EP0712593B1 - Method and casting apparatus for the manufacture of lipsticks having a casing inner core - Google Patents

Abstract

The method involves determining and setting the cycle time for the rotation of the casting table w.r.t. the melting temperature of the poured material that makes up the coloured outer coating of the lipstick, the pre-heat temperature and pre-heating time and the cooling temperature and cooling time of the mould. The core insert is wetted through vertical sprues with a separating medium e.g. silicon oil. The mould is warmed by a warm water circulation. The next step involves the removal of an insert from a ready position and fixture in a pouring position thus forming six moulds in a sector. The space between the core insert and the mould is filled with the molten, coloured coating material from the bottom by dip filling process. The mould is then cooled by water circulation. The insert is then ventilated in two stages, the first has the insert being removed 2 to 3mm from the mould, while the molten material is still soft, and held in this position fro 4 seconds. The second stage of the ventilation has the inset withdrawn 0.5 to 1mm form the mould. The hollow core, formed by the insert is then filled with a second molten material.

Description

Processes and casting machines for the automatic production of a lipstick without a caring inner core are already known.

The known casting plants consist essentially of a fixed table part, a clocked rotating casting table with two rows of radially arranged casting molds, devices for metered filling and temperature control of the casting compound, for heating and cooling the casting molds and for ejecting the shaped object by means of compressed air.

According to the known methods, the casting molds are heated by means of a tempered water circulation and the molten casting compound is introduced into the latter by means of an immersion nozzle. The casting molds are now cooled until the casting compound solidifies, the cast lipstick is then ejected from the casting mold by means of compressed air, and at the same time the base of the lipstick is placed in a lipstick holder.

With these known methods and casting machines, the production of a lipstick with a nourishing inner core is not readily possible.

The invention has for its object to provide the known methods and casting plants in such a way that an automatic, variable and inexpensive manufacture of a lipstick with a nourishing inner core is made possible.

This object is achieved by the features mentioned in claim 1 and in the characterizing part of claim 2. Appropriate configurations of the casting plant are disclosed in claims 3 to 5.

The advantages of the invention are that through training the insert device and the receiving sectors are guaranteed an exact horizontal fixation in the preparation position or in the casting position and vertical guidance during the lifting. By lifting the insert device in two phases, the gap between a core insert and the cast lipstick outer jacket is gradually increased depending on the crystallization process so that the cast lipstick outer jacket is not pulled out of the mold during lifting.
The introduction of the core casting compound into the core cavity and the melting of the head zone of the lipstick outer jacket depending on the crystallization process of the lipstick outer jacket or the inner core and the filling of the inner core ensures a material bond between the two casting compounds in the foot area of the lipstick and thus sufficient anchoring of the Inner core in the lipstick outer jacket. This makes it possible to easily carry out the subsequent demolding of the lipstick from the mold using compressed air.

Fig. 1 -

eine Lippenstif-Gießanlage zur automatischen Herstel lung eines Lippenstiftes mit pflegendem Innenkern in Draufsicht;

Fig. 2 -

die Vorderansicht einer in die Gießformen eingesetz ten Einsatzvorrichtung im Schnitt;

Fig. 3 -

die Anordnung der Gießformen eines Sektors im Gieß tisch in Draufsicht;

Fig. 4 -

die Draufsicht einer in die Gießformen eines Sektors eingesetzen Einsatzvorrichtung;

Fig. 5 -

die Vorderansicht einer Einsatzvorrichtung in Bereit stellungsposition, teilweise im Schnitt;

Fig. 6 -

die Anordnung der Aufnahmebohrungen und der Aufnahme bolzen eines Aufnahmesektors in Draufsicht;

Fig. 7 -

den Schnitt A - A nach Fig. 5.

The invention will be explained in more detail below using an exemplary embodiment. The accompanying drawing shows:

Fig. 1 -

a lipstick pouring system for the automatic manufacture of a lipstick with nourishing inner core in plan view;

Fig. 2 -

the front view of an inserted into the molds th insert device in section;

Fig. 3 -

the arrangement of the molds of a sector in the casting table in plan view;

Fig. 4 -

the top view of an insert device inserted into the molds of a sector;

Fig. 5 -

the front view of an insert device in the ready position, partially in section;

Fig. 6 -

the arrangement of the mounting holes and the mounting bolt of a recording sector in top view;

Fig. 7 -

the section AA according to FIG. 5.

