[go: up one dir, main page]

EP0051881B1 - Process for the continuous production of a monobasic powder - Google Patents

Process for the continuous production of a monobasic powder Download PDF

Info

Publication number
EP0051881B1
EP0051881B1 EP81109638A EP81109638A EP0051881B1 EP 0051881 B1 EP0051881 B1 EP 0051881B1 EP 81109638 A EP81109638 A EP 81109638A EP 81109638 A EP81109638 A EP 81109638A EP 0051881 B1 EP0051881 B1 EP 0051881B1
Authority
EP
European Patent Office
Prior art keywords
nitrocellulose
screw
screw press
solvent
mixing
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
EP81109638A
Other languages
German (de)
French (fr)
Other versions
EP0051881A1 (en
Inventor
Peter Dr. Presinger
Gregor Dipl.-Ing. Stockmann
Alfred Jeck
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
WNC Nitrochemie GmbH
Original Assignee
WNC Nitrochemie GmbH
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Family has litigation
First worldwide family litigation filed litigation Critical https://patents.darts-ip.com/?family=6116601&utm_source=google_patent&utm_medium=platform_link&utm_campaign=public_patent_search&patent=EP0051881(B1) "Global patent litigation dataset” by Darts-ip is licensed under a Creative Commons Attribution 4.0 International License.
Application filed by WNC Nitrochemie GmbH filed Critical WNC Nitrochemie GmbH
Priority to AT81109638T priority Critical patent/ATE6855T1/en
Publication of EP0051881A1 publication Critical patent/EP0051881A1/en
Application granted granted Critical
Publication of EP0051881B1 publication Critical patent/EP0051881B1/en
Expired legal-status Critical Current

Links

Images

Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B30PRESSES
    • B30BPRESSES IN GENERAL
    • B30B11/00Presses specially adapted for forming shaped articles from material in particulate or plastic state, e.g. briquetting presses, tabletting presses
    • B30B11/22Extrusion presses; Dies therefor
    • B30B11/24Extrusion presses; Dies therefor using screws or worms
    • CCHEMISTRY; METALLURGY
    • C06EXPLOSIVES; MATCHES
    • C06BEXPLOSIVES OR THERMIC COMPOSITIONS; MANUFACTURE THEREOF; USE OF SINGLE SUBSTANCES AS EXPLOSIVES
    • C06B21/00Apparatus or methods for working-up explosives, e.g. forming, cutting, drying
    • C06B21/0033Shaping the mixture
    • C06B21/0075Shaping the mixture by extrusion

