DE202022102246U1 - A mold structure that improves heating homogeneity - Google Patents

Abstract

A heating uniformity improving mold structure comprising
a top cover;
a receptacle; and
an accommodating space formed by covering with the top cover in the accommodating case.

Description

field of invention

The present invention relates to a mold structure improving heating uniformity.

The mold structure of the present invention is primarily used in the thermoforming foam art. In the following, this is used as an example for illustration. However, the present invention is not limited to this application. The mold structure of the present invention can be applied to any shape of heated object without departing from the technical scope claimed by the present invention.

State of the art

Since the development of innovative foam beads by BASF in Germany, the processing and manufacturing industry of foam products has developed rapidly. Among them, foam beads are mainly used in the manufacture of insoles. The malleability of the foam beads and the resilience of the final products give the shoes better performance and enable functional improvements, leading the foam materials and related processing industries into a new era.

At present, in the processing and molding process of foam beads, a molding method similar to the molding method of styrofoam particles is still used. As a brief description of this process, foam beads are first introduced into a mold with high temperature and high pressure steam, the foam beads are wetted by steam for several hours in the mold to achieve mutual solution equilibrium between the particles of the foam beads, then the Water vapor pressure released and then reintroduced high temperature and high pressure water vapor to re-foam the particles of the foam beads.

The foamed products obtained by the above process have the advantages of a smooth and less grainy appearance. However, this method requires a high-pressure steam device and long-term wetting with steam. All of the processing equipment has high hurdles and takes a long time to process, thereby increasing the manufacturing cost and selling price of the foam products. Foam beads are used in the market only for relatively high quality products, but in very small quantities, so foam beads cannot be successfully introduced into the market of filling and buffering materials, which are actually in high demand for general foam products, because of the cost of it cannot be covered.

In view of this, there is currently a lack of a foam bead molding tool and its application method, which is relatively simple and in which the processing time is short and no additional high-pressure steam device is required. While maintaining the compressibility property and durability of the foam beads, the processing cost of the foam beads can be reduced and foam beads can be introduced into the general foam product market, thereby expanding the application range of foam beads.

It should be noted that the techniques described above are not to be considered in whole or in part as common knowledge in this field.

object of the invention

In order to solve the problems that the processing equipment for forming foam beads currently has high hurdles to overcome and time-consuming and labor-intensive processing steps are required, and thus foam beads can only be used in the niche market of high-quality foam products and cannot be easily used for general foam products, the present invention provides a mold structure improving heating homogeneity.

A heating uniformity improving mold structure includes a top cover, a receptacle, and a receptacle space formed in the receptacle by covering with the top cover.

Here, the underside of the top cover is provided with a protruding structure which can cover the recessed part of the accommodating case to form the accommodating space.

Here, a middle cover is interposed between the top cover and the accommodating case, with the underside of the middle cover protruding outward, whereby a accommodating space, in which more compression takes place, is formed between the top cover and the accommodating case.

Here, the mold material can be plastic, glass, ceramic, metal or a combination thereof.

At least part of the material of the top cover can be plastic, glass or ceramic and at least part of the material of the receptacle can be plastic, glass or ceramic.

In this case, a compressible object to be heated is introduced into the receiving space.

Here, the compressible object to be heated is a foam material.

Here, the foam material can be unfoamed, semi-foamed or fully foamed material.

Here, the foam material can be foamed particles, foamed blocks, foamed strips or foamed plates.

From the above description it can be seen that the present invention has the following advantages:

1. In the present invention, in the process of compressing the object to be heated made of foam beads using mechanical force, the compression and pressure between the particles of the foam beads can be kept in a relatively homogeneous state, avoiding the problem that foaming degree and internal pressure of all foam beads are different during subsequent heating, which would otherwise result in poor appearance of the molded product. Furthermore, the problems of complex process and high equipment cost which exist in the conventional foam beads can be greatly improved.

2. The foamed molded product of the present invention is highly granular and is suitable for products requiring a granular texture or for use as a filler and buffering material. By using mechanical force, it is not necessary to arrange additional high-pressure steam equipment and associated piping for compression. The manufacturing process is fast and the steps are simple, which can effectively reduce the production cost and processing time, and make a significant contribution to reducing the manufacturing price of the finished product.

character list

• 1 Fig. 12 is a schematic sectional view showing the structure of a first preferred embodiment according to the present invention;
• 2 Fig. 12 is a schematic structural view of a second preferred embodiment according to the present invention;
• 3 Fig. 12 is a schematic structural view of a third preferred embodiment according to the present invention;
• 4 Figure 12 shows a schematic view of the method for improving the heating uniformity of a preferred embodiment of the mold structure according to the invention.

