JP2000102960A - Extruded themoplastic composite molding and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the positional precision of the joining parts of molding materials extrusion-molded separately by a method in which a recessed part is formed on one joining surface of the first extrusion molding material and the second extrusion molding material, a projected part is formed on the other joining surface, and these recessed and projected parts are engaged to be fused/ integrated together. SOLUTION: The first extrusion molding material is extrusion-molded, and the second extrusion molding material constituting a hollow seal part 11 is extrusion-molded from the second ectruder 2 at a position corresponding to the apex part 10a of the fitting part 10. A pair of recessed parts 16 whose cross sections are triangular and whose opening surfaces are wider than the bottom surfaces is formed in the apex part 10a of the fitting part 10, and projected parts 17 of triangular cross sections are formed at the foot lower end of the seal part 11. These positoning recessed and projedted parts 16, 17 are molded silultaneously at the extrusion molding of the fitting part 10 and the seal part 11, the recessed and projected parts 16, 17 are engaged with each other and positioned, and both are fused together to be integrated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermoplastic elastomer (hereinafter, referred to as "weather strip") used for weather strips for automobiles.
It may be simply referred to as “TPE”. ) And a composite extruded product of a thermoplastic resin and a method for producing the same.

[0002]

2. Description of the Related Art Recently, in weather strips for automobiles and the like,
In place of rubber, extruded products of TPE or thermoplastic resin, which can be reduced in cost and recycled, have begun to be used. Such a thermoplastic weather strip has a mounting portion to be attached to a body flange of a vehicle body or the like,
Although it is composed of a door and the like and a seal portion which is in elastic contact with the door and the like, the mounting portion is required to have strength for clamping the body flange, while the seal portion is required to have a flexibility capable of elastically contacting the door and the like. In order to satisfy these requirements, conventional TPE
In such weather strips, a non-foamed (solid) or low-foamed thermoplastic material is used for the attachment portion, and a foamable thermoplastic material is used for the seal portion.

The weather strip 1 of the prior art 1 shown in FIG.
Reference numeral 00 denotes a top surface 101a of a mounting portion 101 made of a non-foamed solid material and having an inverted U-shaped cross section, and a seal portion 103 made of a foam and having an inverted U-shaped cross section is integrated.

The weather strip 1 of the prior art 2 shown in FIG.
04 integrates a hollow cylindrical seal portion 106 made of a foam with an upper end neck portion 105a of a mounting portion 105 made of a non-foamed solid material and having a U-shaped cross section.
5, a decorative lip 107 made of a foam is integrated with the outside.

[0005] The weather strip 108 of the conventional example 3 shown in FIG. 10 is obtained by integrating a sealing portion 110 made of a high foam with an upper end 109a of a substantially T-shaped mounting portion 109 made of a low foam.

[0006] In the above-mentioned conventional examples 1, 2 and 3, a low-foamed or non-foamed (solid) extruded material of TPE or a thermoplastic resin is used for each of the mounting portions.
3, 106, 110 and the decorative lip 107 are made of extruded material of TPE or thermoplastic resin foam or high foam.

[0007] Unlike the case of vulcanized rubber, it is difficult to integrally form a thermoplastic material such as TPE by extruding it integrally from a die portion of one extruder. Therefore, the first extruded material forming the mounting portion and the second extruded material forming the seal portion have been integrated by heat fusion.

[0008]

By the way, the present inventors have tried to produce weather strips such as conventional examples 1, 2 and 3 using a thermoplastic material such as TPE, and found that they were made of foam. The extruded material has poor dimensional stability at the time of extrusion molding as compared with the non-foamed extruded material, and when joining the sealing portion made of foam and the mounting portion made of non-foamed material, the positions of both parts are changed. It has been found that a weather strip having a desired shape may not be obtained. In particular, in the weather strips of Conventional Examples 1, 2, and 3, since the joint surface between the seal portion and the attachment portion and the joint surface between the attachment portion and the decorative lip are flat, the joining position is not determined, and the product shape is not determined. Was not stable.

Further, it has been found that the bonding portion between the sealing portion or the decorative lip and the mounting portion in these weather strips has a width of only about 1 to 2 mm and the bonding cross-sectional area is small, so that the bonding strength is weak.

[0010]

Means for Solving the Problems The present inventors have conducted intensive studies to improve the positional accuracy of the heat-sealed portions (joined portions) of separately extruded molded materials. If a concave portion is formed on one of the joining surfaces of the material and the second extruded molding material, a convex portion is formed on the other joining surface, and these concave and convex portions are fitted and heat-sealed and integrated with each other. It has been found that the positioning of both extruded materials is facilitated, and a stable product shape is obtained.

