TW201625400A - Polymer plate extrusion mold - Google Patents

Abstract

A polymer plate extrusion mold includes a first mold, and a second mold fitting the first mold. The first mold and the second mold together define a feeding channel in an inverted-T shape, a connecting channel communicating the feeding channel, a regulation channel communicating the connecting channel, a discharging channel having a level difference relative to the regulation channel, and a loose channel communicating the regulation channel and the discharging channel in an oblique manner. The flow velocity of the polymer materials is uniform due to the dispersion of the polymer materials by the connecting channel, which improves the quality of the extruded plate (membrane).

Description

Polymer plate extrusion die

The invention relates to a mold, in particular to a polymer flat plate extrusion die.

Polymer extrusion molding can be roughly classified into flat (film) extrusion molding, blow molding, profile extrusion molding, tubular extrusion molding, co-extrusion molding, and the like. No matter what kind of polymer extrusion molding, the key to its main success or failure lies in the design of the mold.

In recent years, with the advancement of technology, not only the demand for polymer plates or films such as optical films or packaging films has increased, but also for product properties such as transparency, gloss, uniformity, etc. of polymer plates or films. The requirements are getting higher and higher.

Referring to Figures 1 and 2, the conventional flat (film) extrusion molding is mostly performed by extrusion molding using a T-die 1 (T-die) as shown in Fig. 1. The T-die 1 includes a tube 11, a A branch pipe 12 that laterally communicates with one end of the tube 11 and a lip 13 that communicates with the branch tube 12. Wherein, the cross section of the branch pipe 12 is substantially circular.

Although the polymer flat plate (film) can be smoothly extruded by the T-die 1, the tube 11 is located substantially at the center of the branch pipe 12. Therefore, the polymer material located at the center of the branch pipe 12 can flow toward the lip 13 faster than the polymer material located on both sides of the branch pipe 12, causing uneven flow rate and affecting product characteristics.

Although the above disadvantages can be improved by increasing the diameter of the branch pipe 12, increasing the diameter of the branch pipe 12 tends to cause the polymer material to remain in the branch pipe 12, thereby causing thermal cracking, which affects the appearance and mechanical properties of the product.

Accordingly, it is an object of the present invention to provide a polymer flat plate extrusion die which can improve the flow rate of a polymer material.

Therefore, the polymer flat plate extrusion die of the present invention comprises a first mold and a second mold matched with the first mold.

The first mold cooperates with the second mold to define an inverted T-shaped feed passage, a connecting passage connecting the feed passage, a regulating passage connecting the connecting passage, and a difference formed between the adjusting passage and the adjusting passage. a discharge passage, and a slack passage obliquely connecting the adjustment passage and the discharge passage, wherein the feed passage has a feed section extending in a length direction, and a flow dividing the feed section in the width direction a connecting section having a first slit section extending in the longitudinal direction and communicating with the splitting section, and a second slit extending in the longitudinal direction and having a height smaller than the first slit section a slit segment that communicates with the second slit segment and extends in a length direction.

The utility model has the advantages of: utilizing the first slit segment extending in the longitudinal direction and connecting the first slit segment and extending along the length The second slit segment extending in the direction of the first slit segment is dispersed in the polymer material to make the flow rate of the polymer material more uniform, thereby improving the quality of the extruded plate (film).

