DE1795164A1 - Process for the production of dimensionally accurate molded bodies from polyamides and injection molding arrangement for carrying out the process - Google Patents

Description

Process for the production of moldings made from polyamides and injection-molded foam strips to form Duron conduct of the proceedings

(Addition to PatantaWe! Dung A 54 509 IV d / 39c)

The invention according to the main patent

(Patent application A 54 509 IV d / 39c) refers to a ver f follow for the production of dimensionally accurate molded articles made of polyamides the injection molding process and arrangements for performing this Process by means of ionic polymerization of caprolactam or perforations of lactams.

After the main patent, the invention consists in that one liquid or for the preparation of one or more molded bodies of powdery Iiactam or a mixture of lactams _f wherein a portion of the catalyst and another part contains the polymerisation, in each case a temperature-controlled reservoir through inlet ™ conduits the feeds the rear end of an injection cylinder, mixes the monomeric lactam or lactam mixture with the additives and exposes it to a temperature causing the polymerization, then melts the polymer formed in the injection cylinder, and finally the melt via a nozzle with the aid of the screw that is rotatably and axially displaceable in the injection cylinder pressed into oine shape and allowed to solidify under vigorous pressure. It is also provided according to the invention of the main patent that the

109884 / U8A _ ₂ _

BATHROOM CWK3INAL

The material exiting from the nozzle of the injection cylinder flows into one Piston cylinder arrives and only then can be displaced by the therein The injection plunger is stored in at least one form of a cavity multi-part form is conveyed, whereupon the fuel piston exercises the intended emphasis. Also in main petitioner emphasized that the Spritzay-1Inder with the screw instead of the lactams or their mixtures with a catalyst and the lactams or their mixtures with oocatalyst (activator) a polymerizable one which has all the necessary components or prepolymerized mixture can be applied, and finally When processing a mixture that has all the necessary components, there is the option of »instead of several storage containers to use only a storage container with a suitable supply line.

The present additional invention is now on a further training of the main application and consists in the fact that the cylinder of a piston injection molding machine has all the necessary components having polymerizable or prepolymerized tea « Lactam-Gemisoh is abandoned for immediate processing is already sufficiently mixed that the lactam mixture is preheated or melted in the cylinder and then either by an axial displacement of the piston over a nozzle area in a form that is set to a temperature that triggers the polymerization is heated, pressed and the polymerization of the lactam mixture to the polyamide is carried out in the mold under pressure below the melting point of the resulting polyamide, or daö

109884/1484,

the polymerizable lactara mixture "already in the cylinder or piston injection molding machine is exposed to a polyamido temperature which triggers the polymerization and is above the melting point of the resulting polyamide, and the resulting polyamide melt is pressed through an axial displacement of the piston over a nozzle area into a mold where the polyamide melt is pressed solidifies emphasis. it may be additionally provided that daa lactam mixture displacement before preheating or melting in the cylinder by an axial J of the piston is compressed. Further i Λ it possible to the cylinder of the piston-opritegußmaschine processing material of any shape For example, additives such as lubricants and mold release agents, pigments, organic dyes, stabilizers and fillers such as glass fibers, graphite, metal powder or molybdenum disulphide can be added to the Luctauian batches.

In the main application it was basically assumed that a greenish mixing process was necessary at the beginning of the process. Mixing is still an essential prerequisite for the economic processing of lactam compounds containing the catalyst and the polymerization activator. However, it was found that the mixing process provided by the main application by a screw unit can be omitted if the lactam mixture containing all the necessary components has already been sufficiently mixed by the manufacturer and is delivered to the consumer in this way.

BAD ORKätNAU

109884 / U84 ₄

An exemplary embodiment of the method according to the invention usable injection molding arrangement is shown schematiach in the drawing.

The injection molding arrangement consists essentially of the injection molding, the dosing unit and the mold clamping unit, of which only the mold itself has been drawn for the sake of simplicity. _ The cylinder 61 has a displaceably mounted spout piston 62 in its interior, which by reciprocal Applied ^ i <of the Druok piston 63 in each desired Able to be brought. The admission is thereby causes a pressure medium via the pipes 64 and 65 is pressed into the pressure chambers 66 and / or 67 of the cylinder 68.

The cylinder 61 as well as the nozzle cap 69 of the cylinder can be provided with heating strips 70 and 71. At more suitable Place dc3 cylinder 61 is the Einfüllöffmwg provided, the * In connection with the storage container 75 via the supply line 72 stands. The storage container 73 can be equipped with old temperature control devices 74 and also with a metering device be. However, it is also possible to install a metering device 75 in the feed line 72 and also the feed line flexible training. This would have the advantage, for example, that shaking movements on the supply line 72 would result in a uniform movement Material metering could be guaranteed. Ea is but also conceivable for the feed line 72 itself to be made of flexible

109884 / U84

To produce material, whereby the metering of material could be done in a simple manner by more or less strong compression of the pipe mouth.

