JPH0479241B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention provides a method for integrating a sole into a shoe shaft with an elastomeric sole and an intermediate sole made of a mixture of isocyanates and polyols that are fully reactive with polyurethane. A forming station for forming, in particular for a circular table arrangement, in which the midsole and the sole are bonded to each other by chemical bonds between the isocyanate and the substance added to the reactive end groups of the elastomer. coupled, the forming station having a height-adjustable beam with a pivotably supported mold part holder, the mold part holder having at least one mold part holder for molding the sole. a second height-adjustable beam having a heatable mold portion and a second height-adjustable beam having a heatable plate disposed below the height-adjustable beam; The pivotable mold part holder cooperates with the heatable mold part of the pivotable mold part holder to mold, and the pivotable mold part holder is placed over the side mold part and the sole to mold the midsole. Relating to a type that cooperates with a shoe shaft.

BACKGROUND OF THE INVENTION Shoes with an intermediate sole made of polyurethane and a sole also made of polyurethane are known (German Patent No. 2 241 493).

To produce such shoes, a circular table arrangement with several molding stations with molds is generally used (brochure of Kretzkner Feromatik Desma, injection direct shoe molding machine DESMA, pages 521-526). .

The round table device has two mixing devices for mixing isocyanate and polyol into a mixture that is completely reactive with polyurethane, and depending on the mixing ratio and additives, the mixture is mixed into abrasion-resistant soles or abrasion-resistant soles. Fully responsive with elastic midsole.

The circular table is rotated in steps to form the sole and midsole. In this case, the forming station is engaged with both mixing devices one after the other.

Both mixing devices are arranged radially movably around and towards the circular table. The forming station is in the closed position 1
It has two side mold parts defining one cutout and two injection passages.

A last swivel body having a last for receiving a shoe shaft and an opposing punch is arranged above the side mold part in a height-adjustable manner.

A bottom punch is arranged under the side mold part so that its height can be adjusted. To form the sole, the sole punch, the lateral mold parts (in the closed position) and the opposing punch define a cavity into which a mixture is provided which is completely reactive to the sole.

To form the midsole, the sole punch with the sole, the side mold parts (in the closed position) and the sole covered with the shoe shaft limit the cavity, in which the midsole is A completely reacted mixture is obtained, and the intermediate sole is completely bonded to the sole and shoe shaft during the course of the reaction.

According to Section 3, Paragraph 2 of the West German Patent Act, a molding station for a circular table is known for molding soles with an elastomer sole and a polyurethane midsole (P3600682.3).

To mold elastomer soles, the elastomer is plasticized, as is known in injection molding machines for processing thermoplastic materials, instead of in mixing equipment that mixes completely reactive mixtures into polyurethane soles. A plasticizing and injection unit is used, in which the elastomer is then injected into the cavity for the sole. Because of the high pressures that occur during the injection of plasticized elastomers, the forming station known according to Section 3(2) of the Patent Law is equipped with a height-adjustable beam with a pivotably mounted mold part holder. A heatable mold part with a cavity corresponding to the sole of the shoe and additionally provided with cooling channels is arranged on a side surface of the mold part holder parallel to the pivot axis.

A second height-adjustable beam is arranged below this beam, which beam has a heatable plate on the side facing the pivotable mold part holder, which plate has a heatable plate. cooperates with the heatable mold part of the mold part holder to produce the mold part holder. A further beam with a recess is arranged immovably above the beam with the pivotable mold part holder. A heatable mold part enters into this cutout together with the elastomeric sole in the cavity, two lateral mold parts located above the cutout and a shoe shaft and polyurethane mold placed over the last. work together to form a made midsole.

Mixtures for soles and midsoles that are fully reactive with polyurethane include primarily polyols, isocyanates, chain extenders and catalysts,
These mixtures depend on the material properties desired for the sole or midsole (i.e. the sole is preferably wear-resistant, the midsole is preferably elastic and has a porous structure). Adjusted by suitable additives.

A chemical reaction begins already when the ingredients are mixed. The mixture completely reacts with the sole or midsole in the mold. Upon complete reaction of the mixture for the midsole, the midsole is simultaneously formed and the connection with the shoe shaft and sole is achieved.

