WO2018094603A1

WO2018094603A1 - Surface-treatment-free die for polyurethane product

Info

Publication number: WO2018094603A1
Application number: PCT/CN2016/106915
Authority: WO
Inventors: 李红领; 苏志锋; 谭鹏展
Original assignee: 广州艾科新材料股份有限公司
Priority date: 2016-11-23
Filing date: 2016-11-23
Publication date: 2018-05-31

Abstract

A surface-treatment-free die for a polyurethane product comprises a male die (1), a female die (2), and a die cavity (3). The male die (1) matches the female die (2), a die cavity (3) is formed between the male die (1) and the female die (2), and a male die edge portion (4) of the male die (1) is in a tightly-lapped connection with a female die edge portion (5) of the female die (2). A die release agent layer (8) is coated on the surface of each of the male die (1) and the female die (2), and an in-die coating layer (9) is coated on each of the die release agent layer (8). A plurality of strip-shaped shallow slots (6) is formed in the male die edge portion (4) or the female die edge portion (2). A raised line (7) higher than the depth of each shallow slot is disposed on one end of the corresponding strip-shaped shallow slot (6) close to the die cavity (3), and one end of the strip-shaped shallow slot (6) distant from the die cavity (3) does not exceed an edge of the male die edge portion (4) or the female die edge portion (5). On the basis that the polyurethane surface is not corroded, the die provides a fine protective layer having a uniform color; the shallow slots (6) are formed in the edge portions of the die, thin films of the in-die coating layers (9) after baking are left on the shallow slots (6), and the thin films are relatively thick, which can facilitate operations; and workers can open each thin film, so as to drive the whole residual thin film to be removed from the die.

Description

Surface-free mold for polyurethane products

Technical field

The present invention relates to a mold for a polyurethane article, and more particularly to a surface-free mold for a polyurethane article.

Background technique

At present, the vulcanization operation of polyurethane product molds is mainly manual. The assembly, disassembly, casting and demoulding of the mold are required to be convenient and can not damage the product. Whether the operation is convenient, not only affects the production efficiency, but also the labor intensity and personal safety of the workers. The mold is generally heavy, and the manual operation is labor intensive. If the design is unreasonable, the opening of the account is inconvenient, and the demoulding is difficult, the labor intensity will be further increased. Therefore, under the premise of ensuring the mechanical strength of the mold, efforts are made to reduce the weight of the mold, and if necessary, the handle and the unloading device are installed to facilitate use. In short, the mold design must take into account the requirements of product quality, product production operation and mold processing and manufacturing. Polyurethane products generally need to be surface treated after injection molding, and the common process is generally to spray a protective layer on the finished surface after the injection molding is completed. This operation requires two processes, which is troublesome and often unevenly sprayed, which is easy to cause. Defects on the surface of the product.

Moreover, in the production process of polyurethane molded products, there are often problems of flow pattern or uneven color. The cause of this problem is often that the toner particles cannot be uniformly dispersed during the mixing process of the pigment and the stream and during the foaming process. Eventually, there will be color unevenness and even flow problems on the surface of the product. In order to improve the flow pattern problem, manufacturers often need to carry out subsequent surface treatment on polyurethane products, such as spraying paint to mask the appearance problems such as flow pattern and color difference. The surface treatment of polyurethane paint tends to adversely affect the surface of polyurethane products, such as corrosion of the skin, which is often detrimental to the appearance of the polyurethane, and also greatly prolongs the production cycle of the product and increases the production cost, and has an impact on the environment.

Summary of the invention

In view of the deficiencies of the prior art, the present invention provides a mold which can eliminate the surface treatment and directly cover the protective layer on the polyurethane product in the injection mold.

