JP2022116792A - Method for manufacturing molded article - Google Patents

Abstract

To provide a method for manufacturing a molded article capable of widening a selection of resins for forming a support medium.SOLUTION: A method for manufacturing a molded article includes a lamination molding step. The lamination molding step is configured to laminate a single layer structure body formed through discharging a flow-state resin while moving a head, and then hardening the discharged resin, so as to form an integrated article in which a molded article composed of the resin and a support medium are integrated. If a gap between the head and the support medium on a center line of a discharge port of the head is G and a diameter of the discharge port of the head is D when forming a layer contacting the support medium, G/D is 0.5 or less.SELECTED DRAWING: Figure 1

Description

The present invention relates to a method for manufacturing a modeled object formed by layered manufacturing.

Additive manufacturing is a method of modeling a three-dimensional object having a predetermined structure. After a material in a fluid state is extruded, it solidifies, and an article is created by layering further materials on top of it. A UV curing method, a hot melt lamination method, and the like have been proposed as lamination modeling methods, but the hot melt lamination method is widely used because the device structure is simple.

There are various types of three-dimensional structures that can be manufactured by additive manufacturing, and some of them include parts that cannot be manufactured without being supported by something else during the manufacturing process. Therefore, when laminate-molding a modeled object, it is common to laminate-model a support that supports at least a part of the modeled object together, and dissolve and remove the support after the completion of modeling (for example, Patent document 1).

JP 2018-099788 A

In general, in order to prevent the separation of the support and the modeled object, the resin for modeling the support is required to have excellent adhesion to the resin for modeling the modeled object. Due to such demands, the range of selection of resins for forming the support is narrowed.

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and provides a method for manufacturing a modeled object that allows a wider range of selection of resins for forming a support.

According to the present invention, there is provided a method for manufacturing a modeled object, which includes a layered manufacturing process, in which a resin in a fluid state is discharged while a head is moved, and the resin is solidified to form a molded object. By laminating the single-layer structure, the molded product made of the resin and the support are integrated to form an integrated product, and the ejection port of the head when forming the layer that contacts the support. A method is provided in which G/D is 0.5 or less, where G is the distance between the head and the support on the centerline of the head and D is the diameter of the outlet of the head.

In the layered manufacturing process of the present invention, since the G/D is 0.5 or less, the discharged resin is strongly pressed against the support, so that the adhesion between the resin and the support is enhanced, and the resin is prevented from slipping. be. Therefore, as the resin for forming the support, it is not always necessary to select a resin that has excellent adhesion to the resin for forming the modeled object. Width is widened.

Preferably, it is the method described above, wherein the support has a recess at a site where the single layer structure is formed.
Preferably, in the method described above, the opening diameter of the recess is smaller than the diameter of the ejection port of the head.
Preferably, in the method described above, when the distance between the head and the lower layer is G1 when forming the next single layer structure on the lower single layer structure, G/G1 is , between 0.1 and 1.

FIG. 1A is a plan view of the model 1, and FIG. 1B is a cross-sectional view taken along line AA in FIG. 1A. 2A is a perspective view showing the three-dimensional network structure 2, and FIG. 2B is a perspective view showing the single layer structures 6, 7, 8. FIG. 3A is a cross-sectional view corresponding to FIG. 1B showing the layered manufacturing process, and FIG. 3B is an enlarged view of region B in FIG. 3A. FIG. 4A is a cross-sectional view corresponding to FIG. 1B showing the monolith 9, and FIG. 4B shows the state after the monolith 9 of FIG.

Embodiments of the present invention will be described below. Various features shown in the embodiments shown below can be combined with each other. Moreover, the invention is established independently for each feature.

1. First Embodiment 1-1. Configuration of Modeled Object 1 FIGS. 1 and 2 show an example of a modeled object 1 that can be manufactured by a method for manufacturing a modeled object 1 according to an embodiment of the present invention. A modeled object 1 is, for example, a breast body such as a bra pad or an artificial breast. is. The modeled object 1 has an upper surface 1a and a lower surface 1b. When the modeled object 1 is a breast, the upper surface 1a has a shape that imitates the contour of the breast, and the lower surface 1b has a shape that fits the outer surface of the user's body on which the modeled object 1 is worn. The lower surface 1b is provided with a concave portion 1c having a complementary shape to the convex portion of the body.

The modeled object 1 is formed by layered manufacturing. Laminate manufacturing is a method of forming a modeled article 1 by stacking single-layer structures forming a part of the modeled article 1 . Laminate modeling may be performed by any method such as a UV curing method or a hot melt lamination method, but a hot melt lamination method in which thermally melted resins are laminated is preferred.