The elastomer sole and the polyurethane midsole are bonded to each other in the area of their interface by chemical bonds between the isocyanate and the reactive end groups of the substances added to the elastomer.

A mixture that completely reacts with polyurethane is a mixture based on ether or ester polyolene, and this mixture is composed of 30-100% by weight of isocyanate, 0.1-10% by weight of catalyst, and a chain residue as a residue. Contains extenders and other commonly used additives.

The catalyst used is in particular the catalyst DABCO-SB, which is available on the market under the trade name Air Products.

The elastomer used to manufacture the sole of the shoe has a rubber content of 0%, such as acrylonitrile rubber, styrene-butadiene rubber, natural rubber, and chloroprene rubber.
It can be mixed with the following compounds or chemicals in amounts of ~20 phr.

Shoe soles can generally be manufactured from all known rubbers, for example when the following substances are incorporated in amounts (relative to the rubber used) from 0 to 20 phr: Phenol formaldehyde resins, for example: Vulkadur A (Bayer AG ), Coretack (BASF) methylolated phenol formaldehyde resin,
For example: SP 1045 (Krahn) Korever (BASF) Resorcin in connection with formaldehyde dispensers, for example: Cohedur A Cohedur RS Cohedur RK (Bayer AG) Silicic acid fillers, for example: Vulkasil S (Bayer AG) Ultrasil (Degussa) Amino alcohols , for example: 3-amino-propanol primary or secondary amines, for example: stearylamine polyvinyl alcohol, for example: Mowiwol (Hoechst) VSH72 (AIR PRODUCTS) VSH73 (AIR PRODUCTS) polyols with a high hydroxyl content, for example: Formrez (Witco) Acrylate rubber (ACM) For example: Hydrin (Polysar) Herclor (Hercules) or combinations of the above-mentioned substances The formation of elastomeric soles is carried out as follows. That is, the elastomer is plasticized at normal processing temperatures and injected into a suitable cavity in an injection molding machine at correspondingly high pressures as in conventional technology.

Control of the temperature of the elastomer is performed as follows. That is, the temperature of the injected sole is cooled to just below the additive temperature of the polyurethane of the midsole to be formed, and then a completely reactive mixture of polyurethane is brought into contact with the molded sole;
In this case, the reactive end groups of the isocyanate react in the boundary layer of the polyurethane which completely reacts the elastomer.

In practice, when controlling the temperature of the elastomer, a temperature increase or decrease of 10 DEG C. causes a shortening or lengthening of the vulcanization time, ie the time for the elastomer to fully react, by 50%.

The cooling rate of the elastomer sole to the temperature at which the mixture completely reacting with the polyurethane midsole is supplied to the cavity for the midsole is determined primarily by the mold part arranged in the pivotable mold part holder. defined by its high heat capacity.

As a result of this cooling rate, the time for forming and cooling the sole is significantly longer than the time required to form the midsole.

Special problems also arise from:
That is, cooling the sole from the relatively high temperature at which the plasticized elastomer is injected to the temperature for forming the midsole results in changes in the dimensions of the sole that are no longer acceptable. In general, it is impossible to ignore this shrinkage in all elastomers, and therefore, the mold section with the cavity that serves to mold the elastomeric sole is then cooled, then the mold for the side molding. It is not possible to cooperate with the shoe shaft, which is placed over the part and the last, for the production of the midsole.

OBJECT OF THE INVENTION It is therefore an object of the invention to improve a forming station of the type mentioned at the outset and to provide a forming station which takes into account the shrinkage in elastomer soles.

Means for Solving the Problem In order to solve this problem, the configuration of the present invention includes:
A pivotably mounted mold part holder has a mold part which, on a side parallel to the second height-adjustable beam, is provided with a cavity for the sole and cooperates with the heatable plate. and on the other side,
a pivotably supported mold part holder having a cavity for receiving an already molded sole and having a lateral mold part and a mold part cooperating with a shoe shaft placed over the last; A height-adjustable last receiver with a last swivel is arranged on the beam with the body, the last swivel receiving a last for the shoe shaft and a molded shoe. A vacuum-loadable punch is provided for taking off the sole and transferring it after cooling to a cavity for an already formed sole.

