although a broad range of temperatures , including temperatures of from about 0 ° c . to about 35 ° c ., may be employed to effect the process , particularly in the case of chocolate , as long as such are below the pour point of the chocolate , it has been discovered that the process may be carried out at ambient , i . e ., normal room temperature , and at temperatures below tempering temperatures . hence , the process may be carried out wherein the material has a temperature on the order of from about 27 ° c . down to about 20 ° c . in such preferred embodiments of the process of the present invention , therefore , external means for heating and / or cooling the chocolate during the process are avoided , the process being carried out without additional heating and / or cooling of the material to be processed . however , for precise temperature control , the use of external heating or cooling means is not excluded , as long as the material being extruded is in a substantially non - pourable state . thus , all temperature of the material during extrusion may be a temperature up to the pour point of the material , which may be up to about 35 ° c . depending on the composition of the material , particularly the amount and type of fat , or fat and fat fraction and / or fat - substitute present , higher temperatures being enabled to be employed when the confectionery material contains higher proportions of high melting fat , or fat fraction and / or fat - substitute components . should it be desired to carry out the process at temperatures lower or higher than ambient temperature , cooling means , provided such as by jacketing an extruder means , may be employed , as may heating means , when higher temperatures are desired . also , as indicated above , extruding the material at temperatures of from about 20 ° c . to about 27 ° c . provides substantial advantage , but plain chocolate may also be processed , for example , within temperature ranges of from about 10 ° c . to 34 ° c ., or from about 15 ° c . to about 32 ° c ., but more preferably from about 18 ° c . to 30 ° c ., and most preferably from about 20 ° c . to about 27 ° c . milk chocolates , including white chocolate , also may be processed at temperatures of from about 10 ° c . to about 30 ° c ., or from about 15 ° c . to about 28 ° c ., more preferably from about 18 ° c . to about 27 ° c . and most preferably from about 20 ° c . to about 26 ° c . although the fat - containing confectionery material may be fed into the barrel of an extruder in a liquid or pourable paste for , which would thereby require subsequent cooling to effect a non - pourable form for flow constriction , plasticizing and non - pourable extrusion , preferably , the material is fed into the extruder in a non - pourable solid or semi - solid form . most advantageously , the present invention enables the material to be processed to be previously maintained in a granular form , particularly buttons , and it has been discovered that when in granular form , the granular nature of the material has been found to be at least substantially , if not entirely , lost during extrusion to give an essentially uniform material . in practice of the present invention , plasticization is generated by a differential pressure across the zone of convergence which is provided by a flow constriction . the zone of convergence may be formed by a flow constriction which may be a narrowing of the cross - sectional area of an extrusion conduit , and most conveniently , such may be provided in association with the configuration an extrusion die integral with the output end of an extruder . the zone of convergence may be effected with any of a variety of extrusion means including but not limited to , for example , ram extruders , constant pressure extruders , single and twin screw extruders , or extrusion means such as a davenport extrusion rheometer or a confirm machine , operating under controlled pressures and rates . as will be appreciated , such apparati may provide for continuous or batch operation . as indicated above , the extrusion process requires a construction of the flow of processed material in a zone of convergence . hence , the material deforms before the outlet of the extruder device . the convergence ratio should be greater than 1 . 5 , the convergence ratio being defined as the ratio of the cross - sectional area prior to flow constriction of the area of minimum flow constriction , which , in the case of a die providing such , is the inlet cross - sectional area to the minimum cross - sectional area of the extrusion outlet die for a simple cylindrical extrusion geometry . a wide range of extrusion pressures may be employed , with the caveat that the pressure employed , in combination with the material temperature , does not cause the material to become pourable . pressures employed may range from about 1 bar to about 1000 bars , preferably from about 5 bars to about 500 bars and most preferably from about 5 bars to about 250 bars . as will be appreciated , the extrusion pressure applied and generated is partially dependent on the convergence ratio , the extrusion temperature and the confectionery composition , and it has been found that for a given die configuration and material composition , the extrusion rate is weakly dependent upon the extrusion pressure . in practice of the present invention , it will be found that the flow rate of the chocolate extruded through the extruder die will depend , primarily on extrusion pressure , temperature , die configuration and material formulation . extrusion rates may vary from 0 . 