kettle design process
TRANSCRIPT
Product DevelopmentThe Electric Kettle Case Study
Tuesday, May 4, 2010
Market Requirements
Volume of boiling water = 2 liters
Kettle weight include water < 3 kg.
Demand of kettle is 2 million/year
Tuesday, May 4, 2010
Objective of Case Study
Functional RequirementsAutomatically stops boiling when water is boiled
Cordless design
Easy to clean
Handle remains cool and safe to touch
Tuesday, May 4, 2010
Objective of Case Study
Materials that can be ruled outPolyphenylene oxide (PPO)
maximum operating temp. is 105 degree Celsius
discolor-able due to outdoor exposure
difficult to mass produce (must be blended with polymers)
Tuesday, May 4, 2010
Objective of Case Study
Materials that can be ruled outPolyethersulphones (PES)
limited exposure to hot water
changes dimension when exposed to moisture
Tuesday, May 4, 2010
Objective of Case Study
Materials that can be ruled outPolyetheretherketones (PEEK)
high cost
excessive working temperature
limited shaping process - difficult to manufacture
Tuesday, May 4, 2010
Objective of Case Study
Materials that can be ruled outAluminum (Al)
corrosive prone
require further treatment before processing
Tuesday, May 4, 2010
Objective of Case Study
Materials that can be ruled outMagnesium (Mg)
corrodes easily
burns if reacted to water, thus coating will be required
Tuesday, May 4, 2010
Objective of Case StudySketch and dimension of kettle body
Dimension
Half Side view
- overall height : 10.5 cm.
- inner radius: 8.003 cm.
- base thickness: 1 cm.
Tuesday, May 4, 2010
Objective of Case StudySketch and dimension of kettle body
Sketch
Tuesday, May 4, 2010
Objective of Case StudySketch and dimension of kettle body
Sketch
Tuesday, May 4, 2010
Objective of Case Study
Consider the mechanical properties affected
wear resistance: considering wear between kettle and plate since the two components have to be contacted during its operating life
Tuesday, May 4, 2010
Objective of Case Study
Consider the mechanical properties affected
thermal resistance: we have to consider thermal resistance of the kettle since the body is in direct contact with the boiling water. It is necessary to have a body which will not conduct heat out the the outer shell.
Tuesday, May 4, 2010
Objective of Case Study
Consider the mechanical properties affected
impact resistance: since we do not want the kettle to break when dropped, we should consider the impact resistance of the material used for the kettle body.
Tuesday, May 4, 2010
Objective of Case Study
Consider the mechanical properties affected
electrical insulation: the kettle consist of electrical system for the heating system, thus we should consider the importance of electrical insulators of the kettle
Tuesday, May 4, 2010
Objective of Case Study
Consider the mechanical properties affected
corrosion resistance: many materials can corrode when exposed to moisture, thus we must consider the corrosion of materials used for the kettle
Tuesday, May 4, 2010
Comparative Cost of Materials
Tuesday, May 4, 2010
Stiffness of Various Plastics:
(GN/M2) StiffnessPolyamide (PA) 1.25Polypropylene (PP) 0.24Polyacetal (Polyoxymethylenes POM) 0.71Polyphenyleneoxide (PPO) 1.6Polyethersulphone (PES) 2.5Polyethertherketone (PEEK) 2.8
Tuesday, May 4, 2010
Materials Density (Kg/M3)
Cost per kg (rel. to steel)
Minimum wall thickness (mm)
Volume of material (M3×10-4)
Material cost per casting (rel. to steel)
Steel 7900 1 0.6 4.87 2.32638
Al 2700 2 0.8 4.87 1.052
Mg 1700 15 0.9 4.87 0.74511
PP 910 5 5.6 4.87 2.21585
POM 1200 8 3.8 4.87 4.6752
PPO 1200 7 3.3 4.87 4.0904
PES 1300 20 2.6 4.87 12.662
PEEK 1300 30 2.5 4.87 18.993
PA 1200 9 3.2 4.87 5.2596
Tuesday, May 4, 2010
Bench Marking for Materials
Tuesday, May 4, 2010
Criteria Weight (100)
PA PP POM PPO PES PEEK
Wear Resistance 5 2.5 3 3 3.5 4 3.5
High Temperature Resist 15 3 3 4.5 3 3.5 4
Insulator Properties 20 2.5 4 4 3 3 3
Chemical Resistance 5 3 4 4 4 3 3.5
Impact Resistance 5 3 4 3 4 3 4.5
Cost 20 4 5 4 4 2.5 2
Durability 15 3 3.5 3 4 3 3
Ease of Manufacturing 15 3 5 2.5 2 4 3
Total 100 307.5 407.5 360 322.5 317.5 307.5
Tuesday, May 4, 2010
Material to useFrom the benchmarking table, the most appropriate material for our kettle is PP or Polypropylene.
Tuesday, May 4, 2010
Objective of Case Study
Choose the material(s) and process(es) for manufacturing the kettle
The material we choose for kettle body is polypropylene (PP). Due to its low cost and ease of manufacturing, we think that this is the most appropriate material to use. Also, the thermal resistance of this material is suitable for such operation as boiling water. The manufacturing process which is the most suitable is blow molding, since the production volume is appropriate. Also the capital cost and tooling cost seems to be the most appropriate.
Tuesday, May 4, 2010