JP5846039B2 - Manufacturing method of molded products - Google Patents

Description

  The present invention relates to a method for manufacturing a molded article. More specifically, the present invention relates to a manufacturing method for manufacturing a relatively large molded product by blowing a raw material from a plurality of raw material supply ports. The present invention relates to a method for manufacturing a molded product, in which an entire relatively large molded product is integrally molded with a single mold, and the entire product can be made more homogeneous.

  Conventionally, in the field of automotive interior materials such as floor silencers, roof trims, door trims, etc., and in the field of products such as building floors, ceilings, walls, carpets, etc., sheet-like materials for the purpose of heat insulation, sound insulation, cushioning, etc. Fiber molded products such as these are used. Such a fiber molded article is manufactured by various methods. For example, a mixed raw material of a binder fiber and a resin foam chip is blown into a hollow mold, heated, and then cooled (see FIG. 5, the broken line arrow in the mold 101 of FIG. Indicates the direction of flow.) In this way, the raw material is blown into the mold and the molding is performed. When a treatment material in which a fibrous binder and a chip such as flexible urethane foam are mixed is blown into the mold, the increase in resistance is detected and the blown air volume is reduced. A method for manufacturing a soundproof material is known (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 2001-60091

  According to the method for producing a soundproof material described in Patent Document 1, it is possible to produce a soundproof material having a uniform material density throughout and having excellent soundproofing properties. However, for example, a vehicle floor silencer has the following problems. That is, since these are large and are molded articles having a three-dimensional shape portion such as a center tunnel portion, there are cases where the raw material is insufficiently filled at the end portion and cannot be molded into a predetermined shape. For this reason, a flat felt is manufactured, scaled, heat-molded, cooled, then trimmed, and then a predetermined shape of felt is bonded to the required location. However, in this method, productivity is not high, and improvement and improvement are required. In addition, since the flat felt bonded product cannot sufficiently follow the body shape, there is a problem that the vibration of the body cannot be suppressed and the quietness cannot be maintained in the vehicle interior.

  The present invention has been made in view of the above-described situation, and when a raw material is blown from a plurality of raw material supply ports, particularly when a molded product having a relatively large size and a three-dimensional shape portion is manufactured, the entire molded product is It is an object of the present invention to provide a method for producing a molded product that can be molded integrally with a single mold and can be made into a more homogeneous product as a whole.

The present invention is as follows.
1. In a hollow mold having a first bottom wall, a side wall and a second bottom wall,
From a plurality of raw material supply ports formed in the first bottom wall, a method for producing a molded product for producing a molded product by blowing a raw material,
At the position where the flow front part of the raw material blown from each of the plurality of raw material supply ports is expected to meet inside the molding die, the first bottom wall is provided with a first ventilation part, and The second bottom wall is provided with a second ventilation part ,
A method of manufacturing a molded product, wherein a planar shape of at least one of the first ventilation part and the second ventilation part is a zigzag shape .
2. When two of the plurality of raw material supply ports are a first raw material supply port and a second raw material supply port,
The first ventilation part is provided so that the first raw material supply port and the second raw material supply port are connected by the shortest line along the inner surface of the first bottom wall and include a substantially midpoint of the line. And
In the second bottom wall, the first ventilation portion is provided at a position substantially opposite to the first ventilation portion. The manufacturing method of the molded article as described in 2.
3. The raw material contains a heat-fusible fiber, resin foam particles and / or a high-melting fiber having a higher melting point than the heat-fusible fiber,
When the total of the heat-fusible fiber, the resin foam particles and the high melting point fiber is 100% by mass, the heat-fusible fiber is 40% by mass or more and less than 100% by mass. Or 2 . The manufacturing method of the molded article as described in 2.

