JPS59140038A - Formation of rim urethane molding - Google Patents

Abstract

PURPOSE:To raise the adhesion in the interface of molding by a method in which the molding faces of upper and lower split type molding machine are heated, PVC powder is packed into the molding cavity, and while melting the PVC powder, urethane resin is injected and expanded to form urethane molding integrated with PVC molding. CONSTITUTION:The molding faces of an upper and lower split type molding device provided with an upper mold 14 and a lower mold 16 having a molding groove 20 in a part of its cavity 18 are heated to a temperature at which urethane resin is expanded. Polyvinyl chloride powder 26 is uniformly packed into the groove 20 of the molds. While softening and melting the vinyl chloride powder 26 at the temperature of the molds, RIM urethane monomer liquid is injected through a mixing head into the molds 10 and expanded in such a way as to integrally forming polyvinyl chloride molding layer 26 on the expanded RIM urethane molding 28. A RIM urethane bamper 30 having strongly joined connections can thus be obtained.

Description

Detailed Description of the Invention The present invention is an improvement on the method of integrally molding a molding made of vinyl chloride on the surface of a urethane foamed cedar product. However, when molding molds on top of these urethane products, it is important to
It is known to assemble the parts using a zipper or adhesive. However, in this method, molding 1. In addition to the fact that the "blocking process" becomes necessary and increases the number of man-hours, there is also the problem that when the joint between the molding and the urethane product collides with each other, it is difficult to make the joint between the molding and the urethane product. Furthermore, it is known that after the seventh stage molding, the molding part and the one-piece hood part are laminated and molded by in-mold, by opening the main part slightly and performing the Ωth stage injection. This method has problems in that the molding step is 1:1 and the adhesive strength is weak. Furthermore, it is conceivable that the molding part and the main part and the product part are integrally molded, and only the molding part is left unpainted, but in this method, the molding has a durability of 16 minutes. This is particularly problematic when the molded product is a bumper.

Another possible method is to paint the molding part and the main product part in different colors after integral molding. However, this method has the problem of complicating the painting process and increasing the painting cost.

The purpose of the present invention is to reduce the processing cost by integrally molding the main product part and the molding part when molding a urethane product, and to It is possible to provide a method for molding a molding in a urethane one-time product that can strengthen the bond with the product part.

The structure of the present invention consists of an upper mold, a lower mold, and a molding molding groove formed in a part of the cavity of the lower mold. ,
Load vinyl chloride powder into the groove for molding, and inject urethane into the molding device while softening and melting the vinyl chloride powder at the mold temperature, and foam molding the urethane to produce a urethane foam molded product. This is a molding method for a RIM urethane molded product, which is characterized by integrally molding a vinyl chloride molding on top of the RIM urethane molding. Here, RIM means reaction injection molding.

According to the present invention, polyvinyl chloride, which is the molding member loaded into the mold, is softened and melted and adhesively adhered to the mold + Mi, and in this state, R becomes the properly blended main product.
IM urethane monomer is injected into the mold through a mixing head. This RIM uredanmo/mer is foamed and solidified while being welded to the polyvinyl chloride. At this time, the vinyl chloride and 81M urethane are intertwined with each other at the interface to form a strong bond. In other words, according to the present invention, although different materials are used, the molding part and the main body/four-part part can be easily integrally molded at the same time, and the bonding AS between the two parts can have a good adhesive strength. You can make products with it.

Embodiments of the present invention will be described below with reference to the drawings.

Referring to the figure, a cross section of a molding die 1'0 with upper and lower parts for molding urethane with molding, counterfeiting, and manpa is shown. Core 12 protruding downward from the center of 10 fkJ type molds
an upper mold 14 constituting a core mold, and a cavity mold 4
A lower mold 16 and a lower mold 16 are provided.

The lower mold 16 has a recess or cavity 18 in the center thereof, and is further provided with a groove 20 for forming a molding portion in the center of the cavity 18.

- An injection dart 21 for injecting the RIM urethane monomer is provided at one upper end of the upper mold 16, and an air vent 22 is provided at the upper end on the opposite side with the cavity 18 in between. . Further, an auxiliary heater 24 is provided below +420 to partially heat the mold.

The product is molded into the shape of the space formed between the core 12 and the cavity 18 when the upper and lower molds are closed together.

