Transcript Manufacturing of a polyurethane shovel for a snow

Supervisor:
MEng Silviya Angelova
TECHNICAL UNIVERSITY OF SOFIA
FINAL YEAR PROJECT
BACHELOR’S DEGREE
MANUFACTURING OF A
POLYURETHANE SHOVEL FOR
A SNOW-FIGHTING VEHICLE
STUDENT: Anita Petrovska
Introduction
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Low cost tooling and extreme wear and abrasion resistance are some of the
benefits cast urethanes can offer – properties that could serve a wide
variety of end markets.
Comparison of polyurethane to rubber, plastic, and metals - Product
engineers prefer urethane. Its parts provide longer service life when
compared to plastics and rubber, and lower noise abatement properties
when compared to metals.
Application
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Power transmission industry
Food processing industry
Sports & Athletic equipment
manufacturing
Mining and drilling equipment
Computer chip manufacturing
Pipe/Plumbing Industry
Marine industry
Ski industry
Etc.
State-of-the-art and trends
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The history of the polyurethane begins in the 1937 when
Dr. Otto Bayer discovers the basic PU chemistry.
The polyurethanes industry is always seeking to reduce
its impact on the environment and is currently exploring
ways of increasing the energy efficiency of manufacturing
processes and creating end products that can be used to
save energy.
"Science For A Better Life“
“Dream production”
Building insulation
Innovative solutions for air, sea and rail transportation
Etc.
Purpose of the project
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Measuring the given model and making sketch with the
corresponding dimensions
Drawing a 3D model of the detail by means of a relevant
software – KOMPAS 3D
Constructive decisions about the mould form – way of
molding the polyurethane, materials, type;
Drawing the tool by means of KOMPAS 3D – technical
documentation about the detail and the tool
Programming with a CAM software – ESPRIT
Manufacturing of the tool parts on CNC vertical center
machine and universal milling machine, assembly of the
parts and welding, and molding of the detail.
Analysis of the given part …
•Measuring of the given part by means of vernier gauge, angle gauge, and durometer
•Decisions about the tearing of the given part – adding ribs and fillets in the critical edges
•Making sketch of the given model
Technical data about the material used
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Physical Properties
Density
Mechanical Properties
Hardness, Shore A
Tensile Strength at Break
Tensile Strength, Yield
Elongation at Break
Compression Set
Processing Properties
Melt Temperature
Mold Temperature
Ejection Temperature
Metric
1.22 g/cc
Metric
86.0
46.0 MPa
46.0 MPa
>= 300 %
11.0 %
@Temperature 23.0 °C
36.0 %
@Temperature 70.0 °C
Metric
200 - 220 °C
20.0 - 40.0 °C
50.0 °C
Drawing of the solid model of the part
by means of KOMPAS 3D
Defining of the mass of the detail
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m [g] = V [cm3].ρ [g/cm3] = 491512 g = 4.915 kg.
The improved element –
with added ribs and
fillets
Construction of the molding tool
The tool for the shovel will consist of
two main parts, so it will be typical twopieced matrix. The first will be a “bed”
for the bottom of the detail, which will
have a dish-form. And the second part
will copy the upper side of the shovel –
its ribs, fillets, etc.
The best way of molding this element
is rotated vertical through its shorter
part of the transom-shape base.
First main part of the tool – “the bed”
For the first main part of the matrix – the
“bed”, it is convenient to be made of Iron.
On its part, the bed will consist of 4 elements,
which will copy the shape of the outer sides of
the shovel, and later on will be welded to form
one whole piece.
When the dimensions for the tool are defined it
is taken into account that the separated parts
should be welded, so ≈4 mm are added to
each side that should be welded to another
one. The shrinkage of the material is 1 %, so
1% is added to each dimension of the tool
elements.
The elements from the first part of the tool are
machined on Universal Milling machine FU 251.
The second main part of the tool –
“Shaping mould surface”
The second main part of the matrix is made
of seven aluminum pieces. It is lighter
material, easier for machining and that is
why we choose it for the upper part. These
elements need much more machining than
the elements from the first part of the tool.
They are the shaping piece of the matrix.
Here is the ready welded model of the
upper-part.
CAM (Computer Aided Manufacturing)
with ESPRIT
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Introduction to ESPRIT
Take the ready 3D model of the part
Put it in ESPRIT and
choosing the allocation
on the table
Use of the appropriate
functions with its appropriate options and parameters –
depth of cut, clearance, retract, % stepover, feed rate,
speed, approach, start position, offset, and many others.
Choosing the tools for the cutting and their modes of
operation
Simulation in ESPRIT
Modeling of the tool parts
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The CNC machine that we use for the purpose is a 3-axis vertical machining center Deckel Maho
DMC 1035v with Heidenhain iTNC 530 -control. It is ISO-based control and machining language.
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X- / Y- / Z-axis
mm
1,035 / 560 / 510
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Main drive (40 / 100% DC)
kW
13 / 9 (19 / 14)
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Speed range up to
rpm.
10,000 (14,000)*
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Rapid traverse X / Y / Z
m/min
30
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Tool magazine
pockets
20 (30)*
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Workpiece weight max.
kg
1,000
Post processing
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“
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0 BEGIN PGM 1 MM
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8 CYCL DEF 32.0 TOLERANCE
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1 BLK FORM 0.1 Z X-240 Y-36 Z-40
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9 CYCL DEF 32.1 T0.01
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2 BLK FORM 0.2 X240 Y36 Z0
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10 CYCL DEF 32.2 HSC-MODE:1 TA5
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3 CYCL DEF 247 DATUM SETTING ~
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11 M03 M08
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12 L X-273.5 Y-3.5 A0. FMAX
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13 L Z+70. FMAX
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14 L Z+2. FMAX
Q339=+4
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;DATUM NUMBER
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;
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;
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;'
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15 L X-274.5 Y-2.5 F150
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16 L X-258.195 Z-.875
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4;
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17 L X-274.5 Z-3.75
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;
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18 L X+269.5
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;
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19 CC X+269.5 Y-7.5
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; TOOL ID FM 050
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20 C X+274.5 Y-7.5 DR-
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5 TOOL CALL 34 Z S700
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21 L Y-19.5
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6 TOOL DEF 2
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22 CC X+269.5 Y-19.5
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;
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23 C X+269.5 Y-24.5 DR-
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7*-
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CONFIRM Q339 NUMBER ABOVE IS CORRRECT
Molding equipment
Free dispensing
Conclusion
The manufacturing of polyurethane
details is quite interesting, but still a
long process, which passes through
many steps. These steps are
obligatory no matter if the detail is
small or big, and if you need only
single one detail or a massproduction. With the modern
technologies and software, and
hardware it is a little bit easier to
systemize the process and be more
accurate.
Thank you for your attention!