2. Tutorial: Engineering technology Topic: Water jet cutting Prepared by: Ing. Josef Martinák st. Projekt Anglicky v odborných předmětech, CZ.1.07/1.3.09/04.0002 je spolufinancován Evropským sociálním fondem a státním rozpočtem České republiky.

3.  For treatment of soft materials is used Clean Water Jet WJM  Suitable abrasive is e.g. natural garnet, olivine and other materials selected to suit the hardness of cut material (e.g. salt, cocoa in food processing industry)  Standard accuracy is ±0,1 mm/m.  Cut material is not strained.  Cutting edge is not affected by heat, it is always cold cutting.

4.  WJM – Water Jet Machining – pure water jet or so called hydrodynamic machining  AWJ – Abrasive Water Jet Machining – machinery by abrasive water jet

5. Abrasive reservoir High pressure water High pressure piping Water jet Mixing chamber Abrasive jet Cutting material Picture Principle scheme AWJ technology WJM technology

6. Picture 2.14. Abrasive input systems for AWJ technology a)Jet with radial abrasive input to water jet b)Jet with axial abrasive input

7. Picture 2.3 Cutting machine description and its components Material for energy absorption Scrap water Scrap arrester Abrasive reservoir water Oil Transport system (high pressure pipes) High pressure pump Transport system and measuring equipment High pressure valve Supporting grate Work piece Output jet Across rail Water jet Mixing chamber Cutting nipple

8. Accumulator High pressure piping with pressurised water Abrasive Cutting nipple Multiplicator Abrasive input Water jet Oil pump Water input Electric engine Principle AWJ technology scheme

9. Output jet Abrasive input High pressure liquid input High pressure pipe High pressure water jet Mixing space Mixing jet Abrasive water ray Picture 2.12 Cutting nipple scheme

12.  Flame cutting examples - glass  Flame cutting examples – different kinds of plastics  Flame cutting examples - aluminium  Flame cutting examples – glass hardened fibres

13.  Water is compressed by pump to pressure of 400 MPa (4 000 bars)  Jet´s diameter is 0,003 mm to 0,4 mm  If we want to reach smooth and accurate cutting, we use smaller travel speed ( about 25%).  Cutting is very noisy, it is possible to turn it down by cutting under water.  Jet´s speed is 3 times higher than speed of sound.

14.  Describe basic techniques – WMJ - AWJ  What material thickness can we cut?

15.  DILLINGER. KOLEKTIV. Moderní strojírenství pro školu i praxi. ISBN 9788086706191. pro konkurenceschopnost, ESF 2007 – 2013. Translation:  www.seznam.cz www.seznam.cz  www.slovnik.cz www.slovnik.cz  JANATA, Petr. Handy slovník technický anglicko-český a česko-anglický. Plzeň: Nakladatelství Fraus, 2000. ISBN 80-7238-075-3  Lingea LEXIKON 5, Technický slovník anglicko-český a česko-anglický. 2010.