Effects of the Invention With this construction, the still hot elastomer sole is received by the opposite punch of the sole receiving part, which can be subjected to vacuum or negative pressure, and after cooling, the elastomeric sole is slightly and slowly contracted. For proper cooling, the mold part is passed into a cavity, which cooperates with the lateral mold parts and the shoe shaft placed over the last to form the polyurethane midsole.

The dimensions of the cavity for molding the elastomer sole are such that after cooling in the opposed punch the sole has the predetermined dimensions in the finished shoe, i.e. it is placed over the side mold parts and the last. The cavity of the mold part cooperating with the shoe shaft is likewise configured to have the dimensions of the sole after cooling, i.e. in the final state.

According to an embodiment of the invention, a mold part with a cavity can be applied with a vacuum for receiving the sole, the mold part having a hole opening into the cavity.

Example Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 schematically shows a circular table arrangement in plan view. On the circular table 1 of this circular table arrangement, fourteen forming stations 2 are arranged, indicated by squares, which at the same time indicate the positions occupied by the forming stations during a stepwise rotation of the circular table. There is. In the illustrated embodiment, each molding station returns to its original position after 15 steps of the circular table. These positions _are designated _201-214 .

A plasticizing and injection unit 3 for the elastomer is arranged around the circular table, which is moved by a radial movement towards the circular table after each working step (see double arrow). ), each time brought into engagement with the forming station 2 occupying position ₂₀₁ . As soon as the plasticizing and injection unit 3 engages the molding station, the elastomer is injected into the molding cavity for the sole.

Furthermore, a mixing device 4 for mixing the polyurethane-reactive mixture is also arranged radially movably towards the circular table. After each working cycle, this mixing device 4 can likewise be engaged with a working station which has reached the corresponding working position ₂₀₃ , whereby the intermediate sole is formed. Depending on the reaction time or vulcanization time of the materials used, the unit 3 and the mixing device 4 can also be interchanged.

In FIGS. 2 to 6, exemplary embodiments of the molding station according to the invention are shown in side views in different working positions, ie in the direction of the plasticizing and injection unit 3 (toward the mixing device 4).

FIG. 2 shows the molding station 2 and the mold parts for molding the sole and the midsole in the closed position.

The forming station has four guides 5, only two of which are visible in the drawing.

The guide, together with a fixed beam 6 and a beam 8 with a recess 7, forms a fixed guide frame for a height-adjustable beam 9;
The height-adjustable beam 9 has a mold part holder 11 which is mounted pivotably about a pin 10.

A second height-adjustable beam 12 is arranged below the height-adjustable beam 9 .

This height-adjustable beam 12 has a mold-holding cylinder 13 on the side facing the beam 6 and a heatable plate 14 on the side facing the beam 9.

Two traveling cylinders 15 are fixed to the beam 6, and piston rods 16 of both traveling cylinders are fixed to the beam 6.
is combined with a height-adjustable beam 12.

The pivotably mounted mold part holder 11 is
In the position shown in the figure, on the side facing beam 12,
It has a mold part 17 with a cavity 18 having the dimensions of the sole to be molded. The mold part 17 is arranged on a heating block 19 which is itself connected via a heat insulating plate 20 to the pivotably mounted mold part holder 11.

The mold part holder 11 has, on a second side opposite the beam 12 and parallel to it, a cooling plate 21 through which a cooling medium flows. A mold part 22 is arranged on the cooling plate 21 .

This mold part 22, which is cooled by a cooling plate 21, has a cavity 23 corresponding to the dimensions of the sole of the shoe.
have.

Inside the beam 8 and above its recess 7 two mold parts 24, 25 for side shaping are arranged, both mold parts delimiting a recess in its closed position, which recess A shoe shaft 27 placed over a last 26 and a mold part 22 with a formed sole (not shown) form a cavity for molding the midsole.

When injecting soles made of elastomer, high injection pressures occur, similar to those in injection molding machines processing thermoplastic materials. It is necessary to provide

As can be seen in FIG.
and a mold part 17.
8, the reaction force is exerted via the frame formed by the beams 6 and 8, in which case the pivotable mold part holder 11 is moved in the edge area of the recess 7 in the beam 8. Supported by

The height-adjustable beam 9 is entrained via rods (not shown) when the beam travels, so that in the position of the travel cylinder shown in FIG. 3, the beam occupies the position shown.

