Structural features of three screw granulator

1. Structural characteristics of three screw extruders (enterprise view)

1. the three screws are arranged on the equilateral triangle, rotating in the same direction, which is equivalent to three pairs of twin screws. A pair of screws has a meshing point, while the three screw has three meshing points, so the shearing function is stronger.

2. the central closed area formed by the arbitrary section of the three screw, the size of the center area varies three times with the screw rotation per week. When the material becomes larger, the material is inhaled. When the material is changed, the material is extruded. The principle is equivalent to a three screw melt pump. When the material is added into the machine, the shear is initially initiated, and when the material is plasticized, it mainly flows in the central area, and the shear disappears, and the central area becomes the dense zone. The ratio of the size of the area in the center area is called the compression ratio, and the compression ratio is 46 in the case of 3- 60. So the three screw extruder has 3 times of large refining function, so it is called the compacting three screw extruder (as with the face, the more the times the kneading, the more the pavement).

2. The advantages of the three screw extruder (enterprise view) 1..

This is determined by its structural principle. After being added into the machine, it was plasticized only in the length of 6D due to strong shear, and then was concentrated in the central area formed by three screws. Taking 3- & 60 machine as an example, when the ratio of length to diameter is 32, and the screw speed is 500 / min, the number of material in the central area is repeated (32-6) * 500 x 3=39000 times / minute. Just imagine what materials can not be fully plasticized and even dispersed.

2. the output is high.

Taking the production of carbon black masterbatch as an example, without high agitate, the 3- diameter 60 machine can produce 50% concentration of carbon black masterbatch in one time, the output is 180 kg / hour, and the 2- diameter 60 (the same type twin screw machine) can produce only 35% concentration of carbon black masterbatch without high stirring or repeated processing, 80 kg / h.

3. electricity saving.

Take 3- 60 machine as an example, 55kW main motor, 500 turn / minute, produce 50% concentration carbon black masterbatch, 180kg/hr, main motor current 90 ampere, the specific power is only 0.2-0.25kw/kg, the electricity cost saving for one year is considerable.

4. the quality of the product is high.

Example 1: twin screw extruder produces 50% concentration of carbon black masterbatch. It must be reinforced and the masterbatch produced is broken with a bite. And three screw extruder, without the mixer, material can be directly into the three screw extruder to produce 50% concentration of carbon black masterbatch, teeth bites will be flat, cracked and unbroken, indicating that the production of good toughness. Why? Because its plasticization is complete, the component is dispersed evenly, the film used to blow 0.005mm is very uniform. With high stirring, the three screw extruder can produce higher concentration carbon black masterbatch, and the particle toughness is better.

Example 2: the 85% calcium carbonate produced by the twin screw machine is filled with PE or PP masterbatch, and it is broken with the finger pinching, and the same proportion of the masterbatch produced with the three screw machine is pinched with the finger, and the dehydrating dryer is also unbroken with the centrifugal dehydrator.

Example 3: production of PP flame retardant cable material, after dense refining, with a long diameter ratio of 36 2- 65 65 screw extruder material, strength of 13Mpa, elongation of 185%. With the 3- three 60 screw extruder, the material strength is 14Mpa and the elongation is 237% without mixing. In addition, three screw extruder can be used for processing aluminum powder or three oxidation and two antimony, with a filling volume of 70%.

5. with molecular grafting function, it can be directly used to produce PP foam beads.

As we all know, PP foam must be made of high melt strength polypropylene (HMS-PP), which requires molecular grafting on ordinary PP, which is much more expensive than ordinary PP. The molecules have branched forks and have enough melt strength and ductility to apply to PP foaming. And many years ago we have done only the ordinary PP, whether it is homopolymer or copolymerization of PP, with three screw extruder can be directly used to produce good EPP beads, foaming rate reached 70 times. This is because the ordinary PP has been grafted onto the three screw extruder and turned into a high melt strength polypropylene. Using ordinary PP to make EPP beads with high obturator rate is our original creation, and its economic value is considerable.

6. compact structure, save site.

All the configurations are on the rack, and nothing external occupies the ground.

7. the machine is safe and reliable and easy to operate.

The quality of the general gear box of the twin screw extruder is one year, and the quality of the three screw extruder gear box is three years.

3. The advantages and disadvantages of three screw in twin screw extruder? (expert opinion) the main advantages of the three screw extruder are complex flow field, long stay time and good mixing performance. It has been proved in the practice of many enterprises. It will be possible in the future of nanocomposite system, high viscosity material mixing, high filling composite system, and high demand for dispersed mixing. It works very well.

Disadvantages: increasing a screw brings great problems in the design of mechanical structure, resulting in an increase in the cost of design and processing; the installation and operation and long-term stability are also tested.