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Design for Manufacture & Environment Final Paper – Redesigning Blender
Name: Pratham Shah
Due Date: 12/13/2013
- Energy
- Signal
- Material
Function Structure – Blender
Energy – Manual;
putting ingredients
in the jar
Energy – Electrical;
through power supply
Establish connection
between motor shaft
and blades inside jar
Material -
Ingredients
Signal – start button
is pressed
Convert electrical
energy to rotational
Energy – Manual;
pushing power button
Store ingredients
Rotating blades cuts
the ingredients
De-establish connection
between motor shaft
and blades inside jar
Clean the jar
Chopped
ingredients
Cleaned jar
Energy – Manual;
place jar on to the
holder
Energy – Manual;
pushing power button
Signal – off button
is pressed
Sound
Vibration
Heat
Filled jar Filled jar
Rotating blades
Filled jar with
ingredients chopped
Dirty jar
Signal – user notices then
ingredients are chopped
Function Structure
Assumptions
Conversion of electrical energy to rotational also produces waste energy in the form of heat, vibration and sound.
Jar needs to be cleaned after use.
The on and off buttons are pressed only once per use. No pulse input is given.
Design Changes The jar shape is like a rectangular cuboid. These can be converted to a cylindrical (more like conical) shape as shown in fig1.
For same volume of these two shapes, the surface area for a cylinder is less than a cuboid and can save material by about 11%.
The environmental impact (eco indicator pointer - 510) of production of polycarbonate (PC) is significantly higher than other
materials. Instead of using polycarbonate for making, glass can be used. Production of glass has significantly lower
environmental impact (eco indicator pointer - 58).
The feeder cap can be eliminated by using a feeder slider (fig2) that is a part of the jar lid. These helps to save material (PC)
used in making the feeder cap.
The base housing is also a bit large compared to all the components that are inside it. There is space wasted inside the housing.
The housing can be made cylindrical in shape (fig3) and can still accommodate all the internal components. This can help in
saving housing material (ABS).
For normal use of 10 minutes per week, a big fan is not required. The fan can be made smaller such that it is sufficient for
providing the necessary cooling ventilation (fig 4). It not only helps in reducing the amount of fan material used, but also
reduce the housing material used.
The highest environmental impact for blender parts comes from steel production (eco indicator pointer - 910). Instead of steel,
the fan can be made of ABS (eco indicator pointer - 400) which has significantly lower environmental impact than steel.
The highest environmental impact of the blender comes from the use of electricity. Electricity can be saved by used of a better
motor with higher efficiency that produces same 450W of power, however with consuming less electricity. A small percentage
of electricity use will be reduced by the smaller and lighter fan made of ABS instead of steel. Suppose the electricity usage can
be reduced by 15% by these methods. Thus, instead of using 19.5 kWh, the new blender will use 16.58 kWh electricity during
its life cycle.
The polycarbonate threaded jar nut is made of ABS to slightly improve the environmental impact.
Bill of Materials (BOM)
ID DESCRIPTION QUANTITY MATERIAL MANUFACTURING
PROCESS FINISH PRIMARY FUNCTION(s)
1 Leak-proof lid 1 Polyethylene Injection Molded None Covering the glass jar
2 Jar 1 Glass Blow Molding None Holding the ingredients
3 Sealing Ring 1 Silicone Rubber Extruded and then cut None Avoid spilling
4 Blade 2 Stainless Steel Stamped Grinding Cutting / blending ingredients
5 Blade Holder 1 Stainless Steel Drawn, Stamped None Mounting blades
6 Threaded Jar Nut 1 ABS Injection Molded None Mounting blades and plastic
jar
7 Oster Label 1 Laminated Paper Printed None Branding, Labeling buttons
and their purpose
8 Bottom Housing 1 ABS Injection Molded None Enclosure, surface for in-mold
marking
9 Rubber Feet 4 Silicone Rubber Casting None Support blender, reduce
vibrations
10 Bottom Cover 1 ABS Injection Molded None Enclosure
11 Screws 3 Stainless Steel Cut from bar stock,
pressed and threaded Zinc
Plated Joining
12 Cooling Fan 1 ABS Injection Molded None Removing heat
13 Hexagonal Screws 4 Hardened Steel Cut from bar stock,
pressed and threaded None Joining
14 Motor 1 Various Materials Assembled None Rotating blade
15 Washer 1 Stainless Steel Stamped None Distribute load
16 Nut 1 Stainless Steel Cold Formed and
threaded None Joining
17 Shaft Screw 1 Stainless Steel CNC None Joining
18 Shaft Disc 1 Stainless Steel Stamped and Pierced None Distribute load on shaft screw
19 Plastic Washer 4 Polyethylene Extruded and then Cut None Reducing Vibrations
20 Circuit Board 1 Various Materials Assembled None Controlling electricity
21 Circuit Board & Buttons Mount 1 Polyethylene Injection Molded None
Mounting circuit board and buttons
22 Buttons 6 ABS Injection Molded None Controlling motor speed
23 Wires 4 Copper, PVC
insulation Extruded copper None Passing electric current
Fig 1
Fig 2
Fig 3
Fig 4
Eco-indicator 99
Purpose
The product being analyzed is an Oster branded 8 speed blender and not any other
branded from the same or different brand.
