CN209738448U - PTFE composite sealing gasket - Google Patents

Abstract

The utility model discloses a PTFE composite seal gasket, include: a support layer consisting of PTFE lathed plates, the thickness of which is between 0.8mm and 1.2mm, preferably 1 mm; and one or more PTFE sealing layers adjacent to the lateral surface of the supporting layer, wherein the PTFE sealing layer is formed by hot-pressing and compounding a plurality of PTFE microporous films, and the thickness of each PTFE microporous film is 0.01-0.03 mm. The utility model discloses the leakage problem that appears among the prior art has been solved effectively.

Description

PTFE composite sealing gasket

Technical Field

the utility model relates to a compound seal gasket, more specifically say, relate to a compound seal gasket of PTFE.

Background

The PTFE composite sealing gasket has high temperature resistance, can be used in the environment of minus 20 ℃ to 200 ℃, and is resistant to strong oxidant, oil and acid and alkali. Is usually used in high temperature, high vacuum and high pressure environment, and is also suitable for oil environment. Because of its various excellent properties, PTFE composite gaskets are widely used in the petroleum, chemical, aerospace, and other sectors.

The existing commonly used PTFE composite sealing gasket has two types: one is a PTFE turning plate, which is mainly made of PTFE suspension material which is sintered into a cylindrical prefabricated blank after being pressed, and then the prefabricated blank is placed on a lathe for turning and forming; the other is a PTFE (polytetrafluoroethylene) expanded gasket which is mainly formed by coating glue on each layer of PTFE microporous film and then superposing and compounding the layers of PTFE microporous films to form a composite structure, wherein the thickness of each layer of PTFE microporous film is 0.01-0.03 mm.

the fluid seal is realized by the close contact between the sealing element and the sealing element, and the elastic-plastic deformation of the sealing element is relied on to reduce the leakage channel so as to increase the flow resistance. However, both of the above-mentioned types of gaskets may cause undesirable phenomena such as leakage during use, and the leakage phenomenon is particularly serious in the case of high temperature and high pressure. The reason for this is that after the first PTFE turned plate is in contact with the sealed member, when the first PTFE turned plate encounters a high-temperature and high-pressure condition, a gap between the sealing member and the contact surface of the sealed member leaks, and an interface leak is formed; the second expanded PTFE gasket is composed of a plurality of layers of PTFE microporous membranes in a composite mode, and when the expanded PTFE gasket is in a high-temperature and high-pressure condition, fluid can permeate and leak through micropores in a PTFE microporous membrane body.

SUMMERY OF THE UTILITY MODEL

To the above-mentioned defect that exists among the prior art, the utility model aims at providing a PTFE composite seal gasket has solved the leakage problem that appears among the prior art effectively.

in order to achieve the above purpose, the utility model adopts the following technical scheme:

a PTFE composite sealing gasket comprising:

A support layer consisting of PTFE lathed plates, the thickness of which is between 0.8mm and 1.2mm, preferably 1 mm; and

And one or more PTFE sealing layers adjacent to the lateral surface of the supporting layer, wherein the PTFE sealing layer is formed by hot-pressing and compounding a plurality of PTFE microporous films, and the thickness of each PTFE microporous film is 0.01-0.03 mm.

The density of the supporting layer is 2.1g/cm 3-2.2 g/cm 3.

The density of the PTFE sealing layer is 0.6g/cm 3-0.8 g/cm 3.

in the technical scheme, the utility model provides a compound seal gasket of PTFE, this compound seal gasket of PTFE adopts the PTFE of different grade type to carry out the complex and make, makes its density can reach 0.9g/cm3 ~ 1.3g/cm3, has very good chemical resistance, high temperature resistant and wearability, and it still has very good creep resistance simultaneously, also can not produce the deformation under high temperature high pressure environment. And the PTFE composite sealing gasket well avoids the phenomenon of micropore permeation in the preparation process, thereby fundamentally solving the phenomena of interface leakage and permeation leakage in the prior art.

Drawings

FIG. 1 is a schematic view of a prior art expanded PTFE gasket being fastened prior to compounding;

FIG. 2 is a cross-sectional side view of a PTFE composite sealing gasket of the present invention;

FIG. 3 is a flow chart of the manufacturing process of the composite sealing gasket of PTFE of the present invention.

Detailed Description

The technical solution of the present invention will be further explained with reference to the accompanying drawings and examples.

