TW202216410A - An evenly heating method for enhancing heating result - Google Patents

Abstract

Present invention is related to an evenly heating method for enhancing heating result having steps of: introducing a foam material into a mould, compressing the foam material by a mechanical force to a preset thickness or status, and heating the foam material to obtain a foam product. By applying the mechanical force to the foam material during the process, the foam material could be compressed into a more compact status in order to be heated more evenly and thoroughly. The present invention provides the foam product in good quality by a simple and low cost heating method.

Description

A method to improve heating uniformity

The present invention relates to a heating method, in particular to a method capable of improving heating uniformity.

The heating method provided by the present invention is firstly used in the foaming thermoforming technology, and the following will be used as an example to illustrate, but the present invention is not limited to this application, and any form of heated object can be applied to The heating method provided by the present invention does not depart from the technical scope claimed by the present invention.

Since the invention of the foamed beads by BASF in Germany, it has swept the processing and manufacturing of foamed products at a lightning-fast speed. Among them, it is mainly used in the manufacture of shoe midsole. The formability and resilience of the foamed beads endow the shoes with better performance and functional improvement, leading the foaming material and related processing industries to enter a new era.

At present, in the processing and molding process of foamed beads, the molding method similar to Styrofoam particles is still used. Generally, the foamed beads are first introduced into a closed mold with high temperature and high pressure water vapor, and the foamed beads are formed by water vapor. Immerse and permeate in the mold for several hours, so that the particles of the foamed beads can reach mutual dissolution equilibrium. Then, after the water vapor is released, the high-temperature and high-pressure water vapor is introduced again to make the foamed beads foam again. .

The foamed product obtained by the aforementioned method has the advantages of being smooth in appearance and less grainy. However, this process method requires high-pressure water vapor equipment and long-term water vapor infiltration, and the overall processing equipment threshold is high and processing time is long. , which also affects the cost and selling price of the final foamed product. Foamed beads are still in the market of relatively high-end but small-volume products. On the contrary, the market for fillers and cushioning materials, which are generally demanded by foamed products, cannot be successfully promoted and applied because they do not meet the cost.

In view of this, there is currently a lack of a method for forming expanded beads that is relatively simple, has a short processing time, and does not require additional high-pressure water vapor equipment. While maintaining the compressibility and durability of the expanded beads, the The processing cost is reduced and it can be introduced into the market of general foamed products, expanding the application level of foamed beads.

It should be noted that any technique mentioned above in the present invention is not an admission that it is all or a part of the basic knowledge or common knowledge in the field.

In order to solve the high-threshold processing equipment and time-consuming and labor-intensive processing steps required for the current foamed beads processing, the foamed beads can only be applied to the niche market of high-end foamed products at this stage, and cannot be successfully promoted. In view of the dilemma of general foamed products, the present invention provides a method for improving heating uniformity, so as to solve the technical problem of prior disclosure.

Please refer to FIG. 1 , a method for improving heating uniformity, the steps of which include: introducing an object to be heated into an accommodating space in a mold; Utilize a mechanical force to shrink the accommodating space and compress the object to be heated; and Applying a heat from the mold heats the object to be heated in the mold.

Wherein, the object to be heated has compressibility.

Wherein, the object to be heated is an unfoamed, semi-foamed or foamed material.

Wherein, the object to be heated is expanded beads.

Wherein, the mold includes an upper cover and a lower cover to form the accommodating space therein, the upper cover abuts the surface of the object to be heated and presses down to shrink the accommodating space and compress the object to be heated.

Wherein, the mechanical force includes electric, pneumatic, hydraulic press applying pressure to the upper cover or the lower cover and compressing the accommodating space, or the mechanical force includes compressing normal temperature gas to directly compress the object to be heated in the accommodating space.

Wherein, the heating source includes one or a combination of an external heating source or an internal heating source.

Wherein, the external heating source includes hot water heating, steam heating, resistance heating element heating, thermal heating, conductive heating, induction electromagnetic heating, capacitive dielectric heating, electric heating tube heating, hot air heating or hot oil heating.

Wherein, the internal heating source comprises radiation heating, such as infrared heating, radio frequency radiation heating or microwave heating.

As can be seen from the above description, the present invention has the following advantages:

1. The present invention utilizes mechanical force in the process of processing and compressing the object to be heated of the expanded beads, so that the compression and pressure between each particle of the expanded beads can be in a relatively uniform state, avoiding subsequent heating. The degree of foaming of the foamed beads is different from the internal pressure, which leads to the problem of poor appearance quality of the molded product, and greatly improves the existing problems of the complicated process and high equipment cost of foamed bead processing.

