CN109595899A

CN109595899A - Wet cutting and dry polyamide pellet

Info

Publication number: CN109595899A
Application number: CN201811265732.8A
Authority: CN
Inventors: 查尔斯·R·克尔曼; 托马斯·A·米茨卡
Original assignee: Invista Textiles UK Ltd
Current assignee: Invista Textiles UK Ltd
Priority date: 2013-05-01
Filing date: 2014-04-10
Publication date: 2019-04-09
Also published as: CN104132518A; TW201504019A; WO2014179031A1

Abstract

This application involves wet cuttings and dry polyamide pellet.System and method described herein is for drying polyamide pellet.In various embodiments, the present invention provides a kind of system for producing polyamide pellet.The system may include rotary dryer, and the rotary dryer removes most surfaces water from wet polyamide pellet to generate partly dry pellet.The system can also include fluidized bed dryer, and the fluidized bed dryer is dry and transmits from pellet partly dry described in the rotary dryer to generate dry polyamide pellet.

Description

Wet cutting and dry polyamide pellet

The application be on April 10th, 2014 applying date, application No. is 201410143326.X and entitled " wet to cut Cut and dry polyamide pellet " application divisional application.

Cross reference to related applications

This application claims the benefit of priority for the U.S. Provisional Patent Application No. 61/818,100 that on May 1st, 2013 submits, Its disclosure is incorporated herein by reference in their entirety.

Technical field

This application involves wet cuttings and dry polyamide pellet.

Background technique

Polyamide is usually by the subunit that water is wherein gradually removed to the reaction to drive polymerization reaction to be carried forward Production.This method generates long sticky polymers, is generally extruded as strands to allow to be further processed.Strands are being hardened it After can be cut into pellet, also referred to as thin slice or particle.Different from strands or stick, pellet can easily flow, can be with It easily packs, and can be melted later to form useful product.Therefore, pellet is the convenient business shape of polyamide Formula.

To allow to squeeze out, tacky polyamide is heated to hold it in molten condition.After extrusion, strands are quick Ground is cooling to stabilize strands and accelerate their hardening to prepare for cutting.Water is for cooling down the useful of polyamide strands Medium.Therefore, usually that polyamide strands are submerged in water or water injection is used after freshly extruded.Similarly, usually used Polyamide strands are cut into pellet by wet pelletizer.However, polyamide is slightly moisture absorption.It is exposed to water for a long time, especially In high temperature, the qualitative change of Partial digestion, fusing and polyamide can be caused.Excessively polyamide can be led to by being exposed to heat Turn yellow.Therefore it should be used for by polyamide pellet from wet strands and from wet pelletizer quick separating dry to produce in suitable temperature Raw useful commercial product.However, ideally quickly carrying out although pellet is dry, it should not cause the condition to turn yellow Lower progress, also should not be so slowly so that occur significant degradation, hydrolysis and pellet fusing.

Summary of the invention

Polyamide pellet is quickly removed from water source and passes through the problem that pellet is dried under suitable conditions and is retouched herein The system and method stated solve.Being granulated the water introduced by the cooling and wet cutting of strands is substantially surface water.The center of pellet Generally there is acceptable water content, unless pellet is exposed to the time significantly long from the moisture that strands are cooling or are granulated.Cause This, pellet solves the problems, such as a part from the transmission for the position that may introduce water.Pellet rotary dryer can be used to remove Most surfaces water.However, it may be inadequate that rotary dryer, which is used alone,.For fully dried granules, can need The long pellet residence time in rotary dryer, or rotary dryer can be needed in high-temperature operation.Long residence time delays Production.The use of high temperature can cause pellet to turn yellow.Long residence time and high temperature are also required to using significant more energy.

These problems are solved by using two driers: removing the rotary dryer of most of water, and pellet is done Dry lower transmission (sub-transport) fluidized bed dryer to specification.

Subject of the present invention is a kind of system for producing polyamide pellet on one side, the system comprises:

A) rotary dryer, the rotary dryer remove most surfaces water from wet polyamide pellet to generate partly Dry pellet；With

B) fluidized bed dryer, the fluidized bed dryer is dry and transmits the partly drying from rotary dryer Pellet is to generate dry polyamide pellet.

Other aspects of subject of the present invention are a kind of systems for producing polyamide pellet, the system comprises:

A) wet cutting pelletizer, the wet cutting pelletizer are configured as cutting polyamide strands in water to generate in grain The outside of material has the pellet of water layer；

B) rotary dryer, the rotary dryer flash away water layer；With

C) fluidized bed dryer, the fluidized bed dryer is by drying and transmits the pellet from rotary dryer.

Other aspects of subject of the present invention are a kind of methods, which comprises

A) wet polyamide pellet is rotarily dried, most surfaces water is removed and generated from the wet polyamide pellet Partly dry pellet；With

B) pellet partly dried is further dried in fluidized bed dryer, the fluidized bed dryer is dry Dry and pellet of the transmission from rotary dryer.

A) by polyamide strands in presence of water it is wet cutting with generate the outside of pellet have water layer pellet；

B) pellet is rotarily dried to flash water layer and generate partly dry pellet；With

C) partly dry pellet is further dried in fluidized bed dryer, the fluidized bed dryer is dry simultaneously Transmit the pellet from rotary dryer.

Detailed description of the invention

Fig. 1 is the drying system that is described herein for continuous polyamide production system of the example according to multiple embodiments The schematic diagram of feature.

Specific embodiment

System and method described herein is formed in strands by rapidly removing pellet and is used in granulation process Water and pellet is effectively dried in the case where not big energy consumption, efficiently reduce polyamide pellet and be exposed to Water and absorption water.

Polyamide pellet can be made up of the polyamide strands that cutting squeezes out.Pelletizer completion can be used in this, with Automatically cut polyamide strands in selected interval.Polyamide is molten condition when coming out from strands die head, and strands It is hardened when they are cooled down.Can strands are submerged in water or and water injection to promote strands cooling.In strands cutting process In there may also be water.(for example, under water or with water injection cutting region) cutting is poly- therefore, it is possible to use in aqueous environment " wet cutting " pelletizer of amide strands.It include that, for example, the rapid cooling of molten polyamide, dust is reduced using the benefit of water, And granulation more clean to a certain degree.However, polyamide pellet can be absorbed water and polyamide pellet should in storage or It is dried before packaging.It is desirable that it is dry quickly and effectively to carry out pellet.

The dry problem of pellet due in pellet there are the water of variable and by during drying means it is expected not The water arrived introduces and occurs.For example, from the other water that strands are cooling or are granulated can it is expected less than interval introduce (example Such as, by dripping or being sprayed on just dry pellet).The water of variable is intermittently added the product for causing difference dry or increase Drying time.Other energy can be needed fully to dry pellet.The configuration of production system can be modified reduction not The incidence that expected water introduces, but this size that the system that may cause is transformed or the unfavorable increase of land occupation, and work as and adopt It is dry that insufficient pellet may be still provided with the reconfiguration of system when single drying unit.

The dry problem of polyamide pellet is solved by using two pellet drying units.First pellet rotarily dries unit Most of water is removed, and second fluidized bed drying unit completes drying process and also transmits pellet far from water source (for example, separate Cooling strands or wet cutting pelletizer).