2‧‧‧First mould

3‧‧‧Second mold

31‧‧‧Men

32‧‧‧Inlay

321‧‧‧ Body Department

322‧‧‧Protruding

41‧‧‧ Feeding channel

411‧‧‧feeding section

412‧‧‧Diversion section

413‧‧‧Diversion area

414‧‧‧Shrinking area

42‧‧‧Adjustment channel

43‧‧‧Drainage channel

44‧‧‧ Relaxation channel

45‧‧‧Connecting channel

451‧‧‧First slit section

452‧‧‧Second slit section

A‧‧‧ Length direction

B‧‧‧Width direction

L‧‧‧ center axis

D1, D2‧‧‧ flow distance

Other features and effects of the present invention will be apparent from the following description of the drawings, wherein: FIG. 1 is a schematic diagram showing a conventional T-die; FIG. 2 is a schematic view of the T in FIG. FIG. 3 is an exploded perspective view showing an embodiment of the polymer flat plate extrusion die of the present invention; FIG. 4 is a schematic view for assisting the description of the feed channel, the connecting channel, the regulating channel, and FIG. The discharge channel and the relaxed channel; FIG. 5 is another schematic diagram illustrating the feed channel, the connection channel, the adjustment channel, the discharge channel, and the relaxed channel; FIG. 6 is an enlarged schematic view illustrating the FIG. 7 is a schematic view showing a state in which a polymer material flows through the first slit segment and the second slit segment; FIG. 8 is a comparative diagram illustrating the present embodiment and the existing T-shape The flow uniformity of the die and the different polymer materials; and FIG. 9 is a comparative diagram illustrating the difference in residence time of the polymer material of the present embodiment and the conventional T-die.

Before the present invention is described in detail, it should be noted in the following In the description, similar elements are denoted by the same reference numerals.

Referring to Figures 3, 4 and 5, an embodiment of the polymer flat plate extrusion die of the present invention comprises a first mold 2 and a second mold 3 cooperating with the first mold 2. The second mold 3 has a mold core 31 and an insert 32 detachably disposed on the mold core 31. The insert block 32 has a body portion 321 disposed on the mold core 31, and a protruding portion. The body portion 321 is substantially a protruding portion 322 of the isosceles triangle.

It should be noted that the insert 32 detachably disposed on the mold core 31 can be replaced with different polymer materials to effectively reduce the mold cost.

The first mold 2 cooperates with the mold core 31 of the second mold 3 to define an inverted T-shaped feed passage 41, an adjustment passage 42, and a discharge passage 43 formed with the adjustment passage 42. And a slack channel 44 that is obliquely connected to the adjustment passage 42 and the discharge passage 43.

Referring to Figures 4, 5 and 6, the feed passage 41 has a feed section 411 extending in the length direction A and a splitter section 412 that communicates the feed section 411 in the width direction B. Wherein, the section of the branching section 412 along the longitudinal direction A is substantially water-dropped, and the section of the branching section 412 along the length direction A can be divided into a semi-circular type and the diverting zone 413 connecting the feeding section 411, and A constricted region 414 that is tapered by the shunt region 413 toward the adjustment passage 42.

Referring to Figures 3 and 4, the first mold 2 cooperates with the insert 32 of the second mold 3 to communicate with the connecting passage 45 of the feed passage 41 and the adjustment passage 42. The connecting channel 45 has a reduced bundle that communicates with the shunt segment 412 a first slit section 451 extending along the length direction A, and a second slit section extending in the longitudinal direction A and having a height less than the height of the first slit section 451 452. The adjustment passage 42 is connected to the second slit section 452 and extends along the length direction A. The body portion 321 of the insert 32 cooperates with the first mold 2 to define the first slit segment 451, and the insert 32 is substantially the protrusion 322 of the isosceles triangle cylinder and the first mold 2 The second slit section 452 is defined to cooperate, and the contraction zone 414 is tapered from the diverting zone 413 toward the first slit section 451 and communicates with the first slit section 451.

Referring to FIG. 7, a central axis L extending along the longitudinal direction A and passing through the feeding section 411 is defined. The flow distance D1 of the polymer material in the longitudinal direction A of the first slit section 451 is from the central axis L to two. As the side is increased, the flow distance D2 of the polymer material in the longitudinal direction A of the second slit section 452 is decreased from the central axis L toward both sides.

By using the design of the main body portion 321 of the insert 32 and the protruding portion 322 of the isosceles triangular cylinder, the flow distance D1 of the polymer material in the longitudinal direction A of the first slit segment 451 is defined by the central axis L. Increasing to both sides, and the flow distance D2 along the length direction A of the second slit segment 452 is decreased from the central axis L to both sides, and the height of the second slit segment 452 is smaller than the first slit. The height of the segment 451 is such that the path of the second slit segment 452 through which the polymer material near the central axis L flows is long, and the second slit through which the polymer material on both sides of the central axis L flows is required. The path of the segment 452 is short, and the flow velocity of the polymer material is adjusted to make the overall flow velocity uniform, thereby improving the quality of the extruded plate (film).

Referring to FIGS. 4 and 5, in practical application, the polymer material is sequentially passed through the feed section 411, the splitting zone 413 and the contraction zone 414 of the splitter section 412, the first slit section 451, and the second slit section. 452. The adjustment channel 42 and the relaxation channel 44 are finally formed into a polymer flat plate through the discharge channel 43.