As can be seen from FIG. 1, the lipstick casting system consists of a clockwise rotating casting table 1, which is peripherally surrounded by a fixed table part 2. The drive of this casting table 1 and the associated control shaft takes place in a known manner via a gear motor which is infinitely variable in speed, the casting table 1 being rotated at a uniform cycle frequency, the cycle time of which can be adjusted electronically in accordance with the composition of the casting compound and other casting parameters. A total of 180 molds 3 are arranged in two rows in the edge region of the casting table 1. The mold bundles 4, d. H. the upper ends of the molds 3 out of the plane of the casting table 1, as shown in Fig. 2. Parallel to and aligned with the two-row radially arranged casting molds 3, two rows of receiving bores 5 are formed in the rotatable casting table 1, which bores serve for the temporary receiving of an insert device 6 (FIGS. 1.5 and 7). With the aid of this insert device 6, the cavity for the nourishing inner core is formed in the interior of the lipstick outer jacket when the manufacturing process is carried out, which will be explained in more detail below.

Six of these receiving bores 5 each form a receiving sector 7, in which the insert device 6 is positioned in preparation (FIG. 6). All receiving bores 5 have the same diameter. The middle receiving bore 5 of the lower row is additionally provided with a sleeve 8, the diameter and projection of which corresponds to the level of the casting table 1 of the arrangement and design of the casting molds 3 (FIGS. 2 and 3). In the upper row of each receiving sector 7, a position-determining element in the form of a receiving bolt 9 is provided between the middle and left or right receiving hole 5, which is connected to one in the insert device 6 trained groove 10 is engaged.

The structure of the insert device 6 is shown in FIGS. 2, 4, 5 and 7.
Such an insert device 6 consists of a trapezoidal plate 11 with 6 core inserts 12, the upper end of which is fastened in the plate 11 and guided flush through it. The core inserts 12 are arranged in the plate 11 so that the distances between their center lines correspond to the center line distances of the casting molds 3. The outer jacket of the core inserts 12 is slightly conical. The upper outer diameter is expediently 5.5 mm and the lower outer diameter is 5 mm.
A vent hole 13 is made along the center line of each core insert 12. The diameter of this vent hole 13 is 30 to 40% of the mean outside diameter of a core insert 12. Preferably, the vent hole 13 has a diameter of 2 mm.
The length of the core inserts 12 protruding from the underside of the plate 11 is greater, preferably 0.5 mm greater than the mean depth of the casting molds 3. The lower end of each core insert 12 has a slope which corresponds to the inclination of the bottom of the casting molds 3 corresponds (Fig. 2). Six recesses 14 to 19 and two grooves 10 are formed on the underside of the plate 11 (FIG. 7). The recesses 14 to 19 serve, on the one hand, to hold the mold bundles 4 and thus to position the insert device 6 horizontally after insertion into a sector of six molds 3. On the other hand, the recess 15 and the two grooves 10 horizontally position the insert device 6 during Provision position within a receiving sector 7. In the plate 11, a filling opening 20 is also provided in the area between the outer jacket of a core insert 12 and the inside diameter of a casting mold 3, through which the casting compound for the coloring outer jacket is introduced into the casting mold 3.

The rear and front end faces of the plate 11 carry one or two recesses 21 for the engagement of two handling devices 22 and 23 arranged on the fixed table part 2.
As further components of the lipstick casting system, two adjustable spray nozzles (not shown in the drawing) directed at the core inserts 12 (not shown in the drawing) in front of the handling device 22 in the area of the two-row receiving bores 5 below the casting table 1 and a spray unit in front of the handling device 22 on the fixed table part 2 24 arranged with two vertically movable, adjustable spray nozzles.
Furthermore, between the handling device 22 and 23 in the direction of rotation of the casting table 1 on the fixed table part 2 one after the other, a device 25 for metered filling of the casting molds 3 with casting compound for the coloring lipstick outer jacket with two vertically movable immersion nozzles, a pneumatic cylinder aligned in the direction of the center of the casting table 26 with an extendable piston rod 27 and with a wedge-shaped plastic body 28, which is connected to the piston rod 27, and an inclined plane 29 with an inclination angle of 2 °.
In the direction of rotation of the casting table 1, the handling device 23 is followed by a device (not shown in the drawing) for optically checking the core inserts 12, a device 30 for metered filling of the cavity formed by the core inserts 12 with core casting compound and a melting unit 31 with an infrared heating element at. These aforementioned devices are also installed on the fixed table part 2 and extend into the edge region of the casting table 1.
The lower part of the casting table 1 is overlaid by a counter-rotating turntable 32, in the outer edge region of which lipstick holders 33, which are also generally referred to as pomade holders, are inserted. This turntable 32 operates at the same clock frequency as the casting table 1 and is arranged so that there is always one cycle two lipstick holders 33 are located over two molds 3 with the cast lipsticks. A pneumatic ejection unit known per se is installed below these two casting molds 3, but is not shown in the drawing.

