JPH047690B2 - - Google Patents

Description

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

Prior Art Conventionally, as a method for obtaining this type of hollow structure,
A plastic hollow body is manufactured individually in advance,
Then, a fiber sheet was attached 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 attaching process is also complicated. Further, hollow structures made of laminated fiber sheets also had wrinkles in the fiber sheets and convex portions due to unevenness in the adhesive, and their appearance was poor in commercial value.

Therefore, the present invention first proposed a method of welding fiber sheets together by blow molding (Japanese Unexamined Patent Application Publication No. 1983-1999-1).
49534, Japanese Unexamined Patent Publication No. 57-49535). According to this method,
Since the fiber sheet is directly welded to the parison during blow molding, the pasting process can be omitted, and furthermore, the fiber sheet can be completely pasted without wrinkles or protrusions. 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 kind 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 increasing the amount of adhesive in order to increase the adhesive strength, it sometimes leaks from between the fiber sheets, and furthermore, uneven application of the adhesive causes convex portions, resulting in an appearance that lacks commercial value. Furthermore, hollow structures that are glued together during blow molding may become unraveled at the cut edges due to the above-mentioned reasons, and fiber waste may adhere to the hollow structures. The fibers were frayed and fluffy, resulting in a lack of commercial value in terms of appearance.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and its purpose is to eliminate the complicated and difficult process of pasting fiber sheets with adhesive, and furthermore, to The purpose is to eliminate the complicated process of cutting during 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. .

The above object of the present invention is to perform blow molding by disposing knit velour, whose base yarn is made of thermoplastic synthetic fiber having a melting point lower than the resin temperature of the parison, between the parisons, welding the knit velour, and simultaneously forming the parison. This is achieved by melting the base threads due to the melting heat of the parison when they come into contact, leaving only the 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 a parison is extruded into a split mold and a pressurized fluid is injected into the parison to blow-mold a hollow body, the parison is inserted between the split mold and the parison. The knit velour, which is composed of a ground yarn made of thermoplastic synthetic fiber with a melting point lower than the resin temperature and a pile yarn made of a fiber with better heat resistance than the above mentioned ground yarn, is arranged so that the pile surface is on the dividing mold side, and then this division is performed. The 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. While this state is maintained, the parison is solidified and knit velour is laminated on the surface of the hollow body. Method of manufacturing structures.

and A hollow structure in which knit velour, which is 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 present invention, as the split mold is closed, the knitted velor comes into contact with the parison, the melting heat of the parison is transferred to the knitted velour, and the ground yarn of the knitted velour is heated to a temperature higher than the melting point and melted. When the split mold is closed in this state, the parisne and the molten ground yarn are placed outside from the pinch-off part at the pinch-off part of the split mold that forms the end of the hollow body, and the pinch-off part becomes a pile. Only the thread will be used. As a result, the knitted velor at the end of the hollow body can be easily torn off, and moreover, the knitted velor welded to the hollow body is firmly welded to the parison and will not easily separate. At the ends of the obtained hollow structure, the pile threads constituting the knit velor are firmly welded to the surface of the hollow structure and do not easily separate, and the appearance is very beautiful, with a so-called velour-like appearance. It will be finished.

Furthermore, if the knit velor pile yarn is composed of fibers with a Young's modulus of 2 g/denier or more in hot water, the fused knit velor pile yarn will not be easily deformed by the heat of the parison, and will maintain its original raised state. It has the effect of continuing to be maintained.

The hollow structure of the present invention has a main body 1 having a double wall structure.
and a lid body 2 and a hinge 3 that connects these together.
Knitted velor 6 is laminated on the surfaces of the main body 1, the inner walls 4 and 5 of the lid 2, and the hinge 3.
In the knit velor 6, the pile threads 32 are raised toward the outside of the hollow structure, giving the hollow structure excellent appearance characteristics. The end 7 of the hollow structure is the outermost part of the mating surface where the main body 1 and the lid 2 meet, and here the knit velor 6 has finished laminating (see Figs. 1 and 2). .

Note that the knitted 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 11 are held facing each other at regular intervals.
A parison 12 is suspended between a and 11b, and a split mold 1 corresponds to the inner wall of the hollow structure.
Knit velor is placed between 1a and parison 12. In view of improving productivity, it is preferable to arrange the knitted velours so that they are fed in sheet form from outside the split mold by an automatic feeding device (not shown in the drawings).