Detailed description of the exemplary embodiments

For a better understanding of the technical features and advantageous effects of the present invention, preferred embodiments will be described in detail below with reference to the accompanying drawings so that the present invention can be easily implemented by those skilled in the art according to the description. The following working examples are used primarily to illustrate the heating of a foam material. However, the mold structure of the present invention is not limited to this foam material. Other compressible materials can also be processed using the present invention.

It will be on 1 referenced. The heating homogeneity improving mold structure 10 (hereinafter referred to as mold 10 ) according to the present invention includes a top cover 11 , and the top cover 11 can cover the receptacle 13 . When the accommodating container 13 is covered with the top cover 11, an accommodating space 14 is formed in the mold 10, which is in the closed state.

The material of the top cover 11 and the receptacle 13 is plastic, metal, ceramic, or any combination thereof. Preferably, the combination of plastic, ceramic, glass, or metal is a combination used for mold 10 that is part plastic, part ceramic, part glass, and/or part metal.

In the specific preferred embodiments of the present invention, the top cover 11 may include a microwave permeable portion and the receptacle may include an electromagnetically heated portion, wherein the microwave permeable portion (the top cover 11) may cover the electromagnetically heated portion (the receptacle 13). , whereby the receiving space 14 is formed in the mold 10 and this is in the closed state.

In this exemplary embodiment, the region of the upper cover 11 of the mold 10 according to the invention which is transparent to microwaves is preferably made of plastic or ceramic material. In this way, the top cover 11 is allowed to have a microwave transmission property, so that the object to be heated (or a foam material) placed in the accommodating space 14 can be heated. Therefore, this area can be referred to as an area transparent to microwaves. The electromagnetically heated portion of the receptacle 13 is preferably made of metal material. In this way, it is possible for the receiving container 13 to conduct heat directly to the objects in the receiving space 14 via the lower heating source. Therefore, this area can be referred to as an electromagnetically heated area.

Further, the microwave transmitting portion and the electromagnetically heated portion may be arranged in the top cover 11 and the accommodating space 13, respectively, inverted or left and right according to the heating requirements. The effects claimed in connection with the present invention can be achieved with all variants.

The first embodiment of the mold 10 is in 1 shown. Its appearance (appearance means the three-dimensional shape formed by the accommodating space 14) may be round, square, rectangular, or any irregular shape. For example, the mold 10 may be in the form of an insole if insoles are to be formed therewith.

It will be on 2 1, which shows the second preferred embodiment of the forming tool 10. FIG. The top cover 11 and the receptacle 13 have a structural relationship of concavo-convex fit. The underside of the top cover 11 is preferably provided with a protruding structure which can cover the recessed part of the accommodating case 13 to form the accommodating space 14 . The above structure is designed in such a way that it can press and fix the foam material in the accommodating space 14 so that it evenly abuts against the wall side of the accommodating container 13 in order to achieve a more homogeneous heating effect.

It will be on 3 referenced. The third preferred embodiment of the mold 10 is designed such that the underside of the top cover 11 is flat and does not protrude outward, the mold 10 further includes a middle cover 12, and the middle cover 12 is in register with the recessed part of the receptacle 13 protrudes outwards, whereby the middle cover 12 can cover the accommodating container 13 to form the accommodating space 14 . the top cover 11 and middle cover 12 can be ruptured by external mechanical force such as B. pneumatic, electric or hydraulic power, are pressurized so that they can cover the receptacle 13 effectively.

As in the 2 and 3 As shown, the second and third preferred embodiments of the molding tool 10 are designed such that the outer surface of the top cover 11 and the inner surface of the receptacle 13 have mating thread structures (111, 131) so that the height when the top cover 11 can be adjusted with the receptacle 13, so as to allow for differences in the shaping effect of the foam material, e.g. B. the thickness of the foamed molding product. It is therefore not necessary to produce new molds. Further, the top cover 11 is pressed onto the foam material, making the molding effect more stable and homogeneous.

In the third preferred embodiment of the present invention, while the outer surface of the top cover 11 and the inner surface of the receptacle 13 have mating thread structures (111, 131), it is preferably used in conjunction with the middle cover 12, with the middle cover 12, after being placed in the receptacle 13, does not rotate together with the top cover 11. Therefore, non-circular or other asymmetric structures can also be formed, and the heating homogeneity and the forming effect can be regulated by the degree of depression of the top cover 11 caused by rotation.

Further, the storage container 13 of the present invention can be equipped with a temperature monitoring device that can monitor the heating temperature in real time during the manufacturing process. The concavo-convex fit design between the top cover 11 and the receptacle 13 of the mold 10 can be achieved by processing methods such as CNC machining, laser machining, casting, stamping, sand casting, rollover, rapid prototyping, hot press molding, injection molding and 3D printing.