A lipstick with a nourishing inner core is produced in the following way:

At the beginning of a production cycle, the core inserts 12 of the insert device 6 in the ready position are sprayed in by means of the spray nozzles installed underneath the casting table 1 and the molds 3 are sprayed with a release agent, preferably silicone oil, by means of the spray unit 24.

Thereafter, the molds 3 are heated by tempered water which flows around the molds 3.

In the next step, the handling device 22 grips an insert device 6 on the trapezoidal plate 11 and fixes it in a sector of six casting molds 3, ie the handling device 22 conveys the insert device 6 into the casting position. The engagement of the casting mold collars 4 in the cutouts 14 to 19 on the underside of the plate 11 ensures a precise horizontal positioning of the insert device 6 in a casting sector with six casting molds 3.
Because the length of the core inserts 12 is greater than the average depth of the casting molds 3, the core inserts 12 are supported on the bottom of the casting molds 3, thereby preventing casting material for the coloring lipstick outer jacket from penetrating at this point, which is not desirable for optical reasons. On the other hand, a ventilation gap is deliberately created between the mold bundles 4 and the underside of the plate 11, which prevents a negative pressure from occurring during the lifting of the insert device 6 forms and the outer lipstick coats are pulled out of the molds 3. At the same time, this gap enables better engagement of the wedge-shaped plastic body 28 during lifting.
The dimensioning of the vent hole 13 is of particular importance insofar as, on the one hand, adequate ventilation must be provided to prevent the occurrence of a negative pressure when the insert device 6 is lifted, on the other hand, a relatively large bore diameter increases the surface pressure at the point of use, which means that at one frequent use of the insert 6 damage to the bottom of the mold 3 can occur.

By means of the device 25, the metered immersion filling of the cavity located between the casting mold 3 and the core insert 12 now takes place with molten casting compound for the lipstick outer jacket. For this purpose, an immersion nozzle passes through the filling opening 20 in the plate 11 and introduces the casting compound from the bottom of the casting mold 3 into the cavity.

After pouring the outer lipstick jacket, the cooling of the molds 3 begins, which is maintained until the complete lipstick is completed. Cooled in a known manner by means of a tempered water circulation which flows around the casting molds 3.

At a point in time when the crystallization process has not yet started within the casting compound for the lipstick outer jacket and thus the shrinking process, the insert device 6 is lifted uniformly in two stages as the next step.
At this point in time, the lipstick outer jacket is still in a somewhat pasty state. The time for lifting is therefore of particular importance, since in the event that the shrinkage has already started, the lipstick outer jacket shrinks onto the core insert 12 and would be pulled out of the mold 3 during vertical lifting.
In the first ventilation stage, the piston rod 27 of the pneumatic cylinder 26 travels horizontally with a uniform movement within 3 seconds while the casting table 1 is at a standstill and presses the wedge-shaped plastic body 28 into the gap between the underside of the plate 11 and the casting table 1.
In order to enable a better engagement, the tip of the plastic body 28 is expediently provided with a radius of 3.5 mm.
This movement of the plastic body 28 causes the insert device 6 to be moved vertically 2 to 3 mm, ie pulled out of the molds 3. The fact that the mold collars 4 are in engagement with the cutouts 14 to 19 on the underside of the plate 11 provides adequate vertical guidance which prevents the insert device 6 from tilting when it is lifted.
The plastic body 28 maintains its extended position for 4 seconds. The casting table 1 now moves further in the next cycle in the direction of rotation, as a result of which the insert device 6 which has been lifted in the first stage is transferred to an inclined plane 29 with an inclination angle of 2 °.
The further rotation of the casting table 1 has the consequence that the insert device 6 in the second stage is again pulled out of the casting molds 3 vertically by 0.5 to 1 mm.

