JPH0443317Y2 - - Google Patents

Description

[Detailed description of the invention] <Field of the invention> This invention relates to a polyolefin resin plate for thermoforming used in press molding and vacuum forming.
In particular, the present invention relates to a polyolefin resin plate for thermoforming, which prevents static electricity during stocking of raw material and is suitable for automating the material supply process.

《Prior art and its problems》 Traditionally, polyolefin resins such as polypropylene and polyethylene are inexpensive and have excellent moldability.
Because of its moderate rigidity, it is often used in automobile interior parts.In particular, as a resource-saving measure, polyolefin-based composite resin materials, which are a mixture of polyolefin-based resin and wood powder filler, are used for door trims and rear parcel panels. It is suitable as a core material for interior parts such as elf.

An example of the process of molding interior parts using these polyolefin resins and polyolefin composite resins will be explained based on FIG. 4. First, a sheet S made of a polyolefin resin or a polyolefin composite resin is extruded from an extrusion molding machine (not shown), and this sheet S is cut into predetermined dimensions with a cutting blade 1. The original fabrics 2 are stored in a stacked state on a material supply station.

Then, the original fabric 2 is clamped one by one by a clamping device 3.
The original fabric 2 is heated and softened by the heater device 4, and then press-molded into a desired shape by the cold press molding device 5 to provide a core material 6 having a curved surface shape.

Currently, automation of molding processes is actively being carried out to reduce production costs, and usually,
In order to take out the original fabric 2 from the material supply station to the clamp device 3, the original fabric supply arm 7 is driven and the original fabric 2 is fed one by one to the clamp device 3 using vacuum suction force. ing.

However, polyolefin resins generally have poor electrical conductivity and tend to be easily charged. Therefore, when a polyolefin resin plate or a polyolefin composite resin plate is used as the raw fabric 2, if these raw fabrics 2 are stored in a stacked state,
Due to the mutual electrostatic attraction force, when the original fabric 2a at the top position of the station is taken out, the original fabric 2b below it is also moved, causing a positional shift, so that the clamping device 3 can accurately hold the original fabric 2b for the next process. It has been pointed out that the disadvantage is that it is difficult to continuously supply the raw fabric 2.

As a countermeasure for this, when manufacturing the sheet S, antistatic agents such as various interfacial lubricants, inorganic salts, and polyhydric alcohols are added to the interior of the resin material to prevent the raw material 2 from being charged, thereby making automation effective. It has also been proposed to prevent the adhesion of dust, etc., but in order to effectively prevent static electricity, it is necessary to set a large addition ratio of this antistatic agent, which leads to a significant increase in cost. This is not an effective measure, especially when using an inexpensive polyolefin composite resin core material made from waste materials to save resources.

《Purpose of the invention》 This invention was made in view of the above-mentioned circumstances, and the purpose of the invention is to
This is a polyolefin resin plate used for thermoforming such as vacuum forming, which has a simple and inexpensive structure, can reliably prevent static electricity, and can automate the raw fabric supply process. It is about providing.

<<Structure and Effects of the Invention>> In order to achieve the above object, the polyolefin resin plate for thermoforming according to the present invention has a polyolefin resin plate on one side of a polyolefin resin substrate used for thermoforming such as press molding and vacuum forming. By laminating a non-woven fabric layer made of resin fibers with a low basis weight in the form of a tape, it is possible to control the charging on the surface of the substrate when the substrate is stocked, and also to control the charging when the substrate is being thermoformed.
The present invention is characterized in that the substrate and the nonwoven fabric layer are integrated.

That is, according to the present invention, these polyolefin resin boards are laminated with a slight gap between them due to the tape-shaped nonwoven fabric layer laminated on one side of the polyolefin resin substrate, so that the resin boards are stacked with each other with a slight gap between them. It is possible to reliably prevent the charging phenomenon caused by contact, and it is possible to continuously take out the polyolefin resin sheets stored in a laminated state one by one. It can automatically and continuously supply plates to accurate positions, greatly contributing to the automation of the forming process.

Furthermore, according to the present invention, an expensive antistatic agent is not used, and the simple structure is that a nonwoven fabric layer made of polyolefin resin fibers with a low basis weight is laminated in the form of a tape on one side of a resin substrate. It becomes possible to easily and inexpensively prevent static electricity on a resin plate.