According to the method for manufacturing a molded product of the present invention, a plurality of raw material supply ports are formed in the mold. At the position where the flow front portions of the raw materials blown from each of the plurality of raw material supply ports are expected to meet inside the mold, the first bottom wall is provided with the first ventilation portion, and the second bottom A second ventilation portion is provided on the wall.
Generally, when raw materials of a plurality of raw material supply ports are blown into a mold, a so-called weld line is easily formed at a portion where flow front portions of the raw materials blown from each of the raw material supply ports meet. It is known that when this weld line is formed, mechanical properties such as tensile strength of this portion are lowered.
According to the method for producing a molded article of the present invention, the first ventilation portion and the second ventilation portion are provided at the position where the flow front portions of the raw materials are expected to meet as described above. Therefore, even if it is a large-sized molded product or a molded product having a three-dimensional shape portion, the entire molded product can be integrally molded with a single mold while suppressing formation of the weld line. In this way, since it can be integrally molded with a single mold, it is possible to improve the yield of raw materials by increasing the productivity compared to the conventional method in which individual members are molded and then trimmed and bonded together. This is also advantageous in terms of cost.
Further, when two of the plurality of raw material supply ports are a first raw material supply port and a second raw material supply port, the first raw material supply port and the second raw material supply port are along the inner surface of the first bottom wall. The first ventilation part is provided so as to be connected by the shortest line and include the substantially middle point of the line, and the second ventilation part is provided at a position substantially opposite to the first ventilation part on the second bottom wall. When provided, the following effects can be obtained. That is, in this case, the ventilation portion is provided at a position where the weld line is easily formed, that is, a position where the raw materials meet. Therefore, the raw material fibers are sufficiently entangled at the meeting position, the raw materials are more integrated at the meeting position, and the formation of the weld line is suppressed, and as a result, a molded product with reduced strength is manufactured. Can do.
Furthermore, since at least one of the planar shape of the first vent and the second vent is zigzag shape, even if some weld lines meeting position is formed, the weld line tends to become zigzag. In this case, the part of the molded product on one side sandwiching the weld line and the part of the molded product on the other side are combined with each other between the end surfaces of the zigzag. Meeting area increases. Therefore, a decrease in strength of this portion is further suppressed.
The raw material contains heat-fusible fibers, resin foam particles and / or high-melting fibers having a melting point higher than that of the heat-fusible fibers, and the heat-fusible fibers and resin foam particles. When the total of the high melting point fibers is 100% by mass, when the heat-fusible fiber is 40% by mass or more and less than 100% by mass, the following effects are exhibited. That is, in this case, since the content ratio of the heat-fusible fiber is higher than usual, it is possible to more easily manufacture a molded product in which the strength reduction is suppressed.

It is the perspective view which looked at the shaping | molding die for having a several raw material supply port and shape | molding the floor silencer of a vehicle from diagonally upward. It is typical sectional drawing for demonstrating a mode that the ventilation | gas_flowing part is provided in the approximate middle point M of the shortest distance along the inner surface of the shaping | molding die between different raw material supply ports. It is typical explanatory drawing showing a mode that the raw materials supplied from the several raw material supply port meet and the raw materials are mixed in the ventilation part vicinity provided in the shaping | molding die. It is a top view of the ventilation part whose planar shape is a zigzag shape. It is typical explanatory drawing showing a mode that a raw material is supplied from one raw material supply port like the conventional, and a molded article is manufactured.

Hereinafter, the present invention will be described in detail with reference to the drawings.
The items shown here are for illustrative purposes and exemplary embodiments of the present invention, and are the most effective and easy-to-understand explanations of the principles and conceptual features of the present invention. It is stated for the purpose of providing what seems to be. In this respect, it is not intended to illustrate the structural details of the present invention beyond what is necessary for a fundamental understanding of the present invention. It will be clear to those skilled in the art how it is actually implemented.

The method for producing a molded article according to the present invention includes a plurality of raw material supply ports formed in the first bottom wall 1 in a hollow mold 100 having a first bottom wall 1, a side wall 3, and a second bottom wall 2 ( For example, a molded product is manufactured by blowing the raw material 5 (the raw material 5 made of a mixture of the heat-fusible fiber 51 and the resin foam particles 52) from nine raw material supply ports N _{1 to} N _9. It is a manufacturing method. Further, at a position where the flow front end of the raw material 5 blown from each of the plurality of raw material supply ports N is expected to meet inside the mold 100 (see reference numeral A in FIG. 2), the first bottom wall 1 together with the first vent 41 is provided, the second bottom wall 2 is provided with a second vent 42 (in FIG. 1, a raw material supply port N _5, between the raw material supply port N ₈ the first vent 41 located, a raw material supply port N _7, first ventilation portion 41A which is located between the feed inlet N _8, a raw material supply port N _8, located between the raw material supply port N ₉ Only the first ventilation portion 41B is shown, and the other first ventilation portions are omitted).

