% VLT, adjustable via 70–110V AC voltage. OFF state delivers deep tint without blocking all light. Zero power consumption in the opaque state reduces energy overhead for always-on installations.
- 30:1 dimming
- 0 W opaque
- Adjustable voltage
Automotive
SPD film meets automotive-grade requirements with DO-160 and AEC-Q100 certifications. Compact 90V AC inverter from 12V DC vehicle supply. CRI ~ 95 preserves color accuracy for driver visibility. Operating range -20°C to 90°C handles vehicle interior extremes. Off→ON ≤ 1 s for responsive user control.
- DO-160 / AEC-Q100
- CRI ~ 95
- ≤ 1 s response
Privacy Partitions with Gradual Transition
Spaces that need privacy but prefer a gradual transition over instant switching — SPD dims smoothly across 30:1 range. Combine with PDLC in hybrid systems: SPD for ambient tint, PDLC for instant full privacy. Smart-home bridge compatible for app and voice control across both technologies.
- Gradual transition
- Hybrid PDLC+SPD
- Smart-home bridge
Certifications
CE
European conformity
UL
Safety certification
GB/T
Chinese national standard
DO-160
Aviation environmental
AEC-Q100
Automotive grade
Procurement Guide
Understanding SPD cost drivers and order requirements before requesting a quote.
- 01
Variant selection
Base (0.38 mm) and standard (0.48 mm) are laminated — most durable for exterior and high-traffic applications. Adhesive type (0.57 mm) supports dry retrofit installation on existing glass at 15–25°C, humidity < 70%.
- 02
Installation method cost
Laminated SPD requires autoclave processing (135–145°C, 12–14 bar) — higher processing cost but superior durability. Adhesive installation eliminates autoclave but requires controlled temperature and humidity conditions during application.
- 03
Control system
SPD requires a dimmable 90V AC transformer (70–110V adjustable) for continuous tint control — more complex than PDLC binary switching. Smart-home bridges support app and voice control. Budget 15–25% above film cost for the complete drive system.
- 04
Volume and MOQ
Minimum order: 1 roll for roll film, 10 pieces for cut sheets, 10 units for controllers. Orders above 100 m² enter the first discount tier. Projects above 500 m² qualify for project-specific pricing.
- 05
Warranty and shipping
12-month standard warranty, extendable to 24 or 36 months. FOB and EXW terms available. Laminated SPD requires crated transport. Lead time 15–25 business days for standard orders.
Planning Tools
The wiring simulator helps plan 90V AC transformer sizing and channel routing for SPD installations before final engineering review.
Smart Film Cost Calculator
Estimate EXW price from your glass dimensions — area, transmittance, power draw, transformer sizing, and required sealant — then carry the configuration to the quote form.
Open tool →Wiring Simulator
Plan transformer sizing and channel routing for centralized or distributed layouts before final engineering review.
Open tool →Transformer & Power Supply
Match a power supply to your total film area — single channel, multi-channel, adjustable, and vehicle options.
Open tool →Frequently Asked Questions
SPD-specific questions about dynamic tint film. See the full FAQ for cross-product questions.
SPD film transitions from opaque to transparent (OFF→ON) in ≤ 1 second and from transparent to opaque (ON→OFF) in ≤ 9 seconds. This is slower than PDLC (≤ 60 ms) but fast enough for user-controlled tint adjustment. The continuous dimming across a 30:1 range means the perceived transition is gradual rather than binary — users see the tint change progressively rather than an instant flip.
SPD film offers a 30:1 dimming ratio — from ≥ 60% VLT in the transparent (ON) state to ≤ 2% VLT in the opaque (OFF) state. The voltage is adjustable from 70–110V AC, allowing continuous control across the entire range. At intermediate voltages, the film settles at proportional tint levels, giving precise control over light transmission for any application.
SPD film operates on 90V AC at 50/60Hz, adjustable from 70–110V AC for continuous dimming control. A dedicated SPD transformer converts mains or DC input to the required AC output. Never connect SPD film directly to mains voltage or DC — always use the matched transformer. For automotive applications, a compact DC-AC inverter converts 12V vehicle supply to 90V AC.
SPD film operates from -20°C to 90°C, covering most exterior application conditions. Laminated SPD (autoclave 135–145°C, 12–14 bar) provides the most durable exterior installation. Adhesive-type film (0.57 mm, dry install at 15–25°C, humidity < 70%) is suitable for protected exterior installations. For unprotected outdoor use, project-specific certification is recommended — contact us for exterior-rated specifications.
PDLC provides binary privacy switching (clear ↔ frosted) in ≤ 60 ms at 48/65V AC and 3.7 W/m². SPD provides continuous dimming across a 30:1 range (≥ 60% VLT to ≤ 2% VLT) at 90V AC, with OFF→ON ≤ 1 s and ON→OFF ≤ 9 s, drawing 3 W/m² transparent and 0 W opaque. Choose PDLC for instant binary privacy; choose SPD for gradual tint control on facades, skylights, and automotive where continuous dimming is needed.
Two installation methods: laminated and adhesive. Laminated SPD (base 0.38 mm, standard 0.48 mm) is processed in an autoclave at 135–145°C and 12–14 bar — the most durable option for exterior and high-traffic applications. Adhesive-type SPD (0.57 mm) uses dry installation at 15–25°C with humidity below 70% — suitable for retrofit on existing glass. Both require neutral-cure silicone edge sealant (DOWSIL 895/795) at 75 ml/m².
References & Resources
Smart Film Overview
Complete guide to switchable film technology
Smart Glass Technologies
PDLC vs SPD vs electrochromic comparison
Specifications
Technical data sheets and certifications
FAQ
Cross-product frequently asked questions
Wiring Simulator
Transformer sizing and channel routing
Get a Quote
Project-specific pricing and specifications
Ready for Continuous Tint Control?
Get an SPD specification with variant recommendation and drive system design.
Variant selection, autoclave or adhesive installation plan, 90V AC transformer sizing, and smart-home integration — all included.