Page 89 - Hot Runner & Control Systems 2020

Straight-Shot Hot Sprue Bushings 87

TR-Series Straight-Shot ™

The DME standard TR-Series Straight-Shot Hot Sprue Bushing,
like the standard T-Series, improves the performance of three-
plate runner molds by minimizing the length of protrusion on the
NOTE: runner system. This bushing features a “reverse taper” design that
The expansion factor must be taken into consideration prior to
machining for and installation of the bushing. This factor (BE) must originates from under the heat source, providing easier start-ups.
then be added to the A dimension. The formula for determining this
expansion factor is as follows:
BE = “A” dimension x 0.00000633 x nozzle set point - 68ºF The TR-Series design can also be used when a reverse taper will
(assuming the mold is at 68ºF during operation). If mold benefit a particular application. The bushing is supplied with a .12
temperature is different, substitute 68ºF with actual mold
temperature. diameter orifice and a .25 long reverse taper. The orifice may be

EXAMPLE: enlarged and the taper increased to suit. The bushing is available
Given a setpoint of 500°F: with either /2" or /4" spherical radius, 120 or 240 volt heater and a
3
1
BE = 1.375 × .0000063 × (500 – 68) = .004 thus 1.375 + .004 = 1.379.
3
Please note that the above information is given as an example. 7 /8" or 1/8" long stripper-plate bushing to suit the application.
Variations may occur based on mold configuration and cooling
factor. In some instances, it may be necessary to obtain an
empirical factor.
5.09
TR-Series Straight-Shot Hot Sprue Bushings
+.000
A = 1 7 8 1.995 DIA.–.005
WITH 120 VOLT WITH 240 VOLT No. 10-24 x LONG .19
1
2
HEATER HEATER F H S (2) INCLUDED
R L
ITEM ITEM
NUMBER NUMBER .97 +.0000 .12
–.0005 DIA.
1 SSBT4517TR107 7 ⁄8 SSBT4517TR207 1.4995 .31 DIA. R
⁄2 SSBT4517TR113 3 SSBT4517TR213 DIA.
1 ⁄8
.97 5˚
3 SSBT6517TR107 7 ⁄8 SSBT6517TR207
⁄4 SSBT6517TR113 1 ⁄8 SSBT6517TR213
3
NOTE: .25 1.69 DIA. .340
5° heater lead is standard. For 90° lead, add “90” to end of .25 Straight-Shot Hot Sprue Bushings | TR-Series Straight-Shot ™
item number (e.g., SSBT4517TR10790). L
Typical Application Important:
TYPICAL APPLICATION
To prevent “pushback” of the hot sprue
bushing due to injection pressure – and
assure a positive tapered seal with the
stripper plate bushing – secure the hot sprue
bushing to the A-Clamping Plate. A dowel
MOLD
OPEN or flat key installed under the locating ring
(shown) or clamping-type locating ring may
be used.
Hot Runner Systems | 4-Zone and 8-Zone Timer-Based Sequencers
For Improved Performance and
Increased Productivity:
.25
X-2 MIN. X-1 A-CLAMPING • Use DME standard T-Series (3-Plate)
PLATE PLATE PLATE
Mold Bases (see DME Mold Bases and
Plates Catalog)

U.S. 800-626-6653 n Canada 800-387-6600 n dme@milacron.com n www.milacron.com