Material Handling
Current material handling procedures for the liner cell are inadequate and have the potential to cause
not only material damage but also safety issues. Currently, liners are set vertically on pallets and
transported via forklift, unrestrained, throughout the facility.
Material handling defects currently account for approximately $6000 of defect costs within the last two
years. Several other unreported incidents have occurred as well, due to material handling. The new
material handling procedures should completely eliminate defects due to material handling.
In order to eliminate material handling defects, a pallet fixture for liners as well as an operator-friendly
method for restraining the liner need to be designed, and operator instructions must be developed.
In order to affix the VBlocks to the pallets, a simple pin system was designed. Using the pins,
VBlocks can be moved to the appropriate place for the length of the liner being transported.
Figure 1: Preliminary Pallet Design
Material Development and Selection
For the pallets, the following materials were considered: wood, steel and aluminum. For the VBlock
fixtures, wood and delrin were both considered. See below for a table of material properties, deflection
due to the applied load and Von Mises stress.
The applied load was considered to be 2000lb (the weight of the heaviest liner provided) over the area
on which the liner would sit. COMSOL was used to analyze the applied loads and their effects on the
materials used. See the appendix for finite element analysis images of stresses on materials.
Table 3: Pallet and VBlock Fixture Material Selection Options
Notes on Material Selection:
Wood
Wooden pallets are cheap
compared to plastic and metal
pallets, and are recyclable and
made from renewable resources.
They have high friction compared
to plastic and metal pallets, are
very strong and stiff in relation to
their cost and can easily be
repaired if damaged.
Galvanized Steel
Steel pallets are strong and are
used for heavy loads, high-stacking
loads and long term dry storage.
Lower cost than that of aluminum,
although higher than that of
wooden pallets.
Aluminum
Aluminum pallets are stronger than
wood or plastic, lighter than steel,
and resist weather, rotting, plastic
creep and corrosion. Costs
approximately 2-3 times that of
carbon steel.
Table 4: Notes on Material Selection
The material which will be used for the pallets is oak, based on customer preference. Pine will be used
for the VBlocks. This is due to low cost and availability as well as ease of replacement.
Once the materials were selected, the angle at which the VBlock is cut must be determined. Through a
series of calculations, it was determined that (despite any angle of the VBlock) the liners must be
strapped to the pallets in order to prevent liners from rolling off of the pallet under worse case
conditions (forklift stopping short). See appendix for calculations.
Material Constraints Development and Selection
Several options were considered for strapping the liners. Considerations had to be made for ease of use
as well as safety and durability. Straps should ideally be attached to the pallets to prevent loss and thus
discontinuation of use over time. The table below shows options for strapping.
Option 1: Retractable Ratcheting Strap
Option 2: Seatbelt Style Strap
Table 5: Strap Concept Selection Options
Bill of Materials
The below bill of materials was developed for material handling.
Table 6: Bill of Materials
Preliminary Test Plan
• Prototype pallet (1-3 units)
– Purchase base pallet to specifications
– Mfg V Blocks in RIT machine shop
• Band Saw, Lathe, Hand Tools
– Done in weeks 1-3 of MSD II
– Mechanical engineer will manufacture
• Run prototype at Dresser Rand
– Use on shelf, floor, forklift
– Place on liners (smallest to largest)
– Check for any failures in the pallet, V blocks or straps
Looking Forward
In MSDII, operator instructions will be developed, the build and test phase will be executed and
materials will be ordered and delivered for final manufacture to be used in-house at Dresser-Rand.
Appendix
VBlock Angle
In order to determine the angle at which the VBlock must be cut is determined using simple
physics.
Figure 1: Liner versus VBlock Angle Analysis
If the forklift carrying the liner stops short, the velocity of the liner (V) is assumed to be the
velocity at which the forklift is travelling. In order to find  (the angle at which the VBlock should be
cut), an analysis of kinetic energy versus potential energy is performed.
where
and
Equations 1-3: Kinetic Energy Equations
where
Equations 4-5: Potential Energy Equations
Setting kinetic energy equal to potential energy, and solving for , we get:
Simplifying:
Using Microsoft Excel, this equation was applied to all sizes of liners, and solved for . After
applying this analysis, it was shown that the angle necessary was too large to be feasible. This proves
that the liners must be strapped in some way in order to keep the liner from rolling off of the fixture in
the event of a forklift stopping short.
Finite Element Analysis
COMSOL was used to analyze the material selection based on the loads applied based on
weights of liners.
Small VBlock Beams
Figure 2: Oak Small VBlock – Inner Holes
Figure 3: Aluminum Small VBlock – Inner Holes
Figure 4: Steel Small VBlock – Inner Holes
Figure 5: Oak Small VBlock Beam – Outer Holes
Figure 6: Aluminum Small VBlock Beam – Outer Holes
Figure 7: Steel Small VBlock Beam – Outer Holes
Figure 8: Oak Small VBlock Beam – Inner & Outer Holes
Figure 9: Aluminum Small VBlock Beam – Inner & Outer Holes
Figure 10: Steel Small VBlock Beam – Inner & Outer Holes
Figure 11: Oak Small VBlock Beam – 3 VBlocks
Figure 12: Aluminum Small VBlock Beam – 3 VBlocks
Figure 13: Steel Small VBlock Beam – 3 VBlocks
Large VBlock Beams
Figure 14: Oak Large VBlock Beam – 2 VBlocks
Figure 15: Aluminum Large VBlock Beam – 2 VBlocks
Figure 16: Steel Large VBlock Beam – 2 VBlocks
Figure 17: Oak Large VBlock Beam – 4 VBlocks
Figure 18: Aluminum Large VBlock Beam – 4 VBlocks
Figure 19: Steel Large VBlock Beam – 4 VBlocks
Figures 20 & 21: Oak Small VBlock
Figures 22 & 23: Delrin Small VBlock
Figures 15 & 16: Oak Large VBlock
Figures 17 & 18: Delrin Large VBlock