Method for saving foam raw material for backrest of passenger car seat and application thereof

Abstract

The application discloses a method for saving foam raw materials of a bus seat backrest, which comprises the following steps: placing a seat backrest framework into a foam mold, wherein the foam mold comprises a mold cavity main body and a back connecting arm mold cavity; placing plasticine at the joint of the mold cavity main body and the back connecting arm mold cavity, so that the plasticine fills the gap between the back connecting arm and the mold; pouring liquid silicone with a curing agent into the back connecting arm mold cavity until the liquid silicone fills the mold cavity at the back connecting arm, then closing the foam mold, opening the foam mold after the liquid silicone is completely cured, and obtaining a silicone soft mold; sleeving the silicone soft mold on the back connecting arm, then placing the whole seat backrest framework into the foam mold, closing the foam mold, and performing foam molding; and taking off the silicone soft mold after the foam molding is completed. By sleeving the silicone soft mold on the back connecting arm in advance, the sponge is prevented from flowing to the back connecting arm during the foam molding, the waste of polyurethane foam raw materials is reduced, and manual cleaning operation is also reduced.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of automobile seat, and particularly relates to a method for saving foaming raw materials of a bus seat backrest. BACKGROUND

[0002] The information disclosed in this Background section is only for the purpose of increasing an understanding of the general background of the application and does not necessarily constitute an admission by the patent applicant or the patent owner that this information forms prior art.

[0003] At present, the main structure of a bus seat is a metal framework supporting the strength of the seat, a sponge covering the metal framework, and an outer seat covering. In the preparation process of the seat, the metal framework of the seat backrest needs to be pre-buried in polyurethane (sponge), and then polyurethane foaming is performed. In the process of polyurethane foaming, the polyurethane will fill the entire foaming mold, and the metal framework and the sponge are integrally formed by foaming. However, since the back connecting arm (used for connecting with the seat cushion framework) on the seat backrest framework is an irregular special-shaped U-shaped structure, when the sponge is foamed, the sponge will completely fill the back connecting arm, and after the foaming is completed, the sponge at the back connecting arm needs to be manually cut and removed. In this process, not only the polyurethane raw material is wasted, but also a large amount of labor cost is generated. According to the estimation, the amount of wasted sponge at the back connecting arm of each seat backrest framework is at least 40 g, and the cost of each seat is increased by at least 5 yuan on average, in addition to the labor cost. SUMMARY

[0004] In order to overcome the above problems, the present application provides a method for saving foaming raw materials of a bus seat backrest. The present application prevents the sponge from flowing to the back connecting arm during foaming by pre-wrapping the prepared silicone soft mold at the back connecting arm, which not only reduces the waste of polyurethane foaming raw materials, but also reduces manual cleaning operations.

[0005] To achieve the above technical purposes, the present application adopts the following technical solutions:

[0006] In a first aspect, the present application provides a method for saving foaming raw materials of a bus seat backrest, which comprises:

[0007] S1, placing the seat backrest framework into a foaming mold, wherein the foaming mold comprises a mold cavity main body and a back connecting arm mold cavity; vertically placing putty at the connection between the mold cavity main body and the back connecting arm mold cavity, and the putty fills the gap between the back connecting arm and the mold;

[0008] S2, pouring liquid silicone with a curing agent into the back connecting arm mold cavity until the liquid silicone fills the mold cavity at the back connecting arm, then closing the foaming mold, and after the liquid silicone is completely cured, opening the foaming mold to obtain a silicone soft mold;

[0009] S3, the silicone soft mold is sleeved at the back connecting arm, then the whole seat back skeleton is placed into the foaming mold, the foaming mold is closed, and the polyurethane raw material is injected into the foaming mold cavity through an injection mechanism to be foamed and formed; after the foaming is completed, the silicone soft mold is removed.

[0010] In one or more embodiments, the back connecting arm mold cavity is provided with two, and the two back connecting arms are respectively in the two back connecting arm mold cavities.

[0011] In one or more embodiments, the part of the seat back skeleton except the two back connecting arms is in the mold cavity main body.

[0012] In one or more embodiments, the putty is in the mold cavity main body, and the thickness of the putty is 1-2 cm.

[0013] In one or more embodiments, before the liquid silicone is added to the back connecting arm mold cavity, pretreatment is needed, and the pretreatment is: cleaning the impurities in the back connecting arm mold cavity, and then smearing a layer of vaseline on the surface of the putty on the side of the back connecting arm mold cavity, so that the silicone soft mold is easy to demold.

[0014] In one or more embodiments, the liquid silicone is a commercially available mold silicone, and the specific type and brand are not limited. The curing agent is a curing agent matched with the mold silicone used, and the ratio of the liquid silicone to the curing agent and the specific curing time can be determined according to the product instructions of the commercially available mold silicone.

[0015] In one or more embodiments, the raw materials used in the polyurethane foaming process, the black material isocyanate and the white material combined polyether, are commercially available products, and the specific brand is not limited; the mass ratio of the white material to the black material is: 100:45-50, the curing time after closing the mold is 210-240 seconds; the temperature of the mold is 50-55℃; and the pouring weight of the sponge raw material is 1000-1400g.

[0016] In the second aspect of the present application, the above method is applied to the preparation of a car seat back.

