CN1387991A - A kind of Teflon third axial multi-directional stretch film and its preparation method - Google Patents

Abstract

A third axial multi-directional extension film of teflon (ePTFE) and a preparation method thereof. It is characterized by that the teflon is undergone the process of vacuum adsorption mode or constant-temp. high-pressure air-blowing mode to make third axial multi-directional extension to increase air content between node and fibre, fibre strength and node strength to increase thickness, after the extension, it is undergone the process of surface heat treatment, then the temp. is reduced to the temperature which can be borne by the adhesive cloth, then the adhesive can be added on the cloth to make attachment, if it is not immediately attached, the quick-cooling system is used to make quick-cooling so as to make the thickness retain optimum state, and when the teflon is furled, it is implemented by using central winding mode to regulate tension to minimum furlable force so as to prevent the thickness of lower portion after furled from reducing.

Description

A kind of Teflon third axial multi-directional stretch film and its preparation method

The invention provides a Teflon (ePTFE) third axial multidirectional stretch film and its preparation method, especially a kind of Teflon stretched in the third axial direction by vacuum adsorption or constant temperature and high pressure wind blowing. , forming a stretched film, so as to increase the air content between the node and the fiber, and the strength of the fiber and the node to increase the thickness. After the extension, the surface is heat-treated, and then the temperature is lowered to the temperature that the laminated cloth can bear. Add adhesive to the cloth to facilitate bonding; if it is not bonded immediately, use a rapid cooling system to rapidly cool down to keep the thickness in the best state, and when rolling, use the center coiling method to adjust Tension to the lowest retractable force to prevent the thickness of the bottom part from changing after retracting.

Due to the acid and alkali resistance of Teflon material, it is widely used in industry, and its other feature is that it has moisture permeability outward and waterproof penetration inward, so it also has its effect on the use of clothing. One very important requirement for wearing clothes is to keep warm. Air is the best insulating material in the world, and the conventional Teflon material can only be extended on a plane. According to the purpose of the present invention, the film is made into a three-dimensional shape to increase the porous effect.

From the above, the application of Teflon is quite extensive. However, there are still shortcomings in the manufacture of Teflon that need to be improved. The Teflon raw material is heated to a certain extent, and then expands into a film However, this traditional method can only produce X-axis and Y-axis extension of Teflon. Repeated implementation only makes Teflon thinner, and the nodes of the fiber can only be expanded in a plane, which is its disadvantage.

The main purpose of the present invention is to eliminate the above-mentioned shortcoming, and provide a kind of Teflon (ePTFE) third axial multi-directional stretched film and its preparation method, wherein the Teflon is blown by vacuum absorption or constant temperature and high pressure wind The multi-directional extension of the third axis is carried out in a manner to increase the air content between the node and the fiber, as well as the strength of the fiber and the strength of the node, and increase the thickness, which is its feature.

It can be seen that one of the objectives of the present invention is to provide a third axially multidirectional stretched film of Teflon (ePTFE), wherein the surface of the Teflon is heat-treated after stretching, and then the temperature is lowered to a temperature that the bonding cloth can bear. Temperature, you can add adhesive to the cloth to facilitate lamination. If it is not immediately laminated, use a rapid cooling system to rapidly cool down to keep the thickness in the best state, and when rolling, use the center to roll The tension is adjusted to the minimum retractable force to prevent the thickness of the bottom part from being reduced after retracting.

Regarding the technology, means and effects adopted in the present invention, a preferred embodiment is given and described in detail in conjunction with the drawings. It is believed that the above-mentioned purpose, structure and characteristics of the present invention can be deeply and specifically understood therefrom.

Fig. 1 is a kind of preparation method flowchart provided by the present invention.

Fig. 2 is another kind of preparation method flowchart provided by the present invention.

Fig. 3 is the flow chart of the rolling method of the first method provided by the present invention.

Fig. 4 is another kind of method flow chart of rolling method provided by the present invention.

Fig. 5 is a partially enlarged schematic view of the present invention and a conventional finished product.