Please refer to fig. 2, the present invention provides a PTFE composite sealing gasket, including:

A support layer 1 made of PTFE lathed plate, wherein the thickness of the support layer 1 is 0.8mm to 1.2mm, preferably 1 mm; and

And one or more PTFE sealing layers 2 adjacent to two side surfaces of the supporting layer 1, wherein the PTFE sealing layer 2 is formed by hot-pressing and compounding a plurality of PTFE microporous films, and the thickness of each PTFE microporous film is 0.01-0.03 mm.

Preferably, the density of the supporting layer 1 is between 2.1g/cm3 and 2.2g/cm3, and the supporting layer has high hardness.

Preferably, the density of the PTFE sealing layer 2 is between 0.6g/cm3 and 0.8g/cm3, and the PTFE sealing layer has certain elasticity.

Please refer to fig. 3, the preparation process of the PTFE composite sealing gasket of the present invention includes the following steps:

1) the PTFE microporous membrane is firstly wound in a positive and negative way, and then is fixed on two sides, the prior PTFE expanded gasket is firstly overlapped with a plurality of layers of PTFE microporous membranes before thermal compounding, and four sides of the PTFE microporous membranes are fastened by bolts (as shown in figure 1), but the process of the utility model only needs to fasten two sides of the bolts;

2) Placing the PTFE microporous membrane coil obtained in the step 1) on a hot-pressing compound machine for primary sintering and compounding, and then performing secondary sintering and compounding to form a PTFE sealing layer 2, wherein the gluing step in the prior art can be directly omitted;

3) the PTFE sealing layer 2 obtained in the step 2) is respectively attached to the two side surfaces of the supporting layer 1, and then the PTFE sealing layer and the supporting layer are placed on a hot-pressing compound machine together for third sintering and compounding to obtain the final PTFE composite sealing gasket of the utility model.

Preferably, the thickness of each layer of PTFE microporous membrane is between 0.01mm and 0.03mm, and the porosity is between 50 percent and 90 percent.

preferably, when the PTFE microporous membrane roll is placed on a hot-pressing compound machine for first sintering and compounding, the method specifically comprises the following steps:

Heating an upper template and a lower template on a hot-pressing compound machine to 250 ℃, and preserving heat for 1 hour;

And then heating the upper and lower templates on the hot-pressing compound machine to 330-350 ℃, and sintering for 2 hours.

Preferably, the PTFE microporous membrane roll is placed on a hot-pressing compound machine for secondary sintering and compounding, specifically:

and (3) heating the upper template and the lower template on the hot-pressing compound machine to 350-390 ℃, and sintering for 2-3 hours.

Preferably, the PTFE sealing layers 2 are respectively bonded to two side surfaces of the supporting layer 1, and then are placed together on a hot-press compounding machine for third sintering and compounding, specifically:

And (3) heating the upper template and the lower template on the hot-pressing compound machine to 300-350 ℃, and sintering for 1-2 hours.

Preferably, the third compounding pressure is 0.01 kg-3 kg, and the heating rates of the upper template and the lower template on the hot-pressing compounding machine are 10-20 ℃/min.

To sum up, the utility model discloses a PTFE composite seal gasket has very good chemical resistance ability, high temperature resistance and wearability, and it still has very good creep resistance simultaneously, can not produce deformation under high temperature high pressure environment yet, the specially adapted chemical industry field. Just the utility model discloses a PTFE composite seal gasket preparation technology is more automatic than prior art's preparation to the labour has been saved.

it will be appreciated by those skilled in the art that the above embodiments are only for illustrating the present invention and are not to be used as limitations of the present invention, and that changes and modifications to the above described embodiments will fall within the scope of the claims of the present invention as long as they are within the spirit and scope of the present invention.

Claims (3)

1. A PTFE composite sealing gasket, comprising:

A support layer consisting of PTFE lathed plates, the thickness of the support layer being between 0.8mm and 1.2mm, and

and one or more PTFE sealing layers adjacent to the lateral surface of the supporting layer, wherein the PTFE sealing layer is formed by hot-pressing and compounding a plurality of PTFE microporous films, and the thickness of each PTFE microporous film is 0.01-0.03 mm.

2. The PTFE composite gasket seal of claim 1, wherein: the density of the supporting layer is 2.1g/cm 3-2.2 g/cm 3.

3. The PTFE composite gasket seal of claim 1, wherein: the density of the PTFE sealing layer is 0.6g/cm 3-0.8 g/cm 3.