CN208573895U - A kind of porous membrane and its molding machine - Google Patents

Abstract

The utility model discloses a kind of porous membrane and its molding machines, its thickness >=0.8mm, and there is the continuously distributed recess for running through its surface layer and bottom, the concave bottom has at least one aperture nesting wherein, a kind of its guide layer for being applied to absorbent article, the porous membrane are made of a kind of molding machine of integrated seamless column netting gear.The porous membrane thickness and recess equivalent diameter of the utility model design are larger, in the guide layer for hygienic articles, it both can be by the of short duration storage of body fluid in the valley, body fluid can be penetrated into absorbed layer again by the aperture of bottom, effectively prevent instantaneously reaching absorbent article due to a large amount of body fluid and occur having little time to absorb so as to cause generation the phenomenon that body fluid back leak and side leakage.

Description

A kind of porous membrane and its molding machine

Technical field

The utility model relates to a kind of field of hygiene products, a kind of porous membrane and its molding machine are particularly related to.

Background technique

Since porous membrane has, seepage velocity is fast, the characteristics such as dry and comfortable, so being often applied to absorbent article as face Layer and guide layer use.When porous membrane is used for the guide layer of absorbent article, body fluid reaches porous membrane through surface layer, porous Film can play the role of of short duration storage body fluid, expand infiltrating area.

Application number 201010249819.3 discloses a kind of three dimensional apertured film for guide layer, with continuous surface With the noncontinuous surface for being typically parallel to the continuous surface and placing and being separated with the continuous surface, the continuous surface and not Continuous surface all has a rear large scale aperture, the large scale aperture due to be originated from the surface and from the surface it is outwardly extending Side wall limits, and its size allows to obtain fluid by gravity, and each surface respectively select including small size aperture, having a size of can lead to It crosses capillary action and obtains fluid.But the diameter of the large scale aperture of the three dimensional apertured film is 400nm ~ 1000nm, is opened Pore size is smaller, thickness is lower, and the liquid storage unit of formation is smaller, cannot effectively play the role of of short duration storage body fluid, and It is possible that having obstructed the infiltration rate of body fluid to a certain extent, the performance that absorbent article absorbs body fluid is affected.

Wherein, the mode that the molding of the porous membrane mostly uses vacuum to punch carries out, i.e., passes through the film of Liu Yanhou One forming screens, and porous membrane is formed in such a way that vacuum is inhaled and broken, therefore the thickness of porous membrane depends on forming sieve Thickness.And the forming screen thickness that currently employed plating mode is formed is up to 0.6~0.7mm or so, therefore porous membrane Thickness be commonly 0.3 ~ 0.5mm, thickness is lower, may make body fluid bleed back to absorb surface layer.

In view of this, the designer for above-mentioned porous membrane and its molding machine design on do not attain improve caused by it is all More missings and inconvenience, and deeply conceive, and actively research improvement has a fling at and develops and design the utility model.

Utility model content

The purpose of this utility model is to provide a kind of porous membranes of high thickness applied to absorbent article, effectively prevent Occur having little time to absorb so as to cause generation the phenomenon that body fluid back leak and side leakage since a large amount of body fluid instantaneously reach absorbent article.

In order to achieve the above objectives, the solution of the utility model is:

A kind of porous membrane, thickness >=0.8mm of the porous membrane, have on the porous membrane through its surface layer and The continuously distributed recess of bottom, and the concave bottom has at least one aperture nesting wherein, in the aperture of the aperture Surface area is greater than aperture bottom area, and the recess thickness is at least one times of aperture thickness.

The upper surface equivalent diameter of the recess is 1.1mm ~ 10mm.

The upper surface equivalent diameter of the aperture is 0.2 ~ 3.5mm.

The bottom equivalent diameter of the recess is greater than or equal to the upper surface equivalent diameter of aperture.

The recess is the first recess, and it is the second recess that first concave bottom, which also has a recess, and described second is recessed Falling into bottom has at least one aperture nesting wherein.

Percent opening >=30% of the upper surface of the recess.

Percent opening >=10% of the aperture.

The hole shape of the recess and aperture is round, polygon or irregular shape.

Gap between the adjacent recessed is 0.5mm ~ 5mm.

Gap between the recess has strip or dot bulge.

The height of the protrusion is 0.02mm ~ 0.08mm.

It is a kind of that for manufacturing the molding machine of the porous membrane, the molding machine is the seamless column netting gear of integral type, Three-dimensional thickness >=0.8mm of the netting gear, the netting gear surface have continuously distributed recess, at least one aperture is nested in The concave bottom, the thickness of the recess are at least one times of aperture thickness.

