CN103243401A

CN103243401A - Polymerization and spinning one-step method technology for nylon 6 fibers

Info

Publication number: CN103243401A
Application number: CN 201210027251
Authority: CN
Inventors: 潘淑娟
Original assignee: BEIJING FENJIN TECHNOLOGY Co Ltd
Current assignee: BEIJING FENJIN TECHNOLOGY Co Ltd
Priority date: 2012-02-08
Filing date: 2012-02-08
Publication date: 2013-08-14

Abstract

Nylon 6 fibers are also called polyamide 6 or polycaprolactam fibers. According to a polymerization and spinning one-step method technology for nylon 6 fibers, caprolactam serves as a raw material, a polymer melt is obtained through ring opening and polymerization of caprolactam monomers, the polymer melt is directly sent to a spinning manifold for spinning rather than subjected to processes of slicing, washing, drying, packaging, fusion squeezing and the like, and the melt is subjected to demonomerization processing to reduce the content of monomers in the melt before being sent to the spinning manifold, so that the melt can meet the spinnability requirement for the spinning technology. By means of the polymerization and spinning one-step method technology, the production process of the nylon 6 fibers is shortened, energy and material consumption is reduced, and 800-1000 yuan can be saved for fiber products per ton.

Description

Nylon 6 fiber polymerization spinning one step technique

Technical field

The invention belongs to chemical industry, chemical fibre field, is the part of synthetic fiber manufacturing technology.

Background technology

Nylon 6/poly closes (polycaprolactam) and the nylon 6 fiber spinning is two mature technique.

Owing to be in a kind of poised state of mutual conversion between caprolactam and its polymer poly caprolactam, namely polymer always tends to decompose (degraded) one-tenth monomer, and when content of monomer was approximately 8%, this decomposable process reached relative equilibrium.The speed of this degradation process raises with temperature to be increased, and reducing with the content ratio of monomer in the polymer increases.

Monomer in the nylon 6/poly compound can evaporate when the polymer spinning is shaped, and when content of monomer was higher, a large amount of evaporations of monomer can influence the success rate of fibre forming, cause fibrous fracture, reduces the as-spun fibre quality, makes spinning to carry out when serious.

In the present production technology, the polymerization of nylon 6 is what to separate with spinning, the polymer melt elder generation Cast Strip of nylon 6, water-cooled, pelletizing, washing (are soaked, the caprolactam monomer in the middle of the polymer particle is also removed in dissolving), dry, packing (perhaps with the dry sliced chip bunker that is delivered directly to) again; Arrive device for spinning, need carry out chip drying (if dry section of crossing, can be no longer dry, but packing cost increases), polymer chips becomes melt through the screw rod extrusion molten, enters spinning manifold, spinning technique then.Supporting with the section washing process, need MONOMER RECOVERY and water treatment system.According to existing technology, go out polymer reactor from polymer and enter the spinning manifold middle a large amount of energy of process need consumption and raw material and water resource to polymer.Preresearch estimates is used for removing monomer and carries out cost that polymer chips handles greatly about more than 1000 yuans/ton.

If can allow polymer melt from the straight-through spinning manifold of polymer reactor, then can save a large amount of energy, reduce production costs.Someone once attempted this production method, and the result causes spinning process broken end a lot of because the content of monomer in the melt is higher, can't carry out ordinary production and ended in failure.

In theory, content of monomer is more low in the polycaprolactam amine polymer, and the spinnability of melt is more good.

Summary of the invention

The present invention increases by one between the final polymer reactor outlet of polycaprolactam process units and spinning manifold be the purpose reactor to remove caprolactam monomer and oligomer, before making that polymer melt enters spinning manifold, wherein monomer and oligomer reduce significantly, satisfy the requirement of spinning spinnability.This content of monomer index is not a concrete numerical value, and the specification of fiber product during according to spinning, spinning speed is different and different.For example, producing fine count fiber produces than the requirement harshness of coarse denier fiber to content of monomer the requirement ratio of content of monomer in the polymer.Concrete content's index, those skilled in the art rule of thumb or the spinning test as can be known, perhaps know by checking relevant handbook.

The invention solves monomer and oligomer height in the polymer melt, can not be directly as the technical problem of spinning melt raw material.

Adopt the technology of the present invention, can simplify polycaprolactam polymer spinning technology, energy-saving and cost-reducing, reduce production costs.