Definitions

  • the invention relates to a process for the continuous production of single-base powder by means of a twin-screw screw press, in which solvent-moist nitrocellulose is introduced into a feed zone of the screw press, mixed in subsequent mixing and kneading zones of the screw press with added solvent and, if appropriate, further additives and thereby gelatinized and at the discharge end of the Screw press is extruded in the form of a strand.
  • FR-A-11 99918 also discloses a method for producing powders based on nitrocellulose or other powder base bodies using a twin-screw extruder.
  • the nitrocellulose and other additives are each brought together via a metering device and then jointly introduced into a first zone of the screw press equipped with kneading elements, where they are mixed further.
  • the first zone is followed by a displacement or separation zone defined by screw elements and another kneading zone defined by kneading elements, in which further additives, e.g. Solvent into which the screw press can be inserted before the gelatinized nitrocellulose mass is extruded at the discharge end of the screw press.
  • the object of the invention is to design the method mentioned in the introduction in such a way that blockages of the screw press by nitrocellulose are avoided.
  • the solvent is added, e.g. Alcohol, separated from the nitrocellulose, at a point on the screw press that follows the feed zone used exclusively for the supply of the nitrocellulose.
  • the screw press or its mixing and kneading screws are designed so that the solvent in a mixing zone, i.e. no kneading zone, comes together with the nitrocellulose already in the screw press and the first kneading zone of the screw press follows this mixing zone.
  • the invention achieves an uninterrupted and, in addition, process sequence so uniform that a high-quality product is obtained which is practically free of quality fluctuations.
  • the components of the powder to be prepared are expediently metered in in a manner known per se.
  • a dosing pump is appropriate for the solvent.
  • the nitrocellulose is advantageously input using a metering screw.
  • a device for the continuous production of single-base powder as main unit comprises a twin-screw screw press 1 of a type known in principle, in which two mixing and kneading screws 2 (only one of the two is shown in the figures) lying in the same direction in FIG turn a screw housing 3 which is eight-shaped in cross section and has a double jacket for temperature control purposes.
  • the two mixing and kneading screws 2 are composed of screw elements 4 with a box profile, screw elements 5 with a rounded profile and disk-shaped kneading elements 6, which are mounted on two screw shafts 7, in a specific configuration adapted to the production process.
  • the screw housing 3 Above the initial section of the mixing and kneading screws 2, the screw housing 3 has a large filling opening 8.
  • the end of the screw housing is closed off by a die arrangement 9, which is only indicated schematically in FIG.
  • the screw elements 4 with a box profile sit on the screw shafts 7.
  • a feed zone E of the screw press that is open through the filling opening.
  • screw elements 5 sit on the screw shafts and define a first mixing zone Me of the screw press there.
  • kneading elements 6 on the screw shafts which define a first kneading zone Ke.
  • further mixing zones Mi which are, however, significantly shorter than the first mixing zone Me
  • further kneading zones Ki which are defined by screw elements 5 or kneading elements 6.
  • the last kneading zone is followed by a comparatively long pressure zone D, likewise defined by screw elements 5, which extends up to the die arrangement 9.
  • a metering device 10 for nitrocellulose is assigned to the filling opening 8. This comprises a feed hopper 11, to which a metering screw 12 connects, which in turn opens into a vertical chute 13 extending into the filling opening 7.
  • a metering device 20 for solvents which comprises a storage container 21 and a metering pump 22 connected to it.
  • a line 23 leading away from the metering pump ends in the region of the first mixing zone Me in the interior of the screw housing 3, specifically cf. Figure 2, approximately at the end of the first third of its longitudinal extension in the working direction.
  • the hopper 11 is loaded with solvent-moist nitrocellulose, e.g. with so-called press-displaced nitrocellulose, the water content of which has been replaced by solvents in the press.
  • the reservoir 21 is filled with solvent, e.g. Filled with acetone.
  • the nitrocellulose is drawn off in metered quantity from the feed hopper 11 by means of the metering screw 12 and is fed into the feed zone E of the screw press via the chute 13.
  • the dosing is carried out in such a way that the screw press works with relining at least in the feed zone.
  • the screw elements 4 in the area of the feed zone E convey the nitrocellulose that has fallen in to the subsequent first mixing zone Me.
  • the solvent supplied continuously under pressure by means of the metering pump 22 is added to the nitrocellulose and mixed with the nitrocellulose in the axial direction while conveying the same.
  • This now highly solvent-moist mixture reaches the first kneading zone Ke, is kneaded there under shear stress and moves on through the subsequent mixing and kneading zones Mi or Ki to the discharge end of the screw press, the mixture being gelatinized.
  • the screw elements in the pressure zone D at the end the gelatinized mixture is pressed through the matrix arrangement 9, i.e. extruded in strand form.
  • the extruded strands can then be processed to the finished powder in a known manner by cutting, drying and possibly post-processing.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Processing And Handling Of Plastics And Other Materials For Molding In General (AREA)
  • Extrusion Moulding Of Plastics Or The Like (AREA)
  • Mixers Of The Rotary Stirring Type (AREA)
  • Processes Of Treating Macromolecular Substances (AREA)
  • Carbon And Carbon Compounds (AREA)
  • Ceramic Products (AREA)

Abstract

1. A method for the continuous production of monobasic powders by means of a twin-shaft screw press, in which nitrocellulose moistened with solvent is fed into an intake section of the screw press, is mixed and whilst doing so gelatinised in subsequent mixing and kneading sections of the screw press with added solvent and if appropriate other additives, and is extruded in continuous form at the discharge extremity of the screw press, characterised in that the solvent for the nitrocellulose is added solely within a mixing section (Me) following the open intake section (E).

Description

Die Erfindung betrifft ein Verfahren zum kontinuierlichen Herstellen einbasiger Pulver mittels einer zweiwelligen Schneckenpresse, bei welchem lösemittelfeuchte Nitrozellulose in eine Einzugszone der Schneckenpresse eingegeben, in anschliessenden Misch- und Knetzonen der Schneckenpresse mit zugegebenem Lösemittel und ggf. weiteren Zuschlagsstoffen gemischt und dabei gelatiniert und am Austragsende der Schneckenpresse in Strangform extrudiert wird.The invention relates to a process for the continuous production of single-base powder by means of a twin-screw screw press, in which solvent-moist nitrocellulose is introduced into a feed zone of the screw press, mixed in subsequent mixing and kneading zones of the screw press with added solvent and, if appropriate, further additives and thereby gelatinized and at the discharge end of the Screw press is extruded in the form of a strand.

