Focused Ultrasonic Probes for Intense Cleaning
Hielscher Ultrasonics hand-held or stand-mounted ultrasonic probes direct highly intense ultrasonic waves to the openings of wire dies, wire guides, extruder dies, extruder plates or spinnerets. This cleans the fine channels and surfaces in seconds from:
- oils and fats
- dirt and dust
- soaps and stearates
- filaments, fines and other debris
- polymer residues and ash
Needle, Drill and Wire Cleaning
Conventional cleaning of extrusion tools and wire dies uses needles, drills or wires to remove material residues and dirt from small channels. Many of the guides and dies are fitted with poly-crystalline diamond (PCD), natural diamond or tungsten carbide (TC), and the mechanical procedure damages the inner surfaces and may affect size, shape and surface roughness of the small channels.
A focused ultrasonic probe does not touch the material surface, but it directs intense ultrasonic vibrations and cavitational shock-waves to the opening of the small channel. This is much faster and safer than the tedious and time-consuming manual needle picking.
Ultrasonic Cleaning Baths or Tanks
While ultrasonic baths and cleaning tanks are good for general parts cleaning, their low intensity falls short in the cleaning of small channels and hidden surfaces. This is called shadowing. Also, most tank are emitting ultrasound from the bottom only. Therefore the cleaning process may take several minutes to hours for a batch of wire dies, extruder dies or guides and still result in incomplete cleaning. The smaller the channel dimensions, the more favorable is a focused ultrasonic cleaning probe.
High-Intensity Focused Ultrasonic Probes
For small channels and pores, we recommend using the UP100H with the pointed MS2 tip. This is a cost-effective ultrasonic device for hand-held or stand-mounted operation. For multi-pore spinnerets, extrusion die plates or multiple wire dies, the UIP1000hdT with a special 100mm diameter probe.
Most of our clients do not require semi-automated or fully automated cleaning systems, because the cleaning takes several seconds only.
For polymers, such as nylon, olefin or polyester, a preparatory heat treatment makes the polymer more brittle. This so-called oven burnout reduces the hardened polymer to ash. For the cleaning, water (with up to 25wt% phosphoric acid) or oil can be used as a simple coupling fluid between the ultrasonic probe and the spinneret.