Furthermore, during press molding and vacuum forming, these polyolefin resin plates are heated and softened, but during this heat softening, the nonwoven fabric layer melts and becomes integrated with the resin substrate, so it is not suitable for thermoforming such as press molding and vacuum forming. It does not cause any trouble.

<Description of Examples> Hereinafter, an example of the polyolefin resin plate for thermoforming according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is an overall perspective view showing a polyolefin resin plate according to the present application, and FIGS. 2 and 3 are explanatory views showing the molding process of the polyolefin resin plate.

In FIG. 1, a polyolefin resin board 10 according to the present application is obtained by extruding a material made of a mixture of polypropylene resin and wood flour filler at an appropriate mixing ratio into a sheet using an extrusion molding machine, and cutting the sheet into a predetermined size. It is composed of a polypropylene composite resin substrate 11 and a nonwoven fabric layer 12 made of polyolefin resin fibers laminated approximately in the center of the substrate 11 in the form of a tape.

The nonwoven fabric layer 12 may be laminated at the same time as the extrusion molding of the substrate 11, and the tape width of the nonwoven fabric 12 laminated into a tape shape is as follows:
The wider the width, the better, but considering the cost, a width of about 20 to 100 mm has the antistatic effect described later.
Furthermore, the basis weight of this nonwoven fabric layer 12 is 10
A low basis weight of ~50g/ ^m2 is sufficient.

Next, the functions and effects of the polyolefin resin plate 10 constructed as described above will be explained based on FIGS. 2 and 3.

First, as shown in FIG. 2, a plurality of polyolefin resin plates 10 are stored in a stacked state on the material supply station 13, and since a nonwoven fabric layer 12 is laminated on one side of each substrate 11,
This non-woven fabric forms a minute gap between the polyolefin resin plates 10, as indicated by the reference numeral d in the figure. The polyolefin resin plate 10 is not electrically charged, and is an automated process in which the uppermost polyolefin resin plate 10a is heated and softened by a feeder (not shown) via a heater device (also not shown), and then set in the cold press molding device 14. In the polyolefin resin plate 10b located below the polyolefin resin plate 10a located at the uppermost position, no electrostatic attraction force acts between the polyolefin resin plate 10a and 10b, so the lower resin plate 10b does not shift position. , is stored in a predetermined position, allowing automatic continuous supply.

As shown in FIG. 3, when the polyolefin resin plate 10 is heated and softened, not only the substrate 11 but also the nonwoven fabric layer 12 is melted into the molded product 15 formed by the cold press molding device 14. Since the fiber material of the nonwoven fabric layer 12 is polypropylene, the nonwoven fabric layer 12 is integrated with the substrate 11 due to the resin compatibility of both the substrate 11 and the nonwoven fabric layer 12. Then, the molded product 15 is molded so that the surface of the molded product 15 is free from minute irregularities of the nonwoven fabric layer 12 and has a smooth surface 15a that matches the mold surface of the cold press molding device 14. Furthermore, a skin material (not shown) may be integrally attached to one side of the molded product 14 during press molding.

As described above, according to the present application, the nonwoven fabric layer 12 made of polyolefin resin fibers made of the same material as the substrate 11 is laminated in the form of a tape on one side of the substrate 11, which is a simple structure, compared to the conventional method of adding an antistatic agent. This invention is inexpensive and highly effective, and has high practical value, such as being able to automatically and continuously supply raw fabric during thermoforming.

[Brief explanation of drawings]

Fig. 1 is an overall perspective view showing a polyolefin resin plate for thermoforming according to the present invention, Figs. It is an explanatory view showing a series of molding steps of a polyolefin resin plate for molding. 10... Polyolefin resin plate, 11... Substrate, 12... Nonwoven fabric, 13... Material supply suction, 14... Cold press molding device, 15...
Molding.

Claims (1)

[Scope of utility model registration request] By laminating a low fabric weight nonwoven fabric layer made of polyolefin resin fibers in the form of a tape on one side of a polyolefin resin substrate used for thermoforming such as press molding and vacuum forming, the surface of the substrate is fixed when the substrate is stocked. 1. A polyolefin resin board for thermoforming, which is characterized in that it regulates the charging of the substrate, and integrates the substrate and a nonwoven fabric layer during thermoforming of the substrate.