TWI706851B - Molding apparatus - Google Patents

Abstract

The disclosure provides a molding apparatus including a bearing portion and a molding portion. The bearing portion is provided with a groove, the groove has a bottom wall and a side wall connected to the bottom wall. The molding portion is on the bottom wall and spaced apart from the side wall. The molding portion has a top surface away from the bottom wall, the top surface is configured for carrying a product to be formed. The contour of the opening of the groove and the contour of the edge of the top surface are the same. The contour of the opening of the groove and the contour of the edge of the top surface are the same, so that the molding apparatus helps to improve the optical properties problem of the film material caused by the stress on the film material in the thermoplastic molding process.

Description

Forming device

The invention relates to the field of tooling and fixtures, in particular to a molding device.

At present, regardless of VR (Virtual Reality, virtual reality) devices, AR (Augmented Reality, augmented reality) devices, wearable computers, etc., it is generally necessary to attach optical films, and the above-mentioned optical films are generally completed by hot pressing. Take the process of forming an optical film by hot press molding as an example, especially when forming a curved optical film. In the process of hot press molding, the film material needs to be placed on a hot press molding jig, which includes a molding The contour of the forming area is the same as the contour of the target product. Pressure is applied to the film material from one side of the film material away from the jig, so that the film material finally forms the target product.

In the conventional jig, when pressure is applied to the film material from one side of the film material away from the jig, the stress of the film material corresponding to the edge of the forming area is stronger, causing the film material to be stretched and deformed, which is further derived from the deformation Changes in the optical properties and material thickness of thin film materials, such as deterioration of optical properties, uneven thickness of thin film materials, etc. The above-mentioned problems will lead to the final formation of target products of thin film materials, which are used in VR devices, AR devices, and wearable computers. The quality of the equipment decreases while waiting for the equipment.

The present invention provides a molding device, which includes: a carrying part, on which a groove is provided, the groove has a bottom wall and a side wall connected to the bottom wall; and a shaping part, the shaping part is arranged on On the bottom wall and spaced apart from the side wall, the molding part has a top surface away from the bottom wall, and the top surface is used to carry the product to be molded; the contour of the opening of the groove is consistent with the top surface The contours of the edges of the surface are the same.

In the molding device provided by the embodiment of the present invention, the contour of the opening of the recess of the carrying portion is set to be the same as the contour of the edge of the top surface of the molding portion. During the thermoplastic molding process, the film material is applied When pressure is applied, the edge stress of the film material is relatively small, which is beneficial to improve the problem of the optical properties of the film material being affected by the stress on the film material in the thermoplastic molding process.

10: Forming device

11: Bearing Department

12: Forming department

111: Groove

112: bottom wall

113: Sidewall

114: opening

121: top surface

d1: depth

d2: height

O: pole

M: first ray

N: second ray

P, Q: intersection point

X, Y: curve

20: Thin film material

D1, D2: opening diameter

FIG. 1 is a schematic diagram of a three-dimensional structure of a molding device provided by Embodiment 1 of the present invention.

Figure 2 is a schematic cross-sectional view of Figure 1 along the direction II-II.

Fig. 3 is a projection pattern of the top surface of the forming part with the opening of the groove.

Figure 4 is a schematic cross-sectional view of the molding device in use.

Figure 5 is another schematic cross-sectional view of the molding device in use.

Example one

Please refer to FIG. 1, the molding device 10 provided in this embodiment includes a supporting portion 11 and a molding portion 12 combined with the supporting portion 11.

As shown in FIG. 1, a groove 111 is provided on the carrying portion 11, and the groove 111 is used to accommodate the product to be molded. The groove 111 has a bottom wall 112, a side wall 113 connected to the bottom wall 112, and an opening 114 away from the bottom wall 112. The molding part 12 is disposed on the bottom wall 112 of the groove 111, and the molding part 12 is accommodated in the groove 111. The molding part 12 is spaced from the side wall 113 of the groove 111.

In this embodiment, the carrying portion 11 and the molding portion 12 are integrally formed. The integral forming method may include, but is not limited to: 3D printing, injection molding, and the integral forming method is more efficient. In another embodiment, the molding part 12 is detachably coupled to the bottom wall 112 of the groove 111. The detachable method includes but is not limited to: gluing and locking with fasteners (such as bolts). When set in a detachable manner, it is possible to replace only the carrying part 11 or the molding part 12 in one molding device, or to achieve the combination of different carrying parts 11 and the molding part 12 to improve the flexibility of component utilization.

As shown in FIG. 1, the molding part 12 has a top surface 121 away from the bottom wall 112 of the groove 111. When the molding device 10 is used to process a product to be molded, the top surface 121 is used to carry the product to be molded, and the product to be molded will be attached to the top surface 121 and pressed. The contour of the edge of the top surface 121 is the same as the contour of the opening 114 of the groove 111.

