Patent ID: 12240156

DETAILED DESCRIPTION

Hereinafter, various embodiments of the present disclosure will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present disclosure. The present disclosure may be modified in various different ways, and is not limited to the embodiments described herein.

Parts that are irrelevant to the description will be omitted to clearly describe the present disclosure, and like reference numerals designate like elements throughout the specification.

Further, in the drawings, the size and thickness of each element are arbitrarily illustrated for convenience of description, and the present disclosure is not necessarily limited to those illustrated in the drawings. In the drawings, the thickness of layers, regions, etc. are exaggerated for clarity. In the drawings, for convenience of description, the thicknesses of some layers and regions are exaggerated.

In addition, it will be understood that when an element such as a layer, film, region, or plate is referred to as being “on” or “above” another element, it can be directly on the other element or intervening elements may also be present. In contrast, when an element is referred to as being “directly on” another element, it means that other intervening elements are not present. Further, the word “on” or “above” means disposed on or below a reference portion, and does not necessarily mean being disposed on the upper side of the reference portion toward the opposite direction of gravity.

Further, throughout the specification, when a part is referred to as “including” a certain component, it means that it can further include other components, without excluding the other components, unless otherwise stated.

FIG.2is a schematic plane view of an injection molding device100according to an embodiment of the present disclosure.

Referring toFIG.2, the injection molding device100according to an embodiment of the present disclosure includes: a first mold110including a first injection port111into which a raw material is injected, a second mold120including a heating member160, a first movable mold130facing the first mold110and having a first cavity131formed therein, and a second movable mold140facing the second mold120and having a second cavity141formed therein. The raw material may include a molten resin for molding plastic products.

The positions of the first mold.110and the second mold120are fixed, but the first movable mold130and the second movable mold140may change positions with each other. Thus, unlike the arrangement illustrated inFIG.2, the first movable mold130may face the second mold120, and the second movable mold140may face the first mold110.

In particular, the position change of the first movable mold130and the second movable mold140may be made through a rotating device150. The side surfaces of the first movable mold130and the second movable mold140may be integrated so that the opening direction of the first cavity131and the opening direction of the second cavity141are identical to each other, and the rotating device150may be located at a lower end of the first movable mold130and the second movable mold140. Therefore, the first movable mold130and the second movable mold140can change positions with each other by the rotation S of the rotating device150. At this time, the rotation axis of the rotation S is preferably parallel to the opening direction of the first cavity131and the opening direction of the second cavity141.

Further, as shown inFIG.2, it is preferable that the side surfaces of the first mold110and the second mold120are also integrated. This is because the first mold110and the second mold120must be in contact with the first movable mold130and the second movable mold140at the same time.

In a state where the first mold110and the first movable mold130are in contact with each other, the injected raw material is injected into the first cavity131of the first movable mold130through the first injection port111of the first mold110, and then molding is performed into the shape of the first cavity131. That is, in the first mold110, injection and molding are performed together with the first movable mold130or the second movable mold140. At this time, if the first injection port111can inject a raw material, the number or location thereof is not particularly limited.

In the second mold120, annealing heat treatment is performed on a molded product produced by injection molding. That is, after the molded product manufactured in the first mold110is moved to the second mold120through the positional change of the first movable mold130and the second movable mold140by the rotating device150, annealing is performed. A specific injection molding method will be described later in detail with reference toFIGS.6to10.

For annealing, it is preferable that the second mold120includes a heating member160. Through the process in which the heating member160rapidly heats the second mold120, followed by gradually cooling, annealing is performed on a molded product in contact with the second mold120. When the molding is a plastic resin, it is preferable that annealing is performed at a temperature equal to or higher than the glass transition temperature of the resin.

In addition, since the annealing process is performed in a state where the second mold120is in contact with the first movable mold130or the second movable mold140, with a molded product being interposed therebetween, it is preferable that the movable mold130and the second movable mold140also include a heating member160for more effective temperature control.

The injection molding device100according to the present exemplary embodiment does not take out a molded product subjected to injection molding, from the first mold110, but moves directly to the second mold120to perform an annealing process. Since the annealing process is performed in the mold, the polymers oriented in the molded product become relaxed, so it is possible to effectively reduce birefringence or internal stress, which may occur in plastic products manufactured by conventional injection molding methods. Eventually, problems such as deterioration of optical properties, bending of a molded product, or cracking of a molded product, which may occur due to birefringence, can be significantly reduced. This will be described again below with reference toFIG.15.

Further, in the conventional molding processes, deformation of the product may occur when annealing is performed in a high temperature chamber to relieve internal stress. In the present embodiment, since the annealing process is performed in a state in which the molded product is located inside the mold, it is possible to prevent the problem of product deformation due to heat treatment.

