JPS60262633A - Hollow-shaped structure and manufacture thereof - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a hollow structure in which knit velor is laminated on the surface of a hollow body, and a method for manufacturing the same. A hollow structure characterized in that knit velor made of thermoplastic fibers with a low melting point is laminated on the surface of the hollow body so that the ends of the hollow structure can be easily processed and beautifully formed, and the same. This relates to a manufacturing method.

Conventional technology The conventional method for obtaining this type of hollow structure was to manufacture a pre-warmed plastic hollow body separately, and then adhere a fiber sheet to the surface of the hollow body using an adhesive or the like. . However, according to this manufacturing method, it is extremely difficult to attach a fiber sheet along the surface of a hollow body having a three-dimensional shape, and the attachment process is also complicated.

Furthermore, even in hollow structures made of laminated fiber sheets, wrinkles occurred in the fiber sheets, and convex portions were generated due to unevenness in the adhesive, resulting in poor commercial value.

Therefore, the present invention has previously proposed a method of welding fiber 1 and 1F sheets together by blow molding (Japanese Patent Laid-Open No. 57-4953
4, Japanese Patent Publication No. 57-49535). According to this method, the fiber [sheet] is directly welded to the parison during blow molding, so the pasting process can be omitted, and furthermore, the fiber sheet can be completely pasted without wrinkles or protrusions. It was. However, this method has the disadvantage that the ends of the hollow structure must be treated with scissors or the like, and the process of secondary processing of the ends is complicated. It has not been easy to cut the fiber sheet with scissors, especially at the edges where the cut must be made along a curve.

Next, regarding this type of hollow structure itself, in a hollow structure in which a fiber sheet is adhered to the surface of a hollow body with an adhesive, sufficient adhesive strength of the fiber sheet cannot be obtained. Therefore, when the amount of adhesive was increased to increase the adhesive strength, it sometimes leaked from between the fiber sheets, and furthermore, uneven application of the adhesive caused protrusions, resulting in an appearance that lacked commercial value. Furthermore, for the hollow structure that was glued together during blow molding, 1.1 tons of fibers from the fiber sheet became frayed at the cut end due to the above-mentioned reasons, and fiber waste was formed into the hollow structure. It has the disadvantage that it has a poor commercial value in terms of appearance due to adhesion, frayed fibers, and hairy appearance.

SUMMARY OF THE INVENTION The present invention has been made in view of the following two points, and its purpose is to eliminate the complicated and troublesome process of pasting fiber sorting with an adhesive, and to improve the bonding process. The aim is to eliminate the complicated process of cutting in post-secondary processing. Another objective is to obtain a beautiful hollow structure without wrinkles, protrusions, or fraying of the fiber sheet at the joint between the hollow body and the fiber sheet or at the end of the hollow structure. It's in the ro.

The second object of the present invention is to perform blow molding by disposing a knit velor whose base yarn is made of thermoplastic synthetic fiber having a melting point lower than the resin temperature of the parison between the parisons, and welding the knit velor at the same time as the molding. This is achieved by the fact that when the parison comes into contact with the parison, the ground threads melt due to the melting heat of the parison, leaving only pile threads at the ends of the hollow structure, and the ends of the hollow structure are easily cut off. . To describe the configuration of the present invention more clearly, when extruding a ballison into a split mold and pressurizing a pressurized fluid into the parison to form a hollow body, the ballison is inserted between the split mold and the ballison. The pile surface of the knit velour, which is composed of a base yarn of thermoplastic synthetic fiber with a melting point lower than the resin temperature and a pile yarn of a fiber with better heat resistance than the base yarn, is placed on the side of the split mold. Afterwards, this split mold is closed and pressurized fluid is injected into the parison to expand the parison and bring the parison and knit velor into close contact.
A method for manufacturing a hollow structure, in which the parison is solidified while maintaining this state, and knit velor is laminated on the surface of the hollow body.

and a hollow structure in which knit velor made of ground yarn with excellent heat weldability and pile yarn with excellent heat resistance is laminated on the surface of a hollow body made of thermoplastic synthetic resin.

The gist of this is as follows.

