JPS63118230A - Method for molding blow molded article composed of plural materials - Google Patents

Abstract

PURPOSE:To mold a molded article made of a plurality of materials forming a double wall having a throttle part so as to provide attractive appearance thereto, by a method wherein a hollow box body having a U-shaped groove provided to the intermediate part of the side surface thereof and divided into different materials on both sides of said groove is formed by blow molding and the greater part of one side having the throttled part across the U-shaped groove is allowed to penetrate into the other side by blow molding. CONSTITUTION:A thermoplastic resin having good flowability is melted under heating to be enclosed in split molds 6, 7, 8 and air is blown in the thermoplastic resin inside the molds 6, 7, 8 from an air blow nozzle and said resin is expanded to be molded to the state of close contact with the molds 6, 7, 8. At this time, by properly setting the width of a U-shaped groove 4, the boundary line 41 of different thermoplastic resins is received in said U-shaped groove 4. Next, a split mold 9 having a projection in said U-shaped groove 4. Next, a split mold 9 having a projection 91 is used and, after flowability is imparted to a hollow body 2 under heating, said box body 2 is pressurized from the left in a drawing by the movable mold 9 to be folded back and air is blown in the space between hollow box bodies 2, 3 by the air blow nozzle 10 to perform blow molding and the molding imparting a final double wall structure is completed.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a method for forming a multi-material blow molded article having a drawn portion for use in floor console boxes of automobiles and other arbitrary applications.

``Conventional technology'' The method of molding resin parts by blow molding has been around for a long time.
It has become possible to form containers with simple shapes with multiple layers of walls. However, in order to coordinate interior and exterior parts, when molding one resin part from multiple materials of 2'PI class or higher with different colors or hardnesses, molding with a drawn part is particularly difficult. In order to mold the product, in the conventional blow molding method, the boundary lines of the mating parts do not pass uniformly, which poses a problem in the appearance of the molded product, which is difficult to deal with with the conventional blow molding method.

"Problems to be solved by the invention" Is the present invention one of the above? ! ff problem, and aims to provide a method for blow-molding a double-walled molded product made of multiple materials with a drawn portion to give a good appearance.

Means for Solving Problems J To achieve the above-mentioned purpose, according to the present invention, a U-shaped groove is provided in the middle of the side surface facing inward over the entire circumference, and different materials are formed using the groove as a boundary. A first step of forming a divided hollow box body by blow molding, and further blow molding so that a large part of one side having a drawn portion with the U-shaped groove as a boundary is fitted into the other side, A second step of forming a double-walled container is provided.

"Operation" According to the above configuration, since the boundaries of different materials are located in the U-shaped groove, even if the boundary line of the mating part is distorted so as to be drawn to one side with the drawn part during blow molding,
The boundary line fits within the U-shaped edge.

"Embodiment" According to the first embodiment of the present invention, the U-shaped groove is partially heated and pressurized from both sides of the molded product, so that both side walls of the U-shaped groove are heated. A method of forming a crimped multi-material blow molded article is provided. According to this aspect, since the inside of the U-shaped arm is hidden from the outside and no disturbance of the boundary line is seen, there is an advantage that the appearance of the molded product is further improved.

According to a second aspect of the invention, the pressure bonding is performed using an adhesive. According to this aspect, there is an advantage that the strength of the portion where the U-shaped edge is crimped is increased.

``Example'' Next, the present invention will be described with reference to an example of a lower console box, with regard to the specific structure shown in the drawings.

As shown in FIG. 1, the floor console box 1, which is the final molded product, consists of a first
The hollow box body 2 consisting of the hollow box body 2 and the second hollow box body 3 has a deep drawn portion 21 and a shallow drawn portion 22. There is a U-shaped 7f between the first hollow box body 2 and the second hollow box body 3.
44 are provided.