Wet polyamide pellet can produce in continuous polyamide production system, which generates the cooling polyamide thread of water Material.The cooling polyamide strands of water can be cut in wet cutting pelletizer.Wet cutting pelletizer can be any appropriate Wet cutting pelletizer.For example, wet cutting pelletizer can be the adjusting (tempered) for being available from Gala (Eagle Rock, VA) Water system pelletizer derives from Bay Plastics such as Gala SLC pelletizer, Gala MAP pelletizer or Gala EAC pelletizer The WSD series pelletizer of Machine (Bav City, MI), or it is available from Rieter Automatik Gmbh, The Rieter Automatik USG polymer strands pelletizer of Grossostheim, Germany.Wet cutting pelletizer can have There is an any appropriate output, such as from about 1L/ minutes to about 5000L/ minutes, about 5L/ minutes to about 1000L/ minutes, about 10L/ points Zhong Zhiyue 100L/ minutes or about 1L/ minutes or lower or 2L/ minutes, 3,4,5,10,15,20,25,50,100,150,200, 250,500,750,1000,2000,3000,4000, or about 5000L/ minutes or higher.The wet cutting pelletizer unit time can be with Generate the pellet of any appropriate amount, such as from about 1000 pellet/minutes to about 100,000,000 pellet/minutes, about 10,000 A pellet/minute to about 50,000,000 pellet/minutes, or about 1000 pellet/minutes or lower, or about 2000,5000, 10,000、20,000、50,000、100,000、250,000、500,000、1,000,000、5,000,000、10,000,000、 50,000,000 or about 100,000,000 pellet/minutes.The temperature for leaving the pellet of pelletizer can be any appropriate temperature Degree, such as from about 20 DEG C to about 250 DEG C, or about 30 DEG C to about 150 DEG C, or about 35 DEG C to about 100 DEG C, or about 20 DEG C or lower, or about 30 DEG C, 50,75,100,125,150,175,200,225 or about 250 DEG C or higher.Leave total water content of the pellet of pelletizer It can be any appropriate water content, such as from about 0.05 weight % to about 90 weight %, about 0.1 weight % to about 50 weight %, 1 weight Measure % to about 30 weight %, or about 0.05 weight % or lower, 0.5 weight %, 1,2,3,4,5,6,8,10,12,14,16,18, 20,25,30,35,40,45,50,60,70,80 or about 90 weight % or higher.Pellet can have any appropriate diameter, such as About 3mm to about 9mm, or about 4 to about 7mm, or about 3mm or lower, or about 4mm, 5,6,7,8 or about 9mm or higher.Pellet can be with With any appropriate length, such as from about 0.05cm to about 10cm, about 0.5cm to about 5cm, or about 0.1cm or lower, or about 0.15cm、0.2、0.25、0.3、0.35、0.4、0.5、0.6、0.8、1、1.2、1.4、1.6、1.8、2、2.2、2.4、2.6、2.8、 3,3.5,4,4.5,5,6,7,8,9 or about 10cm or more.Pelletizer can need sharpening or maintenance with any appropriate interval, such as About January to about 200 months, or about 2 months to about 100 months, or about January or shorter, 2 months, 6,12,24,30,36,42,48,54,60, 70,80,90,100,125,150,175 or about 200 months or longer.

Although the center of polyamide strands and pellet is kept substantially unaffected, water in strands cooling and granulation process Using introducing the water into the surface of pellet.In general, drying means removes surface water from pellet.

First pellet rotary drying unit is configured to receive wet pellet and water from wet cutting pelletizer.Pellet can be fallen, Or it scans out or is sent in the first pellet rotary drying unit.

First pellet rotary drying unit is generally by rotating pellet by centrifugal force to remove water and simultaneously keep pellet It is operated in sieve cage.Hole in sieve, which has, allows water to pass through but pellet is maintained to the pore size in drying unit.It can be used Center rotor with impeller blade rotates pellet.Impeller blade can also do pellet movement by drier and to second fluidized bed Dry unit is mobile.Pellet is passed through into the stream rotation of dry gas (for example, dry air, dry nitrogen or their combination) Turn.

Although it is dry by polyamide pellet that dry air can be used, using dry inert gas or with the oxygen of reduction The inert gas (for example, air of nitrogen or enriched in nitrogen) of the drying of content can reduce oxidation.

Can sieve in the inlet of the first rotary drying unit there are agglomerate with filter out the pellet of agglomeration, gel and other Undesirable particle.This sieve can prevent having greater than about 4cm, or greater than about 3.5cm, or greater than about 3cm, or greater than about 2.5cm, or greater than about 2cm, or greater than about 1.5cm length or width particle entrance.

The atmospheric pressure of rotary dryer can change.For example, rotary dryer may remain under decompression or pressurization.Decompression It may include that atmospheric pressure reduces 6KPa-14KPa or more.For example, rotation is dry instead of the standard atmospheric pressure of about 760mm Hg (support) Pressure in dry device unit in the drying process of pellet can be with less than about 700mmHg, or less than about 600mm Hg, or less than about 500mm Hg, or less than about 400mm Hg, or less than about 300mm Hg, or less than about 200mm Hg, or less than about 100mm Hg. For example, rotary dryer can be by pellet being dried under reduced pressure in about 300-400mm Hg.

Temperature in rotary dryer can be at about 35 DEG C to about 200 DEG C, or about 40 DEG C to about 175 DEG C, or about 45 DEG C extremely In the range of about 150 DEG C, or about 50 DEG C to about 125 DEG C.Lower temperature can reduce flavescence but or increase drying time.

It can be by the pellet dry time for being enough to remove most of water.This Time Dependent is in drying temperature and other changes Measure the volume such as water and the pellet to be dried.

The time for removing enough water can change.Rotary dryer and fluidized bed dryer generally remove and dry surface Water.Therefore, residence time of the pellet in these units needs internally dry situation less than pellet.Pellet can be dry in rotation There is any appropriate residence time in dry device, such as from about 1 second to about 2 hours, or about 5 seconds to about 20 minutes, or about 1 second or more It is short, or about 5s, 10,15,20,25,30,35,40,45,50,55,60s, 1.5 minutes, 2,3,4,5,6,7,8,9,10,30 points Clock, 1 hour or about 2 hours are longer.