The blender has a 5 year lifespan, during which it is operated 1 time/week for 10 min per
use.
The purpose of the analysis is to study the environmental impacts of different aspects of
blender including the materials, processes, usage and disposal in order to recognize the
aspects that can be improved upon considering the environmental impact.
In addition, the environmental impact of new design is compared with the old design to
see the improvements.
Assumptions
Only electricity is considered as part of usage
Blender power - 450 W
Electricity used per blender - 16.58 kWh
All steels are high alloy steel.
PCB, motor, label and wirings are ignored.
All plastic resins are injection molded and all metal parts are stamped.
For approximating weight, all plastics and metal density are considered 0.94 gms/cm3 and
8 gms/cm3 respectively. Volume of the materials are estimated using rough dimensional
measurements.
All disposal is through municipal waste.
Mass area ratio of corrugated cardboard – 0.05 gms/cm2. Packaging material area = 1300
cm2. Thus, its weight – 65 gms
Glass density is 2.5 gms/cm3. The method of preparation is assumed as injection molded.
Old Design
Production
Material Amount Indicator Result
Polyethylene (LDPE) 80 gms 360 28.8
Polycarbonate 185 gms 510 94.35
Silicone Rubber 7 gms (too less quantity) Ignored 0
ABS 310 gms 400 124
Steel 270 gms 910 245.7
Injection Molding PE,ABS 690 gms 21 14.49
Injection Molding PC 184 gms 44 8.09
Stamping Steel 3000 mm2 (assumed) 0.00006 0.18
Cardboard 65 gms 69 4.49
Total (mPt) 520.1
Use
Material Amount Indicator Result
Electricity 19.5 kWh 37 721.5
Disposal
Material & Process Amount Indicator Result
Municipal waste PE 80 gms -1.1 -0.09
Municipal waste PC 195 gms 10 (assumed as of PVC) 1.95
Municipal waste ABS 610 gms -1.1 (assumed as of PE) -0.67
Municipal waste steel 270 gms -5.9 -1.59
Municipal waste cardboard 65 gms 0.64 0.04
Total (mPt) -0.36
Total (mPt) = 520.1 + 721.5 - 0.36 = 1241.24
Life-cycle
Glass
325 gms
PE
85 gms
ABS
350 gms
Silicone
Rubber
7 gms
Steel
110 gms
Injection Molding
Stamped
Assembled
Packaged
Use
Blender
Cardboard
65 gms
Electricity
16.58 kWh
New Design
Production
Material Amount Indicator Result
Polyethylene (LDPE) 85 gms 360 30.6
Silicone Rubber 7 gms (too less quantity) Ignored 0
ABS 350 gms 400 140
Steel 110 gms 910 100.1
Glass 325 gms 58 18.85
Injection Molding PE,ABS 840 gms 21 17.64
Stamping Steel 3000 mm2 (assumed) 0.00006 0.18
Cardboard 65 gms 69 4.49
Total (mPt) 311.86
Use
Material Amount Indicator Result
Electricity 16.58 kWh 37 613.46
Disposal
Material & Process Amount Indicator Result
Municipal waste PE 85 gms -1.1 -0.09
Municipal waste Glass 325 gms -15 -4.88
Municipal waste ABS 350 gms -1.1 (assumed as of PE) -0.39
Municipal waste steel 110 gms -5.9 -0.65
Municipal waste cardboard 65 gms 0.64 0.04
Total (mPt) -5.97
Total (mPt) = 311.86 + 613.46 – 5.97 = 919.35
Improvement over previous design = (1241.24 – 919.35) / 1241.24 = 26 %
Results
The use of electricity has highest environmental impact and thus redesign the blender
needs to focus on reducing the electrical consumption.
The substitution of PC with glass for the jar has significantly reduced the environmental
impact of production.
Overall 26 % improvement have been brought in environmental impact by the new
design.
The performance or usability of the new designed blender has not been compromised in
any way compared to the old design.