Bonding method for silicone product

Abstract

The present invention provides a bonding method for a silicone product. The method comprises the following steps: S1, placing, into a plasma machine according to requirements, a silicone product and an object to be bonded, setting the vacuum degree to be -10 to -100 kPa and the flow rate to be 100-350 sccm, and performing treatment for 8-30 S at a certain power; and S2, taking out the silicone product and said object which have been treated in step S1 from the plasma machine, and performing thermal compression bonding at a certain temperature until the silicone product and said object are firmly bonded, wherein said object contains atoms capable of forming bonds with Si or O atoms in the silicone product. The present method is easy to operate, achieves high bonding precision, and does not cause blockage of fine pores or channels of a silicone product, thereby greatly improving the yield and production efficiency of the silicone product.

Description

Method for bonding silicone product TECHNICAL FIELD

[0001] The present application relates to the technical field of silicone product manufacturing, in particular to a method for bonding silicone product. BACKGROUND

[0002] With the development of society, silicone products are increasingly appearing in people's vision due to their excellent performance, such as baby pacifiers, human trachea, etc.

[0003] There are some silicone products on the market, such as silicone airbags and products with hollow special-shaped channels, which must be separated into shape first and then bonded together during manufacturing. When bonding these silicone products with adhesive, the fine pores or pipelines of the silicone products are easily blocked, resulting in unqualified finished products that need to be reworked, which inevitably reduces the yield and production efficiency of the silicone products. Moreover, many adhesives have volatile irritants and may contain harmful substances such as toluene; if the eyes accidentally come into contact with them, the eyeballs may be injured due to the hardness of the cured glue. Therefore, it is particularly important to invent a method that can accurately bond silicone products firmly and ensure good yield. SUMMARY

[0004] The purpose of the present application is to overcome the shortcomings of the prior art and provide a method for bonding silicone products without using silicone glue and ensuring good yield, which is simple, feasible, easy to operate, has high bonding accuracy and is suitable for large-scale production.

[0005] In order to achieve the above purpose, the present application adopts the following technical scheme:

[0006] A method for bonding silicone products, comprising the following steps:

[0007] S1: placing silicone products and bonded objects into a plasma machine according to requirements, setting the vacuum degree to -10 to -100 kpa, the flow rate to 100 to 350 sccm, and processing for 8 to 30 seconds under a certain power;

[0008] S2: taking the silicone products and bonded objects processed in step S1 out of the plasma machine and performing hot pressing until the silicone products and bonded objects are bonded firmly at a certain temperature;

[0009] The bonded objects contain atoms that can form bonds with Si atoms or O atoms in the silicone products, such as Si, Cu, Al, Fe, O atoms, etc.

[0010] In the present application, when the silica gel product and the adherend are in a three-dimensional structure or a special shape, the silica gel product and the adherend need to be installed on a specific clamp before being put into the plasma machine. The processing time of the silica gel product and the adherend in the plasma machine is affected by the size and thickness of the silica gel product and the adherend.

[0011] In the present application, the adherend is one of silica gel, glass, metal and plastic.

[0012] In the present application, the power in step S1 is adaptively changed according to the size of the plasma machine, and the power is 1-600W.

[0013] In the present application, the temperature of the hot pressing bonding in further step S2 is 50-200℃.

[0014] In the present application, the pressure of the hot pressing bonding in step S2 is 10-170KPa, and the time of the hot pressing bonding is 30-300S.

[0015] In principle, the silica gel product and the adherend of the present application can be bonded at normal temperature and pressure after being processed according to step S1, but too small pressure and too low hot pressing bonding temperature will result in long bonding time. In order to improve production efficiency, the optimal hot pressing bonding temperature is generally selected as 100-180℃, the optimal pressure is 120-170KPa, and the optimal hot pressing bonding time is 50-120S. Too large pressure and too high temperature will easily cause deformation of the silica gel product or the adherend, affecting the quality of the product.

[0016] In the present application, the metal is one of aluminum, copper and iron.

[0017] When the adherend is metal, the surface of the adherend needs to be kept clean before being put into the plasma machine in step S1. The surface of the metal workpiece cannot be touched by hands or other objects.

[0018] In the present application, the plastic is one of PP, ABS, PBT, PPSU, PET, TPU, EVA, PES, PC, PA and POM.

[0019] The reaction mechanism of the present application is as follows:

[0020] In the present application, the silica gel product and the adherend are put into the plasma machine, and processed under predetermined conditions for a period of time, so that the polymer molecular bonds of the silica gel in the silica gel product are broken, and the silicon-oxygen bonds are forged to form an ionic state. When the ionic silicon-oxygen atoms meet the ions in the adherend which can combine with them (such as silicon atoms and aluminum atoms), new chemical bonds are formed, which lock the ions of the adherend firmly and bond the adherend.

[0021] The advantages and beneficial effects of the present application are as follows:

[0022] 1.The method for bonding silica gel products of the present application can firmly bond silica gel and the bonded object by treating silica gel and the bonded object with a plasma machine, is easy to operate, has high bonding precision, will not block the fine holes or pipes of silica gel products, and greatly improves the yield and production efficiency of silica gel products.

[0023] 2.The method for bonding silica gel products of the present application is simple and feasible, avoids the use of silica gel glue, reduces the production cost and the content of voc in silica gel products, is more environmentally friendly and feasible, and is suitable for large-scale production. DETAILED DESCRIPTION

[0024] The present application will be further described below in conjunction with specific examples, but is not limited thereto.