In addition, deformation may occur depending on the extent of molecular orientation or fiber orientation of each product after injection molding, but as in this embodiment, if annealing is performed in a mold, deformation according to the extent of orientation after injection molding can be minimized.

Moreover, an annealing process for a molded product may be performed in the second mold120, and at the same time, injection molding of other molded products may be performed in the first mold110. That is, since the injection molding process and the annealing process can be simultaneously performed through the first movable mold130and the second movable mold140that can change positions with each other, mass production of the molded product is possible through a continuous process, without complication. Mass production is possible. This will also be described later in detail with reference toFIGS.6to10.

Meanwhile, during injection molding, the first mold110may also include a heating member160to maintain the temperature of the first mold110. That is, the healing member160is preferably located not only in the second mold120, but also in each of the first movable mold130, the second movable mold140, and the first mold110.

The heating member160is not particularly limited in its form or method as long as it can heat the first mold110, the second mold120, the first movable mold130, or the second movable mold140, but as shown inFIG.2, it is preferable that it is in heating wire form located inside respective molds110,120,130and140. In addition, although shown as a plurality of heating wires, it is needless to say that the number of heating wires can be freely set as necessary. The heating element160in the form of a heating wire may be a sheath heater.

Further, the heating member160may be in the form of induction heating element, electric heater, planar heating element, or steam heating for rapid heating, and as the heating energy is higher and the surface temperature rise of the molds110,120,130and140is faster, it is more advantageous for technology implementation.

General annealing is performed in a high temperature chamber and takes 30 minutes or more, whereas in the present embodiment, since the annealing is performed in a state where the molded product is located inside the mold, heating and cooling are possible through the aforementioned heating wire, induction heating element, electric heater, planar heating element, steam heating, etc., and thus, an annealing process can be completed within a few seconds to tens of seconds.

FIG.3is a schematic plane view of an injection molding device200according to another embodiment of the present disclosure.

Referring toFIG.3, the injection molding device200of the present embodiment includes a first mold210including a first injection port211through which a raw material is injected, and a second mold220including a heating member260, a first movable mold230facing the first mold210and having a first cavity231formed therein, and a second movable mold240facing the second mold220and having a second cavity241formed therein.

Similar to the injection molding device100ofFIG.2, molding of the composition introduced from the first injection port211is performed in the first mold210, and an annealing process of the molded product is performed in the second mold220. The heating member260may be located in the first movable mold230, the second movable mold240, and the first mold210as well as the second mold220.

Referring again toFIG.3, the first movable mold230and the second movable mold240may be integrated such that the opening direction of the first cavity231and the opening direction of the second cavity241are opposite to each other. The rotating device250may be located on a side surface of the first movable mold230and the second movable mold240, and the first mold210and the second mold220may be separated from each other, with the first movable mold230and the second movable mold240being interposed therebetween.

By the rotation S′ of the rotating device250, the first movable mold230and the second movable mold240change positions with each other, and can alternately face the first mold210and the second mold220. At this time, it is preferable that the rotational axis of the rotation S′ is perpendicular to the opening direction of the first cavity231and the opening direction of the second cavity241.

FIG.4is a schematic plane view of an injection molding device300according to another embodiment of the present disclosure.

Referring toFIG.4, the injection molding device300according to the present exemplary embodiment includes a first mold310including a first injection port311, a second mold320including a heating member360, a first movable mold330having a first cavity331formed therein, and a second movable mold340having a second cavity341formed therein, and an embossed pattern370may be formed on the surface of the second mold320. That is, the injection molding device300has identical or similar configurations to those of the injection molding device100ofFIG.2, except that the embossed pattern370is formed.

Conventionally, in order to form a fine pattern on the surface of a plastic product manufactured through injection molding, an injection process is performed after pattern processing on a mold, or a roll stamping process is performed to separately form a pattern after injection, but there was a problem such as deterioration of the optical properties of the product due to a decrease in the transferability of fine patterns. In the present embodiment, an embossed pattern370is formed on the surface of the second mold320to form a fine pattern on the molded product together with an annealing process for the molded product.

Simultaneously with applying heat in the mold, the mold is closed to imprint a pattern, and thus, it is possible to produce a molded product having uniform transferability, and it is advantageous for reducing the gloss variation and corrosion variation in the final plastic product.

In addition, it is possible to form a fine pattern in the annealing process without adding a separate process, which can save time and costs.

Meanwhile, although the embossed pattern370is formed inFIG.4, it is needless to say that an intaglio pattern (not shown) may be formed, and various shapes may be formed on the surface of the second mold320in accordance with a desired pattern.

FIG.5is a schematic plane view of an injection molding device400according to another embodiment of the present disclosure.