2. The foamed molded product of the present invention has an obvious grainy appearance, and is suitable for use as a product requiring grainy texture or as a filler and a buffer material. Due to the mechanical compression force, there is no need to add additional high-pressure water vapor equipment and related equipment. The pipeline is arranged, and the process is quick and steps are simple, which can effectively reduce the production cost and processing time, and make a significant contribution to the cost price of the finished product.

In order to understand the technical features and practical effects of the present invention in more detail, and to implement them according to the contents of the description, the preferred embodiments shown in the drawings are further described in detail as follows.

Please refer to FIG. 1 , which is a schematic flowchart of a preferred embodiment of a method for improving heating uniformity provided by the present invention. In this embodiment, foamed beads are firstly processed, and will be explained in detail below. The steps of the present invention include: Step 1: introduce an object to be heated 10 into an accommodating space 21 in a mold 20; Step 2: Using a mechanical force 30 to shrink the accommodating space 21 and compress the object to be heated 10; and Step 3: Apply a heating source 40 to the mold 20 to heat the object to be heated 10 in the mold 20 .

Specifically, the object to be heated described in this embodiment preferably has compressive properties, such as semi-foamed or foamed materials, and some unfoamed materials with compressibility may also belong to the scope of the present invention. . For example, expanded beads are particles that may have been in a semi-expanded state, and are commonly made of thermoplastic polyurethane elastomer (E-TPU), polylactic acid (PLA), polypropylene (PP), polyethylene (PE), polyamide Amine (PA), Polystyrene (PS), Polyphenylene Ether (PPE), Thermoplastic Elastomer (TPE), Thermoplastic Polyester Elastomer (TPEE), Polyolefin Elastomer (TPO), Ethylene Vinyl Acetate Copolymer Granular expanded beads formed from EVA (EVA). The mold 20 in this embodiment preferably includes at least an upper cover 22 and a lower cover 23 and the accommodating space 21 is formed therebetween. When the object to be heated 10 (ie the expanded beads, hereinafter referred to as the expanded beads 10 ) is introduced into the mold 20 , the mold 20 may be in a closed or unclosed state, and the step of implementing the present invention is to The upper cover 22 is pressed against and attached to the surface of the foamed beads 10 , and the upper cover 22 is pressed down into the mold 20 to reduce the accommodating space 21 and apply the mechanical force 30 to the foamed beads , at this time, because the foamed beads 10 have compressible characteristics, that is, they may be compressed into a tighter state inside the mold 20, and the close contact or contact area between the particles is greatly increased. When the beads 10 are compressed to the processing preset state, that is, the heating source 40 is applied to the mold 20. Due to the increase in the contact area between the particles, the heat can be more uniformly and rapidly diffused between each particle. In this way, a foamed molded product can be obtained without additionally using any high-temperature steam equipment for a long-term soaking and balancing treatment step.

Further, the present invention utilizes the mechanical force 30 to process and compress the object to be heated on the expanded beads 10, so that the compression and pressure between each particle of the expanded beads 10 can be in a relatively uniform state, During subsequent heating, the foaming degree of each foamed bead 10 is different from its internal pressure, which leads to the problem of poor appearance quality of the molded product.

The aforementioned mechanical force 30 includes an electric, pneumatic or hydraulic press directly applying pressure to the upper cover 22 or the lower cover 23 and compressing the accommodating space 21. Further, the mechanical force 30 may also be the use of an air compressor to compress normal temperature air ( That is, no special heating is required), and the foamed beads are transported to the mold 20 by compressing air at the same time, and the effect of compression can also be achieved during the process. The aforementioned heating source 40 includes one or a combination of an external heating source or an internal heating source, the external heating source includes hot water heating, steam heating, resistance heating element heating, thermal heating, conductive heating, induction electromagnetic heating, capacitive dielectric heating , electric heating tube heating, hot air heating, hot oil heating; and the internal heating source is radiation heating, including infrared (IR) heating, radio frequency radiation (RF) heating, and microwave (MW) heating. In the preferred case of the present invention, it is preferable to use an internal heating source, such as microwave heating, to heat and shape the object to be heated. Since microwaves cause intermolecular vibrations of the object to be heated, heat is generated from the inside, which can have Good heating uniformity and formability.