According to the invention, as the split mold is closed,
When the knit velor comes into contact with the balisne, the melting heat of the balisne is transferred to the knit velor, and the ground yarn of the knit velor is heated to a temperature above its melting point and melted by -C. When the split mold is closed in this state, the hollow body is formed. At the pinch-off part of the split mold that constitutes the end of the mold, the parison and the molten ground yarn are placed outside from the pinch-off part, leaving only the pile yarn in the pinch-off part. As a result, the knit velor at the end of the hollow body can be easily torn off, and the knit velor welded to the hollow body is firmly welded to the parison and will not easily separate. In the obtained hollow structure, the pile yarns constituting the knit velor are firmly welded to the surface of the hollow structure at the ends thereof, and there is no J- which can be easily separated, and the appearance is also similar to that of velor. It comes out very beautifully.

Furthermore, if the knit velor pile yarn is made of fibers with a Young's modulus of 2 g/denier or more in hot water, the welded knit velor pile yarn will not be easily deformed by the heat of the parison, and the knit velor This has the effect of maintaining the original nap state.

The hollow structure of the present invention consists of a main body 1 and a lid 2 having a two-wall structure, and a hinge 3 that connects these together. Knit velor 6 is laminated on the surfaces of the inner walls 4 and 5 of the lid 2 and the hinge 3.

2y) In the velor 6, the pile threads 32 are raised toward the outside of the hollow structure, giving the hollow structure excellent appearance characteristics. The end portion 7 of the hollow structure includes the main body 1 and the lid body 2.
The lamination of the knit velor 6 is completed at the outermost part of the mating surface where the two are joined together (see FIGS. 1 and 2).

Note that the knit velor 6 can also be laminated over the entire circumference of the hollow structure as shown in FIG.

Next, the manufacturing method of the present invention will be explained based on the drawings.

First, split molds 1 held facing each other at regular intervals] a.

], 1b, the parison 12 is suspended, and a knit velor is placed between the parison 12 and the split mold 11a corresponding to the inner wall of the hollow structure.

Considering the productivity, it is preferable to arrange the knit velor so that it is fed in sheet form from outside the split mold by an automatic feeding device (not shown in the drawings).

Knit velor is made by playing two fibers at the same time, one is knitted with fabric, the other is assembled into a large loop structure, and the fibers with this loop structure are shirred to create a raised shape. Finish by brushing. The fibers that make up the fabric are called ground threads, and the other fibers with a shirred loop structure are called pile fibers. FIG. 7 is a perspective view that simply shows the structure of the knit velor used in the present invention. In this figure, 31 is the ground thread,
32 is a pile type. As you can understand from this diagram,
The strength of knit velor as a fabric depends on the strength of the base threads 31. That is, the ground yarns 31 are entangled with each other to form the fabric, and the pile yarns 32 are woven into the ground yarns 31. The knit velor of the present invention refers to pile yarn 32
It is made into a raised shape by shirring, and the raised angle is not particularly limited, and includes 27-way velvet and the like.

The base yarn 31 is made of thermoplastic synthetic fibers having a melting point lower than the resin temperature of the parison when the hollow body is blow-molded, and is made of fibers that have excellent weldability with the hollow body made of thermoplastic synthetic resin. The following shows the melting point of typical thermoplastic synthetic fibers and the resin temperature of parison when blow molding a hollow body.

Melting point of thermoplastic synthetic fibers Polyethylene 1], O~140℃ Polypropylene 165~180℃ Polyhynylidene chloride 160~200℃ Parison resin temperature Polyethylene 150~210℃ Polypropylene 180~270℃ Polyvinyl chloride 190 -220℃ Ethylene-vinyl acetate copolymer system 115-170℃ Polyamide system 220-260℃ In addition, the ground thread is composed of thermoplastic fibers with a melting point lower than the resin temperature of parison by 5℃ or more, or 15℃ or more. I like it.

The melting point of the present invention was determined using a scanning differential thermal analyzer (SSC560) manufactured by Daini Seikosha Co., Ltd. at a heating rate of 10°C.
The sample amount is 10 mg per minute, and the melting endothermic peak is taken as the melting point.

Further, the pile yarn 32 is made of a fiber that does not melt at the resin temperature of the parison when blow molding the hollow body and has better heat resistance than at least the base yarn. For example, natural fibers such as cotton, linen, wool, and silk, viscose (noyon,
Regenerated fibers such as copper ammonia rayon: '1'-synthetic fibers such as Ld1-, acetate, triacetate-1, etc., synthetic fibers such as nylon, polyester, acrylic, vinylon, polypropylene, polyurethane, and blended fibers thereof can be used. .