When molding a product, the mold 10 is heated to a predetermined mold temperature and maintained at that temperature. When using the 81M urethane of this example, 70 to gOC is appropriate. The polyvinyl chloride/mother 26 is uniformly sprinkled onto the groove 20 of the lower mold 16 maintained at a predetermined temperature so that the height is about 2 to 3 mm, as shown in FIG. This /4' kudder has a grain size of about a/~5μ, and the heating penetration according to JISKA7.2.7 is preferably 73 to gOC fineness.The sprayed polyvinyl chloride mother powder 26 has elapsed for about 60 seconds. Then, the layer of powder 26 is softened and becomes a flat layer with a thickness of about 200 to 300 μm from a heaped-up state as shown in FIG.

Next, as shown in Figure i+, the upper and lower molds are closed and the RIM urethane molemer liquid prepared under predetermined conditions is injected into the mold 10 through the mixing head under predetermined molding conditions. The RIM urethane monomer is fully injected into the mold in about 7-2 seconds and begins to react, foam and solidify after 3-1f seconds. RIM urethane 28 solidifies from rising to creaming in one step, and becomes ready for demolding in about 30 minutes. RIM urethane 28 is originally heated during the above reaction process, especially at the time of fd, and has an OC of about 720~/l
At a certain point, the polyvinyl chloride 26 becomes half-melted and becomes a uniform sheet. The RIM urethane 28 and polyvinyl chloride 26 are removed from the mold' when the consistency is down to about 70-gOC.

The removed iRIM urethane and vinyl chloride are completely solidified and the percentage of polyvinyl chloride as shown in FIG.
A RIM urethane pump 30 having a layer 25 is provided.

If we compare the shape of the joint between the molding part of the RIM urethane bumper and the main part of the RIM urethane bumper that has been lumped in this way, and the back of the joint part of ゛, we can see - Figure 6. As shown, in this example, at the interface between the molding part 26 (+9% polyvinyl chloride) and the main product 28 (RIM urethane), the two pieces intertwine with each other and become one piece. This means that when the urethane heats up for about 3 to s seconds, approximately 3 to ψ/d is generated.
This is because foaming heat of θC is generated, making it easier for both components to penetrate each other. On the other hand, in the case of the conventional 2-thread molded product, as shown in FIG. Therefore, in the past, in order to obtain adhesive strength at the interface, adhesives were usually used when performing two-layer molding with different materials, and when using bundled materials, the interface was Although attempts are made to obtain adhesive strength by fusing them, the contact strength is not sufficient.

AS for two-layer molded products of polyvinyl chloride and diurethane made by conventional molding methods and those according to the present invention
TMDgwo'7-4' gTest 1 - A trap to perform practical work 5Il+ of the adhesive strength of the interface according to the method. The results are shown in the table below.

This result also shows that the adhesive strength at the interface of the two-layer molded product according to the present invention is dirty compared to the conventional one.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a finished mold used to practice the method of the present invention;
III Ming diagram showing the state of evil, No.? 1ffl is IP
+7 An explanatory diagram showing the welding state of vinyl chloride, Part IA is an explanatory diagram showing the state after RIM polyurethane injection, 'm
Figure j is a diagonal iid 'IJ of a molding 1-J urethane 1 soot bumper according to the present invention, Figure 6 is an enlarged cross-sectional view of a molded product according to the present invention, and Figure 7 is an enlarged cross-sectional view of a conventional two-layer molded product. It is a diagram. Explanation of symbols 10...I round shape 112...core, 14...
・Upper mold 16 , , Lower mold 18. ,,cavity,2
0. , , groove , 26 , , molding part , 28 . ,,
, the main product part.・Samurai license applicant Toyo Kogyo Co., Ltd. Figure 4 14

Claims (1)

[Claims] The molding surface of the upper and lower sub-mold molding device comprising an upper mold and a lower mold and having a molding molding groove in a part of the lower mold cavity is heated to the thermoforming temperature of urethane, and the molding surface of the molding 1 is Load vinyl chloride powder into the mold, inject urethane into the molding device while softening and dissolving the vinyl chloride powder in a mold IIA, and perform γd molding of the urethane to form a urethane foam molded product. A molding method for a RIM urethane molded product, which is characterized by integrally molding a vinyl chloride molding on top.