Tip Heaters Put Closed-Loop Temperature Control At the Gate

Tip Heaters Put Closed-Loop Temperature Control At the Gate

Dynisco HotRunners has introduced a line of tip heaters that will allow precise gate control with applications that are reverse gated opposite a cosmetic surface, require minimal vestige or involve the use of engineering polymers.

The tip heater independently controls the temperature of the plastic in the hot runner tip. This control is said to allow the processor to change the temperature in each gate without adversely affecting the rest of the process. In turn, this results in a wider processing window and faster start-ups, as well as preventing blush and other problems, according to Dynisco.

Blush typically occurs when trying to gate opposite a cosmetic surface. Blush directly opposite the gate is usually caused by cold material in the gate area. This cold material has a higher viscosity and when it is forced through the orifice, it shears and causes blush.

Because the tip heater provides a local temperature increase, the result is a decrease in material viscosity so material can flow more easily, thus reducing or eliminating blush.

With the use of abrasion resistant alloys on all the flow surfaces, the tip heater has been designed to process a range of materials, including engineering resins. It can also be used with glass, mineral- and carbon-filled materials.

Another feature of the tip heater is the Dynisco-Seal, which allows for enhanced color change capabilities.

Five styles are available:

* HTP-10 has a 10 mm maximum nozzle bore diameter, 86 to 196 mm mold depth, 26 mm tip and 40 mm gate spacing.

* SRP-20 has a 20 mm maximum nozzle bore diameter, 145 to 500 mm mold depth, 32 mm tip, and 114 mm gate spacing.

* SRP-24 has a 25 mm maximum nozzle bore diameter, 185 to 625 mm mold depth, 38 mm tip and 114 mm gate spacing.

* TP-20 has a 20 mm maximum nozzle bore diameter, 160 to 500 mm mold depth, 36 mm tip, and 60 mm gate spacing.

* TP-24 has a 25 mm maximum nozzle bore diameter, 245 to 1000 mm mold depth, 38 mm tip, and 82 mm gate spacing.

Please contact the company directly for pricing information (check out the Key Contact Directory on p 38).

Dynisco HotRunners
Gloucester, MA