• Schritt 1: Einbringen des zu erhitzenden Objekts 20 in den Aufnahmeraum 14, der sandwichartig zwischen der oberen Abdeckung 11 des Formwerkzeugs 10 und dem Aufnahmebehälter 13 vorgesehen ist;
• Schritt 2: Verwenden mechanischer Kraft 30 zum Verkleinern des Aufnahmeraums 14 und zum Komprimieren des zu erhitzenden Objekts 20; und
• Schritt 3: Anwenden einer Heizquelle 40 auf das Formwerkzeug 10, um das im Formwerkzeug 10 befindliche zu erhitzende Objekt 20 zu erhitzen.

3 Fig. 12 is a schematic structural view of a preferred embodiment of the heating homogeneity improving mold structure of the present invention. As in 3 1, a foam material is used as the processing object, and the foam material is preferably foam beads (hereinafter referred to as an object to be heated with reference numeral 20). The object to be heated is described in detail below. The present invention comprises the following steps:

• Step 1: Putting the object 20 to be heated into the accommodating space 14 sandwiched between the top cover 11 of the mold 10 and the accommodating container 13;
• Step 2: Using mechanical force 30 to shrink the accommodating space 14 and compress the object 20 to be heated; and
• Step 3: Applying a heat source 40 to the mold 10 to heat the object 20 to be heated in the mold 10.

In particular, the mold 10 according to the present invention is characterized in that the top cover 11 can be pressed against the accommodating container 13 to reduce the accommodating space 14 and to compress the object 20 to be heated. Preferably, the object to be heated 20, such as. a semi-foamed or foamed material, exhibits the property of compressibility. Non-foamed materials which exhibit some property of compressibility are also within the scope of the present invention.

For example, the foam beads described above are particles that are already in a semi-foamed state. Your common materials are granular foam materials from z. B. expanded thermoplastic polyurethane (E-TPU), polylactide (PLA), polypropylene (PP), polyethylene (PE), polyamide (PA), polystyrene (PS), polyphenylene ether (PPE), thermoplastic elastomer (TPE), thermoplastic polyester elastomer ( TPE-E), olefin-based thermoplastic elastomer (TPO) and ethylene vinyl acetate copolymer (EVAC). In addition to beads, the foam material or the foamed material can preferably also be in the form of strips, blocks or plates. As long as it is a material with the property of being compressible, it is within the scope of the present invention.

When the foam beads (the object 20 to be heated) are introduced into the interior of the mold 10, the mold 10 may be in a closed or non-closed state. The step for implementing the present invention is that the top cover 11 is pressed and abutted against the surface of the foam beads (the object to be heated 20) with the top cover 11 pressed down toward the interior of the mold 10 and mechanical Force 30 is applied to the foam beads (the object to be heated 20). At this time, since the foam beads (the object to be heated 20) have the property of compressibility, they can be compressed in the mold 10 into a denser state, so that the close contact between the particles is greatly improved or the contact area is greatly increased. When the foam beads (the object to be heated 20) are compressed into a predetermined state for processing, the heating source 40 is applied to the mold 10. Due to the increased contact area between the particles, the heat can be distributed more homogeneously and quickly to each particle. In this way, a foamed molded product can be obtained without requiring an additional processing step for equilibration achieved by long-term wetting using any high-pressure steam device.

Further, in the present invention, in the process of compressing the foam beads (the object to be heated 20) using mechanical force 30, the compression and the pressure between the particles of the foam beads (the object to be heated 20) can be kept in a relatively homogeneous state, thereby avoiding the problem that the degree of foaming and internal pressure of all the foam beads are different during the subsequent heating, which would otherwise result in poor appearance of the molded product.

The mechanical force 30 is generated by an electric, pneumatic or hydraulic machine that applies pressure directly to the top cover 11 or the bottom cover 13 to drive the threaded structure (111, 131) in rotation and, by cooperation with this, compression in the receiving space 14 to effect. As an alternative to the mechanical force 30, an air compressor can also be used to compress air at room temperature (i.e. no special heating is required). During the air compression, the foam beads (the object to be heated 20) are conveyed into the mold 10, so that the compression effect can be obtained at the same time during the process.

The heating source 40 includes an external heating source or an internal heating source or a combination thereof, where the external heating source can be hot water heating, steam heating, resistance heating, fire heating, conductive heating, electromagnetic induction heating, capacitive dielectric heating, electric heating tube heating, hot air heating or hot oil heating and the internal Heat source is based on radiant heating and can be infrared (IR) heating, radio frequency (RF) heating or microwave (MW) heating. Preferably, in the present invention, an internal heating source such as a microwave heater is used for heating and shaping the object to be heated. Since microwaves generate intermolecular vibrations in the object to be heated and then heat is generated from the inside, good heating homogeneity and moldability can be obtained in the object to be heated.

