|Publication number||US2371916 A|
|Publication date||Mar 20, 1945|
|Filing date||May 3, 1941|
|Priority date||Jan 16, 1940|
|Publication number||US 2371916 A, US 2371916A, US-A-2371916, US2371916 A, US2371916A|
|Original Assignee||Wolf Rodenacker|
|Export Citation||BiBTeX, EndNote, RefMan|
|Referenced by (3), Classifications (13)|
|External Links: USPTO, USPTO Assignment, Espacenet|
March 20, 1945. w RODENACKER 2,371,916
MELTING APPARATUS Filed May 3, 1941 2 Sheets-Sheet l m 1 g 1- ---I a INVENTOR ATTORNEY March 945- .w. RoDENAcKER I MELTING APPARATUS Filed May 3, 1941 2 Sheets-Sheet 2 VVOZ/ Rodenac'er lNVENTOR 1 %//W ATTORNEY Patented Mar. 20, 1945 MELTING APPARATUS Wolf Rodenacker, Berlin-Zehlendorf, Germany;
vested in the Alien Property Custodian Application May 3, 1941, Serial No. 391,751 In Germany January 16, 1940 1 Claim.
My present invention relates to improvements in method and apparatus for melting the bits of organic compositions thermoplastic and fusible at a high temperature. More particularly, it re lates to an improved method for producing foils, films, and the like from fusible high molecular weight linear polymers.
Organic materials thermoplastic and fusible at a high temperature can. be worked up at a great speed into films, ribbons, and filaments or by in jection molding. The employment of great speeds is, however, limited by the melting velocity of the organic composition. Owing to the low thermal conductivity of most of the compositions the heat-conducting surfaces must be made very large. It is therefore necessary to use large melting vessels which require extensive heating as they are to be kept at high temperatures. A further disadvantage of the large melting vessels resides in the fact that large amounts of molten material are continuously maintained therein. A large volume of composition must, therefore, be maintained in the molten condition in which case dificulties are encountered on account of the sensitivity to heat of most of the fusible organic compositions.
It is an object of my present invention to provide an improved method for melting the bits of organic compositions of the kind mentioned above by which a considerable reduction of the melting apparatus and of the amount of heat is position in any form is introduced. At the end or the conduit l the composition is continuously forced, for instance, by a weight laid on it, against a, drum 2 toothed like a milling cutter. Said drum is kept at the melting temperature by an electric heating element 3 obtainingthe current by means of sliprings t. The exact adjustment of the temperature is, for instance, eiiected by heat transfer to a pump body which is maimtained at a constant temperature by a control mechanism. The rotatable drum 2 is driven by a shaft 5 and thus removes the just melted end of the rod whereupon the rod is forced against another hot surface. The drum can be toothed in such a manner that when the solid rod contacts it, the pro-heated composition is simulta neously cut into chips. The molten mass is transferred with a part 5 of the drum 2 to a pump l shownas a gear pump, part 6 being a worm. The thread of the worm is so constructed that a pressure which efiects a complete filling of the toothed wheels is produced for the pump. The
reached. Further objects will become apparent from the reading or the following description.
The objects of the invention are accomplished by using a moving heating body adapted to melt thebits of an organic material and connected with a device for feeding the material to be melted and, if required, a mechanism for feeding the molten composition.
In order to more clearly define this invention, reference is made to the accompanying drawings in which:
Figure l is a front sectional elevation of the melting device constructed in accordance with and embodying the preferred form of my invention,
Figure 2 is a side sectional elevation of the device shown in Figure 1,
Figure 3 is a front .elevational view partly in section of a melting device suitable for the production of films, and
Figure 4 is a side sectional elevation of the device shown in Figure 3.
Referring to the drawings, numeral l designates a conduit through which the organic compitch is, for example, made progressive for this purpose. To this pressure a further pressuresnay be added. An inert gas, which is necessary to exclude the air from the melting chamber is pressed into the storing vessel. It is, however, also possible to employ a melting device with open filling funnel if, for example, carbon dioxide is used for driving-out the air, the pump 7 serves automatically to control the feed of the molten mass to the spinneret l, for if a. greater portion of the composition is melted than that removed by thepump, the level of the melt rises and the heat transfer is solely efiected by conduction of heat from the walls of the conduit l. The rising of the'level of melt therefore effects a lowering of the output. The pump accordingly regulates the charge as well as the discharge automatically.
The method of the invention can also be carried out in a form other than that shown in Figures 1 and 2. A melting device as described above may be used in spinning processes for producing filaments or ribbons, in casting to form films and thick plates and in injection molding. The melting device is constructed dependent upon the amount and form of the composition and the size of the single apparatus which must correspond to the machines for further treating the molten product. The material to be worked up may be employed in any form, for instance, as endless rods or ribbons, strips, cubes, or in granulated or powdered form. As device for feeding the prod- -uctin the conduit to the melting drums racks are positioned which are provided with saw teeth and adapted to move back and forth. Racks are especially suitable-for'feeding products in pieces. The feeding means may also comprise lateral belt conveyers. For granulated or powdered materials worms are preferably suitable. The melting drums must depend in number and size upon the desired power. It is also evident that the grooving of the elements and the condition of their surfaces must correspond to the form of the materials to be treated.
In Figures 3 and 4 a device is shown which is suitable for producing articles having large areas as, for instance, films. The material which is introduced into the vessel 8 falls on the melting drums Lworking in both directions. The drums are connectedwith the feeding worms in constructed as helical pumps engaging into one another. The worm or helical. pump produces a pressure by which the toothed wheels I I mounted together with the worms and milling cutters on the same shaft are filled. The gear pump feeds the melt into a distributing conduit I! from which it is forced into a casting tube IS. A corresponding melting device can be constructed for a spinning apparatus having a great number of spinnerets.
The advantage of the device according to the invention resides in the fact that the part which is to be maintained at a high temperature is especiaily small whereby the amount of heat necessary for melting the composition can be considerably decreased. This is in particular of importance when temperatures of above 200 0. must be kept which areobtained in most cases by electrical heating. A further great advantage is the regulated melting procedure in which the controlling member simultaneously effects the conveyance of the material.
The melting device of this invention is especially suitable ior producing foils, films, and the like from fusible linear high molecular weight polymers such as polyamides and polyurethanes.
What I claim is:.
In an apparatus for melting a loose mass of organic composition having a low thermal conductivity, a vertical conduit for receiving and feeding said composition, a pair of interengaging longitudinally-ribbed melting drums transverse- 1y disposed in the path of said conduit and working in opposite directions, said drums having at one end registering helical feeding worms. and a gear pump to receive and feed the melt downwardly from the helical pump.
|Citing Patent||Filing date||Publication date||Applicant||Title|
|US2515201 *||May 27, 1948||Jul 18, 1950||Dow Chemical Co||Gear pump for metering and extruding hot organic thermoplastics|
|US3492791 *||Nov 15, 1967||Feb 3, 1970||Ici Ltd||Polymerisation apparatus and process|
|US4299559 *||May 13, 1980||Nov 10, 1981||Fuji Photo Film Co., Ltd.||Method and apparatus for melting gel-like substances|
|U.S. Classification||137/565.3, 432/228, 366/97, 366/262, 241/66|
|International Classification||B29B13/02, D01D1/00, D01D1/04, B29B13/00|
|Cooperative Classification||D01D1/04, B29B13/022|
|European Classification||B29B13/02C, D01D1/04|