The surface shape of the integrated seamless column netting gear is round or polygon.

The upper surface equivalent diameter of the recess is 1.1mm ~ 10mm.

The upper surface equivalent diameter of the aperture is 0.2 ~ 3.5mm.

The bottom equivalent diameter of the recess is greater than or equal to the upper surface equivalent diameter of aperture.

The recess is the first recess, and it is the second recess that first concave bottom, which also has a recess, and described second is recessed Falling into bottom has at least one aperture nesting wherein.

The recess and the horizontal cross sectional geometry of aperture are round, polygon or irregular shape.

Gap between the adjacent recessed is 0.5mm ~ 5mm.

Gap between the recess has strip or dot bulge.

The height of the protrusion is 0.02mm ~ 0.08mm.

After adopting the above structure, the porous membrane of the utility model, which has, is continuously recessed and is nested in opening for concave bottom Hole, and thickness and recess equivalent diameter it is larger, in the guide layer for hygienic articles, both can by body fluid it is of short duration be stored in it is recessed In falling into, and body fluid can be penetrated into absorbed layer by the aperture of bottom, effectively prevent instantaneously reaching due to a large amount of body fluid Absorbent article occurs having little time absorbing so as to cause generation the phenomenon that body fluid back leak and side leakage, at the same the thickness of the porous membrane compared with Height can also effectively prevent body fluid to bleed back absorbed layer.

The molding machine of the production porous membrane of the utility model, efficiently solves that existing plating screen thickness is relatively thin, opens The problems such as porosity is lower, sieve is easily-deformable and cracky.

Detailed description of the invention

Fig. 1 is the utility model molding machine and its structural schematic diagram using process；

Fig. 2 is the structural schematic diagram of the utility model first embodiment porous membrane；

Fig. 3 is cross-sectional view of the Fig. 2 along the face O-O '；

Fig. 4 is the structural schematic diagram of the utility model first embodiment molding machine

Fig. 5 is the structural schematic diagram of the utility model second embodiment porous membrane；

Fig. 6 is cross-sectional view of the Fig. 5 along the face P-P '；

Fig. 7 is the structural schematic diagram of the utility model second embodiment molding machine；

Fig. 8 is the structural schematic diagram of the utility model 3rd embodiment porous membrane；

Fig. 9 is cross-sectional view of the Fig. 8 along the face Q-Q '；

Figure 10 is the structural schematic diagram of the utility model 3rd embodiment molding machine；

Figure 11 is the structural schematic diagram of the utility model fourth embodiment porous membrane；

Figure 12 is cross-sectional view of the Figure 11 along the face R-R '；

Figure 13 is the structural schematic diagram of the utility model fourth embodiment molding machine；

Figure 14 is the structural schematic diagram of the 5th embodiment porous membrane of the utility model；

Figure 15 is cross-sectional view of the Figure 14 along the face S-S '；

Figure 16 is the structural schematic diagram of the 5th embodiment molding machine of the utility model；

The structural schematic diagram of the absorbent article of Figure 17 the utility model application porous membrane.

Specific embodiment

As shown in Figure 1, being a kind of molding machine 1 for manufacturing the utility model porous membrane and the use of molding machine 1 Process, the molding machine 1 are the seamless column netting gear of integral type, the netting gear solid thickness >=0.8mm, the netting gear side surface With continuously distributed recess 11, and at least one aperture 12 is nested in 11 bottoms of the recess, the thickness of the recess 11 At least one times of 12 thickness of aperture, it is described recess 11 upper surface equivalent diameter be 1.1mm ~ 10mm, the aperture 12 it is upper Surface equivalent diameter is 0.2 ~ 3.5mm, and the bottom equivalent diameter of the recess 11 is worked as more than or equal to the upper surface of aperture 12 Measure diameter.

The specific steps of the utility model porous membrane are manufactured using above-mentioned molding machine are as follows:

Polyolefin blend is passed through into screw extruder 13, and flows out to form casting films 14 through T-die, by molding machine 10 are fixed on the vacuum circular column type support cavity 15 being controlled to a vacuum pump, and supporting on cavity 15 has one in axial direction to prolong The long and narrow suction mouth 16 stretched supports the air inside cavity 15 to be pumped out in vacuum pump operation, when casting films 14 reach When suction mouth 16, the internal and external pressure difference of formation is adsorbed in the casting films with certain temperature 14 only on molding die, And 14 surface of casting films is formed into recess 21 and is broken into aperture 22 in concave bottom suction, to form the porous membrane 2.