Bei der klassischen Herstellung einbasiger Pulver werden die Verfahrensschritte des Mischens, Knetens und Formgebens in separaten Maschinen durchgeführt. Aus der DE-B-2825567 ist ein Verfahren zum kontinuierlichen Herstellen von Explosivstoffgemischen im weitesten Sinne unter Anwendung einer zweiwelligen Schneckenpresse bekannt, bei welchem die in Einzugszonen der Schneckenpresse zugeführten Komponenten des Explosivstoffgemisches in abwechselnd aufeinander folgenden Misch- und Knetzonen gemischt und geknetet werden, um die Schneckenpresse am Austragsende als fertiges Explosivstoffgemisch unter Druck zu verlassen. Die Misch- und Knetzonen werden durch Schnekken- und Knetelemente bestimmt, aus denen die beiden Misch- und Knetschnecken der Presse entsprechend der gewünschten Konfiguration der Zonen zusammengesetzt sind. Zur Herstellung einbasiger Pulver aus lösemittelfeuchter Nitrozellulose sind in der DE-B-2825567 keine Einzelheiten offenbart. Soweit bei den in der DE-B 28 25 567 näher erläuterten Verfahrens-Varianten flüssige Komponenten Verwendung finden, werden diese stets zusammen mit einer plastischen oder pulverförmigen Komponente an einer gleichen Stelle in die Schneckenpresse eingegeben, und zwar in einer Förderzone derselben, an die sich in Arbeitsrichtung eine Knetzone anschliesst.In the classic production of single-base powders, the process steps of mixing, kneading and shaping are carried out in separate machines. From DE-B-2825567 a process for the continuous production of explosive mixtures in the broadest sense using a twin-screw screw press is known, in which the components of the explosive mixture fed into feed zones of the screw press are mixed and kneaded in alternating successive mixing and kneading zones leave the screw press at the discharge end as a finished explosive mixture under pressure. The mixing and kneading zones are determined by screw and kneading elements, from which the two mixing and kneading screws of the press are composed according to the desired configuration of the zones. No details are disclosed in DE-B-2825567 for the production of single-base powder from solvent-moist nitrocellulose. Insofar as liquid components are used in the process variants described in DE-B 28 25 567, these are always introduced into the screw press together with a plastic or powdery component at the same place, specifically in a conveying zone of the same connects a kneading zone in the working direction.

Auch aus der FR-A-11 99918 ist ein Verfahren zur Herstellung von Pulvern auf der Basis von Nitrozellulose oder anderen Pulver-Grundkörpern mit Hilfe einer zweiwelligen Schneckenpresse bekannt. Bei diesem Verfahren werden die Nitrozellulose und weitere Zusatzmittel jeweils über eine Dosiereinrichtung zusammengebracht und dann gemeinsam in eine erste, mit Knetelementen ausgestattete Zone der Schneckenpresse eingegeben, wo sie weiter vermischt werden. Auf die erste Zone folgt in der Schneckenpresse eine durch Schraubenelemente definierte Verdrängungs- oder Abscheidungszone und eine weitere, durch Knetelemente definierte Knetzone, bei der über Dosiereinrichtungen weitere Zusatzmittel, z.B. Lösemittel, in die Schneckenpresse eingegeben werden können, bevor die gelatinierte Nitrozellulosemasse am Austragsende der Schneckenpresse extrudiert wird.FR-A-11 99918 also discloses a method for producing powders based on nitrocellulose or other powder base bodies using a twin-screw extruder. In this method, the nitrocellulose and other additives are each brought together via a metering device and then jointly introduced into a first zone of the screw press equipped with kneading elements, where they are mixed further. In the screw press, the first zone is followed by a displacement or separation zone defined by screw elements and another kneading zone defined by kneading elements, in which further additives, e.g. Solvent into which the screw press can be inserted before the gelatinized nitrocellulose mass is extruded at the discharge end of the screw press.

Bei einer praktischen Erprobung des eingangs genannten Verfahrens hat sich herausgestellt, dass eine den bekannten Verfahren entsprechende, gemeinsame Zugabe der Nitrozellulose und des Lösemittels zu unbefriedigenden Ergebnissen führt.During a practical test of the method mentioned at the outset, it was found that a common addition of the nitrocellulose and the solvent corresponding to the known methods leads to unsatisfactory results.

Auf Grund von Brückenbildung der Nitrozellulose an der Einzugszone kommt es hierbei zu Stockungen und vollständiger Unterbrechung der Nitrozellulose-Zufuhr. Andererseits ergeben sich ebenfalls Verstopfungen, wenn die Nitrozellulose ohne vorangegangenen Lösemittel-Zusatz in die erste Knetzone der Schneckenpresse gelangt.Due to the bridging of the nitrocellulose at the feed zone, the supply of nitrocellulose stops and is completely interrupted. On the other hand, there are also blockages if the nitrocellulose reaches the first kneading zone of the screw press without previous solvent addition.

Dementsprechend liegt der Erfindung als Aufgabe die Ausgestaltung des eingangs genannten Verfahrens derart zugrunde, dass Verstopfungen der Schneckenpresse durch Nitrozellulose vermieden werden.Accordingly, the object of the invention is to design the method mentioned in the introduction in such a way that blockages of the screw press by nitrocellulose are avoided.

Diese Aufgabe ist erfindungsgemäss dadurch gelöst, dass das Lösemittel der Nitrozellulose ausschliesslich in einer an die offene Einzugszone anschliessenden Mischzone zugegeben wird.This object is achieved according to the invention in that the solvent of nitrocellulose is added exclusively in a mixing zone adjoining the open feed zone.

