Introduction of plastic pellet mill common sense

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