Knit velor is made by plating and knitting two fibers at the same time.One fiber is knitted with fabric and the other is knitted into a large loop structure.The fibers with this loop structure are sheared to make them stand up.
Finish by brushing. The fibers used to knit the fabric are called ground yarns, and the fibers with the other loop structure sheared are called pile yarns. A perspective view that simply shows the structure of the knitted velor used in the present invention is shown in FIG. In this figure, 31 is the base yarn and 32 is the pile yarn. As can be understood from this figure, the strength of knit velor as a fabric depends on the strength of the base threads 31. In other words, ground thread 3
The pile yarns 32 are intertwined with each other to form the fabric, and the pile yarns 32 are woven into the base yarns 31.
The knitted velor of the present invention is made by shearing the pile yarn 32 into a raised shape, and the raised angle is not particularly limited, and includes knitted 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 melting points of typical thermoplastic synthetic fibers and the resin temperature of parison when blow molding a hollow body are shown below.

Melting point of thermoplastic synthetic fibers Polyethylene 110-140℃ Polypropylene 165-180℃ Polyvinylidene chloride 160-200℃ Parison's resin temperature Polyethylene 150-210℃ Polypropylene 180-270℃ Polyvinyl chloride 190-220℃ Ethylene-vinyl acetate copolymer system: 115 to 170°C Polyamide system: 220 to 260°C Further, the ground yarn is preferably composed of thermoplastic fibers having a melting point lower than the resin temperature of the parison by 5°C or more, or 15°C or more.

The melting point of the present invention is determined by measuring the melting endothermic peak using a scanning differential thermal analyzer (SSC560) manufactured by Daini Seikosha Co., Ltd. at a heating rate of 10°C/min and a sample amount of 10 mg. shall be.

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, silk, etc.
Regenerated fibers such as viscose rayon and copper ammonia rayon, semi-synthetic fibers such as acetate and triacetate, synthetic fibers such as nylon, polyester, acrylic, vinylon, polypropylene and 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 polyester, cotton, triacetate, viscose rayon, etc., the pile surface will have excellent appearance characteristics such as texture and texture. A hollow structure can be obtained.

Next, the split molds 11a and 11b are tightened. As the split molds 11a and 11b are tightened, the mold surface of the split mold 11a presses against the knitted velours 13, bringing the knitted velours 13 and the parison 12 into contact. As mentioned above, the ground thread 31 that makes up the fabric is
Since it is a thermoplastic synthetic fiber with a melting point lower than the resin temperature of the parison 12, the heat of the parison is transmitted through this contact, melting the ground threads 31 and attaching 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 11b are further tightened, the pinch-off parts 14a and 14b of the split molds are brought together, and at this time, the pinch-off parts 14a and 14b are interposed between the pinch-off parts 14a and 14b due to the clamping force of the split molds 11a and 11b. The parison and knit velor are rolled, and the melted ground thread 31 and the parison are pinched off at the pinch-off portions 14a, 1.
4b, only the pile yarn 32 with no fluidity remains between the pinch-off parts 14a and 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 shape the inner surfaces of the divided molds 11a and 11b. 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 as a layer, and the pile yarn 32 is located between the parison 12 and the mold surface, and is exposed to the pressurized fluid. The pressure causes the parison 1 to be compressed by the parison 12.
The ground yarn side portion of the pile yarn 32 is embedded in the inside of the pile yarn 32.

After cooling the parison 12, the divided molds 11a,
11b is opened and the hollow structure with the burr 15, which is the surplus part, is taken out. The burr 15 is removed by pulling it by hand, and the manufacturing method is completed.

According to the present invention, the knit velor 13 remaining in the pinch-off portion is only the pile yarn 32. Since the fabric of the knit velor 13 is made up of ground threads 31, the threads can be easily unknitted using only the pile threads 32. The burr 15 can be easily removed from the pinch-off portion where only the pile yarn 32 remains.

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

The pile yarn 32 is located between the mold surface of the split mold 11a and the parison 12, and is pressed against the mold surface.At this time, the pile yarn 32 is heated by the melting heat of the parison 12, but the pile yarn If 32 is a fiber whose Young's modulus in hot water is 2 g/denier or more,
The raised state of the pile yarn 32 can be easily restored, and a hollow structure with good hand and texture can be obtained. Here, the Young's modulus in hot water refers to the Young's modulus (tensile modulus ).