Beim erfindungsgemässen Verfahren erfolgt also die Zugabe des Lösungsmittels, z.B. Alkohol, getrennt von der Nitrozellulose, und zwar an einer Stelle der Schneckenpresse, die in Arbeitsrichtung auf die ausschliesslich für die Zufuhr der Nitrozellulose verwendete Einzugszone folgt. Hierbei ist die Auslegung der Schneckenpresse bzw. ihrer Misch- und Knetschnecken so getroffen, dass das Lösemittel in einer Mischzone, also keiner Knetzone, mit der bereits in der Schnekkenpresse befindlichen Nitrozellulose zusammenkommt und erst auf diese Mischzone die erste Knetzone der Schneckenpresse folgt.In the method according to the invention, the solvent is added, e.g. Alcohol, separated from the nitrocellulose, at a point on the screw press that follows the feed zone used exclusively for the supply of the nitrocellulose. The screw press or its mixing and kneading screws are designed so that the solvent in a mixing zone, i.e. no kneading zone, comes together with the nitrocellulose already in the screw press and the first kneading zone of the screw press follows this mixing zone.

Hierdurch ist einerseits gewährleistet, dass die Nitrozellulose ohne Brückenbildung in die Schneckenpresse eintritt und diese somit gleichförmig mit Nitrozellulose beaufschlagt wird. Andererseits ist ebenfalls sichergestellt, dass in der Schneckenpresse keine Knetung von Nitrozellulose stattfindet, die nicht zuvor mit zusätzlich beigegebenem Lösemittel vermischt wurde, wodurch ein zu Verstopfungen führendes Trockengehen der Schneckenpresse mit Sicherheit vermieden ist. Insgesamt wird durch die Erfindung ein unterbrechungsfreier und zudem so gleichmässiger Verfahrensablauf erreicht, dass sich ein hochwertiges Produkt ergibt, das von Qualitätsschwankungen praktisch frei ist.This ensures, on the one hand, that the nitrocellulose enters the screw press without bridging and this is thus uniformly loaded with nitrocellulose. On the other hand, it is also ensured that there is no kneading of nitrocellulose in the screw press that has not previously been mixed with additionally added solvent, thereby reliably preventing the screw press from drying out which leads to blockages. Overall, the invention achieves an uninterrupted and, in addition, process sequence so uniform that a high-quality product is obtained which is practically free of quality fluctuations.

In an sich bekannter Weise werden die Komponenten des herzustellenden Pulvers zweckmässigerweise dosiert zugegeben. Für das Lösemittel ist hierzu eine Dosierungspumpe zweckmässig. Die Eingabe der Nitrozellulose erfolgt vorteilhafterweise mittels einer Dosierschnecke.The components of the powder to be prepared are expediently metered in in a manner known per se. A dosing pump is appropriate for the solvent. The nitrocellulose is advantageously input using a metering screw.

Es hat sich gezeigt, dass sich die Vermeidung von Brückenbildung noch sicherer beherrschen lässt, wenn die Nitrozellulose für eine Unterfütterung mindestens der Einzugszone der Schnekkenpresse dosiert wird, man also nicht mit einer vollständigen Füllung der Schneckenpresse arbeitet.It has been shown that the avoidance of bridging can be controlled even more reliably if the nitrocellulose is dosed for relining at least the feed zone of the screw press, i.e. one does not work with a complete filling of the screw press.

Schliesslich ist es im Sinne der Vermeidung von Verstopfungen sehr vorteilhaft, die Nitrozellulose in eine besonders gestaltete, nämlich durch Schraubenelemente mit Kastenprofil definierter Einzugszone einzugeben, in der auf Grund des gewählten Kastenprofiles noch keine zielgerichtete Mischung stattfindet. Eine Mischung erfolgt dann vielmehr erst in der anschliessenden ersten Mischzone, in der das Lösemittel zugeführt wird. Diese Mischzone, die dann anschliessende erste Knetzone und die weiter in Arbeitsrichtung abwechselnd aufeinander folgenden Misch- und Knetzonen sind bevorzugt in der an sich aus DE-AS 28 25 567 bekannten Weise durch Schnecken- und Knetelemente im Zuge der beiden Misch- und Knetschnecken definiert.After all, it is in the sense of avoidance of blockages very advantageous to enter the nitrocellulose in a specially designed feed zone, namely defined by screw elements with a box profile, in which no targeted mixing takes place due to the selected box profile. Rather, mixing then takes place only in the subsequent first mixing zone in which the solvent is supplied. This mixing zone, the first kneading zone which then follows and the mixing and kneading zones which alternate further in the working direction are preferably defined in the manner known per se from DE-AS 28 25 567 by screw and kneading elements in the course of the two mixing and kneading screws.