In addition, when thermoplastic fibers having a melting point are used as the pile yarn, fibers such as nylon, which have a melting point higher than the resin temperature of the parison when blow-molding the hollow body, are used. Furthermore, if the pile yarn is made of fibers with a Young's modulus of 2 g/denier or more in hot water, such as fibers made of Hahoriesdel, cotton, Doria Nanachi 1-, viscose rayon, etc., the texture and texture of the pile surface can be improved. A hollow structure with excellent appearance characteristics can be obtained.

Next, split mold 1.1. a, ] 1 Continue b. As the split molds 11a and Ilb tighten, the split mold 1
], the mold surface of a presses the knit velor 13 and brings the knit velor 13 and the parison 12 into contact. As mentioned above, the ground yarn 31 that makes up the fabric is a thermoplastic synthetic fiber with a melting point lower than the resin temperature of the parison 12.
This contact transfers the heat of the parison, melts the ground yarn 31, and sticks the knit velor 13 to the parison 12. The raised portion of the pile yarn 32, that is, the pile surface side of the knit velor 13, is located between the mold surface of the split mold 11a and the parison 12, and is pressed by the mold surface.

This pile yarn 32 is not melted by the heat of the parison 12 (FIG. 5).

When the split molds 11a and llb are further tightened, the pinch-off parts 14a and 14b of the split molds come together, and at this time,
Split mold], 1. a, 1. ], ,b pinch-off gl<14a, interposed between 14b due to mold clamping force -C
Ground thread 3 made by rolling and melting the parison and knit velor
1 and the parison are extruded from the pinch-off parts 14a, 14b, and only the pile yarn 32 with no fluidity remains between the pinch-off parts 14a, 14b.

After the mold clamping is completed, a pressurized fluid such as compressed air is injected into the parison, and the parison 12 is pressed against the mold surface to form the divided mold 1.
] a, llb Shape the inner surface shape. At this time, in the knit velor 13, the ground yarn 31 is melted by the heat of the parison 12 and adheres to the surface of the parison 12 in a layer, and the pile yarn 32 is located between the parison 12 and the mold surface under the pressure of the pressurized fluid. As a result, the pile yarn 32 is compressed by the parison 12, and the ground yarn side portion of the pile yarn 32 is embedded in the parison 12.

Parison 1? After cooling, the divided money ax l ] a
.

11b is opened, and the hollow structure having the excess portion 15 of ζ1 is taken out. Pull out the burr 15 by hand and remove it! Finish the construction method.

According to Kihatsu 1], the knit velor 13 remaining in the pinch-off portion is only the pile yarn 32. Knit velor 13
Since the fabric is made up of ground threads 31, the threads can easily break apart with only the pile threads 32. Pile thread 32
In the pinch-off portion where only the remaining portion is, the burr 15 can be easily removed.

Furthermore, the ground thread 31 is melted by the heat of the parison 12,
Since it adheres to the surface of the balisne 12, it acts like a kind of adhesive when a part of the pile yarn 32 is embedded into the parisne 12, and the knit velor is more firmly welded.

The pile yarn 32 is connected to the mold surface of the split mold 11a and the parison 12.
The pile yarn 32 is placed between the mold surface and pressed against the mold surface, and at this time the pile yarn 32 is heated by the melting heat of the parison 12.
The pile yarn 32 has a Young's modulus of 2 g/denier or more in hot water.
If the second type of fiber is used, the raised state of the pile yarn 32 can be easily restored and a hollow structure with good feel and texture can be obtained.

Here, Young's modulus in hot water is 1.0% per minute when the fiber is immersed in hot water at 98°C. A tensile test is conducted at a tensile speed of 0%, and the Young's modulus (tensile modulus) of 1 denier light is measured.

The plastic hollow bodies used in the present invention are soft materials such as polyethylene (low density, medium density, high density), polypropylene, ethylene-vinyl acetate copolymer, vinyl chloride, ABS, nylon, polyester, etc.

It is a general term for hollow bodies formed by blow-molding hard and elastic thermoplastics, and the hollow structure of the present invention is not limited to the above embodiments, but can also include containers.