[0025] The method for bonding silica gel products of the present application comprises the following steps:

[0026] S1 silica gel products and the bonded object are placed in a plasma machine according to requirements, the vacuum degree is set to -10 to -100 KPa, the flow rate is 100 to 350 sccm, and the treatment is carried out under a certain power for 8 to 30 S; the set power is adjusted according to the size of the plasma machine, and the power can be generally set to 1 to 600 W;

[0027] S2 the silica gel products and the bonded object treated in step S1 are taken out of the plasma machine, and hot pressing is carried out at a temperature of 50 to 200℃ until the silica gel products and the bonded object are firmly bonded.

[0028] The bonded object contains atoms that can form bonds with Si atoms or O atoms in the silica gel products.

[0029] In the present embodiment, the bonded object is one of silica gel, glass, metal and plastic.

[0030] When the silica gel products and the bonded object are in a three-dimensional structure or a special shape (such as a silica gel airbag or a silica gel nipple), the silica gel products and the bonded object need to be installed on a specific clamp and then placed in the plasma machine.

[0031] 1.Tension test

[0032] In the specific embodiments of the present application, in order to facilitate the test of the bonding strength of the silica gel product and the bonded object, the silica gel product and the bonded object are both selected as a flat sample plate, and the size of the sample plate is 50*15*1.2mm. When hot pressing and fitting, the silica gel product and the bonded object need to be partially fitted along the length direction, and the bonded overlapping part is 20mm, and the exposed unbonded two ends are convenient for tension test. In step S2 of the specific embodiments, hot pressing and fitting can also be carried out at room temperature and normal pressure, but in order to save the bonding time of the silica gel product and the bonded object, the temperature of hot pressing and fitting is generally selected as 100-180℃, the pressure of hot pressing and fitting is 120-170KPa, and the time of hot pressing and fitting is 30-60S. After hot pressing and fitting, the product needs to be placed for 1 hour to cool down before tension test.

[0033] In this experiment, 20 groups of examples are carried out for different silica gel products and bonded objects, and the experimental conditions are shown in Table 1. In each group of examples, 5 silica gel products and 5 bonded objects are selected for parallel test to bond 5 finished products (A, B, C, D, E respectively), tension test is carried out, and the test data is recorded in Table 2. The tension test of this embodiment uses a machine produced by Dongguan Zhiqu Precision Instrument Co., Ltd., model ZQ-990LB.

[0034] Table 1 Bonding conditions of silica gel products and bonded objects in examples 1-20

[0035] Table 2 Tension test results of silica gel products and bonded objects after bonding in examples 1-20

[0036] According to Table 1 and Table 2, the silica gel product and the bonded object silica gel, glass, metal and plastic can be bonded together after being treated in the plasma machine, and all have a certain bonding strength, which meets the requirements of daily silica gel bonding process.

[0037] 2. Air tightness experiment

[0038] 8 groups of silica gel air bag tube semi-finished products and the other half of the silica gel air bag tube matched with them are installed on a special clamp, and are put into the plasma machine as required. The vacuum degree of the plasma machine is set to-25Kpa, the flow rate is 200sccm, and the treatment time is 10s. The treated silica gel air bag tube is taken out of the plasma machine, and is hot pressed and fitted at a temperature of 120℃ and a pressure of 150kpa for 50s to form a silica gel air bag tube finished product F.

[0039] The hot pressing and fitting is left for 1 hour, and the air tightness test is carried out after cooling.

[0040] Then, the other half of the silicone balloon tube is bonded to the eight groups of silicone balloon tube semi-finished products and the other half of the silicone balloon tube matched therewith by using glue to form balloon tube finished products G. After the glue is air-dried and firmly bonded, the balloon tube finished products G are left for one hour and then subjected to air tightness test.

[0041] The air tightness test result shows that the eight silicone balloon tube finished products F are all air-tight and the tracheal pipelines are not blocked; the eight silicone balloon tube finished products G are all air-tight but three of the tracheal pipelines are blocked; it can be seen that the silicone product and the bonded object treated in the plasma machine not only have good bonding effect but also do not have the phenomenon of pipeline or air hole blockage when the product is of special shape or three-dimensional structure (silicone tube, nipple), which shows that the bonding method of the silicone product of the present application can greatly improve the product yield.

Claims

1. A method of bonding a silicone gel article, characterized by The method comprises the following steps: S1: placing the silica gel product and the adherend into a plasma machine according to requirements, setting the vacuum degree to -10 to -100 KPa, the flow rate to 100 to 350 sccm, and processing under a certain power for 8 to 30 S; S2: taking the silica gel product and the adherend processed in step S1 out of the plasma machine, and performing hot pressing bonding at a certain temperature until the silica gel product and the adherend are firmly bonded. The adherend contains atoms capable of bonding with Si atoms or O atoms in the silica gel product.

2. The method of bonding a silicone article according to claim 1, wherein The adherend is one of silica gel, glass, metal, and plastic.

3. The method of claim 1, wherein The power in step S1 is adaptively changed according to the size of the plasma machine, and the power is 1 to 600 W.

4. The method of claim 1, wherein The temperature for hot pressing bonding in step S2 is 50 to 200 DEG C.

5. The method of bonding a silica gel article according to claim 1 or 4, wherein The pressure for hot pressing bonding in step S2 is 10 to 170 KPa, and the time for hot pressing bonding is 30 to 300 S.

6. The method of claim 2, wherein The metal is one of aluminum, copper, and iron.

7. The method of claim 2, wherein When the adherend is metal, the surface of the adherend needs to be kept clean before being placed into the plasma machine in step S1.

8. The method of claim 2, wherein The plastic is one of PP, ABS, PBT, PPSU, PET, TPU, EVA, PES, PC, PA, and POM.

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