Im folgenden ist die Erfindung mit weiteren vorteilhaften Einzelheiten anhand einer schematisch dargestellten Vorrichtung zur Durchführung eines Verfahrens zum kontinuierlichen Herstellen einbasiger Pulver näher erläutert. In den Zeichnungen zeigen:

  • Figur 1 einen Längsschnitt durch eine zweiwellige Schneckenpresse mit Zusatzaggregaten,
  • Figur 2 einen Längsschnitt eines Abschnittes der Schneckenpresse nach Figur 1, in welchem die Einzugszone der Schneckenpresse liegt.
The invention is explained in more detail below with further advantageous details using a schematically illustrated device for carrying out a method for the continuous production of single-base powder. The drawings show:
  • FIG. 1 shows a longitudinal section through a twin-screw screw press with additional units,
  • FIG. 2 shows a longitudinal section of a section of the screw press according to FIG. 1, in which the feed zone of the screw press lies.

Gemäss den Figuren 1 und 2 umfasst eine Vorrichtung zum kontinuierlichen Herstellen einbasiger Pulver als Hauptaggregat eine zweiwellige Schneckenpresse 1 einer im Prinzip bekannten Bauart, bei der sich zwei nebeneinander liegende Misch- und Knetschnecken 2 (in den Figuren ist nur eine der beiden gezeigt) gleichsinnig in einem im Querschnitt achtförmigen Schneckengehäuse 3 drehen, das zu Temperierzwecken einen Doppelmantel hat. Die beiden Misch- und Knetschnecken 2 sind in einer bestimmten, dem Herstellungsverfahren angepassten Konfiguration aus Schraubenelementen 4 mit Kastenprofil, aus Schneckenelementen 5 mit gerundetem Profil und aus scheibenförmigen Knetelementen 6 zusammengesetzt, welche auf zwei Schneckenwellen 7 aufgezogen sind. Über dem Anfangsabschnitt der Misch- und Knetschnecken 2 weist das Schneckengehäuse 3 eine grosse Einfüllöffnung 8 auf. Am Austragsende der Schneckenpresse ist das Schneckengehäuse stirnseitig durch eine in Figur 1 nur schematisch angedeutete Matrizen-Anordnung 9 abgeschlossen.According to FIGS. 1 and 2, a device for the continuous production of single-base powder as main unit comprises a twin-screw screw press 1 of a type known in principle, in which two mixing and kneading screws 2 (only one of the two is shown in the figures) lying in the same direction in FIG turn a screw housing 3 which is eight-shaped in cross section and has a double jacket for temperature control purposes. The two mixing and kneading screws 2 are composed of screw elements 4 with a box profile, screw elements 5 with a rounded profile and disk-shaped kneading elements 6, which are mounted on two screw shafts 7, in a specific configuration adapted to the production process. Above the initial section of the mixing and kneading screws 2, the screw housing 3 has a large filling opening 8. At the discharge end of the screw press, the end of the screw housing is closed off by a die arrangement 9, which is only indicated schematically in FIG.

Im Bereich der Einfüllöffnung 8 sitzen auf den Schneckenwellen 7 die Schraubenelemente 4 mit Kastenprofil. Sie definieren dort eine durch die Einfüllöffnung offene Einzugszone E der Schnekkenpresse. In Arbeitsrichtung unmittelbar anschliessend an die Schraubenelemente 4 bzw. die Einzugszone E sitzen auf den Schneckenwellen Schneckenelemente 5, die dort eine erste Mischzone Me der Schneckenpresse definieren. Hieran anschliessend folgen Knetelemente 6 auf den Schneckenwellen, die eine erste Knetzone Ke definieren. Hieran schliessen sich in abwechselnder Folge weitere, im Vergleich zu erster Mischzone Me allerdings deutlich kürzere Mischzonen Mi und weitere Knetzonen Ki an, die durch Schneckenelemente 5 bzw. Knetelemente 6 definiert sind. Auf die letzte Knetzone folgt eine vergleichsweise lange, ebenfalls durch Schneckenelemente 5 definierte Druckzone D, die bis vor die Matrizen-Anordnung 9 reicht.In the area of the filling opening 8, the screw elements 4 with a box profile sit on the screw shafts 7. There you define a feed zone E of the screw press that is open through the filling opening. In the working direction immediately following the screw elements 4 or the feed zone E, screw elements 5 sit on the screw shafts and define a first mixing zone Me of the screw press there. This is followed by kneading elements 6 on the screw shafts, which define a first kneading zone Ke. This is followed alternately by further mixing zones Mi, which are, however, significantly shorter than the first mixing zone Me, and further kneading zones Ki, which are defined by screw elements 5 or kneading elements 6. The last kneading zone is followed by a comparatively long pressure zone D, likewise defined by screw elements 5, which extends up to the die arrangement 9.