The specific embodiment

Removing the monomer reaction device is example to adopt horizontal reactor, adopt disk reactor or mouse cage structure of reactor, with motor-driven reactor axle, disk or mouse cage that drive is fixed on the axle rotate, the melt that enters inside reactor is pulled into numerous films, increase the specific surface of melt, cooperate vacuum system, make that monomer and the oligomer in the melt removes fast and in a large number.Monomer and oligomer enter after the vacuum system, are recovered in cooling and gathering-device, are sent to the raw material compounding system of caprolactam polymerization device then.The cooling of this vacuum system and gathering-device, for example scraper plate condenser etc. is machinery existing technology and equipment in the industry.Disk reactor and mouse cage structure of reactor, and how to increase the melt specific surface, how to increase the renewal speed of melt films, also be the technology that the insider was familiar with.For example press close to the position of card at disk, at liquid level scraper plate is set, make that the melt film on the card is scraped from disk in the approaching position of getting back to liquid level, so that disk enter liquid level with upper/lower positions after the new melt of contact, pull out new film after going out liquid level, increase the melt films renewal speed.

Method as an alternative can be by transforming polymerisation end reaction device, to realize the purpose of demonomerization.That is: vacuum demonomerization reactor can combine with the end reaction device of polycaprolactam polymerization technique, has polymerizable functional and demonomerization function concurrently at an inside reactor, and its structure of reactor is identical with the demonomerization reactor.

The demonomerization reactor also can adopt the vertical falling-film reactor, forms the bigger melt film of specific surface at inside reactor, cooperates vacuum system, makes that monomer and the quick a large amount of volatilizations of oligomer in the melt remove.

In order to shorten the melt Conveying distance that arrives the spinning machine spinnerets from the outlet of vacuum removal reactor melt as far as possible, can disperse to arrange vacuum demonomerization reactor, namely a polycaprolactam polymer reactor cooperates 2 or many vacuum demonomerization reactors, and a spinning machine cooperates one or many vacuum demonomerization reactors, shorten the time of staying of melt before being transported to spinnerets, avoid polymer melt in course of conveying, to be degraded to monomer or oligomer morely.

The liquid level of vacuum removal reactor detects, except adopting conventional radioactive ray liquid level gauge, can adopt photoelectric tube and photoelectricity to accept system realizes, at vacuum removal monomer reaction device glass vision panel is set, detect the passage of melt level by inside reactor as the light of photoelectric tube emission, detect the liquid level height, remove the foundation of reactor feed and discharging speed as the control monomer.

About device structure and the technology of disk reactor, mouse cage reactor, falling film reactor, vacuum and vacuum condensation system (MONOMER RECOVERY), the detection of photoelectricity liquid level and control system, it is disclosed prior art.

Claims

1. nylon 6 fiber polymerization spinning one step technique of the present invention directly is sent to the spinning manifold spinning with the polymer melt of polycaprolactam polymer reactor, and its technical characterictic is:

Before melt enters spinning manifold, arrange one to remove caprolactam monomer and oligomer are the demonomerization reactor of purpose in the melt, the demonomerization reactor adopts disk reactor axle and disc structure, perhaps adopt the cage-shaped structure of mouse cage reactor, with the polymer melt membrane, enlarge the specific surface of melt;

Reactor links to each other with vacuum system, under vacuum state, makes that monomer and the oligomer in the melt removes in a large number, after content of monomer in the melt reduces, possess spinnability (the spinning end breakage rate is very low), be sent to spinning manifold spinning (as-spun fibre obtains the fiber of all size again through processing later);

Vacuum system adopts the scraper plate condenser, monomer and oligomer that cooling and recovery are extracted out from the reactor gas phase, and the monomer that removes and oligomer are sent to the reuse of polymer reactor feed proportioning system after reclaiming.

2. according to claim 1, disperse to arrange vacuum demonomerization reactor, namely a polycaprolactam polymer reactor cooperates 2 or many vacuum demonomerization reactors;

And a spinning machine cooperates one or many vacuum demonomerization reactors, the melt Conveying distance of shortening from vacuum demonomerization reactor melt outlet arrival spinning machine spinnerets of trying one's best.

3. according to claim 1, the liquid level of vacuum removal reactor detects, and adopts photoelectric tube and photoelectricity to accept system and realizes, at vacuum removal monomer reaction device glass vision panel is set, and detects the passage of melt level by inside reactor as the light of photoelectric tube emission.

4. according to claim 1, vacuum demonomerization reactor can combine with the end reaction device of polycaprolactam polymerization technique, has polymerizable functional and demonomerization function concurrently at an inside reactor, and its structure of reactor is identical with the demonomerization reactor.