The material of these extruded materials may be any combination of materials as long as two extruded materials made of thermoplastic elastomer (TPE) or thermoplastic resin are joined. , TPEs, thermoplastic resins, or a combination of TPE and thermoplastic resin.

TPE is a polymer material which exhibits vulcanized rubber elasticity at room temperature but is easily plasticized and moldable at high temperatures. Depending on its constituent components, styrene (SBC) and olefin (TPO), urethane (T
PU), PVC (TPVC) and the like, and any of these may be TPE.

As the thermoplastic resin, hydrocarbon resins (polyethylene (PE), polypropylene (PP), polystyrene (PS), ABS resin), acrylic resins,
Vinyl acetate resin, halogen-containing resin (vinyl chloride resin (PVC), etc.), polyester resin, polyamide resin,
Examples thereof include polyether resins, and any of these resins may be used.

[0014] The composite molded article of these thermoplastics can be applied irrespective of whether it is a foamed material or not. For example, the present invention can be applied to a combination in which one extruded material is a foam and the other is a non-foam, a combination in which both are foams, and a combination of non-foams. However, it is preferable to apply the present invention to joining of a foam and a non-foam where dimensional stability is a problem, or joining of foams having different specific gravities.

The application of the composite extruded product is not limited to weather strips for automobiles, but can be applied to all fields including trim materials such as furniture and sealing materials for buildings. It is preferable to apply the present invention to an automobile weather strip which requires high dimensional accuracy between a mounting portion to be attached and a seal portion which can elastically contact a door or the like.

As the cross-sectional shape of the uneven portion, various shapes such as a triangle, a quadrangle, a trapezoid and the like, and an arc shape can be adopted, but the uneven portions of both extruded materials are smoothly fitted on a production line. In order to achieve this, it is preferable that the concave portion has a wider opening surface than the bottom surface portion.

Also, as in the case where the attachment portion of the weather strip and the lip are joined, or the attachment portion and the seal portion are joined with a narrow neck portion, the first extruded material and the second extruded material are joined together.
When the cross-sectional area with the extruded material is small, the bonding force is weak. In such a case, if a minute convex portion or a minute concave portion is formed on one of the joining surfaces of the two members, and the material of the other extruded material enters the minute irregular portion during the heat fusion joining, the joining breakage occurs. This is preferable because the area is increased and an anchor effect is exhibited.

The minute concave or convex portion can be applied irrespective of the presence or absence of the above-mentioned positioning concave and convex portion. However, it is preferable to form the concave or convex portion on one of the wall surfaces of the concave portion or convex portion of the joint surface by composite extrusion molding. This is effective in that the positioning of the product and the increase of the joint area can be simultaneously performed. In this case, the minute concave portion or convex portion may be formed on one of the wall surfaces of the concave portion or convex portion for fitting positioning. That is, a minute concave portion or a convex portion may be formed in the positioning concave portion, or a minute concave portion or the convex portion may be formed in the positioning convex portion. Further, it is effective that the minute concave-convex portions are formed so as to protrude or are recessed in a direction different from the disengagement direction so as to have resistance in the disengagement direction after the heat fusion bonding.

The irregularities and the minute irregularities for fitting positioning may be formed at the time of molding each extruded material. That is, when the first extruded material and the second extruded material of the thermoplastic elastomer or the thermoplastic resin are separately extruded and formed, and the joining surfaces of both are heat-sealed and integrated,
At the time of extrusion molding of the first extruded material and the second extruded material, a concave portion for fitting positioning is formed on one joint surface, and a convex portion for fitting positioning is formed on the other joint surface. To In the case of forming the minute uneven portion, it may be formed at the same time when the concave portion and the convex portion are formed.

[0020]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an explanatory view showing a manufacturing process of the weather strip according to the first embodiment, and FIG. 2 is a sectional view of the weather strip.

As shown in the figure, a manufacturing apparatus 2 for a weather strip 1 according to a first embodiment comprises a first extruder 3 for non-foamed TPE, and a second extruder for water foaming of TPE. 4, a cooling tank 5, and a take-off machine 6 are sequentially arranged. A first extruded material (solid material) constituting the mounting portion 10 is extruded from the extruder 3 for TPE solid, and the mounting portion 10 is formed. At the position corresponding to the top 10a of the
A second extruded material (sponge material) constituting the hollow seal portion 11 is extruded from the extruder 2 of (1), and the joining surfaces of the two are heat-sealed and integrated to obtain an extruded molded product, which is then combined with a cooling bath. Cool at 5 to complete the product.