Rotary dryer can be any appropriate rotary dryer, such as be available from Minneapolis, the Carter of MN The rotary dryer of Day, such as Carter Day Spinaway drier or Carter Day Pressurized Spinaway Drier.Rotary dryer can have any appropriate output, and such as from about 1L/ minutes to about 5000L/ minutes, about 5L/ minutes To about 1000L/ minutes, about 10L/ minutes to about 100L/ minutes, or about 1L/ minutes or shorter or 2L/ minutes, 3,4,5,10, 15,20,25,50,100,150,200,250,500,750,1000,2000,3000,4000 or about 5000L/ minutes or longer. Rotary dryer can in the pellet of unit time dry any suitable amount, such as from about 1000 pellet/minutes to about 10,000, 000 pellet/minute, about 10,000 pellet/minute to about 5,000,000 pellet/minutes, or about 1000 pellets/point Clock hereinafter, or about 2000,5000,10,000,20,000,50,000,100,000,250,000,500,000,1,000,000, 5,000,000 or about 10,000,000 pellet/minutes.Rotary dryer can be rotated pellet with any appropriate RPM, such as About 20RPM to about 500,000RPM, or about 1,000RPM to about 200,000RPM, or about 20RPM or slower, or about 50RPM, 100、150、200、250、500、750、1,000、2,000、3,000、4,000、5,000、7,500、10,000、15,000、20, 000,25,000,50,000,100,000,150,000,200,000 or about 500,000 or faster.Pellet can rotarily dry Be exposed in device the air blowed or with any appropriate speed and be in any appropriate temperature gas, such as from about 20 DEG C To about 300 DEG C, or about 30 DEG C to about 200 DEG C, or about 20 DEG C or lower, or about 30 DEG C, 40,50,75,100,125,150,175, 200,225,250,275 or about 300 DEG C or higher.Leave the pellet of rotary dryer total water content can be it is any appropriate Total water content, such as from about 0.1 weight % to about 10 weight %, or about 1 weight % to about 5 weight %, or about 0.1 weight % or more It is low, or about 0.5 weight %, 1,2,3,4,5,6,7,8,9 or about 10 weight % or higher.Leave the total of the pellet of rotary dryer The standard deviation of the weight percent of water content can be any appropriate standard deviation, such as from about 0.001 weight % to about 1 weight %, Or about 0.001 weight % to about 0.5 weight %, or about 0.001 weight % or lower, or about 0.005 weight %, 0.01,0.05, 0.1,0.5 or about 1 weight % or higher.

Rotary dryer removes most of water from pellet.Most (if not all) removed water is surface Water.For example, pellet rotary drying unit can from pellet remove up to 80% or up to 82% or up to 83%, or up to 85% or up to 86% or up to 88% or up to 90% or up to 91% or up to 92% or up to 93%, or up to 94% or up to 95% water.When pellet leaves pellet rotary drying unit, pellet is having less than about 15 weight %, or lacks In about 12 weight %, or less than about 10 weight %, or less than about 8 weight %, or less than about 7 weight %, or less than about 6 weights %, or less than about 5 weight %, or less than about 4 weight %, or less than about 3 weight %, or less than about 2 weight % are measured, or less than about The water of 1 weight %, or less than about 0.8 weight %, or less than the water of about 0.5 weight %.It, will after the removal of the water of this amount Pellet is sent in fluidized bed drying unit.

Fluidized bed drying unit is configured to receive the pellet from pellet rotary drying unit.Fluidized bed dryer unit connects It receives pellet and can fluidize pellet by it on the weir at the other end of drier via conveyer, or by using air Removed from receiving area.For example, conveyer can be the conveyer belt of perforation, middle punch is sufficiently large to allow the logical of gaseous flow It crosses but is less than pellet.Conveyer can also vibrate pellet.This vibration can reduce the agglomeration of pellet.In some instances, may be used To use the air of the heated drying below perforated plate by fluidising granules until the height of fluidisation pellet allows pellet to fall in list On the weir of the far-end of member (opposite entrance), this can contribute to the maintenance for being avoided conveyer belt, and such as repairing is caused by unusual pellet Blocking maintenance.

Pellet is lifted and separates the gaseous flow of pellet from following fluidisation.Gaseous flow can be air, nitrogen or they Combination.For example, gaseous flow can be dry filtered air.As pointed out above for rotary dryer, although dry Air is commonly used in dry polyamide pellet, uses the indifferent gas of the drying of dry inert gas or the oxygen content with reduction Body (for example, air of nitrogen or enriched in nitrogen) can reduce oxidation.Fluidized bed drying unit can also be using dry air or nitrogen Or the atmosphere of the air of enriched in nitrogen.

The example of suitable fluidized bed dryer includes those of the Witte Company production by New Jersey Washington (referring to website at witte.com/products/fbdryer.php).Also vibrating fluid bed dryer, example can be used Such as, commonly used in the type of the dry coated tablet for pharmacy application.This fluidized bed dryer is available commercially from multiple productions Quotient, including Nicomacsrl, Via Curiel, 12,20060 Liscate, Milan, Italy.

Gaseous flow can also be heated to the drying to promote pellet.For example, can by pellet in the fluidisation stream of air About 80 DEG C to about 150 DEG C of temperature heating.Alternatively, the temperature in fluidized bed drying unit can at about 35 DEG C to about 200 DEG C, Or in the range of about 40 DEG C to about 175 DEG C, or about 45 DEG C to about 150 DEG C, or about 50 DEG C to about 125 DEG C.Lower temperature can be with It reduces and turns yellow but drying time can also be increased.

The air pressure of fluidized bed drying unit also can change.For example, fluidized bed drying unit can be maintained at decompression or Under pressurization.Decompression may include that atmospheric pressure reduces 50-100 support or more.For example, instead of the normal atmosphere of about 760mm Hg (support) Pressure, pressure in fluidized bed drying unit in the drying process of pellet can with less than about 700mm Hg, or less than about 600mm Hg, Or less than about 500mm Hg, or less than about 400mm Hg, or less than about 300mm Hg, or less than about 200mm Hg, or less than about 100mm Hg.For example, fluidized bed drying unit can be by pellet being dried under reduced pressure in about 300-400mm Hg.

The time of dried granules can change in fluidized bed drying unit.Fluidized bed drying unit also essentially dry grain The surface of material can need the time fewer than the inside of dried granules.Pellet can have any in fluidized bed dryer The suitable residence time, such as from about 1 second to about 4 hours, or about 5 seconds to about 20 minutes, or about 1 second or shorter, or about 5s, 10,15, 20,25,30,35,40,45,50,55,60s, 1.5 minutes, 2,3,4,5,6,7,8,9,10,30 minutes, 1 hour, 2,3 or about 4 Hour is longer.

Fluidized bed drying unit may include classifier unit.Classifier unit, which allows to remove, has of different shapes Those of anticipate " particulate " (for example, the particulate for passing through 20 meshes), including statically keep.For example, classifier can remove band, Item, fine and other particulate.

Fluidized bed dryer can have any appropriate output, such as from about 1L/ minutes to about 5000L/ minutes, about 5L/ Minute to about 1000L/ minutes, about 10L/ minutes to about 100L/ minutes, or about 1L/ minutes or lower or 2L/ minutes, 3,4,5, 10,15,20,25,50,100,150,200,250,500,750,1000,2000,3000,4000, or about 5000L/ minutes or more It is high.Fluidized bed dryer can in the pellet of unit time dry any suitable amount, such as from about 1000 pellet/minutes to about 10, 000,000 pellet/minute, about 10,000 pellet/minute to about 5,000,000 pellet/minutes, or about 1000 grains Material/minute is lower, or about 2000,5000,10, and 000,20,000,50,000,100,000,250,000,500,000,1, 000,000,5,000,000, or about 10,000,0000 pellet/minute.Pellet can be exposed in fluidized bed dryer The air blowed or the gas with any appropriate speed, so that forming fluidized bed.Air in fluidized bed dryer or Gas can have any appropriate temperature, such as from about 20 DEG C to about 300 DEG C, or about 30 DEG C to about 200 DEG C, or about 20 DEG C hereinafter, Or about 30 DEG C, 40,50,75,100,125,150,175,200,225,250,275 or about 300 DEG C or more.Leave fluidized bed drying The pellet of device can be finished pellets.