Wherein, above-mentioned equivalent diameter described in the text refers to the equal round tube diameter of hydraulic radius, effectively cuts what is always flowed On face, the contact length of fluid and solid wall surface is known as wetted perimeter, is indicated with alphabetical L.The effective sectional area A and wetted perimeter L always flowed it Than being defined as hydraulic radius, indicated with letter r.Equivalent diameter is defined as four times of hydraulic radius, is indicated with D, between each other Reduction formula are as follows: D=4A/L=4R.

The three-dimensional thickness test of netting gear is detected using spiral micrometer.

The test method of the three-dimensional thickness of porous membrane is as follows:

Measuring instrument: the rectangular XTL-200 electron microscope in Shanghai (connection computer), CF-2000MIS image analysis system；

Preparation of samples: one piece of sample is cut along the direction MD with scissors, it is ensured that the aperture at edge is complete, the sample that will be cut It is attached on testing mould；

Testing procedure:

1) sizing calibration: opening 1.5 times of scalable videos, clicks " sizing calibration " icon, standard scale is pulled to correct position It sets, clicks " confirmation ".

2) Image Acquisition: opening CF-2000MIS image analysis system, selects 1.5 times of multiplying power, sample is placed on micro- Under mirror, for testing mould under, sample upward, opens light source, clicks " acquisition image " icon, adjustment focal length to image clearly, really The repetitive unit of 3 to 4 apertures can be seen by protecting on image, then click " freeze frame " icon, carry out picture collection；

3) it measures: clicking " measurement rectilinear geometry parameter " icon, draw a horizontal line in the most bottom surface of sample, then from sample Most top surface to horizontal line draw vertical line, numerical value is the three-dimensional height of porous membrane, and numerical value is accurate to 0.01mm.

In order to which the technical solution of the utility model is explained further, below by specific embodiment come to the utility model into Row elaborates.

Embodiment one:

As shown in Figures 2 and 3, having with a thickness of 0.8mm, the porous membrane 2a for the porous membrane 2a runs through its table The continuously distributed circular recess 21a of layer and bottom, and each concave bottom is nested with a circular aperture 22a, the aperture The open surface area of 22a is greater than aperture bottom area, and one times with a thickness of aperture 22a thickness of the recess 21a is described recessed The upper surface equivalent diameter for falling into 21a is 1.5mm, and the equivalent diameter of the upper surface aperture 22a is 0.5mm, the upper surface recess 21a Percent opening be 35%, the percent opening of aperture 22a is 15%, and the bottom equivalent diameter of the recess 21a is greater than the upper table of aperture 22a Face equivalent diameter, the gap on the porous membrane 2a between adjacent recessed 21a are 2mm.

As shown in figure 4, for a kind of molding machine 1a for manufacturing Fig. 2 and porous membrane a shown in Fig. 3, the molding machine 1a is integral type seamless circular cylindricality netting gear, solid thickness >=0.8mm, the netting gear surface with continuously distributed recess 11a, The bottom recess 11a is nested with an aperture 12a, and 1.2 times with a thickness of aperture 12a thickness of the recess 11a are described recessed The bottom equivalent diameter for falling into 11a is greater than the upper surface equivalent diameter of aperture 12a, and the molding machine 1a manufactures the porous membrane The mode that the mode that 2a is used is punched for vacuum.

The present embodiment is after adopting the above structure since the porous membrane 2a of the high thickness has continuous recess 21a and nesting In the aperture 22a of concave bottom, and the equivalent diameter of porous membrane 2a thickness and the 21a that is recessed are larger, are being used for hygienic articles Guide layer when, can not only be stored in body fluid is of short duration in recess 21a, but also body fluid can be permeated by the aperture 22a of bottom Into absorbed layer, effectively prevent due to occurring having little time to absorb when a large amount of body fluid instantaneously reach absorbent article so as to cause body fluid The generation of back leak and side leakage phenomenon, the gap a1 between the adjacent recessed are greater than 1mm, first layer structure concave have been effectively ensured Fall into will not because being deformed caused by winding, provide porous membrane in the guide layer as hygienic articles on mechanical property needed for machine Energy.

Embodiment two:

As shown in Figures 5 and 6, having with a thickness of 1.5mm, porous membrane 2b for the porous membrane 2b runs through its surface layer And the continuously distributed hexagon recess 21b of bottom, there are four circular aperture 22b, the apertures for the bottom recess 21b nesting The open surface area of 22b is greater than aperture bottom area, and 1.2 times with a thickness of aperture 22b thickness of the recess 21b, institute The upper surface equivalent diameter for stating recess 21b is 2.5mm, and the upper surface equivalent diameter of aperture 22b is 0.8mm, the recess 21b's Percent opening is 58%, and the percent opening of aperture 22b is 20%, and the bottom equivalent diameter of the recess 21b is greater than the upper surface of aperture 22b Equivalent diameter, the gap on the porous membrane 2b between adjacent recessed are 0.8mm.