In order to verify the efficacy of the present invention, the inventors simulated the embodiment of the polymer flat plate extrusion die of the present invention with an existing T-die. The results are shown in Figures 8 and 9.

As shown in Fig. 8, when the polymer material is polypropylene (PP), the flow deviation value (the difference between the maximum value and the minimum value) of the present embodiment is about 6.269%, and the flow deviation of the existing T-die is different. The value is about 27.908%; when the polymer material is polycarbonate (PC), the flow deviation value of the embodiment is about 5.589%, and the flow deviation value of the existing T-die is about 19.043%; and when the polymer material In the case of High Density Polyethylene (HDPE), the flow deviation value of this embodiment is about 6.133%, and the flow deviation value of the existing T-die is about 7.997%.

From the above, it can be seen that the embodiment of the polymer flat plate extrusion die of the present invention can effectively improve the problem of uneven flow of the existing T-die.

It should be particularly noted here that the width of the horizontal axis die in FIG. 8 is equivalent to the center, and the value increases or decreases, that is, from the center to the both sides, and further, is detachably disposed on the mold core 31 ( The insert 32 (shown in Figure 3) shown in Figure 3), in the present invention, replaces the inserts 32 of different sizes for different polymeric materials during the simulation, although the dimensions are different but the overall shape is substantially the same.

As shown in Figure 9, when the polymer material is polypropylene In the case of (Polypropylene, PP), the residence time of the polymer material using the polymer flat plate extrusion die of the present invention is significantly shorter than the residence time of the polymer material using the conventional T-die. Since the polymer flat plate extrusion die of the present invention can shorten the residence time of the polymer material, it is indeed possible to improve the thermal cracking problem caused by the excessive retention of the polymer material in the conventional T-die.

In summary, the polymer flat plate extrusion die of the present invention utilizes the first slit segment 451 that extends through the splitter segment 412 and extends along the length direction A, and communicates with the first slit segment 451 and extends along the length direction A and height. The second slit segment 452 smaller than the first slit segment 451 disperses the polymer material, so that the flow rate of the polymer material can be relatively uniform, thereby improving the quality of the extruded plate (film). The insert 32 detachably disposed on the mold core 31 is replaced by different polymer materials, which not only improves the quality of the extruded flat plate (film), but also effectively reduces the mold cost, so that the present invention can be achieved. The purpose.

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

2‧‧‧First mould

3‧‧‧Second mold

31‧‧‧Men

32‧‧‧Inlay

321‧‧‧ Body Department

322‧‧‧Protruding

Claims (4)

A polymer flat plate extrusion die comprising: a first mold, and a second mold, the first mold cooperates with the first mold to define an inverted T-shaped feed passage, a connecting passage connecting the feed passage, a regulating passage communicating with the connecting passage, a discharging passage formed with the adjusting passage, and a slack passage obliquely connecting the adjusting passage and the discharging passage, wherein the feeding passage has a length extending a feed section, and a splitter section communicating with the feed section in a width direction, the connection passage having a first slit section extending in the longitudinal direction connecting the splitter section, and a first slot section connected to the first slit section a second slit segment extending in the length direction and having a height smaller than the first slit segment, the adjustment passage being connected to the second slit segment and extending in the length direction. The polymer flat plate extrusion die according to claim 1, wherein a longitudinal axis extending through the central axis of the feed section is defined, and a flow distance of the polymer material in the longitudinal direction of the first slit segment is determined by the length The central axis increases toward both sides, and the flow distance of the polymer material in the longitudinal direction of the second slit segment is decreased from the central axis to both sides. The polymer flat plate extrusion die according to claim 1 or 2, wherein the second mold has a mold core, and an insert detachably disposed on the mold core, and the insert has a setting a body portion of the mold core, and a protrusion protruding from the body portion and cooperating with the second slit portion, the body portion cooperating with the first mold to define the first slit segment, The projection cooperates with the first mold to define the second slit segment. The polymer flat plate extrusion die according to claim 3, wherein the cross section of the splitting section has a water droplet shape along a longitudinal direction, and the cross section of the splitting section along the length direction can be divided into a substantially semicircular shape and connected thereto. a splitting zone of the sliver, and a constricted zone extending from the diverting zone toward the connecting passage and extending the first slit section.