TW202019662A - 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

Molding device

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

At present, regardless of VR (Virtual Reality, virtual reality) equipment, AR (Augmented Reality, augmented reality) equipment, wearable computers, etc., it is generally necessary to attach an optical film, and the above-mentioned optical film is generally completed by hot compression molding. Taking the process of forming the optical film by hot compression molding as an example, especially when forming a curved optical film, the film material needs to be placed on the jig for hot compression molding during the process of hot compression molding, which includes a molding The contour of the area and molding area is the same as the contour of the target product. Apply pressure to the film material from one side of the film material away from the jig, so that the film material eventually forms the target product.

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

The invention provides a molding device, which includes: a bearing portion provided with a groove provided with a bottom wall and a side wall connected to the bottom wall; and a molding portion provided with the molding portion The bottom wall is spaced from the side wall, the forming portion has a top surface away from the bottom wall, the top surface is used to carry the product to be formed; the contour of the opening of the groove and the top The contours of the edges of the surface are the same.

The forming device provided by the embodiment of the present invention sets the contour of the opening of the groove of the bearing part to be the same as the contour of the edge of the top surface of the forming part. During the thermoplastic molding process, when the film material is subjected to pressure, the film material edge stress It is relatively small, which is helpful to improve the problem that the optical properties of the film material are affected by the stress on the film material during the thermoplastic molding process.

Example one

Referring to FIG. 1, the molding device 10 provided in this embodiment includes a bearing portion 11 and a molding portion 12 coupled to the bearing portion 11.

As shown in FIG. 1, a groove 111 is provided on the bearing portion 11, and the groove 111 is used to accommodate a 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 portion 12 is disposed on the bottom wall 112 of the groove 111, and the molding portion 12 is accommodated in the groove 111. The molding portion 12 is spaced from the side wall 113 of the groove 111.

In this embodiment, the bearing portion 11 and the molding portion 12 are integrally molded. The methods of integral molding may include, but are not limited to: 3D printing and injection molding. The method of integral molding is more efficient. In another embodiment, the molding portion 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 it is installed in a detachable manner, it is possible to replace only the bearing portion 11 or the molding portion 12 in one molding device, or to realize the combination of different bearing portions 11 and the molding portion 12 to improve the flexibility of component utilization.

As shown in FIG. 1, the molding portion 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 the 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 bearing portion 11 is provided in a hollow cylindrical shape. In order 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 an irregular contour, the wall thickness of the bearing portion 11 is uneven Of it. The present invention does not limit the overall shape of the bearing portion 11. In other embodiments, it may be considered to adjust the appearance of the molding device 10 so that the wall thickness of the bearing portion 11 can be set to be 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 that is recessed toward the bottom wall 112 of the groove 111. In other embodiments, the top surface 121 may be a curved surface protruding 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. The size of the opening of the groove 111 should be 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 molding portion 12 will be further described below:

Please refer to FIG. 2 and FIG. 3 together. The contour of the opening 114 and the contour of the edge of the top surface 121 are orthographically projected on the bottom wall 112 of the groove 111. The resulting projection pattern is shown in FIG. 3, which has curves respectively X and curve Y, curve X is the projection pattern of the contour of the opening 114 on the bottom wall 112, and curve Y is the projection pattern of the contour of the edge of the top surface 121 on the bottom wall 112.

Please refer to FIG. 3, establish a polar coordinate system on the plane where the projected figure is located, take the geometric center of the figure enclosed by the curve Y as the pole, the pole is expressed as O, and the first ray M is drawn in any direction from the pole O as the polar axis, The pole O leads the second ray N in any direction, and the second ray N and the curve X and the curve Y respectively have an intersection point. The intersection point of the second ray N and the curve X is represented as P, the coordinates of the P point are represented as (ρ1, θ1), where ρ1 represents the distance between the pole O and the point P, θ1 represents the point P and the connection between the pole O and the first The angle between the ray M; the intersection point of the second ray N and the curve Y is Q, the coordinates of the Q point are expressed as (ρ2, θ2), where ρ2 represents the distance between the pole O and the Q point, 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.

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.

Referring to FIG. 4, the molding device 10 provided in this embodiment is used to form a target molded object (not shown) by thermoforming. The target molded object is an optical film. In the forming process, the film material 20 is first placed on the bearing portion 11, the film material 20 has not yet entered the groove 111, and then the film material 20 is away from the forming portion 12 side (the plural parallel arrows in FIG. 4 point in the direction) The pressure causes the film material 20 to enter the groove 111 and finally bear against the top surface 121 of the forming portion 12. The film material 20 may be heated and softened before entering the groove 111, or may be heated and softened after entering the groove 111, so that the softened film material 20 bears against the top surface 121 of the forming portion 12 and is pressed to form the top surface 121 shape. In this embodiment, the method of applying pressure is to directly apply pressure to the film material 20 with a mechanical indenter.