The technical solution of the present invention is: a surface-free mold for a polyurethane product, comprising a punch, a die, and a cavity, wherein the punch is matched with the die, and a cavity is formed between the punch and the die. The punch edge of the punch and the die edge of the die are closely overlapped, the surface of the punch and the die is coated with a release agent layer, and the release agent layer is coated with an in-mold paint layer; The edge of the punch or the edge of the die is provided with a plurality of shallow grooves, and the shallow groove of the strip is disposed near one end of the cavity to have a height less than the depth of the shallow groove, and the end of the shallow groove away from the cavity does not exceed the edge of the die. Or the edge of the edge of the die.

The in-mold paint layer is a long-chain polyol resin layer.

The invention has the beneficial effects that a mold release layer is pre-sprayed in the mold, and then an in-mold paint layer is applied, and the surface is dried at room temperature to produce a polyurethane molded product, and the product is finally released from the mold. Can be pre-attached to the mold The in-mold paint transfer of the surface adheres to the surface of the polyurethane product, and provides a layer of uniform and fine protective layer on the basis of not corroding the surface of the polyurethane; the edge of the mold is provided with a shallow groove and a film of the in-mold paint layer after baking is left. The film is relatively thick and can be easily opened by the operator from here to drive the entire residual film out of the mold.

DRAWINGS

1 is a schematic cross-sectional structural view of a surface-free mold for a polyurethane article of the present invention;

2 is a schematic plan view showing a concave mold of the present invention;

3 is a schematic partial cross-sectional structural view of a punch of the present invention;

In the figure: 1-punch, 2-die, 3-cavity, 4-die side, 5-die side, 6-slot shallow groove, 7-strip, 8-release layer , 9-in-mold paint layer.

detailed description

The specific embodiments of the present invention are further described below in conjunction with the accompanying drawings:

As shown in FIG. 1-3, a surface-free mold for a polyurethane product, including a punch 1, a die 2, a cavity 3, a punch 1 matched with a die 2, and between a punch 1 and a die 2 Forming the cavity 3, the punch edge portion 4 of the punch 1 and the die edge portion 5 of the die 2 are closely overlapped, and the surfaces of the punch 1 and the die 2 are coated with a release agent layer 8, a release agent layer 8 is coated with an in-mold paint layer 9; in this embodiment, a mold release layer 8 is pre-sprayed in the mold, and an inner mold layer 9 is further coated, and the surface is dried at room temperature to carry out the polyurethane product. In the production, when the product is finally released from the mold, the in-mold paint pre-attached to the surface of the mold can be transferred and attached to the surface of the polyurethane product, and a uniform and fine protective layer can be provided on the basis of not corroding the surface of the polyurethane.

The punching edge portion 4 or the die edge portion 5 is provided with a plurality of strip-shaped shallow grooves 6 which are disposed near one end of the cavity 3 and have a height less than a shallow groove depth. The strip-shaped shallow groove 6 is far away. One end of the cavity 3 does not exceed the edge of the punch side 4 or the die side 5. The edge of the mold is provided with a shallow groove to leave a film of the in-mold paint layer 9 after baking, and the film is relatively thick, which can facilitate the operator to pry open therefrom and drive the whole residual film out of the mold.

The in-mold paint layer 9 is a long-chain polyol resin layer.

The above embodiments and the description are merely illustrative of the principles and preferred embodiments of the present invention, and various changes and modifications may be made without departing from the spirit and scope of the invention. It is claimed within the scope of the invention.

Claims

A surface-free mold for a polyurethane product, comprising a punch, a die, and a cavity, wherein the punch is matched with the die, the cavity is formed between the punch and the die, and the punch edge of the punch is formed And the die edge of the die is closely overlapped, the surface of the punch and the die is coated with a release agent layer, the release agent layer is coated with an in-mold paint layer; the punch edge or the die The edge portion is provided with a plurality of strip-shaped shallow grooves, and the strip-shaped shallow groove is disposed near one end of the cavity cavity with a ridge having a height smaller than the shallow groove depth, and the strip-shaped shallow groove is away from the cavity end without exceeding the edge of the convex die or the edge of the concave die .
The surface-free mold for a polyurethane article according to claim 1, wherein the in-mold layer is a long-chain polyol resin layer.