The modeled object 1 has, for example, a three-dimensional mesh structure 2 as shown in FIG. 2A. The three-dimensional network structure 2 is a network structure formed by stacking single-layer structures composed of linear resins 2a. When the modeled object 1 has such a structure, the stiffness of the modeled object 1 can be changed by changing the interval between the adjacent linear resins 2a or by changing the thickness of the linear resins 2a. can be done. When the modeled object 1 is a mammary body, the modeled object 1 needs to have rigidity according to the user's request. is easy. In addition, there is a demand to make the rigidity of a part of the modeled object 1 higher or lower than that of other parts. By doing so, the above demands can be easily realized.

The diameter of the linear resin 2a is, for example, 0.5 to 6.0 mm, preferably 1.0 to 4.0 mm. Specifically, this diameter is, for example, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0 mm, and may be in the range between any two of the values exemplified here.

In one example, the three-dimensional network structure 2 is configured by repeatedly stacking single-layer structures 6, 7, and 8 shown in FIG. 2B in this order. The single layer structure 6 has a linear resin 6a composed of a plurality of parallel lines spaced apart from each other. The single layer structure 7 has a linear resin 7a composed of a plurality of parallel lines spaced apart from each other. The single layer structure 8 has a linear resin 8a composed of a plurality of parallel lines spaced apart from each other. The linear resins 6a, 7a, 8a are provided so as to extend in directions that are shifted from each other by 60 degrees.

The resin forming the modeled object 1 is not particularly limited, and examples include ABS, polyolefin (eg, polypropylene), polyester, and thermoplastic elastomer. If the modeled object 1 requires high flexibility, such as a mammary body, the resin forming the modeled object 1 is preferably a thermoplastic elastomer.

Examples of thermoplastic elastomers include styrene elastomers, olefin elastomers, acrylic elastomers, and the like. The thermoplastic elastomer preferably contains a styrenic elastomer. Since a styrene-based elastomer is highly flexible, the inclusion of a styrene-based elastomer in the thermoplastic elastomer increases the flexibility of the thermoplastic elastomer. The proportion of the styrene elastomer in the thermoplastic elastomer is preferably 50 to 100% by mass, more preferably 80 to 100% by mass, specifically, for example, 50, 60, 70, 80, 90, 100% by mass. , within a range between any two of the numerical values exemplified herein.

Styrene-based elastomers are thermoplastic elastomers having styrene units, and styrene-based copolymers (for example, styrene-ethylene-styrene block copolymer (SES), styrene-butadiene-styrene block copolymer (SBS), Styrene-isoprene-styrene block copolymer (SIS), styrene-butadiene rubber (SBR), etc.), hydrogenated styrenic copolymers (e.g., styrene-ethylene/propylene-styrene block copolymer (SEPS), styrene- Ethylene/butylene-styrene block copolymer (SEBS), styrene-butylene/butadiene-styrene block copolymer (SBBS), hydrogenated styrene-butadiene rubber (HSBR), etc.) A blended product can be mentioned.

The Shore A hardness of the thermoplastic elastomer is preferably 0 to 10, specifically, for example, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, and the numerical values exemplified here may be in the range between any two of When the Shore A hardness is within this range, a model having excellent flexibility can be obtained. Shore A hardness is measured based on JIS K6253.

1-2. Method for Manufacturing Modeled Object 1 Next, a method for manufacturing the modeled object 1 according to one embodiment of the present invention will be described. The method comprises an additive manufacturing process and a removal process. Each step will be described below.

(1) Layered manufacturing process In the layered manufacturing process, as shown in FIG. Thus, an integrated object 9 is formed by integrating the model 1 made of the resin 4 and the support 3 .

The layered manufacturing process can be performed by any layered manufacturing method. For example, the single-layer structure can be formed by moving the head 5 while ejecting the resin in a fluid state and solidifying the ejected resin 4 . In the hot-melt lamination method, a resin in a fluid state is discharged by heating, and the discharged resin in a fluid state is solidified by cooling. In the UV curing method, the ejected fluid resin is solidified by UV irradiation.

As an example, in the hot melt lamination method, as shown in FIG. 3, the head 5 is moved in the modeling region R while discharging the resin 4 melted in the head 5 from the discharge port 5a provided at the tip of the head 5. The modeled object 1 can be formed by The form of the resin supplied to the head 5 is not limited, and may be filaments or pellets. When the resin is in the form of a filament, the filament is moved downstream by rotating the gear incorporated in the head 5 in a state where the gear is engaged with the filament, thereby discharging the resin 4 melted in the head 5. be able to. When the resin is in the form of pellets, a screw-type extruder having a built-in screw can be used as the head 5, and the resin 4 melted in the head 5 can be discharged by rotating the screw. If the resin is very flexible, such as a thermoplastic elastomer, it may be difficult to move the filament downstream by rotating the gear. machine is preferred.