In the picture:

10-Teflon raw materials are first heated and pressurized to form a Teflon shaped film

11- The shaped film 10 is sent to the vacuum adsorption process mold

12-Set the constant temperature vacuum suction plate above and below the forward direction of the Teflon shaped film to be extended

13- By the up and down suction of the constant temperature vacuum suction plate, the Teflon is multi-directionally extended to the third axis, forming a multi-directional stretch film of the Teflon third axis

15- The shaped film 10 is sent to the process mold of the constant temperature and high pressure air blowing method

16- Choose a set temperature and high pressure air blowing equipment around the direction of the Teflon oriented film to be extended, and use a groove for the opposite direction of the blowing air

17- Numerous blowing air and countless grooves produce multiple wind-blown film elongations, so that Teflon extends multidirectionally to the third axis, forming a Teflon third-axis multi-directional stretch film

20- After stretching, after surface heat treatment

21- Cool down to the temperature that the laminated cloth can bear

22- Add adhesive to the cloth

23- Make a fit

24- After extension, after surface heat treatment

25-Rapid cooling system for rapid cooling

26- Use the center winding method for winding, and adjust the tension to the lowest retractable force

27- Finish rolling

In order to further understand the technology and method of the present invention, please cooperate with the drawings and give an explanation in the following:

Referring to Fig. 1, the Teflon raw material is first heated and pressurized to form a Teflon shaped film 10, and then the shaped film 10 is sent to the inlet of the vacuum adsorption process mold for feeding. Set the constant temperature vacuum suction plate 12 above and below the advancing direction of the Teflon shaped film, and various angles such as 45°, 60° or other angles in the air holes of the suction plate, such as 45°, 60° or other angles, according to the up and down of the constant temperature vacuum suction plate Suction, so that the Teflon is multidirectionally stretched 13 toward the third axis to form a third-axis multidirectional stretched film.

Referring to Fig. 2, the Teflon raw material is heated and pressurized and stretched to form a Teflon shaped film 10, and then the shaped film 10 is sent to the process mold 15 of the constant temperature and high pressure air blowing method. The entrance of the blowing process mold is fed with Teflon shaped film, and the set temperature and high pressure air blowing equipment is selected around the advancing direction of the Teflon shaped film to be extended, and a groove of more than 16 is used for the opposite direction of the blowing air. The part that accepts the elongation of the wind-blown film uses numerous blowing air and countless grooves to generate multiple wind-blown film elongations, so that the Teflon extends in multiple directions toward the third axis 17 . The high temperature is 340-380°C, and the high pressure is 5-7Kg/cm ² .

Referring to Fig. 3, after stretching and surface heat treatment 20, the temperature is lowered to a temperature 21 that the bonding cloth can withstand, and adhesive 22 can be added to the cloth to facilitate bonding 23.

Referring to Figure 4, after stretching, the surface heat treatment 24, followed by rapid cooling 25 with a rapid cooling system, to keep the thickness in the best state, and when winding, use the center winding method to adjust the tension to The minimum retractable force 26 is used to prevent the thickness of the bottom part from decreasing after retracting, so as to complete the retraction 27 . The purpose of heat treatment is to increase strength, stabilize dimensions, and facilitate subsequent processes.

The Teflon fiber can only be extended in the direction of X and Y axes in the traditional manufacturing method, so the size of the mesh formed by the fiber node frame only changes in a plane, and when the Teflon is processed, the fiber node is It can be increased, and the increase is a three-dimensional change, so the size of the pores can also be changed in a three-dimensional manner, not limited to plane changes, and the number of pores is also increased and the thickness is thickened.

The specific gravity and porosity of Teflon after stretching are as follows: Specific gravity after extension porosity 1.6÷2＝0.8 50% 1.6÷4＝0.4 75% 1.6÷8＝0.2 87.5% 1.6÷12＝0.13 91.7% 1.6÷16＝0.1 93.75% 1.6÷20＝0.08 95% 1.6÷24＝0.06 95.8% 1.6÷30＝0.053 96.7%

In order to further clarify the substantive features of the invention, the following four points are discussed:

1. When to extend the third axis multidirectionally:

Teflon (PTFE) itself has a true specific gravity of 2.15 and a false specific gravity of about 0.53.