[0017] The present application has the following beneficial effects:

[0018] (1) The present application solves the process operation of handling the excess sponge at the back connecting arm in the prior art by sleeving the silicone soft mold at the back connecting arm, reduces the use of demolding agent (which needs to be sprayed at the back connecting arm before foaming, in order to facilitate the cleaning of the excess sponge from the back connecting arm), reduces the waste of foaming raw materials, reduces the manual operation of cleaning the back connecting arm, saves cost and improves efficiency.

[0019] (2) The silica gel soft mold in the application can be reused, has low cost and is simple to operate. BRIEF DESCRIPTION OF DRAWINGS

[0020] The accompanying drawings, which form a part of the specification, are included to provide further understanding of the application and are incorporated in and constitute a part of this specification. The illustrative embodiments of the application and their description are presented to explain the application and to provide a basis for a working of the same.

[0021] Figure 1 Figure 1 is a schematic diagram of a whole foam mold for a seat back frame.

[0022] Figure 2 Figure 2 is a schematic diagram of a vertical section structure of a back connecting arm in the foam mold.

[0023] Figure 3 Figure 3 is a schematic diagram of a passenger car seat. DETAILED DESCRIPTION

[0024] It should be noted that the following detailed description is merely exemplary and is intended to provide further description of the application. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

[0025] It should be noted that the terms used herein are merely for the purpose of describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, the singular form is intended to include the plural form unless the context clearly indicates otherwise, and it should also be understood that the terms "comprise" and / or "include" as used herein indicate the presence of a feature, step, operation, device, component and / or combination thereof.

[0026] In order to enable those skilled in the art to more clearly understand the technical solutions of the present application, the technical solutions of the present application will be described in detail below with specific examples.

[0027] Example 1

[0028] Referring to Figure 1 Figure 1 is a schematic diagram of a whole foam mold for a seat back frame.

[0029] In the prior art, the entire seat back frame is placed in the foam mold, the back connecting arm is coated with a release agent, and then the mold is closed directly, and the sponge is punched into the mold cavity to form. However, this will cause the back connecting arm cavity to also be filled with sponge, and subsequent cleaning of the back connecting arm is required, which wastes raw materials and labor costs.

[0030] The application provides a method for saving foam raw materials of a seat back of a passenger car, which comprises the following steps: placing a seat back framework into a foam mold, dividing the foam mold into a main mold cavity and a back connecting arm mold cavity, vertically placing a rubber clay with a thickness of 1-2 cm at a connecting position of the main mold cavity and the back connecting arm mold cavity in the back connecting arm mold cavity, and the rubber clay is in the main mold cavity and fills the gap between the back connecting arm and the mold; cleaning impurities in the back connecting arm mold cavity, and then smearing a layer of vaseline on the surface of the rubber clay in the back connecting arm mold cavity and on the side of the back connecting arm mold cavity, so that the vaseline facilitates the demolding of the silica gel soft mold; pouring liquid silica gel with a curing agent into the back connecting arm mold cavity until the liquid silica gel fills the mold cavity at the back connecting arm, then closing the foam mold, opening the foam mold after the liquid silica gel is completely cured, and obtaining the silica gel soft mold; the rubber clay has good deformation and can change shape according to requirements, and has a certain plasticity, and the rubber clay placed at the connecting position of the main mold cavity and the back connecting arm mold cavity can prevent the liquid silica gel from entering the main mold cavity. In the production process, the silica gel soft mold is sleeved at the back connecting arm, then the whole seat back framework is placed into the foam mold, the foam mold is closed, polyurethane raw materials are injected into the foam mold cavity through an injection mechanism to perform foaming and molding, commercially available black material isocyanate and white material combined polyether are used for foaming, the mass ratio of the white material to the black material is 100:45-50, the aging time after closing the mold is 210-240 seconds, the temperature of the mold is 50-55 DEG C, the pouring weight of the sponge raw material is 1000-1400 g, and after the foaming is completed, the silica gel soft mold is removed and can be reused.

Claims

1. A method of conserving foam material for a seat back of a passenger vehicle, characterized by, The method comprises: S1, put the seat back skeleton into the foaming mold, the foaming mold comprises two parts of a mold cavity main body and a back connecting arm mold cavity; put the clay vertically at the connecting place of the mold cavity main body and the back connecting arm mold cavity, the clay fills the gap between the back connecting arm and the mold, the clay is in the mold cavity main body, and the thickness of the clay is 1-2 cm; S2, pretreat before adding the liquid silica gel into the back connecting arm mold cavity, the pretreatment is: clean the impurities in the back connecting arm mold cavity, then smear a layer of vaseline on the surface of the clay on the side of the back connecting arm mold cavity; pour the liquid silica gel added with the curing agent into the back connecting arm mold cavity until the liquid silica gel fills the mold cavity at the back connecting arm, then close the foaming mold, open the foaming mold after the liquid silica gel is completely cured, and the silica gel soft mold is prepared; S3, put the silica gel soft mold on the back connecting arm, then put the whole seat back skeleton into the foaming mold, close the foaming mold, inject the polyurethane raw material into the foaming mold cavity through the injection mechanism to perform foaming molding; after the foaming is completed, the silica gel soft mold is removed.

2. The method of claim 1, wherein, The back connecting arm mold cavity is provided with two back connecting arms.

3. The method of claim 1, wherein, The part of the seat back skeleton except the two back connecting arms is in the mold cavity main body.

4. The method of claim 1 is applied to the preparation of the back of the car seat.

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