The handling device 23 grips the insert device 6 on the plate 11, pulls it completely out of the six molds 3 of a sector and sets it down again in the ready position.
In the subsequent method step, the core inserts 12 are visually checked for the presence of parts or complete lipstick outer shells. For this purpose, the insert device 6 is again vertically removed from the receiving sector 7 by the handling device 23 Core inserts 12 are scanned by means of optical sensors and deposited again in the receiving sector 7. The result of the optical check is reported to the control of the casting table 1. In the event that remnants of the lipstick outer casing are on a core insert 12, the rotation of the casting table 1 is stopped so that the core insert 12 can be cleaned.

After the crystallization process of the cast lipstick outer jacket and thus its shrinking process is completed by the continuous cooling of the casting molds 3, in a further process step the device 30 immerses the formed core cavity with molten core casting compound.
For this purpose, an immersion nozzle moves vertically to the bottom of the mold 3 and introduces the casting compound into the core cavity in a metered manner from the bottom up. The core casting compound is dosed so that the nourishing inner core is underfilled by 2 to 3 mm compared to the length of the lipstick outer jacket. The inner core is therefore shorter than the outer lipstick jacket by the aforementioned amount.

Shortly before the end of the inner core shrinking process, which can be seen in the fact that a funnel or a so-called sink crater forms in the upper part of the cast inner core, the head zone of the lipstick outer shell is melted in the subsequent process step with the aid of the melting unit 31. The melted casting compound for the lipstick outer jacket flows into the funnel formed in the inner core, the so-called coring, and melts it down again somewhat. This creates a material bond between the two casting compounds and the inner core is practically encapsulated by the excess lipstick coating compound.
The point in time for melting is of particular relevance. On the one hand, the lipstick outer jacket must have cooled to such an extent that only the head zone and not the rest of the area the outer shell is melted. On the other hand, if the inner core is already relatively cold, the formation of cavities, for example in the form of air pockets, can occur when the molten lipstick coating mass flows in, which counteracts the desired material bond between the two casting compositions. A firm anchoring of the inner core in the lipstick outer jacket cannot be guaranteed in this way.
However, this anchoring is a prerequisite for carrying out the next process step, namely the demolding of the cooled lipstick from the casting mold 3 and the introduction into the lipstick holder 33 by means of compressed air.
As already explained, a pneumatic ejection unit is installed below the two casting molds 3 which are to be removed from the mold and, at the time of the intended removal from the mold, are connected to a bore arranged in the bottom of each casting mold 3. Compressed air is introduced into the casting mold 3 via this bore in a known manner, as a result of which the lipstick is removed from the casting mold 3 and "shot" into the lipstick holder 33.
If there is no firm anchoring between the inner core and the lipstick outer jacket, the inner core is "shot out" of the lipstick outer jacket by introducing the compressed air. This is certainly also favored by the fact that there are still residues of the silicone oil from the wetting of the core inserts 12 on the inner core.

Claims (5)

1. Process for the production of a lipstick with curative internal core with the following phases:

   - Detecting and adjusting the clock time for the rotation of the mould frame depending on the melting temperature of the charge for the colouring external lipstick coat and for the curative internal core, on the preheating temperature and preheating time respectively the cooling temperature and cooling time of the casting moulds;

   - vertically conducted spraying the core inserts an casting moulds with a separating agent, preferably silicon oil;

   - heating the casting moulds by a tempered water circulation;

   - withdrawing an insertion device with six core inserts out of the disposal position and fixed insertion into the casting position, which is formed by a sector of six casting moulds;

   - dosed plunge-filling of the cavity between the casting mould and the core insert, led from the bottom of the casting mould vertically upwards, with melted charge for the colouring external lipstick coat;

   - cooling the filled casting mould by a tempered water circulation;

   - lifting vertically in a uniform way the insertion device in two phases at a moment in which the crystallization process within the charge and thus the shrinking process has not yet started and the external coat of the lipstick is still in a more or less pasty condition, in which the insertion device in the first lifting phase is extracted vertically for 2 to 3 mm out of the casting moulds, this position is maintained for 4 seconds and in the second phase the insertion device is again extracted vertically out of the casting moulds by 0,5 to 1 mm;

