KR20180022487A - Co-injection mold - Google Patents

Abstract

An objective of the present invention is to provide a co-injection mold which improves the uniformity of filling of an injection material (internal material). The co-injection mold according to an embodiment of the present invention includes: a body forming an injection space; an inlet passage formed at one side of the body for introducing an injection material into the injection space; and an overflow well connected to the injection space from the other side of the body through a passage to induce the overflow of the injection material.

Description

{CO-INJECTION MOLD}

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a mold for construction work, and more particularly, to a construction work mold for molding a product made of different materials to which a construction method is applied.

The co-injection method can form a double product with different internal and external structures through sequential injection of different materials. Depending on the pair of different materials, the finished product may become stiff or the plating and painting properties of the product may be improved.

For example, in the construction method, the material is alternately charged into the mold three times per step according to the injection order of the material, and the amount of the inner material (the second charged material) The filling property may be different, and the inner material may not flow to the end of the product, which may cause non-uniform charging of the inner material.

Also, when the outer material is opaque, the filling of the inner material is not observed from the outside. Therefore, there is a disadvantage that the control result of the internal material can not be confirmed in terms of the quality control point.

Accordingly, an object of the present invention is to provide a mold for construction which improves the uniformity of filling of an injection material (internal material). Another object of the present invention is to provide a mold for construction which can confirm the control result of the internal material.

According to another aspect of the present invention, there is provided a mold for construction, comprising: a body defining an injection space; an inlet passage formed at one side of the body for introducing the injection material into the injection space; And an overflow well, which is connected by a passage to induce an overflow of the injection material.

The inflow passage may be connected to a first inlet for introducing the first filling material and a second inlet for introducing the second filling material out of the injection material.

The first inlet and the second inlet may be selectively connected to the inlet passage via a changeover switch.

The volume of the overflow well may be 20-50% of the volume of the injection space.

The overflow well may be connected to the opposite end of the inflow passageway in the injection space.

As described above, an embodiment of the present invention connects an overflow well to an injection space to artificially induce an overflow of an injection material (an outer material or an inner material) into an overflow well in an injection space.

That is, in one embodiment, the overflow of the outer material prevents the occurrence of a dead space in the flow end of the injection space, thereby improving the filling uniformity of the inner material.

In addition, one embodiment can be utilized as a quality control point for filling of the internal material due to the core-surfacing of the internal material due to the overflow of the internal material, Thereby broadening the process window and detecting the expression effect when changing process environmental factors.

1 is a cross-sectional view of a mold for construction according to an embodiment of the present invention.
Fig. 2 is a sectional view of the mold of Fig. 1 in a state where the first filling material (outer material) is filled.
Fig. 3 is a cross-sectional view of the state in which the inside of the first filling material (outside material) is filled with the second filling material (inside material) following Fig. 2;
4 is a sectional view of the state in which the second charged material (inner material) charged inside the first charged material (outer material) is led out of the first charged material (outer material) following FIG. 3;

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In order to clearly illustrate the present invention, parts not related to the description are omitted, and the same or similar components are denoted by the same reference numerals throughout the specification.

1 is a cross-sectional view of a mold for construction according to an embodiment of the present invention. 1, a mold for construction according to an exemplary embodiment is connected to an injector (not shown) through a runner (not shown), and an injection material (e.g., a first filler material (outer material) M1) and a second filling material (inner material) (M2)). The construction mold of one embodiment includes a body 1, an inlet passage 2 and an overflow well 3 which form an injection space 11 corresponding to an injection molded article.

The inflow passage 2 selectively introduces the injection material, that is, the first filler material (outer material) M1 or the second filler material (inner material) M2 formed on the inflow side of the body 1 . The inlet passage 2 is connected to the first inlet 21 for introducing the first filling material M1 and the second inlet 22 for introducing the second filling material M2.

In addition, a changeover switch 23 is provided in the inflow passage 2. The first and second inlets 21 and 22 are selectively connected to the inflow passage 2 in accordance with the selective operation of the changeover switch 23. That is, the first and second filling materials M1 and M2 waiting at the first and second inlets 21 and 22 are connected to the changeover switch 23 and the inflow passage 2 via the selector switch 23, And is supplied to the injection space 11 of the body 1.

The overflow well 3 is connected to the injection space 11 at the other side of the body 1 by the passage 4 so as to discharge the injection material supplied to the injection space 11, M1) or an overflow of the second filling material (inner material) M2.

The passage 4 is formed on the opposite side of the inflow passage 2 of the body 1 so that the injection material (first and second filled materials M1 and M2) flowing into the inflow passage 2 is introduced into the body 1, The injection material overflowed in the injection space 11 of the overflow well 3 is introduced into the overflow well 3.

The volume of the overflow well 3 is 20 to 50% of the volume of the injection space 11. Thus, the injection material can overflow in the injection space 11 through the passage 4 in a sufficient amount to the overflow well 3.

That is, when the volume of the overflow well 3 is formed to be less than 20% of the volume of the injection space 11, the overflow of the first filling material (outer material) It may become difficult to ensure the uniformity of charging of the battery M2.

When the volume of the overflow well 3 is formed in a volume of more than 50% of the injection space 11, the first overflow of the first and second filling materials (other internal materials) , And securing the uniformity of charging of the second charged material (other than the inner material) M1 and M2 may become difficult.

The overflow well 3 is connected to the opposite end of the inflow passage 2 in the injection space 11 of the body 1. [ That is, the overflow well 3 is provided at the flow end of the injection space 11 and connected to the passage 4.