As shown in FIG. 1, in the molding device 10 provided in this embodiment, the top surface 121 of the molding portion 12 has an irregular shape, and the contour of the opening 114 of the groove 111 is set to be the same as the edge contour of the top surface 121. In this embodiment, the carrying portion 11 is arranged in a hollow cylindrical shape to keep the contour of the opening 114 of the groove 111 the same as the contour of the edge of the top surface 121 and is an irregular contour, and the wall thickness of the carrying portion 11 is uneven It. The present invention does not limit the overall shape of the supporting portion 11. In other embodiments, the appearance of the molding device 10 may be adjusted so that the wall thickness of the supporting portion 11 can be set equal.

Please refer to FIG. 2, the top surface 121 is a curved surface. In this embodiment, the top surface 121 is a curved surface recessed toward the bottom wall 112 of the groove 111. In other embodiments, the top surface 121 may be a curved surface that protrudes away from the bottom wall 112 of the groove 111. In another embodiment, the top surface 121 may also be a flat surface. The shape of the top surface 121 is determined according to the shape of the target molded object, the contour of the opening 114 of the groove 111 is determined by the contour of the edge of the top surface 121, and the size of the opening of the groove 111 is larger than the area of the top surface 121.

The relationship between the contour of the opening 114 of the groove 111 and the contour of the edge of the top surface 121 of the forming part 12 will be further explained below: Please refer to FIGS. 2 and 3 together, and the contour of the opening 114 is compared to the top surface 121 The contour of the edge is projected orthographically on the bottom wall 112 of the groove 111, and the resulting projection pattern is shown in Fig. 3. In Fig. 3 there are curves X and Y respectively. Curve X is the projection of the contour of the opening 114 on the bottom wall 112 The figure, the curve Y is the projection figure of the contour of the edge of the top surface 121 on the bottom wall 112.

Please refer to Figure 3. Establish a polar coordinate system on the plane where the projected figure is located. Take the geometric center of the figure enclosed by curve Y as the pole, and the pole is denoted as O. The first ray M is drawn in any direction from the pole O as the polar axis. The pole O draws a second ray N in any direction, and the second ray N has an intersection with the curve X and the curve Y respectively. The intersection of the second ray N and the curve X is denoted as P, and the coordinates of point P are denoted as (ρ1, θ1), where ρ1 represents the distance between the pole O and the P point, and θ1 represents the connection line between the P point and the pole O and the first The angle between the ray M; the intersection of the second ray N and the curve Y is Q, and the coordinates of the Q point are expressed as (ρ2, θ2), where ρ2 represents the distance between the pole O and the Q point, and θ2 represents the connection between the Q point and the pole O The angle between the line and the first ray M. Then the coordinates of point P and point Q satisfy the following relationship: θ1=θ2=the angle between the first ray M and the second ray N, ρ1=S×ρ2, and S>1, that is, ρ1 is greater than ρ2.

That is, the contour of the opening 114 of the groove 111 is the same as the contour of the edge of the top surface 121 and is enlarged on the basis of the top surface 121.

1.5；於另一實施例中，1.5

S

1.75。 In one embodiment, the contour of the opening 114 of the groove 111 is the same as the contour of the edge of the top surface 121, and S

1.5; in another embodiment, 1.5

S

1.75.

Please refer to FIG. 4, the molding device 10 provided in this embodiment is used for thermoplastic molding to form a target molded object (not shown), and the target molded object is an optical film. In the molding process, the film material 20 is first placed on the supporting part 11, at this time the film material 20 has not yet entered the groove 111, and then applied on the side of the film material 20 away from the molding part 12 (the plural parallel arrows in Figure 4 point to the direction) The pressure causes the film material 20 to enter the groove 111 and finally abut the top surface 121 of the molded part 12. The film material 20 can be heated and softened before entering the groove 111, or it can be softened by heating after entering the groove 111, so that the softened film material 20 resists the top surface 121 of the forming part 12 and is squeezed to form the top surface 121 shape. In this embodiment, the way of applying pressure is to directly apply pressure to the film material 20 with a mechanical pressure head.

In order to provide a accommodating space for the mechanical indenter, in this embodiment, the side wall 113 of the groove 111 is perpendicular to the plane where the bottom wall 112 is located, and the side wall 113 has the same height everywhere. The depth d1 of the groove (that is, the height of the side wall 113) is greater than the maximum height d2 of the forming part 12 (the forming part 12 is a curved surface with different heights, so it has a maximum height).

In other embodiments, the method of applying pressure may also be pneumatic, hydraulic, etc., which is not limited in the present invention.

Please refer to FIG. 5, keep applying pressure so that the film material 20 is close to the top surface 121 of the molding part 12. The part of the film material 20 that is in close contact with the top surface 121 of the forming part 12 is the target forming object, and the remaining part is waste. In order to form a target molded object with a desired shape, the top surface 121 of the molding portion 12 is set to be consistent with the shape of the target molded object. In this embodiment, the top surface 121 of the molding part 12 is a curved surface, and the target molded object is a curved optical film.