Finished pellets can be generally uniformly drying, there is no the difference on interior contrast surface water content Not.Dry polyamide pellet can be to be less than 0.3 weight %, less for example, being less than 0.4 weight % having less than 0.5 weight % In 0.2 weight %, it is less than 0.1 weight %, is less than the water content of 0.05 weight % or less than 0.02 weight %.Dry polyamides Amine pellet product also can have below about 1.5%, or be below about 1.0%, or the volatile content below about 0.5%.It leaves Total water content of the pellet of fluidized bed dryer can be any appropriate total water content, such as from about 0.01 weight % to about 5 weights Measure %, or about 0.01 weight % to about 2 weight %, or about 0.01 weight % or lower, or about 0.05 weight %, 0.1,0.2, 0.3,0.4,0.5,0.6,0.7,0.8,0.9,1,1.2,1.4,1.6,1.8,2,2.5,3,3.5,4,4.5 weight % or about 5 weights Measure % or higher.Leave the weight percent of total water content of the pellet of fluidized bed dryer standard deviation can be it is any appropriate Standard deviation, such as from about 0.000,1 weight % to about 0.5 weight %, or about 0.001 weight % to about 0.1 weight %, or about 0.000,1 weight % or lower, or the about 0.005 weight % of weight %, 0.01,0.05,0.1,0.2,0.3,0.4, or about 0.5 weight Measure % or higher.

Total water content of finished pellets can be any appropriate total water content, such as from about 0.01 weight % to about 5 weight %, Or about 0.01 weight % to about 2 weight %, or about 0.01 weight % or lower, or about 0.05 weight %, 0.1,0.2,0.3, 0.4,0.5,0.6,0.7,0.8,0.9,1,1.2,1.4,1.6,1.8,2,2.5,3,3.5,4,4.5 weight %, or about 5 weight % Or it is higher.The standard deviation of the weight percent of total water content of finished pellets can be any appropriate standard deviation, such as from about 0.000,1 weight % to about 0.5 weight %, or about 0.001 weight % is to about 0.1 weight %, or about 0.000,1 weight % or more It is low, or the about 0.005 weight % of weight %, 0.01,0.05,0.1,0.2,0.3,0.4, or about 0.5 weight % or higher.Finished product grain The yellowness index of material can be any appropriate yellowness index, and can be by any appropriate method, such as ASTM D1925 Or ASTM E313 measurement, such as from about 0.001 to about 50, about 0.01 to about 20, about 0.1 to about 15, or about 0.001 or lower, 0.01、0.1、0.5、1、1.5、2、2.5、3、3.5、4、4.5、5、5.5、6、6.5、7、7.5、8、8.5、9、9.5、10、11、12、 13,14,15,20,25,30,40, or about 50 or higher.The oxidative degradation index (ODI) of finished pellets can be any appropriate ODI, such as from about 0.01 to about 0.9, or about 0.1 to about 0.5, or about 0.01,0.05,0.1,0.15,0.2,0.25,0.3,0.35, 0.4,0.45,0.5,0.55,0.6,0.65,0.7,0.75,0.8,0.85, or about 0.9 or higher.The thermal degradation of finished pellets refers to Number (TDI) can be any appropriate TDI, such as from about 0.01 to about 0.9, or about 0.1 to about 0.5, or about 0.01,0.05,0.1, 0.15,0.2,0.25,0.3,0.35,0.4,0.45,0.5,0.55,0.6,0.65,0.7,0.75,0.8,0.85, or about 0.9 or It is higher.

Example polyamide drying system

Fig. 1 shows example polyamide pellet drying system.The system may include rotary dryer unit 10, has and uses In the reception chute of polyamide pellet 20.Pellet is rotated to produce centrifugation in rotating flow 30 and removes water 50.Pellet keeps sieve 60 Pellet is maintained in rotary dryer unit 10, and dry pellet is discharged with the water for including water removal delivery pipe 70 and is System isolation.Rotary dryer, which has, is operably configured to the wheel shaft 80 that rotation pellet keeps sieve 60.Rotary dryer unit 10 With the upward gaseous flow 40 moved upwards that pellet is supported and promoted when they are dried.It is removed in water 50 from the part of pellet Later, they are sent in the fluidized bed drying unit receiving area 90 of fluidized bed drying unit 100.Fluidized bed drying unit Pellet is communicated off receiving area 9`0 via the conveyer 120 for being operably coupled to conveyer motor 130 by 100.Gaseous flow 110 flow upwards through conveyer 120.Conveyer 120 also vibrates pellet, this can reduce agglomeration.Dry pellet is delivered To dried granules case 140.

System and method described herein production or dry nylon 6, nylon 7, nylon 11, nylon 12, nylon can be used 6,6, nylon 6,9；Nylon 6,10, nylon 6,12 or their copolymer.

Test method

Thermal degradation index (TDI) is measurement relevant to the thermal history of polymer.Lower TDI refer in process of production compared with Inviolent temperature history.The available TDI measuring method of those skilled in the art measures 1% of polymer in 90% formic acid (by weight) absorbance of the solution in the wavelength of 292nm.

Oxidative degradation index (ODI) is to be exposed to oxidizing condition relevant amount during its high temperature production to polymer Degree.Lower ODI refers to degradation less serious in process of production.It is by measuring polymer 1% in 90% formic acid (by weight) solution is determined in the absorbance of the wavelength of 260nm.

Relative viscosity (RV) refers to the ratio of the solution and solvent viscosity that measure in capillary viscometer at 25 DEG C.Pass through The RV of ASTM D789-06 measurement be the basis of a test program and be polyamide 90% formic acid (90 weight % formic acid and The water of 10 weight %) in 8.4 weight % solution in 25 DEG C of viscosity (in terms of centipoise) and 90% formic acid from viscous in 25 DEG C Spend the ratio of (in terms of centipoise).

Definition

As used herein term " about " can permit certain variable pitch of value or range, for example, in the value Or in the 10% of the range limit, in 5% or in 1%.

As used herein term " substantially " refers to major part, or mainly, such as at least about 50%, 60%, 70%, 80%, 90%, 95%, 96%, 97%, 98%, 99%, 99.5%, 99.9%, 99.99% or at least about 99.999% or more.

As used herein term " solvent " refers to can be with the liquid of dissolved solid, liquid or gas.The non-limit of solvent Property example processed is siloxanes, organic compound, water, alcohol, ionic liquid and supercritical fluid.

As used herein term " air " refer to with the gas that is generally obtained in ground level from atmosphere Naturally form the mixture of the gas of about the same composition.In some instances, air is derived from ambient enviroment.Air has packet Include about 78% nitrogen, 21% oxygen, 1% argon and 0.04% carbon dioxide, and the composition of a small amount of other gases.

It should explain that the boundary not only to include as range clearly describes with the value of range format expression with flexible way Numerical value, and all independent numerical value or subrange including including within the scope of this, as each numerical value and subrange is bright It really states the same.For example, the range of " about 0.1% to about 5% " or " about 0.1% to 5% " should be construed as not only including about 0.1% to about 5%, and including individual value (for example, 1%, 2%, 3% and 4%) and the subrange in pointed range (for example, 0.1% to 0.5%, 1.1% to 2.2%, 3.3% to 4.4%).Unless otherwise noted, statement " about X to Y " have with " about X to about Y " identical meaning.Equally, unless otherwise noted, statement " about X, Y or about Z " has and " about X, about Y or about Z " phase Same meaning.

