Most of the polymers before into final
products, must be with the mixing, then granulating, become sales of raw
materials. There is many different pellet mill pellet mill design, but all can
be divided into two categories: cold pelletizing system and die surface eager
particle system. The main difference between the two lies in the cutting
process time arrangement. Cold cutting system, in the process of the end of the
cured polymer pelletizing; and in the die surface eager particle system, when
the molten polymer emerged from the die - cutting, while in the lower reaches
of the pellets is cooling. Two kinds of pelletizing system have its own
advantages and disadvantages.
Cold cutting system
Cold cutting system comprises a die,
cooling zone (air or water), dry area (if the water) and the cutting chamber.
Cold cutting system has two categories, namely, sheet and strip material pellet
mill granulation machine.
Sheet Material pellet mill molten polymer
from the mixing equipment through a die or roller mill rolling into a certain
thickness of the polymer film material. Sheet during transport through a
distance of solidification and cooling, and then use the cutting knife cut into
round or square pellets in a chamber. Tablet granulation is a manufacturing
method can be used to aggregate the oldest, from nylon to PVC various polymer.
Almost and Tablet pellet mill strip
granulating machine using the same long history. Including the decease, cooling
section (water bath or dry blower), if use water-cooled) and granule cutter.
Extruder or gear pump extrusion molten polymer formed the material through the
die a horizontally mounted (perish modernization through precision machinery
processing, uniform heating, material output stable quality). The material from
the month after discharge, namely the blower or air / vacuum facilities for
cooling, or bath with water cooling. If the water cooling, strip through a dull
period, with forced ventilation blowing water, then the material is sent to the
cutting chamber.
A method of other mode without the operator
close monitoring, the approach is the use of motor driven grooved feed conveyor.
From die to pellet mill is supported and dividing strip. The rotary force
conveying strip size uniform, not to fall off and scrapped less. Strip
production line, the cost is not high, simple operation, convenient and clean.
This has its advantages for color mixing, because the two batch of diverse
color replacement must be thoroughly cleaning equipment. However, to make the
strip method is cooling section occupies space, to determine its length
according to the temperature of the polymer requirements.
Die surface eager system
Die surface eager system has three basic
types, namely the airflow pellet mill, Sprinkler (water ring) and an underwater
pelletizer. Although such systems can have unusual design, but the typical
system including die, cutting room, electric rotary blade, cooling medium and
dry pellets (if using water).
The die is an important part of die surface
hot granulation system. It vertical or horizontal installation, usually oil,
steam or drum or belt type electric heaters heating. Electric heating is
usually used for the die is small; but the mouth of the larger model commonly
used in steam or oil heating. The die structure materials of different
materials, but regardless of the material or the heating medium, diameter of
die hole must be uniform; there must be enough heat to maintain the temperature
of the polymer extrusion process; cutting knife to the rotary die surface must
be tough and smooth -- these are necessary for manufacturing homogeneous
granules.
When a molten polymer is extruded die, at
very high speed rotation of the cutting knife to cut into pellets. The typical
situation is cutting knife or contact or very close to the die surface. Pellets
were cut, namely by centrifugal force behind the knife, and transported to the
cooling medium. Granule cutter size, shape, material and installation can be
different. In some systems the cutting knife with a spring load automatically adjusts
the spacing granule cutter, die spacing between; and some systems must be
cutting knife to perish adjustment by hand. Due to aggressive cutting tool
material life depends on the cutter abrasion and operators of precision,
polymer mold, in the liquefied state cutting polymer pellets is desirable.
