JP3009877U - Lightweight tray mainly made of unsaturated polyester resin - Google Patents

Abstract

(57) [Summary] [Purpose] To reduce the specific gravity of commercial trays and improve the appearance of trays using cross mesh. [Structure] A bulk molding material obtained by mixing glass balloons into an unsaturated polyester resin is used as a main material, or a bulk molding material obtained by mixing glass balloons with an unsaturated polyester resin mixed with glass fiber chopped strands is used as a main material Lightweight tray with cross mesh placed on both sides and heated and pressed into a tray shape.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a lightweight tray mainly made of unsaturated polyester resin, and more particularly to a lightweight tray for business such as a tray for school lunch.

[0002]

[Prior art]

 As a tray for business use, a tray having a large strength and a low specific gravity is desired in order to carry a large number of stacked sheets or carry tableware, food and the like. As a method of molding such a tray, a molding material in which glass micro hollow bodies (hereinafter referred to as glass balloons) are mixed with unsaturated polyester reinforced with glass fiber is used to mold by heating and pressing in a tray shape. The method is known. With trays molded by this method, some of the glass balloons are molded with parts of the surface of the tray exposed, and the glass balloons are exposed due to abrasion of the tray surface during use. In addition, the exposed portion of the glass balloon was cracked, and dust and the like clogged in the exposed portion, making the surface of the tray look dirty.

[0003]

[Problems to be solved by the device]

 In order to eliminate this drawback, as shown in FIG. 5, a sheet-shaped molding material 1 obtained by mixing glass balloons with unsaturated polyester resin mixed with glass fiber chopped strands is used as a main material, and a cross mesh, for example, glass cloth, is provided on the upper and lower surfaces thereof. A molding method has been developed in which two or three layers are stacked and heated and pressed into a tray shape by molding dies 4 and 5. In this molding method, the limit of the specific gravity of the tray molded with the conventional reinforced plastic material was 1.7 to 1.9, but the specific gravity was up to about 1.1, although it varied depending on the mixing amount of the glass balloons. There are advantages that it can be made lighter and that the glass balloons can be prevented from being exposed on the surface of the tray. However, since the sheet-shaped molding material is used, the fluidity of the resin during molding is inferior.Therefore, there is a problem that the mesh of the cross mesh is conspicuous depending on the viewing angle on the front and back surfaces of the tray, and the appearance is bad, which causes There is also a problem that the weight cannot be reduced further than about 1.1. An object of the present invention is to provide a tray that can solve such problems.

[0004]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, the present invention has a bulk molding material, which is a mixture of unsaturated polyester resin and glass micro hollow body, as a main material, and a cross mesh is arranged on both upper and lower sides thereof, and heated and pressed in a tray shape. The main material is a block-shaped molding material made by mixing glass micro hollow bodies with unsaturated polyester resin mixed with glass fiber chopped strands. It is characterized in that it is formed by heating and pressurizing.

[0005]

【Example】

An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, 6 is a main material, and an unsaturated polyester resin having a particle diameter of preferably 10 to 150 μn and a specific gravity of 1.0 or less is used as an unsaturated polyester resin. It is preferably composed of a block-shaped molding material in which 5 to 35% by weight of the resin is uniformly mixed. A cloth mesh 7 is arranged below the main material 6 and is laid on a female mold 8 for tray molding, and for example, glass cloth is used. Reference numeral 9 is a cross mesh which is arranged on the upper side of the main material 6 and which is covered with the female die 8, and for example, glass cloth is used. 10 is a male mold for tray molding. Then, the male die 10 and the male die 10 are heated to a predetermined temperature, preferably 135 ° C. to 160 ° C., and the male die 10 is applied to the female die 8 at a predetermined pressure, preferably 130 kg / cm ^2. The tray 11 as shown in FIG. 2 is formed by combining the molds as described above. In this tray 11, unsaturated polyester layers 18 and 19 are formed on the front and back surfaces, glass cloth layers 7 and 9 are formed on the inside thereof, and the unsaturated polyester and the glass are formed between the glass cloth layers 7 and 9. A miscible layer 20 with the balloon is formed.

