gravimetric feeder/ volumetric feeder
Volumetric feeder
A volumetric feeder, on the other hand, does this based on volume in speed.
A volumetric feeder is a dosing system that supplies the production system with a certain volume of material in a set timeframe, based on the so-called displacement principle. In contrast to a gravimetric feeder, the dosing speed of a volumetric feeder should be selected manually, which may vary based on the nature of the raw input materials. For example, masterbatch requires a different speed compared to dosing of liquid or powder input material.
For smaller production processes and companies who are looking to save on dosing equipment, a volumetric feeder is favoured over a gravimetric feeder. Yet, a gravimetric feeder enables one to save heavily on the input material by a more precise feeding process. This means that a gravimetric feeding system usually provide for a higher return of investment (ROI) on a long-term basis.
Volumetric feeder
Advantages
Relatively low priced dosing system
Accurate dosing cylinder
Stepper motor speed starting from 0.1 up to 200 rpm
Disadvantages
Manual recalibration required
Limited control over your product quality
No monitoring and reporting options
Cannot automatically compensate for fluctuations in density
Sensitive to material build-up
No automatic detection of material supply interruption
Gravimetric feeder
A gravimetric feeder is a self-calibrating dosing system that doses based on weight in speed.
In gravimetric dosing, the weight of the dosed additive is measured using a load cell that is the foundation of the entire system. Weight is calculated using loss-in-weight technology, which measures the reduced weight while dosing.
In the self-calibrating gravimetric feeder system, the stepper motor automatically alters its speed when a change is detected in the material flow. This eliminates the need for manual adjustment, which is required when using a volumetric feeder. Such a change in material flow can be the result of the addition of new material or fluctuations in the material density, among other factors. This means that, when using a gravimetric feeder to dose, you are in complete control of the quality of your final product. Thanks to the gravimetric feeder's self-calibrating dosing system, you will never run the risk of overdosing and will therefore automatically save costs when using expensive additives.
Gravimetric feeder
Advantages
Self-adjusting / self-calibrating
100% control over your product quality
Easy to operate
Monitoring and reporting options
Higher saving on expensive additives
Fluctuations in density do not effect outcome
In-sensitive to material build-up
Automatic detection of material supply interruption
Accurate dosing cylinder
Stepper motor speed starting from 0.1 up to 200 rpm
Disadvantages
Relatively more expensive than a volumetric feeder, but short ROI.
Application of the Twin Screw Extruder:
- Various plastic inorganic filler, polymer blending (plastic alloy), plastic coloring, ect
- Various engineering plastic reinforcement of glass fiber, flame-retartant pellets
- Various antibacterial, insulated, toughening materials for specific uses
- Light/biology degradable film materials, amylum degradable plastics and multi-functional anti-fog film materials, etc.
- Specific material for automobiles and household appliance and cable materials, etc
- Themoplastic elastomers, such as TPR, TPE, and SBS, etc
- Regenerate pellets for PVC airproof pieces, thermo-soluble glue, etc
|
Model
|
PSHJ-20
|
PSHJ-35
|
PSHJ-50
|
PSHJ-65
|
PSHJ-75
|
PSHJ-127
|
|
Screw Diameter:
MM |
21.7
|
35.6
|
50.5
|
62.4
|
71
|
126
|
|
Central Distance
|
18
|
30
|
42
|
52
|
60
|
102
|
|
Length Diameter Ratio
|
28-52
|
28-52
|
28-52
|
28-52
|
28-52
|
28-52
|
|
Main Motor Power
|
4-5.5
|
22-45
|
75-110
|
110-185
|
160-280
|
90-160
|
|
Max.Screw Speed:
RPM |
600
|
600
|
600
|
600
|
600
|
600
|
|
Output Torque per Shaft：N.m
|
32-43
|
175-358
|
597-875
|
875-1472
|
1273-2228
|
850-1528
|
|
Reference Output: KG/HOUR
|
5-20
|
20-80
|
80-200
|
150-350
|
300-600
|
800-1500
|
|
Max.Screw Speed:
RPM |
800
|
800
|
800
|
800
|
500
|
|
Model
|
C-PSHJ-35
|
C-PSHJ-50
|
C-PSHJ-65
|
C-PSHJ-75
|
C-PSHJ-127
|
|
Screw Diameter:
MM |
35.6
|
50.5
|
62.4
|
71
|
126
|
|
Central Distance
|
30
|
42
|
52
|
60
|
102
|
|
Length Diameter Ratio
|
28-52
|
28-52
|
28-52
|
28-52
|
13-18
|
|
Main Motor Power
|
22-45
|
75-132
|
110-250
|
160-355
|
90-160
|
|
Output Torque per Shaft：N.m
|
131-269
|
448-788
|
657-1492
|
955-2119
|
850-1528
|
|
Reference Output: KG/HOUR
|
150-300
|
200-500
|
400-800
|
500-100
|
800-1500
|
