TW201404570A - Injection molding device to improve the mechanical strength of the workpiece - Google Patents

Abstract

This invention provides a injection molding device to improve the mechanical strength of the workpiece which comprises a mold and a spoiler element on the mold. Each spoiler element includes a reserved hole and an ejection element with setting into the reserved hole and moving between a reserved position and a spoiler position. When the ejection element be set on the reserved position, a part of melt will be stored in the reserved hole. Also, the part of melt will be pushed together with others melt when the ejection element be switched on the spoiler position. Hence, when the total melt finished to inject and not yet to cool, disturbing the molecular orientation of weld line interface improve the mechanical strength of the workpiece by a spoiler element. At the same time, there is a few cost overhead for this invention.

Description

Injection molding device capable of enhancing the strength of plastic workpiece

The present invention relates to an injection molding apparatus, and more particularly to an injection molding apparatus capable of enhancing the strength of a workpiece.

Injection molding is one of the most important manufacturing methods for plastic workpieces. Since injection molding can produce complex, high-precision plastic parts automatically, quickly and in large quantities, injection molding is made into plastic. The most important process technology for workpiece machining.

However, generally, when using the injection molding processing method, due to the multi-gate cavity design or the product design itself, there are holes, which will cause different melt wave front contact formation during the injection molding process. A linear bonding wire, also known as a Weld line.

Referring to FIG. 1 , for example, when the plastic model filling process is performed by injection molding, the melt is poured by the left and right gates in opposite directions (ie, the melted W1 and W2 are facing forward and intersecting), and the melt is melted. A fountain-like flow is formed between the mold walls. When the two melts W1 and W2 meet, the molecules contacting the two melts will be parallel to the contact interface L. Therefore, after the injection molding is completed, the contact interface L is formed. A stitch will be formed.

For a plastic workpiece, the suture not only affects the appearance of the product, but more importantly, the suture is also a place where stress is easily concentrated. Once the plastic workpiece is subjected to external force, it is often deformed by the suture. It is also a problem such as breakage, so the stitching can be said to be the biggest strength weakness of the plastic workpiece.

In today's existing technology, in order to effectively eliminate the sutures generated during the injection molding process, it is often necessary to increase the mold temperature, but the increase in mold temperature will not only increase the cost of injection molding, but also require cooling after molding. The time is also relatively long, so the use of increased mold temperature to reduce the chance of sutures is a very energy-intensive and time-consuming technique for the plastics manufacturing industry.

From the above, how to find a technology that can reduce the influence of sutures at a lower cost is one of the most important issues for the plastics manufacturing industry.

Accordingly, it is an object of the present invention to provide an injection molding apparatus for enhancing the strength of a plastic workpiece, suitable for pouring a melt comprising: a mold having a gate for pouring the melt; and at least a spoiler element is disposed on the mold, wherein each spoiler element comprises: a reserved hole; and a top ejection member disposed in the reserved hole and moving in the reserved hole to Switching between a reserved position and a spoiler position; when the ejecting member is disposed in the reserved position, the reserved hole is used to store a part of the melt when the melt flows through the reserved hole, and when the top is When the output is switched to the spoiler position, part of the melt stored in the reserved hole is led out and collected with the rest of the melt.

Thus, the effect of the present invention is to effectively increase the strength of the plastic workpiece by disturbing the flow direction of the suture, and at the same time, compared to the prior art In terms of increasing the mold temperature to enhance the strength of the plastic workpiece, the additional cost required by the present invention is relatively small.

The details of the related patents and the technical contents of the present invention will be apparent from the following detailed description of the preferred embodiments of the accompanying drawings.

First preferred embodiment

Referring to Figures 2 and 3, a preferred embodiment of the present invention comprises: a mold 5 having a gate unit 51, and at least one spoiler member 52, wherein each spoiler member 52 is disposed in the mold 5 is close to any suture, and includes: a reserved hole 521 and an ejection member 522, and the ejection member 522 is disposed between a reserved position R1 and a spoiler position R2 in the reserved hole 521. mobile.

In addition, in the embodiment, the gate unit 51 includes a first gate 511 and a second gate 512, and the melted by the first gate 511 is referred to as a first melt W1. And the melt injected from the second gate 512 is referred to as a second melt W2.

Referring to FIG. 2, when the mold 5 is subjected to a melt molding, the ejection member 522 is disposed at a reserved position R1, and the melt flows in from the first gate 511 and the second gate 512, and A Weld line is formed on a contact interface L. It should be noted that since the mold 5 has a plurality of spoiler elements 52, and a reserved hole 521 of each spoiler element 52 is disposed near the suture, when the first melt W1 and the second melt When the glue W2 meets, some of the melt will flow into the reserved holes 521, and the original melt will be changed. The flow direction of the glue is an irregular flow direction. Therefore, compared with the prior art, the suture formed by the preferred embodiment has a relatively irregular degree of tortuosity, so that the effect of the suture misalignment can be achieved.

Referring to FIG. 4, after the melt is completely filled into the mold 5, the suture on the contact interface is substantially formed, and the melt is left in the reserved holes 521, since the melt has not yet been melted. The ejecting member 522 is moved from the reserved position R1 to the spoiler position R2. At this time, the melt pre-stored in the reserved hole 521 will be squeezed by the ejecting member 521. And flowing out and collapsing with the original first melt W1, since the melt in the reserved hole 521 is merged into the first melt W1, the melt inflow in the reserved hole 521 will disturb the The molecular flow direction of the partial melt in the first melt W1, so that the flow direction of the contact interface L' will be disturbed into an irregular flow direction (because the molecular flow therein is received by the melted glue in the reserved hole 521) In this case, the effect of the turbulence is achieved, so that the molecular aligning direction when the first melter W1 and the second melter W2 meet at the contact interface L are no longer arranged in a straight line.