If an internal heating source such as e.g. one based on microwaves, is chosen, the heating with the internal heating source can preferably be carried out through the microwave transparent region of the mold 10. Since the material of the microwave-permeable area is preferably a plastic, ceramic or glass material, this area allows the microwaves to pass through better. Alternatively, if electromagnetic induction heating is chosen as the external heating source, the heat is preferably conducted over the electromagnetically heated region of the mold 10. Since the electromagnetically heated portion is made of materials such as metal, ceramics, or glass that can conduct electromagnetic heat, this portion can better conduct heat to the object 20 to be heated.

The foamed molded product of the present invention is highly granular and is suitable for products requiring a granular texture or for use as a filler and buffer material. By using mechanical force, it is not necessary to arrange additional high-pressure steam equipment and associated piping for compression. The manufacturing process is fast and the steps are simple, which can effectively reduce the production cost and processing time, and make a significant contribution to reducing the manufacturing price of the finished product.

In order to demonstrate that the mechanical properties of the foamed molded products produced by the production method according to the invention do not differ from those of the foamed molded products produced by conventional complex production processes, ie the mechanical properties of the foamed molded products are maintained, Table 1 below, in which the performance tests of the foamed molding products produced by the preferred embodiments of the present invention are listed. Here, thermoplastic polyurethane foam beads (E-TPU) were used as foam beads (object 20 to be heated). The average particle weight was 25 ± 10 mg. The test pieces obtained had a thickness of 10 mm and a density of 250 kg/cm ³ . During the processing, the foam beads (the object to be heated 20) were compressed to a compression ratio of 2 by the mechanical force 30 used in step 2, and then heated to shape by microwaves of the heat source 40 with a power of 100 watts (W) for 180 seconds . The test pieces were obtained by leaving them to cool before taking them out. Table 1 performance test test standard value tensile strenght EN ISO 1798 500kPa elongation at break EN ISO 1798 63% Compression set 22h/23°C/50% EN ISO 1856 7% resilience DIN 53512 54% thermal conductivity EN 12667 50mW/(mK) Water intake (1 day) DIN 53428 less than 2% by volume

Further, the foam beads (object to be heated 20) were compressed to a compression ratio of 1 to 3 by the mechanical force 30 used in step 2 by the manufacturing method of the present invention. Several test pieces were molded by heating by a heating source 40 with microwaves having a power of 50 to 100 watts (W) for 120 to 240 seconds. After testing, all the test pieces showed the same or better mechanical properties than the test pieces obtained by other molding methods under the same specifications.

The heating homogeneity improving method of the present invention can be used to produce various foamed products such as microcellular foamed, low foamed and high foamed products including floor mats, insoles, mattresses and so on. The heating process can also be extended to other needs requiring heating, such as: B. heating food. The above description represents only preferred embodiments of the invention and is not intended to limit the protection claims. All equivalent changes and modifications, which can be made by one skilled in the art in accordance with the description and drawings of the invention, fall within the scope of the present invention.

Reference List

10

Mold structure improving heating homogeneity

11

top cover

12

medium coverage

13

receptacle

111, 131

thread structure

14

recording room

20 to

heating object, foam beads

30

mechanical force

40

heating source

Claims (9)

A heating uniformity improving mold structure comprising a top cover; a receptacle; and an accommodating space formed by covering with the top cover in the accommodating case. Mold structure improving the heating homogeneity claim 1 wherein the underside of the top cover is provided with a protruding structure which can cover the recessed part of the accommodating case to form the accommodating space. Mold structure improving the heating homogeneity claim 1 or 2 wherein a middle cover is interposed between the top cover and the accommodating case, with the underside of the middle cover protruding outward, whereby a accommodating space, in which more compression takes place, is formed between the top cover and the accommodating case. Mold structure improving the heating homogeneity claim 1 or 2 , in which the mold material is plastic, glass, ceramic, metal or a combination thereof. Mold structure improving the heating homogeneity claim 1 or 2 wherein at least part of the material of the top cover is plastic, glass or ceramic and at least part of the material of the receptacle is plastic, glass or ceramic. Mold structure improving the heating homogeneity claim 1 or 2 , in which a compressible object to be heated is placed in the receiving space. Mold structure improving the heating homogeneity claim 5 , where the compressible object to be heated is a foam material. Mold structure improving the heating homogeneity claim 7 wherein the foam material is unfoamed, semi-foamed or fully foamed material. Mold structure improving the heating homogeneity claim 6 or 7 wherein the foam material is foamed particles, foamed blocks, foamed strips, or foamed sheets.

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