The plastic hollow bodies used in the present invention include polyethylene (low density, medium density, high density), polypropylene, ethylene-vinyl acetate copolymer, vinyl chloride, ABS, nylon, polyester, etc., soft materials,
It is a general term for hollow bodies formed by blow-molding hard and elastic thermoplastics, and the hollow structures of the present invention include containers, bottles, containers, cases, tanks, and chairs, but are not limited to the above embodiments. ,pillow,
It is also used in automobile interior materials such as armrests, headrests, and ducts, as well as various housing components.

Example: High-density polyethylene (density: 0.96 g/cm ³ , melt index: 0.3 g/10 minutes) is extruded into a parison using a φ90 m/m extruder at a resin temperature of 195°C and a wall thickness of 3 mm. Between the mold and the base yarn, 300 denier monofilament polyethylene thermoplastic synthetic fiber (melting point: 135°C) is used as the pile yarn, and 3 denier polyester synthetic fiber is used as the pile yarn.
Knit velor knitted with No. 30 spun yarn, sheared and brushed (Young's modulus in hot water: 17.7 g/denier, melting point: 263°C) was arranged and blow molded.

After blow molding, the mold was taken out and burrs were removed to obtain the hollow structure shown in FIG. At the end of this hollow structure, the knitted velor could be easily pulled and torn off by hand, so deburring was easy. At the end of the hollow structure after deburring, the pile threads were tightly welded to the surface of the hollow structure, and could withstand long-term use without coming off, and had an extremely beautiful appearance.

Furthermore, the Young's modulus of pile yarn in hot water is 17.7g/
Due to its high denier, the pile yarn is pressed against the mold surface during blow forming and temporarily collapses, but when it is removed from the split mold, it returns to its original raised state, improving its texture and texture. A hollow structure with excellent appearance characteristics was obtained.

Effects of the Invention As described above, in the hollow structure of the present invention, the ground threads of knit velor are easily melted by the heat of the parison, so the pile threads are pushed in and extremely high welding strength is obtained. The knit velor will not peel off even after long-term use.
This allows you to maintain a beautiful appearance.
Furthermore, even at the ends of the hollow structure, the fibers do not fall out, which conventionally occurs, 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 adhesive, and furthermore, it is possible to eliminate the complicated process of cutting in secondary processing after pasting. be. Furthermore, it is possible to obtain a beautiful hollow structure without wrinkles, protrusions or frayed fibers at the joint between the hollow body and the knitted velor or at the end of the hollow structure.

[Brief explanation of drawings]

FIG. 1 is a cutaway perspective view of a hollow structure of the present invention, FIG. 2 is an enlarged view of the main part of FIG. 1, and FIG. A perspective view, FIG. 4 is a sectional view showing the entire manufacturing method of the present invention, FIG. 5 is an enlarged sectional view near the pinch-off part showing the split mold in the middle of closing, and FIG. 6 is a state in which the split mold is closed. An enlarged cross-sectional view near the pinch-off part showing
FIG. 7 is a perspective view illustrating the knitted velor. 1...Body, 6...Nitz velor, 7...End, 12...Parison, 13...Nitz velor,
31... Ground thread, 32... Pile thread.

Claims (1)

[Claims] 1. When a parison is extruded into a split mold and a pressurized fluid is injected into the parison to form a hollow body, there is a gap between the split mold and the parison that is lower than the melting point of the resin of the parison. A knit velour, which is composed of a base yarn made of a thermoplastic synthetic fiber with a low heat resistance and a pile yarn made of a fiber with better heat resistance than the base yarn, is arranged so that the pile surface of the knit velor is on the side of the dividing mold, and then this division is performed. A method for manufacturing a hollow structure, comprising: closing a mold, pressurizing fluid into the parison to expand the parison, bringing the parison and knit velor into close contact with each other, and solidifying the parison while maintaining this state. . 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 comprising a hollow body made of thermoplastic synthetic resin, and knitted velor made of ground yarn with excellent heat weldability and pile yarn with excellent heat resistance laminated on the surface of a hollow body made of thermoplastic synthetic resin. 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.