Since the molecular alignment of the contact interface L' is no longer arranged in a straight line, a larger resistance to external forces can be produced compared to the sutures arranged in a line in the prior art.

Second preferred embodiment

The greatest difference between the preferred embodiment and the first preferred embodiment is that the present invention is also applicable to a single gate mold. For example, referring to FIG. 5, a mold 5 having a single gate 51, the interior thereof Having a barrier member 53 so that the first melter W1 flows through the barrier member 53 to thereby produce a cross-flow effect A first melt split W11 and a second melt split W12 are formed, and the first melt split W11 and the second melt split W12 will be collected in the contact interface L" to form a stitch. Therefore, the spoiler element 52 of the preferred embodiment will be placed close to the suture.

Referring to FIGS. 5 and 6, the contact interface L" is viewed from the viewing angle P direction. When the ejection member 522 is moved to the spoiler position R2, the first melt splitting W11 and the second melt may be disturbed. The sutures formed by the shunting of the W12 are arranged such that the contact interface L" is no longer arranged in a straight line. Therefore, it is possible to produce a larger resistance to external forces than the contact interface L" which is arranged in line in the prior art.

Therefore, for a single gate mold or a multi-gate mold, by the technique of the present invention, the spoiler element is disposed close to any corresponding suture, thereby disturbing the suture to prevent it from being rendered. Arrange in a straight line to increase the strength of the plastic workpiece.

The relevant experimental results of the preferred embodiment are as follows: Firstly, according to the plastic characteristics, the following three different plastics are selected, namely polypropylene PP with high toughness (Yongjiaene 3204) and brittle polystyrene PS (525N, Kaofulex Chemical Corp.) and acrylonitrile-butadiene-styrene ABS (Chi Mei PA756) with high impact strength.

Among them, the injection molding parameters of polypropylene PP are shown in Table 1.

The injection molding parameters of polystyrene PS are shown in Table 2.

The injection molding parameters of acrylonitrile-butadiene-styrene ABS are shown in Table 3.

Related experimental results of an impact test based on the above three different plastics As shown in Figure 7.

As can be seen from Fig. 7, the plastic workpiece injection molded by the present invention, whether applied to polypropylene PP, polystyrene PS, or acrylonitrile-butadiene-styrene ABS material, is compared with the prior art. In other words, the impact strength can be almost doubled, so when the technology of the present invention is applied to a safety device such as a car bumper, the impact resistance of the plastic workpiece can be greatly improved, thereby greatly improving the safety device. Security.

Therefore, it can be known that by the present invention, the method of disturbing the suture is not arranged in a straight line, and the present invention can effectively improve the strength of the plastic workpiece compared to the strength of the plastic workpiece which forms the suture in the prior art. The object of the present invention is that, at the same time, the present invention is relatively less expensive to manufacture than the prior art in order to increase the mold temperature to enhance the strength of the plastic workpiece.

The above is only the preferred embodiment of the present invention, and the scope of the invention is not limited thereto, that is, the simple equivalent changes and modifications made by the scope of the invention and the description of the invention are All remain within the scope of the invention patent.

5‧‧‧Mold

51‧‧‧gate

511‧‧‧ first gate

512‧‧‧second gate

52‧‧‧ spoiler components

521‧‧‧Reserved holes

522‧‧‧ ejection

53‧‧‧Resist

L‧‧‧Contact interface

L'‧‧‧Contact Interface

L"‧‧‧Contact Interface

R1‧‧‧ Reserved location

R2‧‧‧ spoiler location

W1‧‧‧First melt

W11‧‧‧First melt split

W12‧‧‧Second melt split

W2‧‧‧Second melt

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic view showing a first embodiment of an injection molding apparatus for reinforcing the strength of a plastic workpiece according to the present invention; and Figure 3 is a perspective view of the first preferred embodiment of the injection molding apparatus for reinforcing the strength of a plastic workpiece according to the present invention; Side view of a first preferred embodiment of an injection molding apparatus for plastic workpiece strength; Figure 4 is a schematic view of the melt flow of the ejection member when the ejection member is moved to the spoiler position; Figure 5 is a top view of the second preferred embodiment of the injection molding device for enhancing the strength of the plastic workpiece of the present invention; Figure 6 is an enhanced view of the present invention; A side view of a second preferred embodiment of an injection molding apparatus for plastic workpiece strength; and Figure 7 is a comparison of experimental results of the present invention with prior art in an impact test.

511‧‧‧ first gate

512‧‧‧second gate

52‧‧‧ spoiler components

521‧‧‧Reserved holes

522‧‧‧ ejection

L‧‧‧Contact interface

R1‧‧‧ Reserved location

R2‧‧‧ spoiler location

W1‧‧‧First melt

W2‧‧‧Second melt

Claims (3)

An injection molding device capable of enhancing the strength of a plastic workpiece, suitable for pouring a melt, comprising: a mold having a gate for pouring the melt, and the melt forming a seam in the mold And at least one spoiler element disposed on the mold, wherein each spoiler element comprises: a reserved hole; and a top ejection member disposed in the reserved hole and in the reserved hole Moving to switch between a reserved position and a spoiler position; when the ejection member is disposed in the reserved position, the reserved hole is used to store a partial melt when the melt flows through the reserved hole, and When the ejection member is switched to the spoiler position, a portion of the melt stored in the reserved hole is led out and collected with the remaining melt. An injection molding apparatus capable of enhancing the strength of a plastic workpiece according to the first aspect of the patent application, wherein a direction of movement of the ejection member in the reserved hole is different from a flow direction of the melt. An injection molding apparatus for enhancing the strength of a plastic workpiece according to the scope of claim 2, wherein each of the spoiler elements is disposed in the mold adjacent to the suture.