The forming station is a beam 8 with a cutout 7
It has a height-adjustable last receptacle 29, known per se, with a last swivel 31 which can be pivoted about a pin 30.

A shoe last 26 and a punch 32 having an end plate 33 are fixed to the last rotating body 31.

The plate 33 has passages 34 opening on its surface, to which a vacuum or negative pressure can be applied via a vacuum device (not shown).

FIG. 2 shows the position of the beam of forming station 2 at position ₂₀₁ .

In this position the plasticizing and injection unit 3 is moved radially towards the forming station.
It is brought into contact with an injection hole (not shown) in the cavity 18, and at this time, the plasticized elastomer is injected into the cavity.

The molding station is located in the cavity 18 according to the appropriate number of working steps on the circular table _.
The closed state is maintained from the position 2 ₀₂ , 2 ₀₃ , 2 ₀₄ , . . . 2 ₀₈ , 2 ₀₉ , 2 ₁₀ until reaching the position 2 ₁₁ again.

Traveling cylinder 1 again in the obtained position 2 ₁₁
5 is loaded in such a way that both height-adjustable beams 9, 12 occupy the position shown in FIG.

In this position of both beams, the pivotably mounted mold part holder 11 is swiveled through 180°;
As a result, the cooled mold part 22 is located opposite the heated plate 14, and the mold part 17 with the still hot elastomeric sole occupies the position of the mold part 21 shown in FIG. .

The height-adjustable last receptacle is moved from the position shown in FIG. 2 to its upper end position, and at the same time the lateral mold parts are moved into their maximum open position. The last swivel is swiveled through 180 DEG, so that the end plate 33 of the punch 32 is directed towards the elastomer sole.

As shown in FIG. 4, the height-adjustable last receptacle is moved into its lower end position, at the same time the running cylinder 15 moves the movable beam 12.
The spring 36 moves the upper beam 9 to a height that moves it to the position shown, and this movement continues until the sole L is contacted by the plate 33.

The passages 34 of the plate 33 are then loaded with a vacuum or negative pressure, so that the sole is taken up by the plate 33.

As shown in FIG. 3, the slidable beam 9 with the pivotably mounted mold part holder 11 is moved into the lower position shown in FIG. 3, so that it can be pivoted. The turning range for turning the mold part holder is opened.

In this position of the slidable beam 9, the pivotable mold part holder is pivoted through 180 DEG, so that the cavity of the mold part 22 is again oriented towards the sole.

The slidable beam 9 with the pivotable mold part holder is then moved into the upper position shown in FIG. 6, in which the cavity of the mold part 22 is further directed towards the plate 33.

The height-adjustable last receiver is moved towards the mold part 22 until the cooled elastomer sole contacts the cavity 23 .

Pressure is then applied to the channels 34 of the plate 33, so that the cavity 23 takes on the sole of the shoe. The mold part 22 has a hole 3 that opens into the cavity.
5, in which case the cooled sole is taken over by the vacuum load. After the sole is ejected into the cavity 23, the height-adjustable last receiver is moved to the upper position shown in FIG. In this position, the last swivel is pivoted through 180° so that the last, together with the shoe shaft placed over it, is directed towards the sole.

The side mold parts are brought into a closed position and the slidable beam with the pivotable mold part holder is moved towards the side mold parts until contact is made.

At the same time, the height-adjustable last receiver is moved towards the lateral mold part in the closed position, and this movement causes the sealing seat of the shoe shaft, which is placed over the last, to be positioned in the lateral mold part. It will continue until

Through injection holes (not shown) confined by the side mold parts in the closed position, the polyurethane-reactive mixture is poured into the shoe shaft over the side mold parts and the last. and the sole of the shoe.

The shoe with the finished sole is then demolded and a new shoe shaft is placed over the last.

As can be seen from the above, in the stationary operation of the circular table device, the sole and the midsole are simultaneously injected and the finished product is simultaneously injected at a take-off station (not shown) in the area between positions 2 ₀₄ or 2 ₁₄ . A ratty shoe is removed, the shoe shaft of which has an integrally molded sole with an elastomer sole and a polyurethane midsole.