Since the true specific gravity cannot be achieved by ordinary rolling machines, it is necessary to add about 20% of additives such as kerosene during the processing of the extended Teflon (ePTFE), plus its own false specific gravity relationship, mixing Extruded, the specific gravity after rolling is about 1.6, its If the specific gravity is 2.2: porosity = $\left(\frac{1-1.6}{2.2}\right)\×100\%=100-72.73=27.27\%$ If the specific gravity is 2.15: porosity = $(1-\frac{1.6}{2.15})\×100\%=100-74.42=25.58\%$ If the specific gravity is 2.1: porosity = $(1-\frac{1.6}{2.1})\×100\%=100-76.20=23.80\%$

When the substrate is rolled out, its porosity is already about 30%, and it can also have the function of ventilation, but the effect is not very obvious. (It can be tested by the pore size test method (EBP) to measure the size and distribution of the pores).

Theoretically, the base material can be stretched in multiple directions in the third axis, but the effect of pretreatment will be very insignificant if the fibers of the base material are not formed, and the stretching ratio of the base material is 2×2=4 or more to carry out the multi-directional stretching in the third axis The sexual extension effect can be shown.

The elongation ratio of the substrate is in the range of 4-100 by multiplying the X-axis by the Y-axis, which is an ideal processing range.

2. The actual basis for dealing with the multi-directional extension of the third axis. It can be clearly seen from the figure that there are very obvious nodes in the fiber structure of the substrate. The thickness and length of the fibers can be clearly seen at the nodes due to the elongation magnification. There are also the size of the nodes; the third axial multi-directional extension is carried out by using high-pressure positioning hot air, and there are two methods. The first is to use vacuum suction, and set a positioning vacuum suction plate above and below the direction in which the stretched film advances. , Various angles such as 45°, 60° or other angles in the air hole of the suction plate within 90° and beyond.

The second way is to use a groove for positioning the high-pressure wind blowing and blowing air to accept the elongated part of the wind-blown film, within 10 times of the film thickness, to prevent excessive blowing and stretching to cause rupture.

3. After stretching, the shape of the third axial multi-directional film of Teflon (ePTFE) is thickened:

The purpose of extension is to increase the air content between nodes and fibers, as well as the strength of fibers and nodes to increase thickness. After stretching, heat treatment on the surface, and then cooling down to the temperature that the laminating cloth can withstand, an adhesive can be added to the cloth to facilitate lamination. If it is not bonded immediately, use a rapid cooling system to rapidly cool down to keep the thickness in the best state, and when winding, use the center winding method to adjust the tension to the lowest retractable force to prevent curling The thickness of the rear bottom part varies.

4. The relationship between the increase in volume and the decrease in specific gravity of Teflon (ePTFE) after extension:

After stretching, Teflon (ePTFE) is the most characteristic raw material in today's polymer materials. Its molecular weight is as high as tens of millions. Therefore, once the conditions are well controlled during production and processing, the degree of fibrosis should reach one molecule per fiber. The connection is very small, and the connection between fibers is the most ideal finished product.

Therefore, experiments have proved that if the substrate can be extended 10 times, its specific gravity should be 1/10 of the raw material. However, the results of many tests are greater than the proper proportion of the extended multiple. For example, the specific gravity of the base material is 1.5. When it is extended 10 times, it should be 0.15, but the actual specific gravity must be greater than 0.15. This is because the principle of extension is to elongate the fibers between nodes and pull them to a certain length. At least 2 or more nodes are split, and the higher the molecular weight, the more fibers and less nodes the extended Teflon (ePTFE) membrane can be produced, which is the most ideal structure.

The present invention develops in a three-dimensional space, and the experienced users are limited to the multi-directional rolling of the XY axis and the same plane. Viewed with a microscope (refer to the comparison diagram of the present invention and conventional products in Figure 5), it presents a very obvious composition of fibers and nodes. After different temperatures and elongation magnifications, the fibers and nodes will be significantly different. , the extension of large magnification, the original node is split into fibers and smaller nodes again, and such splitting forms a nanometer (abbreviated nm, full name nano milli) (nanometer (nm) is 10 -9 times square unit) fibers, the thickness increases, the overall volume increases, and the porosity also increases, which is quite different from the habitual users.

