https://www.avient.com/sites/default/files/2020-10/2020-gravi-tech-design-guide-.pdf
Base Resin ABS PA PBT PC PE PEEK PP PPS
Barrel Temperatures °F (°C)
Rear Zone 400–475(200–250)
480–540
(248–282)
480–520
(250–270)
480–570
(250–300)
400–445
(200–230)
660–700
(350–475)
400–440
(200–225)
520–600
(270–300)
Center Zone 410–480(205–253)
490–550
(254–287)
485–525
(251–273)
500–580
(260–305)
410–455
(207–237)
670–710
(357–385)
410–450
(205–230)
550–610
(285–310)
Front Zone 420–490(210–257)
500–560
(260–293)
490–530
(254–276)
515–590
(267–310)
420–465
(213–243)
680–720
(363–400)
420–455
(215–235)
570–620
(300–320)
Nozzle 425–500(215–260)
510–570
(265–298)
490–540
(254–282)
530–600
(275–315)
430–475
(220–250)
700–730
(370–395)
430–460
(220–240)
610–620
(320–325)
Melt Temperature 425–515(215–270)
510–570
(265–298)
490–540
(254–282)
530–615
(275–325)
430–495
(220–260)
700–725
(370–385)
430–475
(220–250)
610–635
(320–335)
Mold Temperature 140–200(60–90)
150–300
(65–148)
140–280
(60–137)
160–240
(70–115)
80–140
(25–60)
300–400
(150–200)
80–140
(25–60)
190–300
(90–150)
Drying Parameters
190 (90)
2–4 Hours
0 .01%–0 .15%
180 (82)
4–5 Hours
0 .10%–0 .20%
275 (135)
3–4 Hours
0 .02%–0 .04%
250 (125)
3–4 Hours
0 .02%
160 (70)
2 Hours
300 (150)
3–4 Hours
0 .10%
160 (70)
2 Hours
280 (135)
2–3 Hours
0 .01%–0 .20%
Nozzle Type General Purpose Nylon or Reverse Taper General Purpose General Purpose General Purpose General Purpose General Purpose General Purpose
Injection Velocity1 2–5 in/sec; 50–127 mm/sec
Injection Pressure 1,000–2,000 psi; 7–14 Mpa
Back Pressure 50–100 psi; 0 .3–0 .7 Mpa
Screw Speed 25–75 RPM
Cushion 0 .125–0 .250 in; 3–6 mm
Screw Compression Ratio2 2 .0:1–2 .5:1
Comments
1 .
CHAPTER 3 | PART DESIGN GUIDELINES
Wall Thickness (mm)
C
o
o
li
n
g
T
im
e
(
S
e
c
)
40
35
30
25
20
15
10
5
0
0 1 2 3 4
ABS
PC
Nylon 6/6
Figure 2 - Designing for Wall Thickness Changes
Bad
Better
Recommended
Recommended
Poor
High Stress
Ideal
Figure 3 - Internal and External
Radius Guidelines
.5W Min
Inside Rad + W
Poor
High Volume
FIGURE 1 - Wall thickness vs . cooling
time of various plastics
FIGURE 2 - Designing for
wall thickness changes
FIGURE 3 - Internal and external
radius guidelines
Design Guide 9
RIB DESIGN GUIDELINES
The minimum distance ribs should be spaced is
three times the nominal wall thickness (3W) .
The boss should extend into the nominal wall of
the part, to avoid a thick region and possible sink
Figure 4 - Drafting Guidelines for
Nominal Wall Thickness
Cross section
showing draft
Figure 5 - Rib design guidelines
1/4˚—–1˚
2.5W
W
3W Min.
.01" R Min. or .25W
.75W for a low shrink material
.50W for a high shrink material
Figure 6 - Wall thickness changes due
to rib placement
16.00
14.00
12.00
10.00
8.00
6.00
4.00
2.00
5.00 10.00 15.00 20.00 25.00 30.00 35.00
Rib-height (mm)
M
a
x
D
is
p
la
c
e
m
e
n
t
M
a
g
n
it
u
d
e
(
m
m
)
0
FIGURE 4 - Drafing guidelines for
nominal wall thickness
FIGURE 5 - Rib design guidelines
FIGURE 7 - Wall thickness changes
due to rib placement
FIGURE 6 - Rib height vs. stiffness
10 Gravi-Tech
FIGURE 8 - Side Wall Boss Design Guidelines
Sink
Not Recommended Preferred Design
A
= Diameter
= A
= Primary Wall
= A
= 2A
FIGURE 9 - Guidelines Design Guidelines
4W
W
2W
.75W For a Low Shrink Material
.50W For a High Shrink Material
FIGURE 9 - Side wall boss design guidelines
FIGURE 10 - Gusset design guidelines
FIGURE 11 - Structural hole
design guidelines
area .