The temperature of the resin 4 immediately after being discharged from the discharge port 5a is defined as the modeling temperature. The molding temperature is preferably 120-230°C. This is because, in this case, the resin 4 is easily solidified sufficiently during cooling, and deterioration due to heating of the modeling material is less likely to occur. Specifically, the molding temperature is, for example, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, and 230°C. may be within the range.

Since the model 1 has a recess 1c, it is necessary to prepare the support 3 and form the part 1d on the support 3 in order to form the part 1d above the recess 1c (shown in FIG. 1B). be.

In Patent Literature 1, a modeled object and a support are modeled together, but in such a method, there is a problem that the modeling time is lengthened by the amount of the support. Therefore, in this embodiment, the modeling time is shortened by using the support 3 prepared in advance.

The method of forming the support 3 is not particularly limited, and it can be formed by lamination molding, injection molding, or the like. When the support 3 is formed by injection molding, it is easy to smoothen the surface of the support 3, and in this case, the inner surface of the concave portion 1c of the model 1 can be smoothed. When the modeled object 1 is a breast body, the inner surface of the concave portion 1c is the surface that comes into contact with the body, so smoothing this surface can improve the quality of the breast body.

The melting point of the resin constituting the support 3 (hereinafter referred to as “support resin”) is preferably higher than the melting point of the resin 4 . In this case, by modeling at a temperature between the melting point of the support resin and the melting point of the resin 4, the model 1 can be modeled without melting the support 3. FIG. Further, in this case, since the support 3 does not melt, the support 3 separated in the later-described removing process can be reused in the layered manufacturing process for manufacturing the next modeled object. The melting point of the support resin is preferably higher than the modeling temperature. In this case, the modeled object 1 can be modeled without melting the support 3 . As used herein, "melting point" means the melting peak temperature Tpm measured according to JIS K 7121:2012.

As shown in FIG. 3B, the support 3 has an inclined surface 3a. The inclined surface 3a may be flat or curved. When the modeled object 1 is a breast body, it is preferable to provide an inclined surface on the inner surface of the concave part 1c for fitting the modeled object 1 to the body. The inner surface of the can also be provided with an inclined surface. The inclination angle of the inclined surface 3a with respect to the horizontal plane is, for example, 5 to 85 degrees, preferably 10 to 80 degrees. Specifically, this angle of inclination is, for example, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85 degrees, where It may be in a range between any two of the numerical values given.

By the way, when the resin 4 is discharged onto the support 3, the resin 4 may slip on the support 3, making it impossible to obtain the model 1 having a desired shape. Therefore, it is preferable to provide a slip suppression structure for suppressing slippage of the resin 4 on the support 3 . .

One example of an anti-slip configuration is that the support resin and the resin 4 have monomers in common. Since resins having common monomers (that is, resins of the same family) generally have high affinity, the use of such a combination of resins suppresses slipping of the resin 4 . For example, when the resin 4 is a styrene-based elastomer, it is preferable to employ a styrene-based elastomer or a styrene-based resin other than an elastomer as the support resin. The ratio of common monomers of the support resin and the resin 4 is, for example, 50 to 100% by mass, specifically, for example, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100. % by weight and may be in a range between any two of the values exemplified herein.

Another example of the anti-slip configuration is that the value of ΔSP is 1.3 or less, where ΔSP is the absolute value of the difference in Hansen solubility parameter between the support resin and the resin 4 . ΔSP is an index indicating the affinity between resins, and since the smaller the value of ΔSP, the higher the affinity between the support resin and the resin 4, a combination of resins with a value of ΔSP of 1.3 or less is used. Thereby, the slippage of the resin 4 is suppressed. ΔSP is preferably 1.0 or less, more preferably 0.5 or less. 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, and may be in the range between any two of the values exemplified herein.

Another example of the anti-slip configuration is, as shown in FIG. 3B, to provide a concave portion 3b in the portion of the support 3 where the single layer structure is formed (inclined surface 3a in FIG. 3B). In this case, the resin 4 enters the concave portion 3b and solidifies, so that the resin 4 is engaged with the support 3, and the resin 4 is prevented from slipping. When this slip prevention structure is adopted, even if the compatibility between the support resin and the resin 4 is low, the resin 4 is prevented from slipping. The opening diameter of the recess 3b is preferably smaller than the diameter of the discharge port 5a. In this case, the amount of the resin 4 entering the concave portion 3b does not become too large, and the deformation of the shape caused by the resin 4 entering the concave portion 3b is suppressed.

When the support 3 is a porous body, the pores of the porous body function as the recesses 3b. The porous body may be a material such as zeolite which itself is porous, or may have a three-dimensional network structure 2 as shown in FIG. 2 formed by layered manufacturing. Further, when the support 3 is a molded body formed using a mold, the concave portion 3b may be formed by transferring the convex portion of the mold.