Referring toFIG.5, the injection molding device400according to the present embodiment includes a first mold410including a first injection port411, a second mold420including a heating member460, a first movable mold430having a first cavity431formed therein, and a second movable mold440having a second cavity441formed therein. The second mold420may further include a second injection port421through which an additional raw material is injected. That is, the injection molding device400has identical or similar configurations to those of the injection molding device100ofFIG.2except that the second injection port421is formed. Therefore, it is needless to say that the first mold410, the first movable mold430, and the second movable mold440as well as the second mold420may include a heating member460.

In the injection molding device400of the present embodiment, since the second injection port421is formed in the second mold, double injection molding is possible. In other words, the molded product formed by injection molding in the first mold410is moved to the second mold420, and then additional raw material is injected from the second injection port421to perform additional injection molding on the molded product.

The additional raw material may be the same material as the raw material injecting from the first injection port411, or may be a different material. In addition, the position or number of the second injection port421is not particularly limited, and can be freely adjusted according to the design of the final product.

The injection molding device400of the present embodiment is capable of double injection molding through the second injection port421, and furthermore, by adjusting the position or number of the second injection port421and the amount of additional raw material injected therein, final products of more various structures and materials can be produced.

Meanwhile, similar to the injection molding device100ofFIG.2, an annealing process may be performed in the second mold420of the injection molding device400of the present embodiment, and the order of the additional injection molding and annealing processes is not limited. This will be described later inFIG.14.

FIGS.6to10are plane views illustrating an injection molding method using the injection molding device100according toFIG.2.

Referring toFIG.6, the injection molding method according to an embodiment of the present disclosure, includes injecting raw material into the first cavity131of the first movable mold130facing the first mold110and molding the material to produce a primary molded product101. Specifically, the raw material is injected through the first injection port111, and the primary molded product101is produced in conformance with the form of the first cavity, in a state where the first mold110and the first movable mold130are in contact.

Subsequently, referring toFIG.7, a step of moving the position of the first movable mold130so that the primary molded product101faces the second mold120is performed.

Specifically, the first movable mold130is separated from the first mold110, and then movement is made to the position of the first movable mold130, without the primary molded product101being taken out from the first cavity131. By the rotation S1of the rotating device150, the first movable mold130moves to face the second mold120, and the second movable mold140moves to face the first mold110. Since the opening direction of the first cavity131and the opening direction of the second cavity141are identical to each other, the rotation axis of the rotation S1for positional movement is parallel to the opening direction of the first cavity131and the opening direction of the second cavity141.

Subsequently, referring toFIG.8, a step of heating and then gradually cooling the second mold120to anneal the primary molded product101, and a step of injecting a raw material into the second cavity141of the second movable mold140facing the first mold110and molding the material to produce a secondary molded product102are performed.

At this time, it is preferable that the step of annealing the primary molded product101and the step of producing the secondary molded product102are performed simultaneously.

Specifically, in the state where the second mold120and the first movable mold130are in contact with each other, the second mold120and the heating member160inside the first movable mold130are heated at a temperature equal to or higher than the glass transition temperature and then gradually cooled to anneal to the primary molded product101.

Simultaneously therewith, with respect to the raw material injected through the first injection port111, in a state where the first mold110and the second movable mold140are in contact with each other, the secondary molded product102is formed in conformance with the shape of the second cavity141,

However, it is needless to say that, if necessary, the secondary molded product102may be produced after the primary molded product101is annealed, or alternatively the primary molded product101may be annealed after the secondary molded product102is produced.

Subsequently, referring toFIG.9, a step of moving the position of the second movable mold140so that the secondary molded product102faces the second mold120is performed.

Specifically, the primary molded product101inFIG.8in which the annealing step is completed is taken out, and without having the secondary molded product102taken out from the second cavity141, movement is made to the movable mold140. By the rotation S2of the rotating device150, the first movable mold130is moved to face the first mold110again, and the second movable mold140is moved to face the second mold120again.

Subsequently, referring toFIG.10, a step of heating and then gradually cooling the second mold120to anneal the secondary molded product102, and a step of injecting into the first cavity131of the first movable mold130facing the first mold110and molding the material to produce a tertiary molded product103are performed.

Similarly, it is preferable that annealing the secondary molded product102and producing the tertiary molded product103are performed simultaneously.

Specifically, in the state where the second mold120and the second movable mold140are in contact with each other, the heating member160inside the second mold120and the second movable mold140is heated at a temperature equal to or higher than the glass transition temperature and then gradually cooled to anneal the secondary molded product102.

Simultaneously therewith, for the raw material injected through the first injection port111, the tertiary molded product103is formed in conformance with the shape of the first cavity131, in a state where the first mold110and the first movable mold130are in contact with each other.

However, it is needless to say that, if necessary, the tertiary molded product103may be produced after annealing the secondary molded product102, or alternatively the secondary molded product102may be annealed after producing the tertiary molded product103.