[1] Mold Die 100 is hollow and includes a first bottom wall 1, a side wall 3, and a second bottom wall 2 (see FIGS. 1 and 2). The shape of the internal space of the mold 100 is substantially the same as the outer shape of the molded product. The material of the mold 100 is not particularly limited, but is preferably made of metal in consideration of ease of handling and heat resistance. The type of metal is not particularly limited, but stainless steel, aluminum, or the like can be used. If it is made of stainless steel, it can be made a mold 100 having sufficient strength and hardly rusting, and if made of aluminum, it can be made a mold 100 having sufficient strength and light weight. .

A plurality of raw material supply ports (N _{1 to} N ₉ ) for blowing and supplying the raw material 5 into the mold 100 are formed in the first bottom wall 1 of the bottom walls of the mold 100. A raw material 5 is blown from each raw material supply port N, and a preformed product which is an aggregate of the raw materials 5 is formed in a mold. The number of raw material supply ports N can be set according to the dimensions including the three-dimensional shape part of the molded product. For example, in the case of a vehicle interior material, in a molded product that is large like a floor silencer and has many three-dimensionally shaped parts, the raw material supply ports N can be 6 to 12, particularly 7 to 9. . In addition, for molded products with large curved surfaces such as roof trims and relatively small molded products such as door trims, the required number of strength reductions can be controlled in consideration of the shape and dimensions of each. be able to.

  At the position where the flow front part of the raw material 5 blown from each of the plurality of raw material supply ports N is expected to meet inside the mold 100, the first bottom wall 1 is provided with the first ventilation part 41, The 2nd ventilation part 42 is provided in the 2nd bottom wall part 2 (In addition, the arrow on either side of FIG. 3 has shown the transfer direction of the raw material, and the raw material 5 supplied from the different raw material supply port from a different direction. It shows how it is transported). The position where the flow front end of the raw material 5 blown from each of the plurality of raw material supply ports N is expected to meet is governed by various factors. For example, this position is governed by the mutual positional relationship of the raw material supply ports N, the three-dimensional shape of the molded product, and the like.

As described above, the expected meeting position varies depending on many factors. However, as a result of extensive studies by the inventors, two of the plurality of raw material supply ports N are the first raw material supply port and the second raw material supply port. In this case, it was found that the first raw material supply port and the second raw material supply port are often approximately the midpoint. For example, explaining the case of Figure 2, even when between the first raw material supply port and a second raw material supply port is three-dimensional-shaped portion, the first raw material supply port N ₅ and the second raw material supply port N ₈ second 1 It has been found that when the shortest line L is connected along the inner surface of the bottom wall 1, the approximate midpoint M of the line L is the expected meeting position.

  Further, at the expected meeting position of the raw material 5 blown from each of the plurality of raw material supply ports N, a first ventilation part 41 is provided in the first bottom wall 1 and a second ventilation is provided in the second bottom wall part 2. A portion 42 is provided. Moreover, it is preferable that the 1st ventilation part 41 and the 2nd ventilation part 42 are provided in the substantially opposing position of the 1st bottom wall 1 and the 2nd bottom wall part 2 (refer FIG. 2, 3).

  Further, at least one of the planar shapes of the first ventilation portion 41 and the second ventilation portion 42 is a zigzag shape (see FIG. 4). It is preferable that both the first ventilation part 41 and the second ventilation part 42 have a zigzag shape. If the planar shape of the 1st ventilation part 41 and the 2nd ventilation part 42 is a zigzag shape, the fiber of the raw material 5 which flowed from one side and the raw material 5 which flowed from the other will fully entangle at an expected meeting position. easy. Therefore, the strength reduction of the molded product at the expected meeting position is sufficiently suppressed, and a more uniform molded product can be obtained.