Der Einfüllöffnung 8 ist eine Dosiervorrichtung 10 für Nitrozellulose zugeordnet. Diese umfasst einen Aufgabetrichter 11, an den sich eine Dosierschnecke 12 anschliesst, welche ihrerseits in einen senkrechten, bis in die Einfüllöffnung 7 reichenden Fallschacht 13 mündet.A metering device 10 for nitrocellulose is assigned to the filling opening 8. This comprises a feed hopper 11, to which a metering screw 12 connects, which in turn opens into a vertical chute 13 extending into the filling opening 7.

Ferner ist eine Dosiervorrichtung 20 für Lösemittel vorgesehen, welche einen Vorratsbehälter 21 und eine daran angeschlossene Dosierpumpe 22 umfasst. Eine von der Dosierpumpe wegführende Leitung 23 endet im Bereich der ersten Mischzone Me im Inneren des Schneckengehäuses 3, und zwar vgl. Figur 2, ungefähr am Ende des ersten Drittels ihrer Längserstreckung in Arbeitsrichtung.Furthermore, a metering device 20 for solvents is provided, which comprises a storage container 21 and a metering pump 22 connected to it. A line 23 leading away from the metering pump ends in the region of the first mixing zone Me in the interior of the screw housing 3, specifically cf. Figure 2, approximately at the end of the first third of its longitudinal extension in the working direction.

Zur Herstellung von einbasigem Pulver wird der Aufgabetrichter 11 mit lösemittelfeuchter Nitrozellulose beaufschlagt, z.B. mit sogenannter pressenverdrängter Nitrozellulose, deren Wassergehalt in der Presse durch Lösemittel ersetzt wurde. Der Vorratsbehälter 21 wird mit Lösemittel, z.B. Aceton gefüllt. Aus dem Aufgabetrichter 11 wird die Nitrozellulose mittels der Dosierschnecke 12 in dosierter Menge abgezogen und über den Fallschacht 13 in die Einzugszone E der Schneckenpresse eingegeben. Hierbei erfolgt die Dosierung derart, dass die Schneckenpresse mindestens in der Einzugszone mit Unterfütterung arbeitet. Die Schraubenelemente 4 im Bereich der Einzugszone E fördern die hereingefallene Nitrozellulose zur anschliessenden ersten Mischzone Me. In dieser wird der Nitrozellulose das mittels der Dosierpumpe 22 kontinuierlich unter Druck zugeführte Lösemittel zugegeben und mit der Nitrozellulose bei Förderung derselben in Axialrichtung vermischt. Dieses nunmehr stark lösemittelfeuchte Gemisch gelangt in die erste Knetzone Ke wird dort unter Scherbeanspruchung geknetet und wandert weiter durch die anschliessenden Misch- und Knetzonen Mi bzw. Ki dem Austragsende der Schneckenpresse zu, wobei eine Gelatinierung des Gemisches erfolgt. Mittels der Schneckenelemente in der Druckzone D am Ende wird das gelatinierte Gemisch durch die Matrizen-Anordnung 9 gepresst, d.h. in Strangform extrudiert. Die extrudierten Stränge können dann in bekannter Weise durch Schneiden, Trocknen und ggf. Nachbearbeitung zum fertigen Pulver verarbeitet werden.To produce single-base powder, the hopper 11 is loaded with solvent-moist nitrocellulose, e.g. with so-called press-displaced nitrocellulose, the water content of which has been replaced by solvents in the press. The reservoir 21 is filled with solvent, e.g. Filled with acetone. The nitrocellulose is drawn off in metered quantity from the feed hopper 11 by means of the metering screw 12 and is fed into the feed zone E of the screw press via the chute 13. The dosing is carried out in such a way that the screw press works with relining at least in the feed zone. The screw elements 4 in the area of the feed zone E convey the nitrocellulose that has fallen in to the subsequent first mixing zone Me. In this zone, the solvent supplied continuously under pressure by means of the metering pump 22 is added to the nitrocellulose and mixed with the nitrocellulose in the axial direction while conveying the same. This now highly solvent-moist mixture reaches the first kneading zone Ke, is kneaded there under shear stress and moves on through the subsequent mixing and kneading zones Mi or Ki to the discharge end of the screw press, the mixture being gelatinized. By means of the screw elements in the pressure zone D at the end, the gelatinized mixture is pressed through the matrix arrangement 9, i.e. extruded in strand form. The extruded strands can then be processed to the finished powder in a known manner by cutting, drying and possibly post-processing.