In this embodiment, it is possible to mold the tray 11 which has a specific gravity of 1 or less, is light enough to float on water, and has strength, although it depends on the amount of glass balloons mixed. Such a light tray is not suitable for washing by dipping it in water like a school lunch tray, but when using it just by wiping the surface of the tray like a tray used at a bakery shop. It is suitable for

In FIG. 3, reference numeral 12 denotes a main material, which is a unsaturated polyester resin mixed with glass fiber chopped strands and a glass balloon having a particle size of preferably 10 to 150 μn and a specific gravity of 1.0 or less with respect to the unsaturated polyester resin. Preferably, it is composed of a lump-shaped molding material in which 5 to 35% by weight is uniformly mixed, and the mixing amount of the glass fiber chopped strands is adjusted so that the specific gravity of the main material 12 is 1 to 1.05. Reference numeral 13 denotes a cross mesh which is arranged below the main material 12 and which is laid on a female mold 14 for forming a tray. Reference numeral 15 denotes a cross mesh which is arranged on the upper side of the main material 12 and which covers the female mold 14, and for example, glass cloth is used. 16 is a male mold for tray molding. Then, while the female mold 14 and the male mold 16 are heated to a predetermined temperature, preferably 135 ° C to 160 ° C, the male mold 16 is applied to the female mold 14 at a predetermined pressure, preferably 130 kg / cm ² By performing mold matching as described above, the tray 17 as shown in FIG. 4 is formed. In this tray 17, unsaturated polyester layers 21 and 22 are formed on both front and back surfaces, and glass cloth layers 13 and 15 are formed inside thereof, and the unsaturated polyester and the glass fiber are formed between the glass cloth layers 13 and 15. A mixed layer 23 of chopped strands and glass balloons is formed.

In this embodiment,

It is possible to mold a tray 17 having a specific gravity of 1 to 1.05, which is even lighter than the specific gravity of about 1.1 of the tray formed by using the sheet-shaped molded material 1 described in 1.

[0009]

[Effect of device]

 Since the present invention is configured as described above, it is possible to provide a tray that is lighter in weight than the conventional lightweight tray and has a strength comparable to that of the conventional tray, and when using a large amount of trays. It is very useful for labor saving and efficiency improvement. In addition, since a block-shaped material is used as the main material, the fluidity of the resin during molding is much better, and the smoothness of the tray surface is increased, and the mesh shape of the cross mesh on the front and back surfaces of the tray depends on the viewing angle. It is possible to provide a well-formed tray without any noticeability.

[Brief description of drawings]

FIG. 1 is a diagram showing a positional relationship of a block-shaped molding material, a cross mesh, and a molding die immediately before molding.

FIG. 2 is an enlarged cross-sectional view of the tray obtained by the molding process of FIG.

FIG. 3 is a diagram showing a positional relationship of another block-shaped molding material, a cross mesh, and a molding die immediately before molding.

FIG. 4 is an enlarged cross-sectional view of the tray obtained by the molding process of FIG.

FIG. 5 is a diagram showing a positional relationship of a sheet-shaped molding material, a cross mesh, and a molding die immediately before molding.

[Explanation of symbols]

6 ... Main material, 7 ... Cross mesh, 9 ... Cross mesh,
11 ... Tray, 12 ... Main material, 13 ... Cross mesh, 1
5 ... cross mesh, 17 ... tray.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location C08K 7/28 C08L 67/06 MSE

Claims (2)

[Scope of utility model registration request] 1. An unsaturated polyester obtained by molding a bulk molding material, which is a mixture of an unsaturated polyester resin and glass micro hollow bodies, and arranging a cross mesh on the upper and lower sides thereof and heating and pressurizing it in a tray shape. A lightweight tray made mainly of resin. 2. A bulk molding material obtained by mixing glass micro hollow bodies in an unsaturated polyester resin mixed with glass fiber chopped strands is used as a main material, and cross meshes are arranged on both upper and lower sides thereof, and heated and pressed in a tray shape. A lightweight tray made mainly of molded unsaturated polyester resin.