  Of the mold wall of the mold 100, the side wall 3 has air permeability. The side wall 3 may be provided with a side wall vent, or the side wall 3 may be formed using a material having air permeability. The number and shape of the side wall vents are not particularly limited. For example, the shape may be a circle, an ellipse, a polygon such as a triangle or a rectangle. Further, when a material having air permeability is used, the ventilation portion has the same shape as the outer peripheral shape of the product.

  The size of the side wall vent is not particularly limited as long as the supplied raw material 5 does not leak from the side wall vent. Furthermore, it is preferable that the side wall vents are provided substantially evenly on the entire side wall 3 of the mold 100, whereby a molded product that is more uniform in the planar direction can be produced.

[2] Supply of Raw Material and Molding of Molded Product The method for supplying the raw material 5 by blowing it from the raw material supply port N is not particularly limited. For example, a method is adopted in which a raw material is flown and blown from a container (not shown) containing the raw material 5 together with an air flow using a blower or the like and blown. In FIG. 1, the first bottom wall 1 is an upper bottom wall, and the raw material 5 is blown from above and supplied, but the first bottom wall 1 is illustrated as a lower bottom wall. The raw material 5 can be blown from below and supplied.

  The raw material 5 usually contains a heat-fusion component that melts by heating and fuses the fibers, particles, etc. of the raw material 5. Then, after the raw material 5 is blown and supplied into the molding die 100, the preform is heated to melt the heat fusion component, and the fibers of the raw material 5 and the particles are joined. Then, a molded article is manufactured by cooling. The heating temperature should be a predetermined temperature that takes into consideration the material of the raw material 5 and the melting point of the heat fusion component, etc., and the non-heat fusion component does not melt at all, but only the heat fusion component melts and functions as a binder. Can do. Further, the heating time is not particularly limited depending on the material of the raw material 5, the heating temperature, and the like, but almost all of the heat-sealing component is melted and the fibers of the raw material 5 and the particles are sufficiently joined. As long as heating is performed for a short time, it is preferable.

  The heating method described above is not particularly limited. For example, the mold 100 filled with the raw material 5 can be heated by a method of allowing hot air to pass through. Further, the mold 100 filled with the raw material 5 can be heated by a method of passing through a heating furnace, standing in the heating furnace for a predetermined time, or heating with a far infrared heater or the like. Thereby, a heat-fusion component can be softened and melted. Thereafter, the molded product can be manufactured by cooling the mold by a method of allowing room temperature or low-frequency wind to pass through, a method of air-cooling the mold from the outside, a method of forced cooling with cold air, cold water, or the like. Further, at the time of heating, at the expected meeting position of the raw material 5, the heat-sealing component of the associated raw material 5 may be melted to form a so-called weld line. The weld line is a thin line mark generated at a place where two or more flow fronts (flow front ends) meet. In the manufacturing method of the present invention, even if a weld line is formed, the molten raw material 5 is sufficiently fused by the weld line, and a homogeneous molded product in which a decrease in strength is suppressed can be obtained.

  According to the method for manufacturing a molded product of the present invention, for example, molded products such as various interior materials such as a vehicle floor silencer, a roof trim, and a door trim, particularly a floor silencer having a large number of three-dimensional shape parts, such as a felt having a predetermined shape, etc. Without requiring bonding, it can be molded in a predetermined shape close to the final product. Therefore, there is no need for trimming and reworking after molding, and it can be used as it is.

[3] Raw material The raw material 5 is not particularly limited. Usually, the mixed raw material 5 containing the heat-fusible fiber 51 serving as a binder and the resin foam particles 52 and / or the high-melting fiber having a higher melting point than the heat-fusible fiber 51 is used (FIG. 3). In FIG. 3, the heat-fusible fiber 51 and the resin foam particles 52 are used.

