CREATING THE A-SOLID
Data to start up Foam A-surface
•
•
•
•
•
H-point
oscar,
frame,
mating components(plastics, pillars, console, etc...),
trim drawings (trim cover thickness,tie down locations, tie down types,
etc…)
Critical foam areas that should be checked
• Foam thickness at the top surface, bottom surface and side
surfaces from frame to STO.
• Foam thickness at centerline, paying particular attention to
foam thickness below seams.
• Foam thickness at radial corners of STO from frame to STO.
• Foam thickness above frame components.
• Potential thin foam to thick foam areas.
• Foam thickness behind frame (back frame).
• Value or absence of blend radii on STO.
• Foam thickness between A and B surface.
• Foam interface to plastics and mating components
Creating Cutting Planes for Sections
CUTTING PLANE
• Back Pad
– perpendicular to the torso angle(HORIZONTAL)
– (Y) plane through H-point(LONGITUDINAL)
• Cushion pad
– (Y) plane through H-point(LONGITUDINAL)
– (X) plane, which is perpendicular to the a-surface
line at H-point of the STO
Cut sections through the STO
Pad Symmetry Sections
AGGRESSIVE BOLSTERS
PACKAGING TO A CONSOLE
Try to match the STO as close as
possible using
1) Circles
2) Conics
3) Arcs
4) Splines
Insert surface creation
Avoid bridge across the insert area
Sidewall
Sidewall
Sidewall cushion
Bolsters surface
• 1.Create a horizontal line tangent to the high line of the bolster at each section
• 2. Create a circle which is tangent to the high line of the bolster and
the offset sidewall curve with a radius that is 60% of the STO radius (15mm MINIMUM)
• 3. Next, create a curve (circle, conic, arc, or spline) that is tangent to the 60% STO radius
(15mm MIN) through the endpoint of the trimmed insert offset curve with
a radius that is equal to the STO bolster radius
Step-1 and 2
Step-3
4.Need to check the integrity of the bolster offset curve when a tie down trench is added
5. To revise the bolster offset curve, change the endpoint of the insert offset curve by moving
it toward the center of the pad without going
Bolsters (multiple curves):
1. the foam will be line to line with the high line
2. determine the theoretical intersection of the flat top and bolster curve on the STO
• Create a curve that is equal to the bolster curve radius that intersects the endpoint of the
trimmed offset insert curve and the theoretical intersection of the flat top and bolster curve
Top (back pads):
Front & Rear (cushion pads):
Bottom (back pads) – BITE LINE
CREATING THE SLAB SURFACES FOR THE
FOUNDATION SOLID
CREATING TRENCHES FOR TIE DOWNS AND SELVEDGE
LOCAL TRENCH OVERBUILD SET UP
Hog ring location
B-SIDE
Completed foam PAD
WHAT IS POLYURETHANE FOAM?
It is chemical reaction between
polyisocyanate + polyol
Character of foam
1.Elasticity
2.Thermal Insurability
PROCESS
1.Hot Cured molding method –low density, higher investment cost, longer cycle time
2.Cold cured molding method –high density ,lower investment cost, lower cycle time
Hot cured Molding Method
Cold cured Molding Method
How foam are produced ?
Typical Cushion DIE
https://youtu.be/66JsLIfwclI
Typical Back DIE
Performance of Seat foam
1.Density
2.Hardness (ILD-INDENTATION LOAD DEFLECTION)
3.Impact Resilience Rate
4.Deflection amount
Density: Usually higher density is preferred
Hardness:
3.Impact Resilience Rate :Is more related to Ride comfort
Usually measured a steel ball of 16 diameter (weight of 16.29 gram) from a height
of 460 mm
4.Deflection amount
This refer to the amount when a constant load is applied to foam