The mounting portion 10 is formed in an inverted U-shaped cross section.
A locking lip 13 that elastically contacts a body flange (not shown) is integrally formed on the wall surface of the U-shaped groove 12.
The locking lip 13 is formed simultaneously with the extrusion of the mounting portion 10. At the time of the extrusion, the mounting portion 10 can be extruded in the form of an inverted U-shaped cross section from the beginning, but in the present embodiment, the mounting portion 10 is extruded into a strip shape, and is heat-sealed with the seal portion. After completion of the composite extruded product, the composite extruded product is passed through a bending roll of a bending machine and bent into a U-shape.

A band-shaped core member 15 made of metal or hard resin is buried in the mounting portion 10. The core member 15 is supplied to the first extruder 3 and is fed from the base at the tip of the cylinder. What is necessary is just to extrusion-mold with TPE. on the other hand,
The seal portion 11 is formed by extruding a cross section into a substantially inverted U-shape.
Heat-sealed.

At the joint between the mounting portion 10 and the seal portion 11, means for positioning the two are fitted. As this positioning means, on the top 10a of the mounting portion 10,
A recess 16 having a pair of right and left triangular cross-sections and an opening surface wider than the bottom surface is formed, and a projection 17 having a triangular cross-section is formed at the lower end of the leg of the seal portion 11 corresponding to the recess. These positioning concavo-convex portions 16 and 17 are formed at the same time when the mounting portion 10 and the sealing portion 11 are extruded. When the mounting portion 10 and the sealing portion 11 are laminated, the concavo-convex portions 16 and 17 are fitted and positioned with each other. Are integrated by heat fusion. Therefore, the positioning of the seal portion 11 with respect to the mounting portion 10 is facilitated, and a stable product shape is obtained.

In the weather strip 1 of the second embodiment shown in FIG. 3, an inverted U-shaped TP made of a non-foamed material is used.
A TPE seal portion 11 made of a foam is formed with a wide inverted trapezoidal concave portion 16 at the top 10a of the E mounting portion 10.
Is formed in a hollow cylindrical shape, and a convex portion 17 having a rectangular cross section is integrally formed at the bottom thereof.
Are fitted and fused to each other. The method of forming the mounting portion 10 and the sealing portion 11 and the method of laminating and combining are described in the first section.
This is the same as the embodiment.

In the weather strip 1 of the third embodiment shown in FIG. 4, a positioning recess 16 having a triangular cross section is formed in the middle of the top 10a of the TPE mounting portion 10 made of a non-foamed material. TPE seal part 11 consisting of body
Is formed in a cylindrical shape, and a leg 11b projecting downward is integrally formed at the bottom thereof. At the lower end of the leg portion 11b, a convex portion 17 having a triangular cross section which is fitted and positioned in the concave portion 16 on the mounting portion 10 side is formed, and these concave and convex portions 16, 17 are heat-sealed to each other.

Further, a sponge-like decorative lip 19 is heat-sealed to the tip of the solid convex strip 18 outside the leg 10b of the mounting portion 10. A hook-shaped protrusion 20 is formed at the tip of the protruding strip 18, and a hook-shaped recess 21 is formed at the base end of the decorative lip 19 corresponding to the protrusion 20. After being positioned to be fitted, they are integrated by heat fusion.

The protruding strips 18 and the protruding portions 20 are integrally extruded when the mounting portion 10 is extruded. In the manufacturing apparatus 2 shown in FIG. 1, a third extruder (not shown) for forming a lip is added to a stage subsequent to the second extruder 4 for forming a seal portion. By arranging the composite extruded products, a composite extruded product can be easily formed.

In the weather strip 1 of the fourth embodiment shown in FIG. 5, the mounting portion 10 is made of a low-foaming TPE and the seal portion 11 is made of a high-foaming TPE. A convex portion 17 having a triangular cross section is formed at the central upper end 10 c of the V-shaped mounting portion 10, and the V-shaped sealing portion 11 is formed.
At the lower end, a concave portion 16 having a triangular cross section whose opening surface is wider than the bottom surface is formed, and after the two 16 and 17 are fitted and positioned, they are integrated by heat fusion.

