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Are your color
mixing nozzles helping or hurting your productivity?
The most common use of mixing nozzles is to deliver a more uniform distribution
of color additives so part appearance is enhanced and the scrap rate is
reduced. Mixing nozzles can also increase the usable level of regrind. All
mixing nozzles do these things to varying degrees, but certainly some perform
more effectively and efficiently than others. In fact, some poorly designed
mixing nozzles are so difficult to work with, they can actually hurt your
bottom line. |
| +
GOOD, WELL DESIGNED MIXING NOZZLES such as the New EZ Flow from IMS
allow quick screw recovery and low temperature settings
which can result in cycle times and energy consumption being minimized. |
| + Poorly designed, all
purpose mixing nozzles sometimes make it necessary to adjust process parameters
to overcome poor performance. For example, you can adjust machine back
pressure, but this only slows screw recovery, and in many cases increases total
cycle time. Mixing problems may also be overcome by increasing
temperature settings for the barrel and nozzle. This often improves the melt
quality, but it also increases part cooling time and the use of electricity.
Inconsistent melt temperatures may result in unacceptable "Seams" or "Flow
Lines" in the molded parts. |
| HOW MIXING NOZZLES WORK |
| Disruption of the laminar flow through the nozzle creates turbulent flow
changes forcing the layers of plastic to collide into one another. |
| There are two main designs that create this turbulent flow: |
| A.) Designs that use increasing and decreasing pressure flow moving the polymer
into areas of greater volume then forcing the flow through areas of lesser
volume. The EZ Flow units, shown below, are examples of this type of
flow action and are recommended for unfilled stable polymers like nylons,
polypropylenes and polycarbonates for the distribution of non-fiber additives
like color. |
| B.) Designs that displace the laminar flow layers, moving the center flow to
the outer edges and back to the center. Typically this method is not as
effective as pressure designs in their blending action, but these designs are
much gentler allowing their use on shear sensitive materials or other resins
like Nylon G/F with fiber additives. The IMS
In-Line Color Mixing Nozzles are examples of this type of action. |
| Note: NO SINGLE MIXING NOZZLE CAN
BE EFFECTIVE IN ALL APPLICATIONS |
That’s why IMS now
gives you
11 different size/style mixing nozzles from which to choose |
| The effect of flow rate on injection pressure is based on the flow volume
through the mixing elements. The proper size unit will create little, if any,
pressure drop through the mixing element. Each element design offers
recommendations as to the machine’s shot size limitations for the element. If
pressure drop creates a molding problem, moving to a different design in the
same size unit with a higher flow volume may solve the problem. If not, a large
size unit may be required. |
New EZ Flow Mixing
Nozzles from IMS:
— MIXING ELEMENT SPECIFICATIONS — |
| Model |
Unit Flow
Volume
(Square Inches) |
Unit Blending
Action
(Scale of 1 to 10) |
Recommended
Shot Size
(Ounces) |
Element
Length
(Inches) |
Element
O.D.
(Inches) |
 |
| EZ Flow 20 |
0.120 |
3.5 |
Up to 20 |
2.275 |
0.650 |
| This is the first effective mixing NOZZLE TIP and it’s
sized for machines with 20 oz. shot sizes or less |
 |
| EZ Flow Xtra 80 |
0.075 |
3.0 |
Up to 80 |
4.700 |
0.625 |
| This design offers a very specialized mixing action
for flow restrictive or shear sensitive materials |
 |
| EZ Flow 95 |
0.075 |
5.0 |
Up to 95 |
6.100 |
0.625 |
| This design offers very aggressive mixing action in an
easy-to-use and clean design |
 |
| EZ Flow Groove 95 |
0.095 |
4.5 |
Up to 95 |
6.100 |
0.625 |
| This design offers very aggressive mixing action in an
easy-to-use and clean design |
 |
| EZ Flow 180 |
0.125 |
5.0 |
Up to 180 |
6.100 |
0.937 |
| This design offers very aggressive mixing action in an
easy-to-use and clean design |
 |
| EZ Flow 260 |
0.200 |
5.0 |
Up to 260 |
7.000 |
1.250 |
| This design offers very aggressive mixing action in an
easy-to-use and easy-to-clean design. It also provides a blending action for
greatly improved color mixing |
 |
| EZ Flow 360 |
0.450 |
6.5 |
Up to 360 |
10.500 |
1.250 |
| This design offers very aggressive mixing action in an
easy-to-use and easy-to-clean design. It also provides a blending action for
greatly improved color mixing |
|
| 3 ADDITIONAL IMS MIXING NOZZLE STYLES |
In-Line
Color Mixing Nozzles with seven-flute internal reversing helix
Pineapple
Color Dispersion Nozzles
Color
Dispersion Plugs for use in modified nozzles |
FOR QUESTIONS OR ASSISTANCE IN MIXING NOZZLE SELECTION, contact
William Kramer
e-mail: wkramer@www.imscompany.com or
phone: 440-543-1615 ext. 133 |