The foamed molded product of the present invention has obvious graininess in appearance, and is suitable for use as a product requiring grainy texture or as a filler and a buffer material. Because of the mechanical compression force, there is no need to add additional high-pressure water vapor equipment and related pipeline arrangements. , and the process is fast and steps are simple, which can effectively reduce the production cost and processing time, and make a significant contribution to the cost price of the finished product.

In order to confirm that the process method provided by the present invention has no difference in the mechanical properties of the foamed molded products obtained by the existing complex process, that is, the effect of maintaining the mechanical properties of the foamed molded products, the following table 1 is the use of the aforementioned present invention. The performance test of the foamed molded product obtained in the preferred embodiment. The foamed beads 10 used are thermoplastic polyurethane foamed beads (E-TPU), the average particle weight is 25±10 mg, the thickness of the prepared test piece is 10 mm, and the density is 250 kg/cm ³ . In the process of processing, the present invention uses the mechanical force 30 in step 2 to compress the expanded beads so that the compression ratio of the expanded beads is 2, the heating source 40 is heated by microwaves with a power of 100% for 180 seconds, and is then left to cool before taking out. Test coupons.

Table 1 Test performance standard test Numerical value Tensile strength DIN EN ISO 1798 500 kPa Elongation at break DIN EN ISO 1798 63 % Compression set rate Compression set 22hrs/23°C/50% DIN EN ISO 1856 7% Rebound resilience DIN 53512 54% Heat Conductivity DIN EN 12667 50mW/m*K Water absorption (1 day) DIN 53428 Less than 2 Vol.-%

Further, the present invention utilizes the provided manufacturing method to compress the expanded beads with the mechanical force 30 applied in step 2 so that the compression ratio of the expanded beads is 1-3, and the heating source 40 is heated by microwaves with a power of 50-100% for 120- After testing, several test pieces formed in 240 sec have the same or better mechanical properties than the test pieces obtained by other molding methods under the same specification.

The method for improving heating uniformity provided by the present invention can be applied to the manufacture of various foamed products such as micro-foaming, low-foaming or high-foaming, including floor mats, insoles or mattresses, etc. The heating method can also be extended to For other heating needs, such as food heating. The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the scope of the claims of the present invention. All other equivalent changes or modifications without departing from the spirit disclosed by the present invention shall be included in the present invention. within the scope of the patent application.

10: Object to be heated, expanded beads 20: Mold 21: accommodating space 22: upper cover 23: Lower cover 30: Mechanical force 40: Heating source

FIG. 1 is a schematic flowchart of a preferred embodiment of the present invention.

10: Object to be heated, expanded beads

20: Mold

21: accommodating space

22: upper cover

23: Lower cover

30: Mechanical force

40: Heating source

Claims (10)

A method for improving heating uniformity, the steps comprising: introducing an object to be heated into an accommodating space in a mold; Utilize a mechanical force to shrink the accommodating space and compress the object to be heated; and Applying a heat from the mold heats the object to be heated in the mold. The method for improving heating uniformity according to claim 1, wherein the object to be heated has compressibility. The method for improving heating uniformity according to claim 1 or 2, wherein the object to be heated is an unfoamed, semi-foamed or foamed material. The method for improving heating uniformity according to claim 1 or 2, wherein the object to be heated is expanded beads. The method for improving heating uniformity as claimed in claim 1, wherein the mold comprises an upper cover and a lower cover to form the accommodating space therein, the upper cover abuts the surface of the object to be heated and presses down to make the accommodating space Space reduction and compression of the object to be heated. The method for improving heating uniformity as claimed in claim 1 or 5, wherein the mechanical force includes an electric, pneumatic or hydraulic press applying pressure to the upper cover or the lower cover and compressing the accommodating space, or the mechanical force includes a combination of compressing The normal temperature gas is directly compressed in the accommodating space for the object to be heated. The method for improving heating uniformity according to claim 1, wherein the heating source comprises one or a combination of an external heating source or an internal heating source. The method for improving heating uniformity according to claim 6, wherein the external heating source comprises hot water heating, steam heating, resistance heating element heating, thermal heating, conductive heating, induction electromagnetic heating, capacitive dielectric heating, and electric heating pipes Heating, hot air heating or hot oil heating. The method of improving heating uniformity of claim 6, wherein the internal heating source comprises radiant heating. The method for improving heating uniformity according to claim 8, wherein the radiation heating comprises infrared heating, radio frequency radiation heating or microwave heating.

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