In the weather strip 1 according to the fifth embodiment shown in FIG. 6, of the concave and convex portions 16 and 17 for fitting and positioning of the mounting portion 10 and the seal portion 11, the concave portion 16 having a triangular cross section is formed. A plurality of rows of minute projections 23 projecting in the vertical direction are formed on the wall surface, and the material on the side of the seal part 11 enters between the minute projections 23 and is integrated when the seal part 11 is thermally fused to the projections 17. Therefore, the joint area on the seal portion 11 side is increased by the minute convex portion 23, and an anchor effect can be provided. Since the minute projections 23 project perpendicularly to the inclined wall surfaces 16a of the recesses 16, even if an external force is applied to the seal portion 11 and the external force is applied upward, the minute projections 16 become a resistance, and the joining force is increased. Will be higher.

In the weather strip 1 according to the sixth embodiment shown in FIG. 7, the contrary to the fifth embodiment is described.
A small concave portion 24 having a trapezoidal cross section is further formed on the bottom central wall surface of the concave portion 16 having a triangular cross section on the mounting portion 10 side. The material flows in and exerts an anchor effect.

[0032]

As is apparent from the above description, according to the present invention, since the uneven surface is formed on the joining surface of the first and second extruded materials of TPE or thermoplastic resin, The positioning of the molding material is easy, and a stable product shape is obtained. In addition, if fine irregularities are further formed on the wall surfaces of these irregularities, the fused area is increased, so that there is an advantage that a product having a strong adhesive force can be obtained.

[Brief description of the drawings]

FIG. 1 is a diagram showing a manufacturing process of a weather strip according to a first embodiment of the present invention.

FIG. 2 is a sectional view of the same weather strip.

FIG. 3 is a cross-sectional view of a weather strip according to a second embodiment.

FIG. 4 is a cross-sectional view of a weather strip according to a third embodiment.

FIG. 5 is a sectional view of a weather strip according to a fourth embodiment;

FIG. 6 is an enlarged sectional view of a weather strip according to a fifth embodiment;

FIG. 7 is an enlarged sectional view of a weather strip according to a sixth embodiment;

FIG. 8 is a cross-sectional view of a weather strip of Conventional Example 1.

FIG. 9 is a cross-sectional view of a weather strip of Conventional Example 2.

FIG. 10 is a cross-sectional view of a weather strip of Conventional Example 3.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Weather strip 2 Manufacturing apparatus 3 1st extruder 4 2nd extruder 5 Cooling tank 6 Take-up machine 10 Mounting part 11 Seal part 16 Concave part 17 Convex part 19 Decorative lip 23 Micro convex part 24 Micro concave part

 ──────────────────────────────────────────────────続 き Continued on front page F term (reference) 3J059 AD05 BC04 BC05 CB05 EA20 GA20 4F207 AA04 AA11 AA13 AA14 AA21 AA45 AG03 AG06 AG20 AG21 AH18 AH23 KA01 KA11 KA17 KA20 KB22 KK82 KL65

Claims (8)

[Claims] 1. A composite extruded product in which a first extruded material and a second extruded material of a thermoplastic elastomer or a thermoplastic resin are heat-sealed and integrated, wherein the two extruded materials are A composite extruded product in which a concave portion is formed on one of the joining surfaces and a convex portion is formed on the other, and these concave and convex portions are fitted together and integrated by heat fusion. 2. The composite extruded product according to claim 1, wherein the recess has an opening surface wider than a bottom surface. 3. One of the wall surfaces of the concave portion and the convex portion,
2. A micro-projection or a micro-recess is formed, and the material of the other extruded material enters the micro-projection or the micro-concavity and is integrated by thermal fusion of the two extruded materials.
Or the composite extruded product according to 2 4. The composite extruded product according to claim 1, wherein said first extruded material is a non-foamed material, and said second extruded material is a foamed material. 5. A composite extruded product according to claim 1, wherein the two extruded materials are foams having different specific gravities. 6. The extruded product is a weather strip for an automobile, the first extruded material is a mounting portion for mounting a vehicle body, and the second extruded material is elastically contactable with a door or the like. The extruded product according to claim 1, 2, 3, 4, or 5, wherein the extruded product is a suitable seal portion. 7. Production of a composite extruded product in which a first extruded material and a second extruded material of a thermoplastic elastomer or a thermoplastic resin are separately extruded, and both are heat-sealed and integrated. A method of forming a concave portion on one of the joining surfaces and forming a convex portion on the other at the time of extrusion molding of the two extruded materials, and fitting these concave and convex portions to each other when the two extruded materials are heat-sealed. For producing composite extruded products by heat-sealing. 8. One of the wall surfaces of the concave portion and the convex portion,
8. The composite extrusion according to claim 7, further comprising forming a minute convex portion or a minute concave portion, and when the two extruded members are heat-sealed, the material of the other extruded member is integrated into the minute convex portion or the minute concave portion. Manufacturing method of molded article.