The overflow well 3 is connected to the flow end of the injection space 11 to control the dead space of the first filling material M1 and the gas filling device It does not require the same facilities.

The overflow well 3 artificially forms a large clearance space to induce a short-shot of the first filling material (outer material) M1 at the flow end so that the second filling material As an index of quality control on the amount of charge of the fuel (M2).

For example, the first filling material M1, which is an outer material, is formed of polycarbonate (PC), which is a transparent resin, and the second filling material M2, which is an inner material, is a PC, ABS resin (acrylonitrile- butadiene-styrene resin black.

Fig. 2 is a sectional view of the mold of Fig. 1 in a state where the first filling material (outer material) is filled. Referring to FIG. 2, the first switch 21 is connected to the inflow passage 2 by controlling the changeover switch 23, and the first filler material M1, which is an outer material, is supplied first to the first inlet 21 do.

The first filled material M1 to be supplied is charged into the injection space 11 of the body 1 via the first inlet 21 and the inflow passage 2. The first filled material M1 overflows to the overflow well 3 via the passage 4 while being filled in the injection space 11. [

The first filling material (outer material) M1 controls the dead space at the flow end of the injection space 11 so that no additional equipment such as a gas injection device for unfilled space control is required .

Fig. 3 is a cross-sectional view of the state in which the inside of the first filling material (outside material) is filled with the second filling material (inside material) following Fig. 2; 3, the changeover switch 23 is controlled to connect the second inlet 22 to the inflow passage 2 and to supply the second filling material M2, which is the inside material, to the second inlet 22 later do.

The supplied second filling material M2 is charged into the injection space 11 of the body 1 via the second inlet 22 and the inflow passage 2. [ At this time, the second filling material M2 advances into the first filling material M1 in the injection space 11, and the first filling material M1 passes through the overflow well 3 ). ≪ / RTI >

A dead space is not generated at the flow end of the injection space 11 because the first filling material M1 is overflowed and the charging uniformity of the second filling material M2, .

4 is a sectional view of the state in which the second charged material (inner material) charged inside the first charged material (outer material) is led out of the first charged material (outer material) following FIG. 3; Referring to FIG. 4, the second filling material M2, which is an inner material, is further supplied to the second inlet 22. The second filling material M2 filled in the injection space 11 and led into the interior of the first filling material M1 overflows to the overflow well 3 via the passage 4. [

The overfilled second filling material (inner material) M2 can be utilized as a quality control point due to the injection space 11 and core-surfacing of the injection-molded article, Thereby enabling to detect the expression effect when the process environmental factor is changed.

Table 1 shows examples and comparative examples.

Experimental factor unit Example 1 Example 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Mold temperature ℃ 40 40 80 40 80 80 Second filling material weighing amount ml 85 85 85 85 95 85 The second filling material injection pressure Bar 150 180 150 150 150 180 Overflow well - O O X X X X Comparison factor - Overflow well application Reference mold
Temperature Second filling material weighing amount The second filling material injection pressure

Referring to Table 1, in Examples 1 and 2, the overflow well 3 was applied to a mold for construction, and Comparative Examples 1 to 4 did not apply an overflow well to a mold for construction.

Table 2 shows the experimental results for the examples and comparative examples.

Experimental factor unit Example 1 Example 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Second charge material charge amount % 96.1 96.5 91.5 91.3 90.9 90.7 Other bad - - - Dead space Poor extraction

Referring to Table 2, in the second comparative example, the temperature change of the mold for the construction did not affect the variation in the uniformity of filling of the second filling material (M2) as the internal material.

In the comparative example 3, an increase in the amount (95 ml) of the second filling material (M2) as the internal material increased the filling amount (90.9%) of the second filling material. However, The unfilled space of the first filled material M1 could not be buried.

An increase in the injection pressure (180 bar) of the second charged material M2 as the internal material in Comparative Example 4 could bring about a change in the charged amount of the second charged material M2. However, the forced increase in the injection pressure of the second charged material M2 Burrs of the parting-line and the mold-sticking phenomenon at the take-out.

On the other hand, in the first and second embodiments, the large-area overflow well 3 induced the most uniform flow phenomenon of the first filling material M1 as the outer material. The overflow well 3 side in the molding can be easily removed through cutting (see FIG. 3).

Large overflow wells 3 in Examples 1 and 2 are utilized as quality control points due to core-surfacing of the second filling material (inner material) M2 (See FIG. 4), widening the process window for producing good products, and detecting the expression effect when changing process environmental factors.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, And it goes without saying that the invention belongs to the scope of the invention.

1: Body
2: inlet passage
3: Overflow Well
4: passage
11: Injection space
21: First entrance
22: Second entrance
23: Conversion switch
M1: First filling material (outer material)
M2: Second charging material (inner material)

Claims (5)

A body defining an injection space;
An inflow passage formed at one side of the body for introducing the injection material into the injection space; And
And an overflow well which is connected to the injection space by a passage at the other side of the body to induce an overflow of the injection material,
A mold for construction. The method according to claim 1,
The inlet passage
Wherein the injection material is connected to a first inlet for introducing the first filling material and a second inlet for introducing the second filling material. 3. The method of claim 2,
The first inlet and the second inlet
And is selectively connected to the inflow passage via a changeover switch. The method according to claim 1,
The volume of the overflow well
Wherein the molding space is formed with a volume of 20 to 50% of the injection space. The method according to claim 1,
The overflow well
And is connected to the opposite end of the inflow passage in the injection space.

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