Herein, unless the context clearly indicates otherwise, using term "one", "an" or " described " to be to include One or more than one.Unless otherwise noted, non-exclusive "or" is referred to using term "or".In addition, it is to be appreciated that It purpose that words or terms that are using herein and not defining differently are merely to illustrate and is non-limiting.Any section The use for falling title is expected to the understanding for helping article and is not interpreted to limit；Information relevant to paragraph heading can be Occur inside or outside special paragraph.

By following embodiment example drying unit and using this unit style for the method for polyamide, it is contemplated to show Example and is non-limiting embodiment.

Conventional methodIt prepares 6,6 polymer of nylon and is passed through as fusant with about 58L/ minutes rate and include The extruder discharge of extruder chamber with multiple die plates is to generate subsequent granulated nylon strands.Extruder chamber has 10 die heads Plate, each has 30 capillaries, and each capillary corresponds to the strands squeezed out.Strands from capillary (for example, die holes) with About 6.83M/ minutes rate of each capillary comes out.The strands come out have 6mm diameter, 270 DEG C of temperature, Yi Jiyue 0.1% overall weight percent water, is mainly internal water.

Embodiment 1: drying-granulating machine.

Conventional method is provided below.Strands march to drying-granulating machine, by strands with about 4.8 million grains per minute The rate of material is cut into 2.5mm long pellet.

Pelletizer about needs to close for cleaning and sharpening every 2 weeks.The pellet of about 0.000,1 weight % fuses.

Embodiment 2: wet granulation uses conveyer belt drier.

Conventional method is provided below.Strands march to wet pelletizer to get from Bay Plastics Machine (Bav City, MI) WSD series pelletizer, strands are cut into 2.5mm long grain with the rate of about 4.8 million pellets per minute Material.Pellet is covered with water.

Conveyer belt drier is entered with the rate of about 4.8 million pellets per minute after pellet.When pellet enters transmission When band drier, they have the total moisture content and about 80 DEG C of temperature of about 10 weight %.Conveyer belt drier, which has, to be kept The vibration band of pellet, wherein blowing 100 DEG C of air upwards passes through pellet.However, not forming fluidized bed.Pellet is protected in drier It holds about 5 minutes.Pellet leaves drier with the rate of about 4.8 million pellets per minute.Finished pellets have about 0.7 weight % Total moisture content (standard deviation with about 0.2 weight %), and about 90 DEG C of temperature.

Wet cutting pelletizer is closed every about 2 months needs for cleaning and sharpening.The grain of about 0.000,02 weight % Material fusion.Finished pellets have about 4 yellowness index measured according to ASTM D1925.Finished pellets have 0.35 thermal degradation Index and 0.3 oxidative degradation index.

Embodiment 3a: wet granulation uses rotary dryer.

Conventional method is provided below.Strands march to wet pelletizer to get from Bay Plastics Machine (Bay City, MI) WSD series pelletizer, strands are cut into 2.5mm long grain with the rate of about 4.8 million pellets per minute Material.Pellet is covered with water.

Pellet enters Carter Day Spinaway rotary dryer with the rate of about 4.8 million pellets per minute.When When pellet enters rotary dryer, they have the total moisture content and about 80 DEG C of temperature of about 10 weight %.Rotary dryer Pellet is rotated with about 500RPM and pellet is exposed to be blown into 100 DEG C of air.Pellet is maintained in rotary dryer About 5 minutes average times.Total moisture content (standard with about 0.2 weight % of the finished pellets with about 0.7 weight % Difference), and with about 90 DEG C of temperature.

Embodiment 3b: wet granulation uses lower transmission fluidized bed pellet dryer.

The Witte by New Jersey Washington is entered with the rate of about 4.8 million pellets per minute after pellet The fluidized bed dryer of Company production.When pellet enters fluidized bed dryer, they have total moisture of about 10 weight % Content and about 80 DEG C of temperature.Fluidized bed dryer has the vibration band for keeping pellet, wherein blowing 100 DEG C of air upwards passes through grain Material, forms the Air Fluidized bed of pellet.Pellet is kept for about 5 minutes in fluidized bed dryer.Pellet is with per minute about 4.8 hundred The rate of ten thousand pellets leaves fluidized bed dryer.Total moisture content of the finished pellets with about 0.5 weight % (has about 0.2 The standard deviation of weight %), and with about 90 DEG C of temperature.

Wet cutting pelletizer is closed every about 2 months needs for cleaning and sharpening.The grain of about 0.000,02 weight % Material fusion.Finished pellets have about 5 yellowness index measured according to ASTM D1925.Finished pellets have 0.4 thermal degradation Index and 0.5 oxidative degradation index.

Embodiment 4: wet granulation using rotary drying and uses conveyer belt drier.

Pellet enters Carter Day Spinaway rotary dryer with the rate of about 4.8 million pellets per minute.When When pellet enters rotary dryer, they have the total moisture content and about 80 DEG C of temperature of about 10 weight %.Rotary dryer Pellet is rotated with about 500RPM and pellet is exposed to be blown into 100 DEG C of air.Pellet is maintained in rotary dryer About 30 seconds average times.

Conveyer belt drier is entered with the rate of about 4.8 million pellets per minute after pellet.When pellet enters transmission When band drier, they have the total moisture content and about 90 DEG C of temperature of about 0.4 weight %.Conveyer belt drier, which has, to be kept The vibration band of pellet, wherein blowing 100 DEG C of air upwards passes through pellet.However, not forming fluidized bed.Pellet is protected in drier It holds about 2 minutes.Pellet leaves drier with the rate of about 4.8 million pellets per minute.Finished pellets have about 0.35 weight Total moisture content (standard deviation with about 0.2 weight %) of % is measured, and with about 90 DEG C of temperature.

Embodiment 5: wet granulation, using rotary dryer and lower transmission fluidized bed pellet dryer, in rotary dryer Use 210 DEG C.

Pellet enters Carter Day Spinaway rotary dryer with the rate of about 4.8 million pellets per minute.When When pellet enters rotary dryer, they have the total moisture content and about 80 DEG C of temperature of about 10 weight %.Rotary dryer Pellet is rotated with about 500RPM and pellet is exposed to be blown into 210 DEG C of air.Pellet is maintained in rotary dryer About 20 seconds average times.

The Witte by New Jersey Washington is entered with the rate of about 4.8 million pellets per minute after pellet The fluidized bed dryer of Company production.When pellet enters fluidized bed dryer, they are total wet with about 0.4 weight % Gas content and about 150 DEG C of temperature.Fluidized bed dryer has the vibration band for keeping pellet, wherein it is logical to blow 100 DEG C of air upwards Pellet is crossed, the Air Fluidized bed of pellet is formed.Pellet is kept for about 30 seconds in fluidized bed dryer.Pellet is with per minute about The rate of 4.8 million pellets leaves fluidized bed dryer.Finished pellets (have with total moisture content of about 0.05 weight % The standard deviation of about 0.02 weight %), and with about 90 DEG C of temperature.

Wet cutting pelletizer is closed every about 2 months needs for cleaning and sharpening.The grain of about 0.000,02 weight % Material fusion.Finished pellets have about 20 yellowness index measured according to ASTM D1925.Finished pellets have 0.4 thermal degradation Index and 0.5 oxidative degradation index.It is attributed to the drying efficiency of fluidized bed dryer, fluidized bed dryer is occupied than reality Apply the volume of the drying system few about 30% of example 2 and 4.

