Plastic Extrusions
Plastic extrusion is the transformation of a thermoplastic material or resin into a shape that can be used as produced or that can be further converted into a usable product. The extrusion process is used to produce items such as films, sheets, coatings, pipes, tubes, fencing & deck railings, window frames, weather-stripping, straws, and wire insulation to name a few. Typical plastic materials that are used in extrusion include, but are not limited to, acrylonitrile butadiene styrene (ABS), polyamides (PA), polycarbonate (PC), polyethylene (PE), polypropylene (PP), acetal, acrylic, polystyrene (PS), polyvinyl chloride (PVC), and polypropylene (PP).
Innovations
Color values are good indicators of process quality. All parameters in the production process (temperature, pressure, production speed, feeders, pumps, etc.) have a direct impact on color values.
Equitech’s In-Line Process Spectrophotometer (IPS) makes possible continuous color measurement directly in the process. For plastic profiling, customers have a choice of probes for contact or non-contact measurement.
In-Line and Real-Time Measurement
For those customers wanting to measure directly in the polymer melt before the extrudate is formed, Equitech offers the Reflection Polymer Melt Probe (RPMP). The RPMP is installed in the exit (adapter) of the capstock extruder using a ½”-20 UNF thread where it enters in direct contact with the melt stream. The RPMP consists of the threaded body, optical fibers and sapphire lens. The sapphire lens on the tip of the probe is the observation window and is very well suited to the harsh extrusion conditions (high temperature, pressure and friction). The self-cleaning function of the sapphire is ensured by the shear stress of the material flow.
For those customers that prefer to measure color directly on the extruded shape, Equitech offers the Large Area Surface Probe (LASP). The LASP can be mounted over the extruded vinyl siding. It measures color without contacting the product. The probe measures the diffusely scattered component of the light reflected from the vinyl siding while ignoring the specular components. Because it is ‘blind’ to the specular reflection, this probe may be used to measure the color of a glossy surface, while being insensitive to the ‘gloss’ or ‘shine’.
User Benifits
- Comprehensive quality audit of final product
- Feedback loop for L* closed loop control via feeder
- Impact of speed changes on the quality of the extrusion
- Controlled color changes: start phase, end of run
- Avoidance of off-spec batches
- Adjustment and fine tuning of recipes
- Reduce costs - higher ROI