Beispiel:Example:

Auf einer Vorrichtung gemäss obiger Beschreibung wurden 100 Kilogramm (Trockengewicht) pressenverdrängter Nitrozellulose verarbeitet, die 32 Kilogramm Alkohol enthielt. Der alkoholfeuchten Nitrozellulose wurden in der Schnekkenpresse als Lösemittel 44 Kilogramm Aceton dosiert zugesetzt, wobei im Aceton 1 Gew.-% Stabilisatoren gelöst waren. Die in der Schnekkenpresse gelatinierte Nitrozellulose-Masse wurde durch eine entsprechende Matrize in Form von 51 Strängen extrudiert, die jeweils einen Aussendurchmesser von 1 mm und einen Innendurchmesser von 0,2 mm hatten. Während der Verarbeitung mit einer Schneckendrehzahl von ca. 50 min-' kam es nirgends in der Schneckenpresse zu einer Verstopfung oder einem Festsetzen von Material. Die austretenden Stränge hatten eine gleichförmige Struktur und Dichte. Nach dem wie üblich durchgeführten Trocknen, Schneiden und Oberflächenbehandeln der Stränge ergab sich ein Endprodukt, das gegenüber einem solchen aus in klassischer Weise hergestellten Strängen keinerlei nachteilige Eigenschaften zeigte.100 kg (dry weight) of press-displaced nitrocellulose containing 32 kg of alcohol were processed on a device as described above. 44 kg of acetone were added as a solvent to the alcohol-moist nitrocellulose in the screw press, 1% by weight of stabilizers being dissolved in the acetone. The in the Schnek The press of gelatinized nitrocellulose was extruded through a corresponding die in the form of 51 strands, each having an outside diameter of 1 mm and an inside diameter of 0.2 mm. During processing with a screw speed of approx. 50 min- ', there was nowhere in the screw press that material was clogged or stuck. The emerging strands had a uniform structure and density. After the drying, cutting and surface treatment of the strands, which was carried out in the usual way, an end product was obtained which did not show any disadvantageous properties compared to that obtained from strands produced in a conventional manner.

Claims (5)

1. A method for the continuous production of monobasic powders by means of a twin-shaft screw press, in which nitrocellulose moistened with solvent is fed into an intake section of the screw press, is mixed and whilst doing so gelati- nised in subsequent mixing and kneading sections of the screw press with added solvent and if appropriate other additives, and is extruded in continuous form at the discharge extremity of the screw press, characterised in that the solvent for the nitrocellulose is added solely within a mixing section (Me) following the open intake section (E).
2. A method according to claim 1, characterised in that the solvent is added by means of a metering pump (22).
3. Method according to claim 1 or 2, characterised in that the nitrocellulose is fed in by means of a metering screw (12).
4. Method according to claim 3, characterised in that the nitrocellulose is meted to underfeed at least the intake section (E) of the screw press (1).
5. Method according to one of the claims 1 to 4, characterised in that the nitrocellulose is fed into an intake section (E) delimited by screw elements (4) with a box section.
EP81109638A 1980-11-12 1981-11-11 Process for the continuous production of a monobasic powder Expired EP0051881B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT81109638T ATE6855T1 (en) 1980-11-12 1981-11-11 PROCESS FOR CONTINUOUSLY MANUFACTURING MONOBASE POWDERS.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3042697A DE3042697C2 (en) 1980-11-12 1980-11-12 Process for the continuous production of monobasic powders
DE3042697 1980-11-12

Publications (2)

Publication Number Publication Date
EP0051881A1 EP0051881A1 (en) 1982-05-19
EP0051881B1 true EP0051881B1 (en) 1984-03-28

Family

ID=6116601

Family Applications (1)

Application Number Title Priority Date Filing Date
EP81109638A Expired EP0051881B1 (en) 1980-11-12 1981-11-11 Process for the continuous production of a monobasic powder

Country Status (4)

Country Link
EP (1) EP0051881B1 (en)
AT (1) ATE6855T1 (en)
DE (1) DE3042697C2 (en)
ES (1) ES8300312A1 (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5266242A (en) * 1989-05-11 1993-11-30 Wnc-Nitrochemie Gmbh Method and apparatus to prepare a tribasic propellat charge powder
GB2258656B (en) * 1991-08-15 1994-01-12 Albright & Wilson Processing of powder

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1048212B (en) * 1957-08-09 1958-12-31 Dynamit Nobel Ag Device for the continuous production of gunpowder and propellants
GB1283265A (en) * 1969-05-26 1972-07-26 Seikisui Chemical Co Ltd Process for the extrusion of a homogeneous mixture of a thermoplastic material with a liquid
FR2325491A1 (en) * 1975-09-25 1977-04-22 Poudres & Explosifs Ste Nale PYROTECHNIC COMPOSITIONS PURLING PROCESS, AND SCREW PADDING
FR2326289A1 (en) * 1975-10-01 1977-04-29 Poudres & Explosifs Ste Nale OPENABLE HOLDER
DE2825567B1 (en) * 1978-06-10 1979-11-15 Dynamit Nobel Ag Process for the continuous production of explosive mixtures

Also Published As

Publication number Publication date
ES507083A0 (en) 1982-11-01
DE3042697C2 (en) 1986-02-20
ATE6855T1 (en) 1984-04-15
ES8300312A1 (en) 1982-11-01
EP0051881A1 (en) 1982-05-19
DE3042697A1 (en) 1982-06-03