Embodiment 6: wet granulation, using rotary dryer and lower transmission fluidized bed pellet dryer, in rotary dryer Use 150 DEG C.

Pellet enters Carter Day Spinaway rotary dryer with the rate of about 4.8 million pellets per minute.When When pellet enters rotary dryer, they have the total moisture content and about 80 DEG C of temperature of about 10 weight %.Rotary dryer Pellet is rotated with about 500RPM and pellet is exposed to be blown into 150 DEG C of air.Pellet is maintained in rotary dryer About 25 seconds average times.

The Witte by New Jersey Washington is entered with the rate of about 4.8 million pellets per minute after pellet The fluidized bed dryer of Company production.When pellet enters fluidized bed dryer, they are total wet with about 0.4 weight % Gas content and about 125 DEG C of temperature.Fluidized bed dryer has the vibration band for keeping pellet, wherein it is logical to blow 100 DEG C of air upwards Pellet is crossed, the Air Fluidized bed of pellet is formed.Pellet is kept for about 30 seconds in fluidized bed dryer.Pellet is with per minute about The rate of 4.8 million pellets leaves fluidized bed dryer.Finished pellets (have with total moisture content of about 0.15 weight % The standard deviation of about 0.02 weight %), and with about 90 DEG C of temperature.

Wet cutting pelletizer is closed every about 2 months needs for cleaning and sharpening.The grain of about 0.000,02 weight % Material fusion.Finished pellets have about 4 yellowness index measured according to ASTM D1925.Finished pellets have 0.37 thermal degradation Index and 0.35 oxidative degradation index.It is attributed to the drying efficiency of fluidized bed dryer, fluidized bed dryer is occupied than reality Apply the volume of the drying system few about 30% of example 2 and 4.

Embodiment 7: wet granulation, using rotary dryer and lower transmission fluidized bed pellet dryer, in fluidized bed dryer It is middle to use 210 DEG C.

The Witte by New Jersey Washington is entered with the rate of about 4.8 million pellets per minute after pellet The fluidized bed dryer of Company production.When pellet enters fluidized bed dryer, they are total wet with about 0.4 weight % Gas content and about 90 DEG C of temperature.Fluidized bed dryer has the vibration band for keeping pellet, passes through wherein blowing 210 DEG C of air upwards Pellet forms the Air Fluidized bed of pellet.Pellet is kept for about 20 seconds in fluidized bed dryer.Pellet is with per minute about 4.8 The rate of million pellets leaves fluidized bed dryer.Total moisture content of the finished pellets with about 0.05 weight % (has about The standard deviation of 0.02 weight %) and with about 150 DEG C of temperature.

Embodiment 8: wet granulation, using rotary dryer and lower transmission fluidized bed pellet dryer, in fluidized bed dryer It is middle to use 150 DEG C.

The Witte by New Jersey Washington is entered with the rate of about 4.8 million pellets per minute after pellet The fluidized bed dryer of Company production.When pellet enters fluidized bed dryer, they are total wet with about 0.4 weight % Gas content and about 90 DEG C of temperature.Fluidized bed dryer has the vibration band for keeping pellet, passes through wherein blowing 150 DEG C of air upwards Pellet forms the Air Fluidized bed of pellet.Pellet is kept for about 25 seconds in fluidized bed dryer.Pellet is with per minute about 4.8 The rate of million pellets leaves fluidized bed dryer.Total moisture content of the finished pellets with about 0.15 weight % (has about The standard deviation of 0.02 weight %) and with about 125 DEG C of temperature.

Embodiment 9: wet granulation uses rotary dryer and lower transmission fluidized bed pellet dryer

The Witte by New Jersey Washington is entered with the rate of about 4.8 million pellets per minute after pellet The fluidized bed dryer of Company production.When pellet enters fluidized bed dryer, they are total wet with about 0.4 weight % Gas content and about 90 DEG C of temperature.Fluidized bed dryer has the vibration band for keeping pellet, passes through wherein blowing 100 DEG C of air upwards Pellet forms the Air Fluidized bed of pellet.Pellet is kept for about 30 seconds in fluidized bed dryer.Pellet is with per minute about 4.8 The rate of million pellets leaves fluidized bed dryer.Total moisture content of the finished pellets with about 0.15 weight % (has about The standard deviation of 0.02 weight %) and with about 90 DEG C of temperature.

Wet cutting pelletizer is closed every about 2 months needs for cleaning and sharpening.The grain of about 0.000,02 weight % Material fusion.Finished pellets have about 1.5 yellowness index measured according to ASTM D1925.Finished pellets have 0.30 heat drop Solve the oxidative degradation index of index and 0.20.It is attributed to the drying efficiency of fluidized bed dryer, fluidized bed dryer occupies ratio The volume of the drying system of embodiment 2 and 4 few about 30%.

Embodiment 10: wet granulation, the lower transmission fluidized bed grain of the dry gas using rotary dryer and using oxygen reduction Expect drier.

Pellet enters Carter Day Spinaway rotary dryer with the rate of about 4.8 million pellets per minute.When When pellet enters rotary dryer, they have the total moisture content and about 80 DEG C of temperature of about 10 weight %.Rotary dryer Pellet is rotated with about 500RPM and pellet is exposed to the air (50% nitrogen, 50% air) of be blown into 100 DEG C of enriched in nitrogen. Pellet is maintained to about 30 seconds in rotary dryer average times.

The Witte by New Jersey Washington is entered with the rate of about 4.8 million pellets per minute after pellet The fluidized bed dryer of Company production.When pellet enters fluidized bed dryer, they are total wet with about 0.4 weight % Gas content and about 90 DEG C of temperature.Fluidized bed dryer has the vibration band for keeping pellet, wherein blowing 100 DEG C of enriched in nitrogen upwards Air (50% nitrogen, 50% air) forms the Air Fluidized bed of pellet by pellet.Pellet is kept in fluidized bed dryer About 30 seconds.Pellet leaves fluidized bed dryer with the rate of about 4.8 million pellets per minute.Finished pellets have about 0.15 weight Measure total moisture content (standard deviation with about 0.02 weight %) of % and with about 90 DEG C of temperature.

Wet cutting pelletizer is closed every about 2 months needs for cleaning and sharpening.The grain of about 0.000,02 weight % Material fusion.Finished pellets have about 1.4 yellowness index measured according to ASTM D1925.Finished pellets have 0.30 heat drop Solve the oxidative degradation index of index and 0.18.It is attributed to the drying efficiency of fluidized bed dryer, fluidized bed dryer occupies ratio The volume of the drying system of embodiment 2 and 4 few about 30%.

Herein cited or all patents for referring to and be openly subject of the present invention one of ordinary skill in the art level Instruction, and each this cited patent or it is open therefore by reference particularly in connection with to and individually through reference With its all in conjunction with or provide herein the identical degree of entire contents.Applicant retains will be from the special of any this reference The right being bound to sharp or disclosed any and all material and information physical in this specification.

Specific method, device and composition described herein be the representative of preferred embodiment and be example and The not expected limitation as the range to subject of the present invention.Those skilled in the art will recognize that it after considering this specification His object, aspect and embodiment, and as included by subject of the present invention.One skilled in the art will readily appreciate that be can To carry out a variety of replacements to present invention disclosed herein and be altered without departing from scope and spirit of the present invention.