"The mold halves 76 and 77 adjoining the mold cavities ivsieon holes 73 on, dio almost exclusively in the area of the ! cruenhohlrUuuo arranged; riud. aluroh diooo iianäle or holes 73 Heia- odor Kühlrad ion can be jejcliiokt to thereby the best possible mold temperature for the "respective process reach. I; the form 76, 77 can of course also be operated electrically verdon.

A work process for the production of dimensionally accurate moldings by means of uer betchriebonen f'pritz juCanordiiun ^ runs ira wonontlichen like foliot off;

\ ip.xm the heating bands 70 and 71 Ueo cylinder 61 or the nozzle areaod o9 and gosebenenfalla dia temperature control devices 74 I

of the storage container 73 after switching on the Llasohine the ^ cv / Uncchtc temperature is reached and the nozzle of the 3 cylinder touches the Ϊόιί.ι 7o, 77, opens; the heatable Bo3iervorrichcunj 75 dL ·? Supply line 72, unc aua aeri reservoir 73 flows oiii «v> rdetermined iJenjo do ^: i zu vciU.rboitenden.-Iaterials in don Syl ^ dr 61. PaHu ea sich ali, advantageously erwoiaen aollto, can daa fijint.in-.i ^ enion. ^ e afterwards uur-h uiiiu Axiulver3ohunken dos ί-ipril · .- '· -.' ■ '■■ -. ■ ν, ρ 62 compressed v / ordrr:'ir; In this case a üiM would be: 'r.zusotzen). Tio H <«ii.bä; l ·! -R ^ O and 71 cause each

10988A / U8i BADOWQINAL

after the set temperature, only a melting of the Lactam Gremenges, for example at 100 ° C, or additionally the Polymerization of the Lactaui mixture, for example at 250 ° C, whereupon by a further axial displacement of the injection plunger 62 the mold filling with lactam melt or. Polyamide melt takes place. It is important to ensure that in front of the fuel piston a sufficiently large cushion of mass remains to pass through the intended Emphasis on maintaining effective shrinkage compensation. In the mold 76, 77 either the polymerisation of the injected takes place Lactams at 150 ° to 200 ° C, or the solidification of the injected polyamide.

109884/1484

Claims (1)

nnKERUIERK HaRQBBERD Claims Process for the production of perfectly fitting molded articles from polyamides by means of ionic polymersat ion of caprolactam or mixtures of lactams, but producing one or more Molded body Jlüesiü'GS or powdered ■ -lactam 'or a "Lactams supply, of which one! Part the catalyst and part the other part contains the polymerization activator, also in each case a temperature-controllable storage container via feed lines to the ritnlc.väiti ^ en end of a syringe cylinder, the monomer Lactam or Laetam mixture mixed with the additives and exposed to a temperature causing the polymerization, then the polymer formed melts in the injection cylinder, finally-the melt with the help of the rotating in the injection cylinder axially displaceable screw via a nozzle in presses a mold and allows it to solidify under vigorous pressure, or with from which the material emerging from the nozzle of the injection cylinder material first oineci piston cylinder or 'feeds and only then thanks to the injection plunger, which is slidably mounted in it, in min- ■ d? 3 at least one mold cavity is conveyed to a multi-part mold, whereupon the fuel piston exerts the intended pressure, according to patent (patent application A 54 509 IV d / 59c), characterized in that the cylinder of a Kolban injection molding machine a polymerizable or pre-polymer is iertef that has all the necessary components! Lactam mixture 10988.4 / 1A84 - ο - üluiehk "~ ΊΕΗΟ is abandoned, which is already sufficiently mixed for immediate processing that the lactam mixture in Cylinder is preheated or melted, and that finally the mixture prepared for deformation is passed through an axial displacement of the piston over a SUsenbereich pressed into a heated mold and polymerized under pressure below the melting point of the resulting polyamide leaves. 2. The method according to claim 1, characterized in that the Lactam mixture already in the cylinder for polymerization the triggering temperature above the melting point of the resulting polyamide is heated, and that after the polymerization, the resulting polyamide melt by an axial displacement of the piston over a The nozzle area is pressed into a mold, where it solidifies under force. 3. The method according to one or both of the preceding claims, characterized in that dao lactam mixtures before preheating or melting in the cylinder by an axial displacement of the piston is compressed. 4 «Method according to one or more of the preceding claims, characterized in that the cylinder of the piston injection molding machine a liquid or powdery lactam mixture is abandoned. '-w. * ■ *. · - £ ■' ■ ·> ■■ · iAD ORIGINAL 109884 / U84 _ _q _ nuHflHBEHa ERUJ flHB 5. Injection molding arrangement for carrying out the. Method according to a or more of the preceding claims 1 to 4, characterized in that the givonfall3 is a metering device (75) having and between the storage container (73) and the cylinder (61) arranged supply line (72) designed to be flexible is. C. Cprita casting arrangement according to claim 5 * characterized in that '(( that the feed line (72) is at least partially made of flexible ■■ 'material is made. 7. Injection molding arrangement for performing the method according to one or more of the preceding claims 1 to 4 and according to claims 5 and 6, characterized in that the cylinder (61) is arranged vertically. BATH 109884/14 8Ά e e r e i t e