1 cm / sec to in excess of 1 m / sec , for instance . the sectional geometry of the die may be of a square or profiled form , the configuration employed also being affected if such is to be employed as the flow constriction device to provide the zone of convergence . advantageously , the die has a flared or conically shaped entry portion fitted in the extrusion barrel , with a product inlet portion to outlet portion angle , with respect to a longitudinal axis of the extruder , of from about 10 ° to about 90 °, preferably from 30 ° to about 60 °, and most preferably from about 40 ° to 50 °. the extrusion die shapes provide for preparing solid or hollowed profiled products , e . g ., bars , rods , spirals , twists , springs , hollow sections such as tubes and more complex shapes such as the letters of the alphabet , as well as thin films having a thickness which may be as little as 100 microns . the dimensions of the die depend on a desired size of the extruded product , and extruded products may be cut at the die with such as a flying cutter or rotary knife . two or more fat - based materials may be co - extruded in accordance with the process of the present invention , and the fat - containing confectionery material may be co - extruded with other food materials , such as ice creams , fondants , etc ., such being advantageous when the fat - containing confectionery material is extruded in a hollow or tubular form . hence , in such embodiments , a multi - orifice die and / or associated equipment , as are known to those skilled in the art , may be employed . advantageously , the flow constriction plasticizing zone of convergence aspect of the present invention also may be integrated with a mold to provide an integral injection molding process , in which case , the final shape of the product conforms to that of the mold , e . g ., hollow shells , such as &# 34 ; easter eggs &# 34 ;, and other solid shapes . in contrast to other injection molding processes , cooling means and equipment are not essential , and the molded product can be packaged directly . the injection molding therefore is easy to control , and significantly less losses of material , as compared with conventional injection molding using a molten material , advantageously are realized . injection molding thus is effected at the processing temperatures described above , and the material , e . g ., chocolate , is extruded through a flow constriction which forms the injection nozzle of the molding machine . although the temperature of the mold may differ from that of the temperature of the extruded material , it is conveniently approximately the same as the extrusion temperature within the ranges hereinabove described for the extrusion process . in one injection - molding embodiment , the chocolate may flow within channels of the mold and subsequently flow through a narrow gate , e . g ., from 100 and 500 microns , into a mold . the chocolate extrudes into the mold as a flexible filament of semi - solid chocolate . as the extrusion continues , the mold progressively fills with chocolate until all of the mold is filled . at this point , the pressure within the mold is sufficient to allow the full consolidation of the chocolate to occur . when this point has been reached , no further flow occurs and the extrusion pressure can be released . at this point , the mold can be opened and the injection - molded entities removed from the mold either mechanically or , for example , with the air of vacuum means known to those skilled in the art . the injection molding process may also include multi - feed injection into molds using different components in each feed . in addition , the process may be used for coating centers which are positioned in the empty mold before injection molding . the injection molding process may , if desired , be fully automated . the products of the present invention maintain good organoleptic properties and , significantly , they retain their shape and advantageously have an initial flexibility or plasticity after extrusion which may persist for up to several hours before being lost , particularly when the temperature of the extruded products are maintained at a temperature which approximates its extrusion temperature . the flexibility may last or be maintained , for example , for up to 4 hours although such lasts or is maintained for up to 2 hours and more often for from 5 minutes to 1 hour . owing to the flexibility or plasticity of the extrudate , physical manipulation or plastic deformation of the extrudate is possible before the flexibility or plasticity is lost , e . g ., bending , tying into knots , downstream of the die enabling more complex forms of finished products to be achieved . the following examples and description of the accompanying drawing figures are presented to illustrate the present invention further and are meant to be non - limiting . fig1 - 5 illustrate extruded product pressure profiles and flow rates of the process of the present inventions carried out in accordance with examples set forth below . fig6 and 7 illustrate an extruder embodiment for carrying out the process of examples 1 - 4 below . fig8 - 10 illustrate further embodiments of an extruder embodiment which may be employed in carrying out the present invention . set milk chocolate buttons are fed into the barrel of a davenport extrusion rheometer , the barrel having been modified in order to provide a side - mounted pressure transducer immediately above the extrusion die as shown in fig6 and 7 , which illustrate a barrel 10 , piston 11 , pressure transducer 12 , extrusion die 13 of length l , cross - section d and entry angle φ , and a retaining nut 14 . the barrel of the extruder for carrying out the example has a diameter of 19 . 