The subject of the present invention schematically described herein can be suitably there is no any one or more elements, or Person's one or more is implemented in the case where limiting, specifically necessary not open herein.The method schematically described herein Can suitably sequence in different step it implement with process, and method and process are not necessarily limited to herein or right is wanted The sequence for the step of being pointed out in asking.

This patent cannot all be construed to be defined in the specific example disclosed particularly herein or implementation under any circumstance Scheme or method.This patent cannot be all construed to by any other of any auditor or patent and trademark office under any circumstance Official or any statement for making of employee limit, unless in the written reply of applicant specifically and without restricted or Reservation clearly uses this statement.

Illustratively term uses and not restrictive used terms and expressions, and is not intended at this Any equivalent or part of it given by being excluded in the use of kind terms and expressions with the feature of description, but it should be appreciated that It is that in the range of the claimed invention, multiple modifications are possible.It is therefore understood that although the present invention is logical It crosses preferred embodiment and optional feature discloses particularly, the modifications and variations of concept disclosed herein can be by this field Technical staff takes, and this modifications and variations are considered as in the sheet limited by appended claim of the invention and statement In the range of invention.

Broadly and the present invention has been generally described herein.Each of fall in general open narrower species and Subclass group also forms a part of the invention.This includes with this hair limited from a kind of limitation for removing any theme or reverse side Bright general remark, and it is unrelated with excluded material whether is particularly pointed out herein.In addition, with the term of marlcush group In the case where describing features or aspect of the invention, it will be apparent to one skilled in the art that the present invention is to also with marlcush group Any individual member of member or the term description of subgroup.

Statement:

1. a kind of system for producing polyamide pellet, the system comprises:

B) fluidized bed dryer, the fluidized bed dryer is dry and transmits the part from the rotary dryer The dry pellet in ground is to generate dry polyamide pellet.

2. system described in statement 1, the system also includes extruder, the extruder is configured as generating by its preparation The polyamide strands of the wet polyamide pellet.

3. system described in statement 1 or 2, the system also includes extruder, the extruder, which is configured as generating, to be had The polyamide of the water of about 0.01% to 0.5%, or about 0.05% to 0.3%, or about 0.1% to 0.25% weight percent Strands.

4. system described in any one of 1-3 is stated, wherein the polyamide come out from extruder in the system Strands there is about 200-300 DEG C of temperature.

5. state system described in any one of 1-4, it is described wet poly- the system also includes being prepared for cooling by it The water cooling system of the polyamide extruded strands of amide pellet.

6. stating system described in any one of 1-5, the system also includes wet cutting pelletizer, the wet cutting is made Grain machine is configured as the strands for cutting polyamide in water to generate the wet polyamide pellet.

7. system described in any one of 1-6 is stated, wherein the wet polyamide pellet has on their outside Water layer or form in the slurries with water.

8. system described in any one of 1-7 is stated, wherein the wet polyamide pellet has about 1 weight % to 50 weights Measure %, or about 1 weight % to 40 weight %, or about 2 weight % to 30 weight %, or about 3 weight % are to the weight of 20 weight % The water of percentage.

9. state system described in any one of 1-8, wherein wet polyamide pellet has about 20 DEG C to about 200 DEG C, or About 30 DEG C to about 150 DEG C, or about 35 DEG C to about 100 DEG C of temperature.

10. system described in any one of 1-9 is stated, wherein there is the wet polyamide pellet acceptable yellowing to refer to Number.

11. state system described in any one of 1-10, the system is configured as wet polyamide pellet from granulation Machine is delivered to the rotary dryer.

12. system described in any one of 1-11 is stated, wherein water is centrifuged by the rotary dryer from the pellet It removes.

13. system described in any one of 1-12 is stated, wherein the rotary dryer includes for removing water The sieve or basket of the pellet are kept simultaneously.

14. system described in any one of 1-13 is stated, wherein the rotary dryer includes having in impeller blade Heart rotor.

15. system described in any one of 1-14 is stated, wherein the rotary dryer includes being lifted the pellet Gaseous flow.

16. system described in any one of 1-15 is stated, wherein the rotary dryer further includes heater.

17. state system described in any one of 1-16, wherein the rotary dryer further includes heater, it is described to add Hot device is configured as the pellet in the rotary dryer being maintained at about 25 DEG C to about 200 DEG C, or about 30 DEG C to about 180 DEG C, Or about 30 DEG C to about 150 DEG C, or about 30 DEG C to about 100 DEG C of temperature.

18. stating system described in any one of 1-17, the system is configured as generating partly dry pellet, The pellet partly dried has when they come out from the rotary dryer is lower than the polyamide beads fuse temperature The pellet temperature of degree.

19. stating system described in any one of 1-18, come from wherein the fluidized bed dryer is configured as receiving The partly dry pellet of the rotary dryer.

20. system described in any one of 1-19 is stated, wherein the pellet partly dried enters institute when them With about 0.3% or more, or about 0.5% or more, or about 1.0% or more, or about 2.0% or more when stating fluidized bed dryer, or The water of about 3.0% or more weight percent.

21. system described in any one of 1-20 is stated, wherein the fluidized bed dryer includes supporting or fluidizing institute State the gaseous flow of pellet.

22. system described in any one of 1-21 is stated, wherein the fluidized bed dryer includes for moving pellet The dynamic conveyer by the fluidized bed dryer.

23. state system described in any one of 1-22, wherein the fluidized bed dryer includes the conveyer of perforation, The conveyer of the perforation uses the mobile gaseous flow by the perforation.

24. system described in any one of 1-23 is stated, wherein the fluidized bed dryer includes shaking the pellet Conveyer.

25. system described in any one of 1-24 is stated, wherein the fluidized bed dryer includes heater.

26. state system described in any one of 1-25, wherein the fluidized bed dryer includes heater, it is described to add Hot device heats gaseous flow.

27. state system described in any one of 1-26, wherein the fluidized bed dryer includes heater, it is described to add Hot device is configured as at about 25 DEG C to about 200 DEG C, or about 30 DEG C to about 180 DEG C, or about 30 DEG C to about 150 DEG C, or about 30 DEG C extremely About 100 DEG C of temperature heated gaseous stream.

28. system described in any one of 1-27 is stated, wherein the pellet of the drying works as them from the fluidized bed Have when drier comes out about 0.5% hereinafter, or about 0.4% hereinafter, or about 0.3% hereinafter, or about 0.2% hereinafter, or about The water of 0.1% weight percent below.

29. stating system described in any one of 1-28, the system is configured for the continuous life of polyamide pellet It produces.

30. stating system described in any one of 1-29, the system is configured as synthetic nylon 6, nylon 11, nylon 12, nylon 6,6；Nylon 6,9；Nylon 6,10；Nylon 6,12；Or their copolymer.

31. a kind of method, which comprises

A) wet polyamide pellet is rotarily dried, to remove most surfaces water from the wet polyamide pellet with generating unit The pellet for dividing ground dry；With

B) pellet partly dried is further dried in fluidized bed dryer to generate dry polyamide Pellet.

32. method described in statement 31, the method also includes generating polyamide strands by molten polyamide.