These include bottles, containers, cases, tanks, chairs, pillows, automobile interior shrines such as erno rests, headrests, ducts, and various housing parts.

Example High-density polyethylene (density: 0.96 g/cIIl, melt index: 0.3 g/10 min) was made of φ90T! X
A parison is extruded using an extruder at a resin temperature of 195°C and a wall thickness of 3 mm, and a 300 denier monofilament polyethylene thermoplastic synthetic fiber (melting point: 135°C) is placed between the parison and the mold as a ground thread. The pile yarn was twisted and sheared using a No. 30 spun system of 3 denier polyester synthetic fiber, and the Young's modulus in hot water was 17.
7 g/denier, melting point 263°C) Knit velor was arranged and blow molded.

After blow molding, remove from the mold and remove the paris.
The hollow structure shown in the figure was completed. At the ends of this hollow structure, the knit velor can be easily pulled and torn by hand, so it is easy to remove the tension. It was welded to the surface, withstood long-term use, did not come off, and had an extremely beautiful appearance.

Furthermore, the Young's modulus of pile yarn in hot water is 1.7.7 g/
Due to its high denier, the pile yarn is pressed against the mold surface during blow molding and temporarily collapses, but when taken out from the split mold, it restores to its original raised state.
A hollow structure with excellent appearance characteristics in terms of feel and texture was obtained.

Effects of the Invention As stated in ``2'', in the hollow structure of the present invention, the knit velor ground yarn is easily melted by the heat of the balisne, so the pile system is pushed in and extremely high welding strength is obtained, and the hollow structure is Even when the shaped structure is used for a long period of time, the knit velor does not peel off, and the beautiful appearance can be maintained.

Furthermore, even at the ends of the hollow structure, the fiber removal i'j that conventionally occurs does not occur, and beautiful ends with high commercial value can be obtained.

According to the manufacturing method of the present invention, it is possible to omit the complicated and difficult process of pasting with an adhesive, and furthermore, it is possible to eliminate the troublesome process of cutting in secondary processing after being pasted. Moreover, it is possible to obtain a beautiful hollow structure without wrinkles, protrusions, or frayed fibers at the joint between the hollow body and the knit velor or at the end of the hollow structure.

[Brief explanation of drawings]

FIG. 1 is a perspective view of the hollow-shaped gift of the present invention. Fig. 2 is an enlarged view of the main part of Fig. 1, Fig. 3 is a partially cutaway perspective view showing another example of the hollow structure of the present invention, and Fig. 'f54 is a cross section showing the entire manufacturing method of the present invention. Figure 5 is an enlarged sectional view near the pinch-off part showing the split mold in the middle of closing;
The figure is an enlarged sectional view of the vicinity of the pinch-off portion showing the divided mold in a closed state, and FIG. 7 is a perspective view illustrating the knit velor. 1 Wood body 6 Knit velor 7 End 12 Parison 13 Knit velor 31 Ground thread 32 Pile thread Patent applicant Kyoraku Co., Ltd. Figure 1 1 Figure 21 1 Figure 3 Figure 5 Figure 6 Figure l

Claims (4)

[Claims] (1) In blow molding a hollow body by extruding a parison into a split mold and pressurizing fluid into the parison,
Between the split mold and the parison, a knit velor consisting of a thermoplastic synthetic fiber ground yarn with a melting point lower than the resin temperature of the parison and a pile yarn of a fiber with better heat resistance than the ground yarn is placed between the split mold and the parison. After arranging the split mold so that its surface is facing the split mold side, the split mold is closed, pressurized fluid is injected into the parison to expand the parison, and the parison and knit velor are brought into close contact with each other. A method for producing a hollow structure, characterized by solidifying the parison while maintaining the parison. (2) The method for manufacturing a hollow structure according to claim 1, wherein the knit velor is made of pile yarn of fibers having a Young's modulus in hot water of 2 g/denier or more. (3) A hollow structure characterized in that a knit velor made of pile yarn with excellent heat resistance is laminated on the surface of a hollow body made of thermoplastic synthetic resin on a ground yarn with excellent heat weldability. (4) The hollow structure according to claim 3, wherein the knit velor is made of pile yarn of fibers having a Young's modulus in hot water of 2 g/denier or more.