With the popularization and promotion of
plastic pellet mill, plastic pellet mill is recognized and accepted by the
majority of users, but most people, granulating principle and technology of
plastic pellet mill are not known. Below let the plastic industry to everyone
on the plastic granulation technology to do the analysis and presents a
thorough. Waste plastic recycling all must pass through the extrusion
granulation, then, can be sales of raw materials. While there are many
dissimilar plastic pellet mill and plastic particles machine design, but all
plastic pellet mill and plastic particles machine can be divided into two
categories: water drawing granulating plastic pellet mill and die surface eager
particle plastic pellet mill. The principal difference between the two lies in
the cutting process time arrangement. Water drawing cutting pellet mill,
plastic polymer melt state from Tricholoma drawing out first by water cooling,
and then by cutting machine cutting; plastic pellet mill in die surface are
grain, when the molten plastic polymers from die when cutting, then the plastic
particles formed air or water. Two kinds of pelletizing system have its
specific advantages and disadvantages.
Water drawing cut plastic pellet mill
particles include the host, an auxiliary machine, die, cooling section (water
bath or dry blower), if use water-cooled) and granule cutter. Plastic pellet
mill host or gear pump extrusion die molten polymer through a horizontally
mounted and the formation of plastic granules (die modernization through
precision machinery processing, uniform heating, measurable output stable quality).
The material from the month after discharge, namely the blower or air / vacuum
facilities for cooling, or bath with water cooling. If the water cooling, strip
through a temperate period, with forced ventilation blowing water, then the
material is sent to the cutting chamber. By utilizing a fixed shear knife and
rotary knife, the strip accurately cut to the desired length.
Die surface eager plastic granulating
machine system, the diet is an important part of die surface hot granulation
system. It vertical or horizontal installation, usually oil, steam or drum or
belt type electric heaters heating. Electric heating is usually used for the
die is small; but the mouth of the larger model regularly used in steam or oil
heating. The die structure materials of different materials, but regardless of
the material or the heating medium, diameter of die hole must be uniform; with
enough calories to maintain the whole process of polymer extrusion granulation
temperature; cutting knife to the rotary die surface must be tough and smooth
-- these are necessary for manufacturing homogeneous granules.
When a molten polymer is extruded die, at
extremely high speed rotation of the cutting knife to cut into pellets. The
typical situation is cutting knife or contact or very close to the die surface.
Pellets were cut, namely by centrifugal force behind the knife, and transported
to the cooling medium. Granule cutter size, shape, material and installation
can be different. In some systems the cutting knife with a spring load
mechanically adjusts the spacing granule cutter, die spacing between; and some
systems must be cutting knife to die adjustment by hand. Due to aggressive
cutting tool material life depends on the cutter abrasion and operators of
precision, polymer mold, in the liquefied state cutting polymer pellets is
desirable.
The molten polymer from the heated
extrusion die, is a mold surface rotating cutter rotating cut into pellets.
This dry granular system characteristic is its special design of the water
spray granulating chamber. Spiral wound because of water flow, until Gan particle
room. Aggregate cut, that is thrown into the water, a preliminary quenching.
Aggregate slurry into the aggregate slurry tank is further cooled, and then
into the centrifugal dryer to remove moisture.
Plastic pellet mill is unique under water
is that it has a smooth surface water flows through the die, and die surface
direct contact. The cutting chamber size of just enough to make the cutting
knife to rotate freely over the die surface and does not restrict the flow of.
The molten polymer is extruded from the die, rotary cutting pellets. Pellets
were after tempering water granulating chamber into the centrifugal dryer. In
the dryer, the water is discharged back into the tank, cooling and recycling;
pellets by centrifugal dryer to remove moisture. Underwater plastic pellet will
require the use of uniform heat distribution and die with superior insulation
facilities. Small granule cutter by electrothermal; die cutting knife needs to
use large burning oil or steam heating. Process water under conventional
heating to the highest temperature, but the heat should not be enough to free
flow of granular material harmful effects. Underwater plastic pellet mill
granulation capacity for most polymers, some models can reach 22679.62kill.
When used to low viscosity or adhesion of the polymer particle cutting water
through the mouth mold surface is an advantage, but for some polymers such as
nylon and reliable brands of polyester this characteristic may cause die
freezing. Further advantages are: because in the molten state cut grain, and
water plays a sound effect, low noise emissions; in comparison to replace
granule cutter with fewer cold cutting system.
Source: http://www.zhengchangfeedmill.com