33. system described in statement 31 or 32, the system also includes squeeze out to be enough to substantially avoid strands fusion The strands for the polyamide that strands spacing distance separates.

34. stating method described in any one of 31-33, the method also includes being enough to harden by polyamide strands It is hung under conditions of the polyamide strands, to generate the strands of hardening.

35. state method described in any one of 31-34, the method also includes generate with about 5 to 6.5mm it is flat The polyamide strands of equal diameter.

36. state method described in any one of 31-35, the method also includes generate have about 0.01% to The water of 0.5%, or about 0.05% to 0.3%, or about 0.1% to 0.25%, or about 0.05% to 0.25% weight percent Polyamide strands.

37. stating method described in any one of 31-36, the method also includes generating with about 200-300 DEG C The polyamide strands of temperature.

38. stating method described in any one of 31-37, the method also includes being water-cooled polyamide strands.

39. method described in any one of 31-38 is stated, wherein the wet polyamide pellet is in the slurries with water Form.

40. method described in any one of 31-39 is stated, wherein the wet polyamide pellet is covered with water.

41. method described in any one of 31-40 is stated, wherein the wet polyamide pellet has about 0.1 weight hundred The water content inside of the water of score.

42. method described in any one of 31-41 is stated, wherein the wet polyamide pellet is with about 20 DEG C to about 200 DEG C, or about 30 DEG C to about 150 DEG C, or about 35 DEG C to about 100 DEG C of temperature.

43. method described in any one of 31-42 is stated, wherein the wet polyamide pellet has acceptable yellowing Index.

44. state method described in any one of 31-43, wherein by water from described wet poly- during rotary drying The centrifugation of amide pellet removes.

45. method described in any one of 31-44 is stated, wherein in spin drying process while removing water The wet polyamide pellet is maintained in sieve or basket.

46. method described in any one of 31-45 is stated, wherein by the wet polyamide grain while rotary drying Material is dry in gaseous flow.

47. method described in any one of 31-46 is stated, wherein by the wet polyamide grain in spin drying process Expect at about 25 DEG C to about 200 DEG C, or about 30 DEG C to about 180 DEG C, or about 30 DEG C to about 150 DEG C, or about 30 DEG C to about 100 DEG C of temperature Degree heating.

48. method described in any one of 31-47 is stated, wherein the grain partly dried after spin drying Material has about 0.3% or more, or about 0.5% or more, or about 1.0% or more, or about 2.0% or more, or about 3.0% or more weight Measure the water of percentage.

49. method described in any one of 31-48 is stated, wherein the pellet partly dried passes through in the stream Change the gaseous flow support or fluidisation for supporting or fluidizing the pellet in bed dryer.

50. method described in any one of 31-49 is stated, wherein making the pellet partly dried on a conveyor It is mobile to pass through the fluidized bed dryer.

51. method described in any one of 31-50 is stated, wherein making the pellet partly dried in the biography of perforation Movement on device is sent to pass through the fluidized bed dryer, the conveyer of the perforation uses the mobile gaseous flow by perforating.

52. method described in any one of 31-51 is stated, wherein when the pellet partly dried is along the stream They are vibrated when changing the conveyer movement in bed dryer.

53. method described in any one of 31-52 is stated, wherein by the pellet partly dried in the fluidisation It is heated in bed dryer.

54. method described in any one of 31-53 is stated, wherein in the fluidized bed dryer by described in partly Dry pellet is at about 25 DEG C to about 200 DEG C, or about 30 DEG C to about 180 DEG C, or about 30 DEG C to about 150 DEG C, or about 30 DEG C to about 100 DEG C of temperature heating.

55. method described in any one of 31-54 is stated, wherein the pellet of the drying has about 0.1%, or about The water of 0.2%, or about 0.3%, or about 0.4%, or about 0.5% weight percent.

56. method described in any one of 31-55 is stated, wherein the pellet is in continuous polyamide production system Production.

57. state method described in any one of 31-56, wherein the polyamide be nylon 6, nylon 11, nylon 12, Nylon 6,6；Nylon 6,9；Nylon 6,10；Nylon 6,12；Or their copolymer.

The feature of following following claims summary system and method described herein.

Claims

1. A method for drying polyamide pellets, the method comprising:

a) Spin drying wet polyamide pellets having a diameter of 3 mm to 9 mm and a length of 0.05 cm to 10 cm at a temperature of 35 to 200° C. to remove most of the surface water from the wet polyamide pellets and to produce partially dry pellets, wherein the temperature of the wet polyamide pellets is 35 to 100°C; and

b) further drying the partially dried granules at a temperature of 35 to 200° C. in a fluid bed dryer which dries and conveys the granules from the rotary dryer,

wherein the wet polyamide pellets have an internal weight percentage of 0.1% to 0.5% water,

the partially dried pellets have 0.3% to 5% water by weight, and

The dried polyamide pellets have a weight percent water of less than 0.3% when the pellets exit the fluid bed dryer.

2. The method of claim 1, further comprising wet cutting polyamide strands in the presence of water to produce the wet polyamide pellets.

3. The method of claim 1, further comprising cooling polyamide strands with water and cutting the polyamide strands to produce the wet polyamide pellets.

4. The method of claim 1 wherein the wet polyamide pellets are coated with water.

5. The method of claim 1 wherein water is centrifugally removed from the wet polyamide pellets during spin drying.

6. The method of claim 1 wherein the pellets are dried in a gaseous stream concurrently with spin drying.

7. The method of claim 1 wherein the pellets are heated in a rotary dryer at a temperature below the melting temperature of the wet polyamide pellets.

8. The method of claim 1, wherein the partially dried pellets have a weight percent water of 0.5% to 4%.

9. The method of claim 1, wherein the partially dried pellets are moved through the fluid bed dryer on a conveyor.

10. The method of claim 1, wherein the partially dried pellets are moved through the fluid bed dryer on a perforated conveyor using a gaseous state flowing through the perforations flow.

11. The method of claim 1 wherein the partially dried pellets are shaken as they move along a conveyor in the fluid bed dryer.

12. The method of claim 1, wherein the partially dried pellets are heated in the fluid bed dryer.

13. The method of claim 1 wherein the dried polyamide pellets have a weight percent water of less than 0.2% when the pellets exit the fluid bed dryer.

14. The method of claim 1, wherein the wet polyamide pellets are produced in a continuous polyamide production system.

15. The method of claim 1, wherein the polyamide is nylon 6, nylon 11, nylon 12, nylon 6,6, nylon 6,9, nylon 6,10, nylon 6,12, or a copolymer thereof.

16. A system for producing polyamide pellets, the system comprising:

a) A rotary dryer that removes most of the surface water from wet polyamide pellets having a diameter of 3 mm to 9 mm and a length of 0.05 cm to 10 cm at a temperature of 35 to 200° C. to produce partially dried pellets material, wherein the temperature of the wet polyamide pellets is 35 to 100°C; and

b) a fluid bed dryer that dries and conveys said partially dried pellets from said rotary dryer at a temperature of 35 to 200° C. to produce dried polyamide pellets,

the partially dried pellets have 0.3% to 5% water by weight, and

17. The system of claim 16, further comprising an extruder configured to produce polyamide strands from which the wet polyamide pellets are made.

18. The system of claim 16, further comprising a wet cut pelletizer for producing wet polyamide pellets.