REFLECTION POLYMER MELT PROBE For In-Line Color Measurement
INTRODUCTION
The Reflection Polymer Melt Probe (RPMP) is an accessory invented and developed by Equitech for use with the Equispec Inline Process Spectrophotometer (IPS) (FIG 1). It is designed explicitly for reflected color measurements from a molten plastic stream in an extruder.
The RPMP (FIG. 2) consists of the body or “bolt” that is installed in the extruder and a removable fiber assembly that sends light to and receives light from the sample (FIG 3 & 4). In addition, there are six illumination fibers surrounding a central detection fiber.
The fiber assembly is typically manufactured to a length of 5 meters; longer fiber runs are achieved using extension fibers to the required length.
The RPMP requires the use of a calibration fixture, black trap, and white master calibration tile (matte finish) to complete the RPMP calibration before a color measurement with the EquiSpec IPS. In addition, the RPMP must be installed in the extruder in a location with good material flow.
EXTRUSION OPERATION BENEFITS
The use of the RPMP provides extruders and compounders the opportunity to monitor in-line and in real-time variables such as:
- Residence time distributions
- Optimization of screw design
- Optimization of extrusion rate
- Optimization of feeder flow rates
- Determination & resolution of feeder issues
- Determination & resolution of blending issues
- Reactive extrusion monitoring
- Measurement of the concentration of chemical additives
- Alarm of off-specification color or additives
- Continuous, real-time quality assurance
- Enable closed-loop control
Optical | Physical |
---|---|
Sensing Region Max point sensitivity = between 0 and 0.5mm | Mounting = ½-20 UNF w/5.715mm (0.225”) well depth |
Lens/Window Material = Sapphire | Body & Materials = 316 SS w/Nickel Alloy Tip |
Numerical Aperture = 0.22 NA | Body Dimensions = 165.1mm (6.5”) length; tip length 5.436mm (0.214”) |
Spot size = 1mm | Seal Type = Sapphire to metal |
Optical Fiber Type: NIR 6-(400 microns) fibers around 1- (400 microns) fiber* | Seal Material = Sapphire / Nickel Alloy Tip |
Fiber Packaging: Teflon® – coated (220°C) armored fiber bundle | Temperature Range = -20° to 400°C (500°C available) |
Fiber Length: 5 m standard* | Maximum Pressure = 345 bar (5000 psi) |
Fiber Termination: SMA 905 | |
* Other fiber sizes and lengths available upon request ** Other materials available upon request |