Another example of an anti-slip configuration is the slippage between the head 5 and the support 3 on the centerline 5b of the outlet 5a of the head 5 when forming the layer in contact with the support 3, as shown in FIG. 3B. , and the diameter of the ejection opening of the head 5 is D, G/D is set to 0.5 or less. G/D is generally set to about 0.8, but when G/D is set to such a value, the resin 4 easily slides on the support 3 . In order to suppress the slippage of the resin 4, it is conceivable to increase the affinity between the support resin and the resin 4, but in that case, there is a problem that the degree of freedom in selecting the support resin is narrowed.

In order to solve such a problem, the present configuration employs a configuration in which G/D is 0.5 or less. When G/D is set to such a value, the discharged resin 4 is strongly pressed against the support 3, so that the adhesion between the resin 4 and the support 3 is enhanced, and the resin 4 is prevented from slipping. Therefore, the adoption of this configuration widens the range of material choices for the support 3 . G/D is, for example, 0.1 to 0.5, specifically, for example, 0.10, 0.15, 0.20, 0.25, 0.30, 0.35, 0.40, 0.45, 0.50, and may be in the range between any two of the values exemplified herein.

Further, when G1 is the distance between the head 5 and the lower layer when forming the next single layer structure on the lower single layer structure, G/G1 is preferably 0.1 to 1. 0.3 to 0.8 are preferred. G and G1 indicate so-called molding pitches. In order to facilitate separation of the support 3 and the model 1, the modeling pitch when forming the single layer structure on the support 3 is , that is, G/G1 is larger than 1, but in this configuration, by setting G/G1 to 1 or less, the resin 4 on the support 3 to prevent slippage. G/G1 is specifically, for example, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0 and may be in a range between any two of the numerical values exemplified here.

This configuration is particularly effective when used in combination with a configuration in which the support member 3 is provided with the concave portion 3b. In this case, it becomes easier for the resin 4 to enter the concave portion 3b, and the slippage of the resin 4 is further effectively suppressed.

(2) Removal Step In the removal step, the support 3 is removed from the integrated object 9 by separating the integrated object 9 shown in FIG. 4A into the support 3 and the modeled object 1 as shown in FIG. 4B. Thus, the modeled object 1 is obtained.

When at least one of the support resin and the resin 4 is a highly flexible resin such as an elastomer, the separation can be performed by deforming the support 3 or the modeled object 1 . When both the support 3 and the resin 4 have high rigidity, the separation can be performed by applying a force in the direction of separating the support 3 and the modeled object 1 from each other. For example, with the support 3 fixed to another member, the separation can be performed by pushing the model 1 with an ejector pin provided in the support 3 or its surrounding area.

The support 3 removed in the removing process can be reused in the layered manufacturing process for manufacturing the next modeled object 1 . For this reason, it is preferable to perform the separation so as not to damage the support 3 . Further, by reusing the support 3, it is possible to reduce the time and cost required to manufacture the support 3. FIG.

2. Other Embodiments In the above-described embodiment, the support 3 having the inclined surface 3a and the recess 3b is used. good.
- In the above-described embodiment, the support 3 prepared in advance is used to perform the layered manufacturing process, but the support 3 may be formed in the layered manufacturing process without preparing the support 3 in advance.
- In the above embodiment, the support 3 is separated and reused, but the support 3 may not be reused. In this case, in the removing step, the support 3 may be removed from the monolith 9 by any method such as dissolution.

1: Molded object 1a: Upper surface 1b: Lower surface 1c: Concave portion 1d: Part 2: Three-dimensional network structure 2a: Linear resin 3: Support 3a: Inclined surface 3b: Concave portion 4: Resin 5: Head 5a: Discharge port 5b: Center line 6 : Single layer structure 6a : Linear resin 7 : Single layer structure 7a : Linear resin 8 : Single layer structure 8a : Linear resin 9 : Integrated object R : Molding area

Claims (4)

A method for manufacturing a modeled article,
Equipped with an additive manufacturing process,
In the layered manufacturing process, a modeled object and a support made of the resin are laminated by stacking single-layer structures formed by discharging resin in a fluid state while moving a head and solidifying the discharged resin. form a united entity,
Let G be the distance between the head and the support on the center line of the ejection port of the head when forming the layer in contact with the support, and D be the diameter of the ejection port of the head.
The method, wherein G/D is 0.5 or less. 2. The method of claim 1, wherein
The method according to claim 1, wherein the support has a recess at a site where the single layer structure is formed. 3. The method of claim 2, wherein
The method according to claim 1, wherein the opening diameter of the recess is smaller than the diameter of the ejection port of the head. The method according to any one of claims 1 to 3,
A method, wherein G/G1 is 0.1 to 1, where G1 is the distance between the head and the lower layer when forming the next single layer structure on the lower layer single layer structure.

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