  The heat-fusible fiber 51 is preferably a low-melting polyester fiber or polyolefin fiber that can be melted at a relatively low temperature and can be bonded to the resin foam particles 52 and the like. Moreover, as the heat-fusible fiber 51, a core-sheath fiber composed of a low melting point sheath and a high melting point core that does not melt at the temperature at which the sheath melts can be used. As such a core-sheath fiber, the following are mentioned, for example. That is, the sheath is made of polyester having a relatively low melting point, the core is made of polyester having a relatively high melting point, the sheath is made of polyethylene, and the sheath is made of polyethylene and the core is made of polypropylene. Can be mentioned. Furthermore, as the heat-fusible fiber 51, side-by-side fibers such as side-by-side fibers of polypropylene and polyethylene can also be used. As the heat-fusible fiber 51, only one type of these fibers may be used, or two or more types may be used in combination.

  As the resin foam particles 52, various resin foam particles such as polyurethane foam and polyolefin foam can be used. As the resin foam particles 52, only one type of these particles may be used, or two or more types may be used in combination. Moreover, as the resin foam particles 52, unused foam particles may be used, and waste materials can be reused as long as a molded product of a predetermined quality can be obtained. For example, crushed material contained in the remainder of the shredder dust of the vehicle, except metal, glass, wire harness, etc., and trimming when manufacturing automotive interior materials such as floor silencers, floor carpets, roof trims, door trims, etc. It is also possible to reuse the scraps generated by the above.

  The shape of the resin foam particles 52 is not particularly limited, and may be any shape. For example, the crushed material and the end material are indefinite. The dimensions of the resin foam particles 52 are not particularly limited, and the resin foam particles 52 having a maximum dimension of 8 to 18 mm, particularly 10 to 15 mm can be used. The maximum size of the resin foam particles 52 is preferably set to an appropriate size depending on the thickness of the molded product.

  As the high melting point fiber, various synthetic fibers that do not melt at the temperature at which the heat-fusible fiber 51 melts can be used. Examples of the synthetic fiber include polyester fibers such as polyethylene terephthalate fibers and polybutylene terephthalate fibers, and polyamide fibers such as nylon 6 fibers and nylon 66 fibers. As a high melting point fiber, only 1 type of these fibers may be used and 2 or more types may be used together.

  Further, the mass ratio between the heat-fusible fiber 51 and the resin foam particles 52 and / or the high-melting-point fibers is also set so that the resin foam particles 52 and the like are not easily dropped by the heat-fusible fibers 51. There is no particular limitation as long as it can be joined. When the total of the heat-fusible fiber 51, the resin foam particles 52 and the high melting point fiber is 100% by mass, the heat-fusible fiber 51 is 40% by mass or more and less than 100% by mass, particularly 60 to 95% by mass. Furthermore, it is preferable that it is 75-90 mass%. In this way, by increasing the content ratio of the heat-fusible fiber 51 than usual, it is possible to more easily manufacture a molded product in which a decrease in strength or the like is suppressed. It is preferable that the heat-fusible fiber 51 and the resin foam particles 52 and / or the high melting point fiber are sufficiently uniformly dispersed and mixed.

  The raw material may contain various additives as required. Such additives include, for example, antioxidants, ultraviolet absorbers, lubricants, flame retardants, flame retardant aids, softeners, inorganic or organic to improve the impact resistance and heat resistance of the fiber structure, etc. Various fillers, antistatic agents, colorants, plasticizers and the like. Moreover, these additives can be contained in a molded article by blending with at least one of the heat-fusible fibers 51, the resin foam particles 52, and the high melting point fibers.

[4] Use of molded product, etc. The use of the molded product of the present invention is not particularly limited. It can be used in a wide range of products such as vehicles and building materials, and is particularly useful as an interior material for vehicles. Examples of the vehicle interior material include various interior materials such as a floor silencer, a roof trim, and a door trim. Since the molded product is used in these various applications, the thickness is not particularly limited, and can be set to an appropriate thickness depending on the application. The thickness of the molded product is usually 5 to 100 mm, particularly 5 to 75 mm. If the thickness of the molded product is particularly 5 to 75 mm, it has sufficient strength and the like in many applications and can be suitably used as a lightweight member.