The conventional user has utilized air blowing or vacuum to do processing, yet its purpose is to want this Teflon membrane to be closely covered on the mould, thereby manufactures the finished product that is identical with the mould's shape, and although the use of the present invention utilizes Vacuum or blowing, but its purpose is to process the base material instead of the finished product, and the present invention aims to split the original nodes into fibers and smaller nodes again, so that the splits form nanometer-scale (abbreviated nm, full-scale) Named nano milli) (nanometer (nm) is 10-9 power unit) fibers, and the habitual users only stop at fixing the shape of Teflon, so the two are completely different.

The description of the present invention and its tables and formulas are all based on ready-made formulas to calculate the detection value of finished products produced by the present invention, so the data in the tables are only the results calculated by the formulas, and the table and formula content are It is the calculated value of the finished product after the implementation of the present invention, and its calculation is also compared with the raw material base.

Finally, the raw materials, composition, components and physical characteristics of the new ePTFE triaxial multi-directional stretched film are described as follows. Multi-directional stretched film, this film is viewed with a microscope, showing a very obvious composition of fibers and nodes. After different temperatures and elongation ratios, the fibers and nodes will be significantly different. Large-magnification extensions are not Extend the existing fiber length, but split the original nodes into fibers and smaller nodes again, and form nanometer scale (abbreviated nm, full name nanomilli) (nanomilli (nm) is 10 -9 power unit) fibers.

In addition, its winding is also the method of making the third axial multidirectional stretching film of Teflon (ePTFE), that is, its winding tension is improper, so that the aforementioned stretching will lose its effect, which is enough to affect the products produced. Therefore, the present invention passes through The multi-channel tension control system achieves this winding purpose, and winding is also one of the manufacturing steps of the third axial multi-directional stretched film of Teflon (ePTFE).

Claims (8)

1. A Teflon third axial multi-directional stretched film is characterized in that the extension of the Teflon base material at a large rate makes the original nodes and the fibers of the nodes elongated and elongated to a certain length , the node splits into multiple smaller nodes with at least two nodes; the increase of fiber nodes adopts a three-dimensional change, and the size of the holes also changes three-dimensionally, the number of holes increases and the thickness also increases to form the third Teflon Axial stretch film. 2. The stretched film of Teflon's third axial multidirectionality according to claim 1 is characterized in that the higher the molecular weight of Teflon, the more stretched film with many fibers and few nodes can be produced. 3. The Teflon third axial multidirectional stretched film according to claim 1, wherein the elongation ratio of the base material is multiplied by the X axis by the Y axis, and is between 4 and 100. The distance is appropriate; the thickness of the stretched film is within 10 times. 4. a preparation method of the stretched film of the third axial multi-directionality of Teflon, it is characterized in that: (1) The Teflon raw material is first heated and pressurized to form a Teflon shaped film; (2) Then the sizing film is delivered to the vacuum adsorption process mold; (3) Positioning vacuum suction plates are set up and down in the forward direction of the Teflon shaped film to be extended; (4) With the up and down suction of the constant temperature vacuum suction plate, the third axis of Teflon can be extended in multiple directions. 5. A preparation method of a teflon third axial multidirectional stretched film, characterized in that: (1) The Teflon raw material is first heated and pressurized to form a Teflon shaped film; (2) Then send the sizing film to the process mold of the constant temperature and high pressure wind blowing mode; (3) Choose a set temperature and high pressure wind blowing equipment around the direction in which the Teflon shaped film to be extended is set, and the blowing direction has a groove; (4) Numerous blowing air and countless grooves produce multiple wind-blown film elongations, reaching its Teflon triaxial multi-directional extension. 6. by the preparation method of the stretched film of the teflon 3rd axial multi-directionality described in claim 4, it is characterized in that the coiling system method is: (1) After extension, surface heat treatment; (2) Cool down to the temperature that the laminated cloth can bear; (3) Add adhesive to the cloth; (4) Carry out lamination and complete the rolling of Teflon after its extension. 7. by the preparation method of the stretched film of the teflon the 3rd axial multi-directionality described in claim 5, it is characterized in that the coiling system method is: (1) After extension, surface heat treatment; (2) Rapid cooling system to rapidly cool down; (3) Use the center coiling method for coiling, and adjust the tension to the lowest retractable force; (4) Complete the roll-up, complete the roll-up of Teflon after its extension. 8. The method for preparing the Teflon third axial multidirectional stretched film according to claim 5, characterized in that the high temperature is 340-380°C and the high pressure is 5-7Kg/cm ² .

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