Hot Runner & Control Systems

Straight-Shot Hot Sprue Bushings TR-Series Straight-Shot ™

87

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 runner system. This bushing features a “reverse taper” design that originates from under the heat source, providing easier start-ups. The TR-Series design can also be used when a reverse taper will benefit a particular application. The bushing is supplied with a .12 diameter orifice and a .25 long reverse taper. The orifice may be enlarged and the taper increased to suit. The bushing is available with either 1 / 2 " or 3 / 4 " spherical radius, 120 or 240 volt heater and a 7 / 8 " or 1 3 / 8 " long stripper-plate bushing to suit the application.

NOTE: The expansion factor must be taken into consideration prior to machining for and installation of the bushing. This factor (BE) must 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 (assuming the mold is at 68ºF during operation). If mold temperature is different, substitute 68ºF with actual mold temperature.

EXAMPLE: Given a setpoint of 500°F:

BE = 1.375 × .0000063 × (500 – 68) = .004 thus 1.375 + .004 = 1.379. Please note that the above information is given as an example. 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 –.005

A =

7 1

1.995 DIA.

8

No. 10-24 x LONG F H S (2) INCLUDED 2 1

WITH 120 VOLT HEATER

WITH 240 VOLT HEATER

.19

R

L

ITEM NUMBER

ITEM NUMBER

.12 DIA.

.97

+.0000 –.0005

R

SSBT4517TR107 SSBT4517TR113 SSBT6517TR107 SSBT6517TR113

SSBT4517TR207 SSBT4517TR213 SSBT6517TR207 SSBT6517TR213

7 ⁄ 8

1.4995 DIA.

.31 DIA.

1 ⁄ 2 3 ⁄ 4

1 3 ⁄ 8

.97

7 ⁄ 8

1 3 ⁄ 8

1.69 DIA.

.340

.25

NOTE: 5° heater lead is standard. For 90° lead, add “90” to end of item number (e.g., SSBT4517TR10790).

.25

L

Typical Application

TYPICAL APPLICATION

Important: 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 or flat key installed under the locating ring (shown) or clamping-type locating ring may be used.

MOLD OPEN

For Improved Performance and Increased Productivity: • Use DME standard T-Series (3-Plate)

.25 MIN.

X-2 PLATE

X-1 PLATE

A-CLAMPING PLATE

Mold Bases (see DME Mold Bases and Plates Catalog)

U.S. 800-626-6653 n Canada 800-387-6600 n dme.net n store.dme.net

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