   - completely extracting the insertion device out of a sector of six casting moulds and laying it down again in disposal position;

   - withdrawing an insertion device out of the disposal position, optical check of the core inserts on the presence of charge of the external lipstick coat and signalling defects to the control system of the mould frame;

   - dosed plunge-filling, conducted from the bottom of the casting mould vertically upwards, of the core cavity with melted charge for the curative internal core after the crystallization process of the cast external lipstick coat and thus its shrinking process has ended, introducing the charge for the internal core into the core cavity in a level that is by 2 to 3 mm lower than the level of the cast external coat of the lipstick;

   - melting-on the head zone of the external coat of the lipstick shortly before the end of the shrinking process of the internal core and encapsulating the cast internal core, at the same time going on with the cooling of the casting moulds;

   - cooling the casting moulds until the crystallization and solidification of the melted-on head zone of the external coat of the lipstick as well as of the internal core;

   - removing the cooled lipstick from the casting mould and inserting it in the lipstick holder by means of compressed gas, preferably compressed air.
2. Casting plant for the production of a lipstick with curative internal core, essentially consisting of a fixed frame part, a rotating clocked mould frame with casting moulds disposed radially in two lines, of a device for the dosed filling and tempering of the charge, for heating and cooling the casting moulds as well as for expelling the formed object by means of compressed air, characterized by the fact that parallel and aligned as to the casting moulds (3) disposed radially in two lines, in the rotating mould frame (1) two lines of location holes (5) are formed for temporarily locating an insertion device (6) for forming each time the internal core cavity, in which each time six location holes (5) form a location sector (7) and the central location hole of the lower line of a location sector (7) is provided with a manifold (8), whose diameter and protrusion as to the plane of the mould frame (1) correspond to the arrangement and form of the casting moulds (3) and in the upper line of each location sector (7) between the central and the left respectively right location hole (5) each time a position-defining element in the form of a location bolt (9) is provided and that the insertion device (6) includes a trapezoidal plate (11) with six core inserts formed slightly conically (12), in which the upper ends of the core inserts are fixed in the plate (11) and are carried through it evenly, the length of the core inserts (12) that protrudes out of the lower side of the plate (11) is longer than the mean depth of the casting moulds (3) and the lower end of each core insert (12) presents a slope which corresponds to the inclination of the bottom of the casting moulds (3), and that along the centre line of each core insert (12) a ventilation hole (13) is applied, the diameter of which is 30 to 40% of the mean external diameter of a core insert (12) and the core inserts (12) are arranged in the plate (11) according to the centre line distances of the casting moulds (3) of a sector, and that the insertion device furthermore is distinguished by the fact that on the lower side of the plate (11) six recesses (14 to 19) for locating the collars (4) of the casting moulds protruding out of the frame mould (1) plane and two grooves (10) for the two location bolts (9) are provided, that, radially staggered as to the core inserts (12) each time a filling opening (20) is applied in the plate (11) and that at the rear and front frontal surface [sic] of the plate (11) one or two countersinkings (21) are provided for the engagement of two handling apparatuses (22 and 23), and characterized by the fact that between a device (25) for the dosed filling of the casting moulds (3) with charge for the colouring external lipstick coat and the second handling apparatus (23) on the fixed frame part (2) that surrounds the frame mould (1) peripherically, one after the other, a pneumatic cylinder (26) oriented in direction of the mould frame centre whose extractable piston bar (27) is provided with a wedge-shaped plastic body (28), as well as a tilted plane (29) with an inclination angle of 2° are arranged, and that between the second handling apparatus (23) and a device (30) for the dosed filling of the core cavity with core charge, a device for the optical control of the core inserts (12) is installed on the fixed frame part (2) and that the device (30) for the dosed filling of the core cavity is followed by a melting-on unit (31) with an infrared heating bar.
3. Casting plant according to claim 2, characterized by the fact that the lower external diameter of the conical core inserts (12) is 5 mm, the upper external diameter is 5,5 mm and the diameter of the ventilation bore (13) 2 mm.
4. Casting plant according to claim 2, characterized by the fact that the length of the core inserts (12) that protrudes out of the plate (11) is longer by 0,5 mm than the mean depth of the casting moulds (3).
5. Casting plant according to claim 2, characterized by the fact that the tip of the wedge-shaped plastic body (28) has a radius of 3,5 mm.

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