Figure 2 is a cross-sectional view taken along the line ■-■ in Figure 1;
Hollow box body 2 and hollow box body 3 have different colors in character groove 4 2
The ingredients of the rice knife are mixed. The two-dot line f in FIG. 2 indicates the shape during blow molding, and is cut after blow molding. The 0-shaped groove 4 may be left in the same shape as it was during blow molding, but in order to further improve the appearance, it is preferable to perform a concealing treatment, as shown in Fig. 3(a).
, (b) shows the second side of the method of concealing the part where the materials are mixed in the U-shaped clearing 4 to improve the appearance, as shown in Fig. 3(a). , a method may be adopted in which the entrance of the U-shaped groove 4 is partially heated and pressure is applied to the hollow box body 2.3 from both upper and lower sides, thereby narrowing the entrance of the U-shaped groove 4 (see FIG. 3). As shown in b), while the inside of the O-shaped groove 4 is partially heated, the console box 1 is pressurized from both upper and lower sides of the hollow box body 2.3, and both side walls of the U-shaped groove 4 are heated. A method of crimping may also be used.

According to the method shown in FIG. 3(b), since the inside of the U-shaped groove 4 is completely hidden from the outside, the appearance is further improved.

In addition, when performing the processing method shown in FIG. 3(b),
U-shaped? When the adhesive 5 is interposed between both side walls of II4, both side walls are firmly joined, and the strength of the crimped portion is improved.

FIG. 4 shows the blow molding process for forming the hollow box body 2.3. For blow molding, a thermoplastic resin with good flow is heated and melted, and is confined in a split mold 6,7°8. Inside the molds 6, 7.8, air is blown into the thermoplastic resin using an air blower nozzle (not shown) to expand the resin and mold it in close contact with the molds 6, 7.8. During the blow molding, in the cross section where the deep drawn portion 21 exists, the boundary line 41 is inevitably drawn toward the deep drawn portion 21 side, and the fourth
Although it is distorted to the left in FIG. 4 compared to the boundary line 41 in the cross section where the shallow draw portion 22 (not shown) exists, the boundary line 41 can be adjusted to the left by appropriately setting the width of the U-shape 14. It can be housed inside the U-shaped 7F14. As shown in Fig. 4, when the hollow boxes 2 and 3 have been completely formed by blow molding in the previous step, the vertical width of the hollow box 3 on the right side of the figure is the same as that of the hollow box 2 on the left side. is larger than the width of the Moreover, the 0-shaped groove 4 is formed between the split molds 7.8.

Next, in the final step, as shown in Figure 5,
A split mold 9 having a protrusion 91 is used, and after heating the hollow box 2 to give it fluidity, the movable mold 9 presses it from the left side in the figure and folds it back. Blow molding is performed by blowing air through the air blow nozzle 10 during this period, and the molding is completed into the final double wall shape. After the final product is molded as a two-color air blow molded product in this manner, the console box 1 is manufactured as described above by cutting the bottom of the wide hollow box body 3 as shown in FIG. .

"Other Examples" In the above examples, the floor console box was manufactured as a two-color blow molded product, but any double-walled container with a drawn part can be molded using the same method. be. Further, the present invention is not limited to two-color blow-molded products, but can also be applied to multi-colored molded products made of multiple materials, and can be similarly applied to multiple materials having different hardness, strength, and other properties. It is possible.

"Effects" As described above, since the method of the present invention has the above configuration, it has the excellent effect of being able to blow mold a multi-material molded product that has a double wall with a drawing part and has a good appearance. There is.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of a floor console box showing an embodiment of the present invention, Fig. 2 is a sectional view taken along the line ■-■ in Fig. 1,
3(a) and 3(b) are sectional views showing the two sides of the U-shaped groove processing method, FIG. FIG. 5 is a cross-sectional view showing the final double-walled shape formed by blow molding. 100. Floor console box, 2,3. ,. Hollow box body, 4, U-shaped groove, 511. glue,
21. Deep drawing section, 22. Shallow drawing section. Figure 1 Figure 2 Figure 3 (a) (b) Figure 4

Claims (3)

[Claims] (1) A first step of forming a hollow box body by blow molding, in which a U-shaped groove is provided in the middle of the side surface facing inward all around the circumference, and the hollow box body is divided into different materials using the groove as a boundary; Further, a second step of blow molding is performed so that most of one side having a constricted portion with the U-shaped groove as a boundary is fitted into the other side to form a double-walled container. A method for molding a multi-material blow molded product characterized by: (2) The U-shaped groove is formed by applying pressure from both sides of the molded product in a partially heated state to press-bond both side walls of the U-shaped groove. Method for forming multi-material blow molded products. (3) The method for molding a multi-material blow molded product according to claim 2, wherein the pressure bonding is performed using an adhesive.