The inventive design of the forming station therefore results in a circular table arrangement with even shorter step times.

It is also within the scope of the invention to use the shaping stations individually, which is particularly advantageous in non-volume production and in experimental production. For this purpose, the mixing device for mixing the completely reactive mixture for the polyurethane and the plasticizing and injection unit for the elastomer must be arranged, for example, one above the other or diametrically opposite each other.

As already mentioned, the injection of the plasticized elastomer into the cavity for the sole shoe takes place in the position ₂₀₁ of one of the molding stations 2;
This forming station then moves from position ₂₀₁ to position ₂₁₁ with the slidable beam unchanged. From position 2 ₁₁ to position 2 ₀₃ , see Figure 2~
The movements of the slidable beam and the slidable sole receiver, as well as the pivoting movements of the pivotable last part holder and last swivel body, as described above with respect to FIG. 6, are carried out, after which the intermediate A closed cavity for the bottom is fed with a mixture that is fully reactive with the polyurethane. This applies to all molding stations 2.

The same holds true for round table arrangements with multiple or fewer molding stations and round table positions.

The particularly significant advantages of the device according to the invention include the following. In other words, according to the invention, different mold parts are used to completely cure the injected elastomer sole and to cool the fully cured sole, so that complete vulcanization is achieved. The time for cooling and the time for cooling can be determined independently of each other.

Yet another big advantage is: In other words, according to the invention, the total time required for complete vulcanization and cooling of the sole for subsequent processing is reduced by first heating the sole for complete vulcanization and then cooling the sole for subsequent processing. This is significantly shorter than when using a cooled mold section to cool the mold.

[Brief explanation of the drawing]

Figure 1 is a plan view of the circular table device; Figure 2 is a plan view of the circular table device;
3, 4, 5 and 6 are side views showing the forming station in different operations. 1... Circular table, 2... Molding station, 3
...Plasticization and injection unit, 4...Mixing device, 5...Guide, 6, 8, 9, 12... Beam, 7... Notch,
DESCRIPTION OF SYMBOLS 10... Pin, 11... Mold part holder, 13... Mold holding cylinder, 14... Plate, 15... Traveling cylinder, 16... Piston rod, 17... Mold part, 18
... Cavity, 19... Heating block, 20... Heat insulation plate, 21... Cooling plate, 22... Mold part,
23... Cavity, 24, 25... Mold portion for side molding, 26... Shoe last, 27... Shoe shaft, 29... Shoe last receiving part, 30... Pin, 31... Shoe last rotating body, 32...
punch, 33...plate, 34...passage, 35...
Hole.

Claims (1)

[Scope of Claims] 1. A molding station for integrally molding a sole with an elastomer sole and an intermediate sole made of a mixture of isocyanate and polyol completely reactive with polyurethane onto a shoe shaft, comprising: in which the midsole and the sole are bonded to each other by a chemical bond between the isocyanate and the substance added to the reactive end groups of the elastomer;
The forming station has a height-adjustable beam with a pivotably supported mold part holder, the mold part holder having at least one heatable mold part for forming the sole. It has
A second height-adjustable beam with a heatable plate is arranged below the height-adjustable beam, the mold part holder being pivotable for forming the sole. of the type, in which the pivotable mold part holder cooperates with the lateral mold parts and the shoe shaft placed over the last to form the midsole;
A pivotably mounted mold part holder 11 is mounted on the second
On the side parallel to the height-adjustable beam 12, it has a mold part 17 with a cavity 18 for the sole and cooperating with the heatable plate 14, and on the other side, A pivotably supported mold having a cavity 23 for receiving an already molded sole and having a mold part 22 cooperating with a lateral mold part and a shoe shaft placed over the last. A height-adjustable last receptacle 29 with a last swivel 31 is arranged on the beam with the partial holder, which last swivel 31 holds the last 26 for the shoe shaft. and a punch 32 which can be subjected to a vacuum for taking off the formed sole and transferring it after cooling to a cavity for an already formed sole. station. 2. A molding station according to claim 1, wherein the mold part with the cavity can be applied with a vacuum for receiving the sole. 3. The molding station according to claim 1 or 2, wherein the mold portion has a hole opening into the cavity.