What is a gravimetric blender？  The gravimetric blender is used in the injection and extrusion industries where a variety of raw materials need to be accurately mixed in proportion. It is also an important equipment for automated factories to gravimetric and blender the production materials. The gravimetric blender adopts a PLC controller. It integrates the characteristics of automatic weighing, automatic measurement, automatic mixing, automatic discharging, etc. The mixing accuracy can reach up to ±0.05%. , And use advanced batching algorithm to ensure the high quality and comprehensive technical characteristics, so that the product has excellent performance, stable operation and safe and reliable operation.
It adopts modular and detachable structure design, which saves space and is easy to clean; and can process a variety of raw materials at the same time; built-in suction control program can save suction control cost; adopt PLC controller to ensure stable and reliable performance and easy maintenance; Adopt advanced control algorithm, self-optimization, automatic adjustment compensation and vibration prevention functions to ensure the best batching accuracy; color graphic display, touch screen operation, multi-language online switching; weighing, volume mixed metering mode to increase batching Ability; with recipe storage function, up to 100 groups of recipes can be stored; hierarchical security password control and alarm history recording function; the controller is equipped with a standard USB2.0 interface, which can save the mixing ratio data to the U disk for easy production Quality control: With sound and light alarms, it is convenient for the equipment personnel to quickly and accurately reach the site of the faulty machine. All parts in contact with the raw materials are made of stainless steel to prevent the raw materials from being contaminated. It can be installed directly on the machine or can be installed next to the machine with an optional tripod.
Solve the problems of manual ingredients weighing errors and uneven ingredients mixing, and save manpower, enterprise space, if the bottom bracket is equipped with mobile pulleys, it will be more convenient for large and medium-sized enterprises to use one machine for multiple purposes![Plastic dryer encyclopedia]
Working principle of gravimetric blender：  For gravimetric blender that control the amount of material by weighing, the accuracy of the load cell is very important, but it is only a part of the mixing system. The real uniqueness of the weighing blender lies in its design. The weighing blender weighs materials in a sequential manner. For example, to mix 3 materials, including the first main resin, the second resin and an additive, add one material at a time, with the smallest component first and the largest component behind. In this case, the additive as the smallest component is first sent to the weighing bin, then the second resin, and finally the main resin. After completion, the pneumatic cylinder puts the batch of materials into the mixing chamber.
One. Material characteristics
Mainly refers to the fluidity, moisture absorption, uniformity of the shape of the material, and the viscosity of the material. These factors will directly affect the flow of materials during the preparation process, thereby affecting the accuracy of the ingredients.
Two. Control of feeding amount
1. The influence of the material level in the silo: the material level in the silo is too low or lack of material may cause the feeding to fail to reach the set value.
2. Feeding speed: the feeding speed index and the feeding accuracy index are contradictory, speeding up the feeding speed can reduce the batching time, And to improve the accuracy of the ingredients, the feeding time must be extended.
3. The height from the discharge port of the feeder to the weighing hopper: cut off the power supply of the feeder, and after stopping the feeding, the aerial blanking (drop) between the feeder and the weighing hopper is one of the main sources of error that affects the accuracy of the batching 1. The greater the height from the feeder outlet to the weighing hopper, the greater the drop value, and the more difficult it is to control the accuracy.
Three, weighing hopper
If less materials are prepared each time in the system, the weight of the weighing hopper will affect the selection of the load cell range. The stiffness of the weighing hopper will also affect the force of the sensor.