Hereinafter, the present invention will be described specifically by way of examples.
Example 1
As the raw material, heat-fusible fibers and resin foam particles were used. As the heat-fusible fiber, the core-sheath short fiber (Toray) whose core is made of polyethylene terephthalate (melting point: 260 ° C.) and whose sheath is a copolymer polyester resin (melting point: 110 ° C.). (Trade name “T9611”, average fineness; 2.2 decitex, average fiber length; 10 mm). Further, as the resin foam particles, granular polyurethane foam, which is a crushed product obtained by crushing a lump-like soft polyurethane foam, was used (density: 0.015-0.030 g / cm ³ , maximum dimension: 15 mm). . Further, when the total of the heat-fusible fiber and the resin foam particles was 100% by mass, the heat-fusible fiber was 75% by mass.

The above-mentioned heat-fusible fiber and granular polyurethane foam are dry blended, and the mixture is a stainless steel mold 100 having the shape shown in FIG. 1 (a mold for molding a floor silencer of a passenger car). ) Provided to each of the nine raw material supply ports N _{1 to} N ₉ were air-fed for 20 seconds at a speed of 25 g / second, and a total of 4500 g was supplied. Thereafter, hot air of 200 ° C. was made to pass through the mold 100 to soften and melt the heat-fusible fiber, and the heat-fusible fiber and the resin foam particles were joined. Next, a room temperature wind was made to pass through and the temperature was lowered to room temperature, and a passenger car floor silencer was molded. This floor silencer was finished in a predetermined shape up to its side edge, and there was no need for trimming.
Further, when a high melting point fiber is used instead of the resin foam particle, and when the resin foam particle and the high melting point fiber are used in combination, a floor silencer having a predetermined shape can be formed in the same manner.

  It should be noted that the above description is for illustrative purposes only and is not to be construed as limiting the invention. Although the invention has been described with reference to exemplary embodiments, it is to be understood that the language used in the description and illustration of the invention is illustrative and exemplary rather than restrictive. As detailed herein, modifications may be made in the embodiments within the scope of the appended claims without departing from the scope or spirit of the invention. Although specific structures, materials, and embodiments have been referred to in the detailed description of the invention herein, it is not intended to limit the invention to the disclosure herein, but rather, the invention is claimed. It covers all functionally equivalent structures, methods and uses within the scope.

  The present invention can be used in a wide range of product fields such as vehicles and building materials, and a molded product produced by the method of the present invention does not require trimming after molding, is not easily deformed, and does not easily break. It is useful as an interior material such as various members in the above-mentioned product field, particularly a vehicle floor silencer, roof trim, door trim and the like.

100,101; mold, 1; first bottom wall, 2: second bottom wall, 3: sidewall, N and _N 1 to N _9; feed inlet, 41, 41A, 41B; first vent, 42; 2nd ventilation part, 5; Raw material, 51; Heat-fusible fiber, 52; Resin foam particle, A; Expected meeting position, L; Adjacent raw material supply port along the inner surface of the first bottom wall Connected line, M; approximately midpoint of line L.

Claims (3)

In a hollow mold having a first bottom wall, a side wall and a second bottom wall,
From a plurality of raw material supply ports formed in the first bottom wall, a method for producing a molded product for producing a molded product by blowing a raw material,
At the position where the flow front part of the raw material blown from each of the plurality of raw material supply ports is expected to meet inside the molding die, the first bottom wall is provided with a first ventilation part, and The second bottom wall is provided with a second ventilation part ,
A method of manufacturing a molded product, wherein a planar shape of at least one of the first ventilation part and the second ventilation part is a zigzag shape . When two of the plurality of raw material supply ports are a first raw material supply port and a second raw material supply port,
The first ventilation part is provided so that the first raw material supply port and the second raw material supply port are connected by the shortest line along the inner surface of the first bottom wall and include a substantially midpoint of the line. And
2. The method for manufacturing a molded product according to claim 1, wherein the second ventilation wall is provided at a position substantially opposite to the first ventilation part on the second bottom wall. The raw material contains a heat-fusible fiber, resin foam particles and / or a high-melting fiber having a higher melting point than the heat-fusible fiber,
The heat-fusible fibers, in case of a total 100 wt% of the resin foam particles and the high melting fibers, the heat-fusible fibers 40 mass% or more, according to claim 1 or less than 100 wt% 2. A method for producing a molded article according to 2 .

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