Waterjet cutting systems are much like other shape cutting systems
utilizing computer controlled motion, post processing of tool paths,
and multi-head configurations.
Water jet machines
can cut any known material including composite, laminates, plastics,
rubbers, castings, forging, aluminum, stainless steels, hardened or tool
steel, exotic alloys, heat sensitive materials, synthetics, and any
materials that may release harmful vapors when cut using other methods.
Abrasive water jet cutting will eliminate the need for machining stock
or slag caused by heat processes like laser, flamecut or plasma, and
will not affect material properties or temper.
Cutting Edge Water Jet Service dual head dynamic 90,000-psi abrasive waterjet cutting machine.
Waterjet cutting systems are adjustable to cut at a variety of
pressures up to 90,000 psi, with or without the introduction of abrasive
material. High-pressure water moving through the orifice at nearly
3,000 miles per hour provides the necessary energy for cutting soft
materials or with the introduction of abrasive can cut materials
approaching the hardness of diamond.
Photo provided by Jet Edge showing water jet cutting head and cross-section.
Conventional waterjet cutting systems create a natural edge taper
during cutting. The faster you cut the more taper that is created,
resulting in a lower shape cost (time is money), while cutting slower
will minimize the amount of edge taper; the result is a higher shape
cost.
Photo provided by Ward Jet shows affect of conventional waterjet cut speeds.
Dynamic waterjet cutting uses complex algorithms to reduce edge taper
by tilting cutting head during cutting up to 7 degrees per side. The
resultant part will have little edge taper, while the scrap will have
twice that of conventional waterjet cutting. Major advantage: faster cut
speeds with controllable taper.
Photo provided by FLOW showing tilt during dynamic high-pressure water jet cutting.
The waterjet industry recognizes five standard cut qualities
(controlled by speed) Q1, Q2, Q3, Q4, and Q5, although cut speeds can be
dialed-into any percentage between these standards. Pricing is based on
assigning cut qualities to each specific shape entity, in any
combination. Ra finish for a Q5 cut is typically around 80Ra. As a
non-contact process, tolerances can be challenging to consistently
maintain. While selecting the appropriate cut quality is important for
targeting a tolerance range, other factors can negatively impact
resultant tolerances/sizes, such as material stress, preliminary
machining/grinding/heat treating, poor table construction, and material
warpage.
Photo provided by Ward Jet showing waterjet industry cut quality standards.
Article prepared by Ron Fairchild of Cutting Edge Water Jet Service;
South Beloit Illinois. Ron has nearly 15-years of experience in hands on
waterjet applications. Cutting Edge Water Jet Service is a job shop
provider of water jet services for all industries in the United States.
They offer 90,000 psi conventional and dynamic
abrasive waterjet cutting using a variety of multi-head waterjet cutting systems.
Original Source- http://www.cuttingedgewaterjet.com/articles/understanding-water-jets/