5 mm . two batches of buttons are processed . the chocolate buttons of each batch are equilibrated at a temperature of about 24 ° c ., and are forced at a pressure of about 50 bars through the die , which has a circular cross - section of 4 mm diameter and 8 mm length and a 45 ° entry angle . smooth continuous extrusions , which have flow rates of about 16 mm / sec are obtained , the time evolution of the pressure profile during extrusion being illustrated in fig1 and 2 . as will be seen , after an initial yield pressure is reached , the extrusion pressure drops to an essentially constant value . on the cessation of flow ( after 180 seconds in fig1 ), there is a relaxation of the extrusion pressure . a solid non - pourable , rod - shaped product is obtained which retains its shape , but which is flexible for 30 minutes , during which period it can be bent or even twisted into knots before hardening , if desired . a procedure similar to that described in example 1 is followed , except that the button material extrusion temperature is about 28 ° c . the profile and rate results for two samples are shown in the accompanying fig3 and 4 . a procedure similar to that described in example 1 is followed , except that the button material extrusion temperature is about 18 ° c . the profile and rate results are shown in fig5 . using a hydraulically - driven piston at an essentially constant pressure , it is found that a mass of chocolate extruded through a 4 mm diameter circular orifice with output flow rates of between 1 cm / sec and 100 cm / sec exhibits weak dependence on the differential pressure across the die characterized by a logarithmic - linear relationship when extruding . using the procedure described in example 4 , a chocolate is extruded through a 4 mm die at various temperatures . the following pressures produce similar rates of output : ______________________________________ start - up flowtemperature pressure pressure ° c . bar bar______________________________________20 500 47024 200 18027 50 40______________________________________ a procedure similar to that described in example 4 is followed except that the orifice is replaced by a slit with dimensions of 1 mm × 20 mm . a solid , non - pourable flexible thin ribbon of chocolate is produced at flow rates of from 1 cm / sec to 100 cm / sec . a florin hydraulically driven ram extruder , such as illustrated in fig8 comprises a barrel 15 , a hydraulically driven ram 16 , feed opening 17 , extrusion die 18 having a cross - section of 4 mm diameter and an internal barrel diameter of 25 mm . chocolate buttons having a temperature of about 23 ° c . are dropped in the feed opening 17 followed by hydraulically advancing the ram at a pressure of about 80 bars , and semi - continuous solid non - pourable rods 19 of about 4 mm diameter are produced which retain their shape and have an initial flexibility which lasted for about 40 minutes . a florin extruder , such as that illustrated in fig8 but having a centered &# 34 ; torpedo &# 34 ; 20 positioned in the barrel , is illustrated in fig9 . the same procedure is followed as in example 7 , but instead of producing rods , solid non - pourable hollow tubular sections 21 are produced having an outer diameter of about 10 mm and an internal diameter of about 6 mm . co - extrusion with fondant may be carried out by using a &# 34 ; torpedo &# 34 ; provided with a longitudinal channel through which the fondant flows to give a chocolate coated fondant . a florin ram extruder , such as that illustrated in fig8 but whose die has a cross - section of 5 mm diameter , is adapted to form the injection nozzle of a molding machine , such as illustrated in fig1 . the injection molding of the chocolate is carried out in a manner so that the temperature of both the extruder and the mold is about 25 ° c ., and a pressure of about 80 bars is applied by the ran , and the split mold is clamped using hydraulic pressure . semi - continuous rods 22 flow within the channels 23 and then through the gates 24 , each having a width of about 200 microns , into the hollow spherical molds 25 , each having a diameter of about 12 mm . the chocolate extrudes into each mold as a flexible filament of semi - solid chocolate . as the extrusion continues , the mold progressively fills with chocolate until all of the mold is filled . at this stage , the pressure within the mold is sufficient to allow full consolidation of the chocolate to occur . when this point has been reached , no further flow occurs , and the extrusion pressure is released . the mold then is opened , and the injection molded chocolate entities are removed from the mold . unlike most other injection molding processes , it is not necessary to cool the product immediately after the injection molding , and the product is enabled to be packaged directly . as is clear from the foregoing , various modifications of the present invention may be made without departure from the spirit and scope of the disclosure , and the invention may be practiced suitably in the absence of elements and / or process steps not specifically disclosed herein .
chocolate products are formed by feeding solid set chocolate to an extruder and passing the chocolate through the extruder at a temperature below the pour point of the chocolate to deform and extrude the chocolate .