In the molding device 10 provided in this embodiment, by setting the contour of the opening 114 of the groove 111 to be the same as the contour of the edge of the top surface 121 of the molding portion 12, when the film material 20 is squeezed during the thermoplastic molding process, the film material The edge stress of 20 is relatively small, and the stress on the entire bearing surface is relatively balanced, which helps to keep the structure of the film material 20 unchanged, so that the film material 20 maintains its original characteristics. Therefore, it is beneficial to improve the problem of excessive stress on the film material 20 during the thermoplastic molding process, which causes the film material to be pulled, the structure changes, and the optical properties are affected.

The following is a comparison of the effects of the molding device of the comparative example and the molding device 10 in this case: Please refer to Table 1: 12 is exactly the same, the top surface is an irregular shape), the relationship between the pressure applied to the film material and the stress at the edge of the film material. In Table 1, taking the cylindrical opening of the molding device as an example, two data sets of opening diameters of 65mm and 70mm are shown:

Please refer to Table 2: Table 2 shows the relationship between the pressure applied to the film material 20 and the stress at the edge of the film material 20 using the molding device 10 in this case. Table 2 shows two sets of data when the magnification ratio of the opening 114 of the groove 111 to the top surface 121 of the forming part 12 is 1.5 (ie S=1.5) and 1.75 (ie S=1.75):

Refer to the fifth set of data in Table 1, the first set of data in Table 2, and the sixth set of data in Table 2. In the above three sets of data, the pressure applied to the film material 20 is all 0.3, when the pressure applied to the film material 20 is 0.3 When using the forming device of the comparative example, the edge stress of the film material is 4.4141% (the first set of data in Table 1), and when the forming device 10 in this case is used, the stress on the edge of the film material 20 is 2.4588% (the first data in Table 2). A set of data) and 2.5087% (the sixth set of data in Table 2), indicating that when the same pressure is applied to the film material, the use of the molding device 10 in this case is smaller than the molding device of the comparative example, the stress on the edge of the film material is smaller.

Further, please refer to the first set of data in Table 1 and the first set of data in Table 2. Using a comparative molding device, when the pressure applied to the film material is 0.138, the stress at the edge of the film material reaches 2.4588%. The forming device 10 applies a pressure of 0.3 to the film material 20, and the stress at the edge of the film material 20 is consistent with the comparative example. That is to say, if in one embodiment, the edge of the film material can withstand a stress of 2.4588%, the use of the molding device 10 in this case will have a larger range of pressure that the film material can withstand than the molding device of the comparative example.

According to the above analysis, the molding device 10 provided in this embodiment can effectively improve the film material 20 in the thermoplastic molding process by setting the contour of the opening 114 of the groove 111 to be the same as the contour of the edge of the top surface 121 of the molding portion 12 The upper stress causes the problem that the optical properties of thin film materials are affected.

Those of ordinary skill in the art should realize that the above embodiments are only used to illustrate the present invention, but not to limit the present invention. As long as they fall within the essential spirit of the present invention, the above embodiments are appropriate Changes and changes fall within the scope of protection of the present invention.

10: Forming device

11: Bearing Department

12: Forming department

111: Groove

112: bottom wall

113: Sidewall

114: opening

121: top surface

Claims (7)

A molding device, which is improved in that it includes: a bearing portion, on which a groove is provided, the groove has a bottom wall and a side wall connected to the bottom wall; and a forming portion, the forming portion is provided On the bottom wall and spaced apart from the side wall, the molding part has a top surface away from the bottom wall, and the top surface is used to carry the product to be molded; the contour of the opening of the groove is consistent with the The contours of the edges of the top surface are the same; the depth of the groove is greater than the height of the forming part. During the thermoforming, the carrying part is used to carry the product to be formed, and in the product to be formed When pressed, the product to be molded is held against the top surface of the molding part; the contour of the opening and the projection pattern formed by the top surface on the bottom wall of the groove satisfy The following relationship: a polar coordinate system is established on the projection figure, the geometric center of the projection figure on the top surface is taken as the pole, and the coordinates of the point of the projection figure on the outline of the opening are expressed as (ρ1, θ1), the The coordinates of the points of the projection figure of the top surface contour are expressed as (ρ2, θ2), ρ1, ρ2 are the distances between the points and the poles, and θ1, θ2 are the angles between the line between the points and the poles and the polar axis; , When θ1=θ2, ρ1=S×ρ2, S

1.5. The molding device described in claim 1, wherein: 1.5

S

1.75. The molding device according to claim 1, wherein the contour of the top surface of the molding portion is consistent with the contour of the target molded object. The molding device according to claim 3, wherein the top surface of the molding part is a curved surface. The molding device according to claim 3, wherein the top surface of the molding part is a flat surface. The molding device according to claim 1, wherein the supporting portion and the molding portion are integrally molded. The molding device according to claim 1, wherein the molding part is detachably provided on the bottom wall of the groove.

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