That is, as described above, since the positions of the first movable mold130and the second movable mold140may be repeatedly moved one or more times, and an annealing process for a molded product whose injection molding is completed and a process of performing new injection molding thereafter can be performed continuously, this is advantageous for mass-producing plastic products with reduced birefringence or internal stress. In particular, without need to provide a separate additional device or process for annealing, it can be performed together with the injection molding process, thus simplifying the overall manufacturing process, minimizing process parameters, and a reduction of costs can also be expected.

FIGS.11and12are plane views illustrating an injection molding method using the injection molding device200according toFIG.3. However, descriptions of parts overlapping with the injection molding method using the injection molding device100according toFIG.2will be omitted.

Referring toFIG.11, the injection molding method of this embodiment includes moving the position of the first movable mold230so that the primary molded product201faces the second mold220. Specifically, the primary molded product201produced between the first mold210and the first movable mold230is moved to face the second mold220by the rotation S′1of the rotating device250, without being taken out from the first cavity231. Since the opening direction of the first cavity231and the opening direction of the second cavity241are opposite to each other, the rotation axis of the rotation S′1for positional movement is perpendicular to the opening direction of the first cavity231and the opening direction of the second cavity241.

Subsequently, referring toFIG.12, a step of heating and then gradually cooling the second mold220to anneal the primary molded product201, and a step of injecting a raw material into the second cavity241of the second movable mold240facing the first mold210and molding the material to produce a secondary molded product202are performed.

Similarly, it is preferable that annealing the primary molded product201and producing the secondary molded product202are performed simultaneously. Annealing the primary molded product201is performed in a state where the second mold220and the first movable mold230are in contact with each other, and producing the secondary molded product202is performed in a state where the first mold210and the second movable mold240are in contact with each other. In addition, the raw material is injected through the first injection port211.

In the injection molding method of the present embodiment, the positional movement of the first movable mold230and the second movable mold240may be repeatedly performed one or more times, and an annealing process for a molded product whose injection molding is completed and subsequent processes of conducting new injection molding can be performed continuously. This is redundant with the previous description, so a detailed description will be omitted.

FIG.13is a plane view illustrating an injection molding method using the injection molding device300according toFIG.4. However, the overlapping portion will be omitted, and the step of annealing the primary molded product301will be described.

Referring toFIG.13, in a state in which the second mold320and the first movable mold330are in contact with each other, annealing is performed on the primary molded product301positioned in the first cavity331. At the same time, in the state where the first mold310and the second movable mold340are in contact with each other, the raw material is injected into the second cavity341through the first injection port311to produce the secondary molded product302.

At this time, since the embossed pattern370is formed on the surface of the second mold320, annealing of the primary molded product301is performed and at the same time, a shape corresponding to the embossed pattern370, that is, an intaglio shape, can be imprinted on the primary molded product301.

In this way, since the embossed or intaglio shape is imprinted in the mold simultaneously with applying heat, there is an advantage in that a molded product having uniform transferability can be produced, and the gloss variation or corrosion variation in the final plastic product can be reduced. In addition, as described above, it is needless to say that various shapes can be formed on the surface of the second mold320according to the desired pattern.

FIG.14is a plane view illustrating an injection molding method using the injection molding device400according toFIG.5. However, the overlapping portion will be omitted, and annealing the primary molded product401will be described.

Referring toFIG.14, in a state where the second mold420and the first movable mold430are in contact with each other, annealing the primary molded product401located in the first cavity431may be performed. The annealing of the primary molded product401may further include injecting an additional raw material404into the primary molded product401.

In more detail, annealing the primary molded product401may include performing double injection molding by injecting an additional raw material404through the second injection port421. However, since there is no limitation in the order for each annealing of the primary molded product401and injection of the additional raw material404, annealing may be performed on both the primary molded product401and the additional raw material404after the additional raw material404is injected, or additional raw material404may be injected after annealing for the primary molded product401is performed. In addition, annealing may be performed simultaneously the injection of the additional raw material404.

Meanwhile, simultaneously with annealing of the primary molded product401, the secondary molded product402may be produced in the second cavity441of the second movable mold440. This is redundant with the description inFIG.8and thus will be omitted.

As previously mentioned with reference toFIG.5, the position or number of the second injection ports421and the amount of the additional raw material404to be injected may be adjusted to produce final products of various structures and materials.

FIG.15is a photograph of a plastic product manufactured through an injection molding device according to an embodiment of the present disclosure.

Referring toFIG.15, a portion indicated in black indicates an area without birefringence. Since the annealing process was performed in the mold, it was confirmed that internal stress and birefringence were effectively reduced. In addition, unlike the conventional heat treatment, there is no deformation of the optical product, and the annealing process can be completed within 1 to 2 minutes depending on the capacity of the heating member.

Although the preferred embodiments of the present disclosure have been described in detail above, the scope of the present disclosure is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present disclosure defined in the following claims also belong to the scope of rights.