The Problem : Current laser recycling methods often fail when processing mixed plastic waste. Because plastic trash varies drastically in thickness, a single continuous laser beam causes major issues. If the laser is set high enough to cut thick plastic, it instantly overheats thin plastics. This causes the thin material to catch fire, melt into a sticky mess, or burn into toxic soot and carbon dust.

The Innovation : The DPAPR solves this by using a smart, real-time circuit that "looks before it zaps." Instead of a dangerous, continuous beam, it uses an infrared light sensor to instantly detect plastic thickness. It then uses Pulse-Width Modulation (PWM) to break the laser beam into ultra-fast, microscopic pulses of energy, preventing heat buildup.

How It Works : When a thin piece of plastic passes by, the sensor signals the microcontroller to fire ultra-short, microsecond pulses. This cracks the molecular bonds without creating any heat. When a thick plastic jug arrives, the system automatically increases the pulse frequency. This allows the laser to chew through the layers safely without ever starting a fire.

Estimated Budget

Arduino Brain: ₹600

Infrared Laser Diode: ₹1,500

High-Speed Driver Switch: ₹250

Thickness Sensors: ₹150

Power Supply: ₹500

Total Theoretical Cost: ₹3,000

Basic python codes for this ( I used ai , cuz I dont know code too much ):

# System Loop for this project

while Plastic_Is_Present:

    Thickness = Read_Sensor_Value()

    if Thickness == "Thin":

        Set_Laser_Pulses(ON_Time=10, OFF_Time=90) # Ultra-short bursts

    elif Thickness == "Thick":

        Set_Laser_Pulses(ON_Time=50, OFF_Time=50) # Deeper cutting bursts

    Fire_Laser()