Composition of gravimetric blender：
The gravimetric blender is mainly composed of hopper, weighing instrument, mixing barrel, PLC, electric box and other accessories
Models and characteristics of various gravimetric blender gravimetric blender, it is a machine with Ethernet communication function, realizes the centralized monitoring function of networking with the molding machine, and adopts PLC program control. When all materials are uniformly mixed by weighing and metering, the metering accuracy can be ±0.05%. There is also an automatic repeat calibration function, which will automatically calibrate the program after each weighing to ensure the best batching accuracy. It has a batching formula storage function that can store more than 100 batching formulas at most. It is equipped with automatic alarm and history recording function machine. The low level meter of the batching hopper is convenient to alarm in advance when the raw material is lacking. It can be equipped with a USB data collection function to read the actual data of each batch of raw materials, recycled materials, color masterbatches, and additives. Adding ratio, special material bridging breaker can be prepared, used for film, sheet or irregularly crushed recycled materials; fuselage type can be prepared for ground installation, optional tripod and movable pulley can be freely and conveniently moved, down Material valve, storage barrel and suction box. Different mixing tanks can be selected according to the raw materials. The feeding, mixing and discharging speed can be set freely. The power consumption can be reduced according to different models and speeds,
The gravimetric blender can be divided into gravimetric blender and loss-in-gravimetric blender.
Loss in weight
This type of gravimetric blender measures the "loss in weight" from two or more hoppers using a load cell under each hopper. Material is usually dispensed from the hoppers using a screw conveyor. All materials are dispensed together and the rate of dosing from each hopper is controlled to ensure the correct blend is achieved.
Gain in weight (sometimes called a batch blender)
A gain in weight gravimetric blender has two or more hoppers arranged above a weigh-pan. These hoppers contain the components which are to be mixed, at the base of each hopper there is a valve to control the dispensing of material from the component hopper into the weigh-pan. The components are dispensed one at a time into the weigh pan until the target or batch weight is reached. Once the batch has been weighed out the contents of the weigh-pan are dispensed into a mixing chamber where they are blended. The resulting mixture exits the base of the mixing chamber into the processing machine.
A typical application of a gravimetric blender would be mixing virgin plastic granules, recycled plastic, and masterbatch (an additive used to colour plastics) together. Body parameters of gravimetric blender
| Model HGB- |
50 |
100 |
200 |
400 |
600 |
800 |
1200 |
2000 |
2500 |
3000 |
| Components |
4 |
4 |
4 |
4 |
4 |
4 |
4 |
4 |
4 |
4 |
| Mixing Capacity（L/hr） |
50 |
100 |
200 |
400 |
600 |
800 |
1200 |
2000 |
2500 |
3000 |
| Batch Weight（L） |
0.6 |
1.2 |
2.2 |
4.5 |
6 |
8 |
12 |
20 |
25 |
30 |
| Main Material Dosing Range (%) |
5~100 |
5~100 |
5~100 |
5~100 |
5~100 |
5~100 |
5~100 |
5~100 |
5~100 |
5~100 |
| Additive Dosing Range（%） |
0.5~10 |
0.5~10 |
0.5~10 |
0.5~10 |
0.5~10 |
0.5~10 |
0.5~10 |
0.5~10 |
0.5~10 |
0.5~10 |
| Main Hopper Volume（L） |
18 |
25 |
32 |
45 |
70 |
100 |
130 |
160 |
180 |
230 |
| Additive Hopper Volume（L） |
18 |
25 |
32 |
45 |
70 |
100 |
130 |
160 |
180 |
230 |
| Mixing Barrel Volume（L） |
6 |
6 |
20 |
20 |
40 |
40 |
80 |
80 |
100 |
180 |
| Power Supply(V/Hz) |
1Φ |
1Φ |
1Φ |
1Φ |
1Φ |
1Φ |
3Φ |
3Φ |
3Φ |
3Φ |
| |
230/50 |
230/50 |
230/50 |
230/50 |
230/50 |
230/50 |
400/50 |
400/50 |
400/50 |
400/50 |
| Total Power（KW） |
0.12 |
0.12 |
0.25 |
0.25 |
0.55 |
0.55 |
1.5 |
1.5 |
1.5 |
3 |
| Compressed Air （kgf/cm2） |
6~8 |
| Max. Noise Level（dB） |
<75 |
Due to the different weighing units around the world, it can be converted according to the density of raw materials.
Note: 50-3000L/hr or 50-3000kg/hr or 110-6613lb/hr
The actual connection design plan of the gravimetric blender |