In order to provide a receiving 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 height of the side wall 113 is equal 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 molding portion 12 (the molding portion 12 is a curved surface, and the heights are not equal everywhere, so it has the maximum height).

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

Please refer to FIG. 5 to keep the pressure applied so that the film material 20 is in close contact with the top surface 121 of the forming portion 12. A part of the film material 20 which is in close contact with the top surface 121 of the forming part 12 is the target forming object, and the rest is waste. In order to form a target shaped object of a desired shape, the top surface 121 of the forming portion 12 is set to conform to the shape of the target shaped object. In this embodiment, the top surface 121 of the molding portion 12 is a curved surface, and the target molding 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 extruded in 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 maintain the structure of the film material 20 unchanged, so that the film material 20 maintains the original characteristics. Therefore, it is beneficial to improve the problem that the film material 20 is pulled too strongly in the thermoplastic molding process, the film material is pulled, the structure changes, and the optical characteristics 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: Table 1 uses a comparative molding device (the opening of the groove of the bearing part is circular, the molding part is exactly the same as the molding part 12 above, and the top surface is an irregular shape), which is applied to the film material The relationship between pressure and stress on the edge of the film material. In Table 1, taking the cylindrical opening of the molding device as an example, two sets of data with opening diameters of 65 mm and 70 mm are shown: Table 1

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

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 comparative molding device, the film material edge stress is 4.4141% (the first set of data in Table 1), while using the molding device 10 in this case, the film material 20 edge stress is 2.4588% (Table 2 One set of data) and 2.5087% (the sixth set of data in Table 2) show that when the same pressure is applied to the film material, using the forming device 10 in this case is less stressful than the comparative example forming device.

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 on the film material is 0.138, the stress on the edge of the film material reaches 2.4588%, and the The forming device 10 applies a pressure of 0.3 to the film material 20 so that the stress on the edge of the film material 20 is consistent with the comparative example. It means that, in an embodiment, if the film material edge can withstand a stress of 2.4588%, using the molding device 10 in this case is greater than the comparative molding device, the film material can withstand a larger pressure range.

Based on 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 the thin film material are affected.

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

10: Molding device 11: Carrying Department 12: Molding Department 111: groove 112: bottom wall 113: Side wall 114: opening 121: top surface d1: depth d2: height O: pole M: first ray N: second ray P, Q: intersection X, Y: Curve 20: Film material D1, D2: opening diameter

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

FIG. 2 is a schematic diagram of the cross-sectional structure of FIG. 1 along the direction II-II.

Fig. 3 is a projection pattern of the top surface of the molding portion of the groove opening.

Fig. 4 is a schematic cross-sectional view of the use state of the molding device.

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

10: Molding device

11: Carrying Department

12: Molding Department

111: groove

112: bottom wall

113: Side wall

114: opening

121: top surface

Claims (10)

An improvement of a molding device includes: a bearing portion provided with a groove provided with a bottom wall and a side wall connected to the bottom wall; and a molding portion provided with the molding portion On the bottom wall and spaced from the side wall, the forming part has a top surface away from the bottom wall, the top surface is used to carry the product to be formed; the contour of the opening of the groove and the The contours of the edges of the top surface are the same. The molding device according to claim 1, wherein the contour of the opening and the projection pattern formed by the top surface and the bottom wall of the groove satisfy the following relationship: On the projection surface Establish a polar coordinate system, taking the geometric center of the projection pattern of the top surface as the pole, the coordinates of the point of the projection pattern of the outline of the opening are expressed as (ρ1, θ1), and the point of the projection pattern of the contour of the top surface The coordinates are expressed as (ρ2, θ2), ρ1, ρ2 are the distance between the point and the pole, θ1, θ2 are the points and the angle between the line between the poles and the polar axis; where, when θ1=θ2, ρ1= S×ρ2, S>1. The molding device according to claim 2, wherein: S≥1.5. The molding device according to claim 2, wherein: 1.5≤S≤1.75. The molding device according to claim 1, wherein the depth of the groove is greater than the height of the molding portion. The molding device according to claim 1, wherein the contour of the top surface of the molding portion coincides with the contour of the target molding object. The molding device according to claim 6, wherein the top surface of the molding portion is a curved surface. The molding device according to claim 6, wherein the top surface of the molding portion is a flat surface. The molding device according to claim 1, wherein the carrying portion and the molding portion are integrally molded. The molding device according to claim 1, wherein the molding portion is detachably provided on the bottom wall of the groove.

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