Similar Documents

Publication Publication Date Title
EP0231034B1 (en) Method of manufacturing pastes or plastic masses containing peroxide
DE2601696A1 (en) METHOD AND DEVICE FOR PRODUCING AN EXTRUDATE FROM A PLASTIC RESIN AND A SOLID PARTICLE ADDITIVE IN AN EXTRUDER FOR PLASTICS
DE1729301A1 (en) Multi-stage extruder
DE3341090A1 (en) METHOD AND DEVICE FOR PRODUCING EXTRUDED FOODSTUFFS
DE2304088A1 (en) SCREW PRESS FOR EXTRUDING (EXTRUDING) NON-EXPANDABLE RESINS AND PROCEDURES FOR YOUR OPERATION
CH615143A5 (en)
DE2540934C3 (en) Device for producing fillers, in particular foams containing waste foams
EP0113402B1 (en) Process and apparatus for the manufacture of a monobase or plural base propellant
DE3036048A1 (en) PLASTIC EXTRUDER WITH A DEVICE FOR INJECTING A LIQUID ADDITIVE INTO THE MOLTEN PLASTIC FLOW
DE3042662C2 (en) Twin screw press for the manufacture of explosives
EP0203260B1 (en) Kneading machine
EP0424490A1 (en) Process and device for producing a tribasic propellent powder.
DE2316538B2 (en) Process for the production of Gudol powder
EP0051881B1 (en) Process for the continuous production of a monobasic powder
DE409577C (en) Extrusion press for plastic masses
DE2165148B2 (en) Device for mixing dry and liquid materials
AT307012B (en) Device for the continuous production of fibrous molding compounds
DE3044577C2 (en) Process and device for the continuous production of propellant charge powder
EP0039957A2 (en) Extrusion process
DE3421916A1 (en) Apparatus for producing insulating mortar
DE1136605B (en) Device provided on sausage filling machines or the like for supplying filling material
DE3031201A1 (en) Extruder force feed for film plus granulate - granulate laterally enters conical part of vertical screw for film
DE3546489C2 (en)
DE3448139C2 (en) Device for producing plastics-bound propellant powders and explosives
DE1646285B2 (en) CONTINUOUS PRODUCTION OF POWDER WITHOUT SOLVENTS

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Designated state(s): AT BE CH FR GB IT LI NL SE

17P Request for examination filed

Effective date: 19820720

ITF It: translation for a ep patent filed
GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Designated state(s): AT BE CH FR GB IT LI NL SE

REF Corresponds to:

Ref document number: 6855

Country of ref document: AT

Date of ref document: 19840415

Kind code of ref document: T

ET Fr: translation filed
PLBI Opposition filed

Free format text: ORIGINAL CODE: 0009260

26 Opposition filed

Opponent name: DYNAMIT NOBEL AKTIENGESELLSCHAFT

Effective date: 19841222

NLR1 Nl: opposition has been filed with the epo

Opponent name: DYNAMIT NOBEL AG

PLBN Opposition rejected

Free format text: ORIGINAL CODE: 0009273

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: OPPOSITION REJECTED

27O Opposition rejected

Effective date: 19860608

NLR2 Nl: decision of opposition
ITTA It: last paid annual fee
EAL Se: european patent in force in sweden

Ref document number: 81109638.7

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 20001013

Year of fee payment: 20

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: CH

Payment date: 20001016

Year of fee payment: 20

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: AT

Payment date: 20001023

Year of fee payment: 20

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: NL

Payment date: 20001026

Year of fee payment: 20

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: SE

Payment date: 20001030

Year of fee payment: 20

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 20001101

Year of fee payment: 20

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: BE

Payment date: 20001116

Year of fee payment: 20

BE20 Be: patent expired

Free format text: 20011111 *WNC NITROCHEMIE G.M.B.H.

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LI

Free format text: LAPSE BECAUSE OF EXPIRATION OF PROTECTION

Effective date: 20011110

Ref country code: GB

Free format text: LAPSE BECAUSE OF EXPIRATION OF PROTECTION

Effective date: 20011110

Ref country code: CH

Free format text: LAPSE BECAUSE OF EXPIRATION OF PROTECTION

Effective date: 20011110

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: NL

Free format text: LAPSE BECAUSE OF EXPIRATION OF PROTECTION

Effective date: 20011111

Ref country code: AT

Free format text: LAPSE BECAUSE OF EXPIRATION OF PROTECTION

Effective date: 20011111

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SE

Free format text: THE PATENT HAS BEEN ANNULLED BY A DECISION OF A NATIONAL AUTHORITY

Effective date: 20011129

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

REG Reference to a national code

Ref country code: GB

Ref legal event code: PE20

Effective date: 20011110

NLV7 Nl: ceased due to reaching the maximum lifetime of a patent

Effective date: 20011111