As shown in fig. 7, for a kind of molding machine 1b for manufacturing Fig. 5 and porous membrane 2b shown in fig. 6, the molding machine 1b is integral type seamless circular cylindricality netting gear, solid thickness >=0.8mm, the netting gear surface with continuously distributed recess 11b, For the bottom recess 11b nesting there are four the 11b that is recessed, 1.2 times with a thickness of recess 11b thickness of the recess 11b are described recessed The bottom equivalent diameter for falling into 11b is greater than the upper surface equivalent diameter of recess 11b, and the molding machine 1b manufactures the porous membrane The mode that the mode that 2b is used is punched for vacuum.

Since aperture 22b nested in porous membrane 2b recess 21b is more in the present embodiment, use has been further speeded up Porous membrane 2b as guide layer hygienic articles in the case where instantaneously being reached due to a large amount of body fluid, body fluid passes through recess The speed that the aperture 22b of the bottom 21b infiltrates into absorbed layer is speeded, and is more effectively avoided after leading to body fluid not in time because of absorption The generation of leakage and side leakage phenomenon.

Embodiment three:

As can be seen from figures 8 and 9, having with a thickness of 1.6mm, porous membrane 2c for the porous membrane 2c runs through its surface layer And the continuously distributed hexagon of bottom is recessed 21c, the bottom recess 21c is nested with a hexagon aperture 22c, described small The open surface area of hole 22c is greater than aperture bottom area, and 1.0 times with a thickness of aperture 22c thickness of the recess 21c, The bottom equivalent diameter of the recess 21c is equal to the upper surface equivalent diameter of aperture 22c, the upper surface equivalent of the recess 21c Diameter is 2.5mm, and aperture 22c upper surface equivalent diameter is 2.0mm, and the percent opening of the recess 21c is 58%, aperture 22c Percent opening be 30%, the gap between the upper adjacent recessed of the porous membrane 2c is 0.8mm.

It as shown in Figure 10, is a kind of molding machine 1c for manufacturing Fig. 8 and porous membrane 2c shown in Fig. 9, the molding dress Setting 1c is integral type seamless circular cylindricality netting gear, and solid thickness >=0.8mm, the netting gear surface has continuously distributed hexagon Be recessed 11c, and the bottom recess 11c is nested with a hexagon aperture 12c, the 11c that is recessed with a thickness of aperture 12c thickness 1.0 times, the bottom equivalent diameter of the recess 11c is equal to the upper surface equivalent diameter of aperture 12c, the molding machine 1c manufacture The mode that the mode that the porous membrane 2c is used is punched for vacuum.

Since the bottom equivalent diameter of hexagon recess 21c is equal to the upper surface hexagon aperture 22c equivalent in the present embodiment Diameter, so recess 21c and aperture 22c forms a big through-hole, therefore when porous membrane 2c is applied to leading for absorbent article When fluid layer, body fluid can be guided to absorbed layer quickly through through-hole, while big through-hole can also keep in more body fluid, effectively mention High porous membrane 2c liquid storage performance.

Example IV:

As shown in FIG. 11 and 12, having with a thickness of 2.0mm, porous membrane 2d for the porous membrane 2d runs through its table The continuously distributed pentagon recess 21d of layer and bottom has the second recess 23d in the bottom recess 21d, and described second is recessed The bottom 23d nesting is fallen into there are three circular aperture 22d, and 2 times with a thickness of aperture 22d thickness of the recess 21d, described second The upper surface equivalent diameter of 1 times with a thickness of aperture 22d thickness of recess 23d, the recess 21d is 3.5mm, and described second is recessed The upper surface equivalent diameter for falling into 23d is 2.5mm, and aperture 22d upper surface equivalent diameter is 1.0mm, and the aperture 22d's opens Hole surface area is greater than aperture bottom area, and the percent opening of the recess 21d is 65%, and the percent opening of aperture 22d is 18%.

It as shown in figure 13, is the molding machine 1d of porous membrane 2d shown in manufacture Figure 11 and Figure 12 a kind of, the molding Device 1d is integral type seamless circular cylindricality netting gear, and solid thickness >=0.8mm, the netting gear surface has five continuously distributed sides Shape recess 11d, the bottom recess 11d have the second recess 13d, and there are three circle is small for the second recess bottom the 13d nesting Hole 12d, the molding machine 1d manufacture the mode that the mode that the porous membrane 2d is used is punched for vacuum.

There is the second recess 23d, the second recess bottom 23d in the recess bottom 21d due to porous membrane 2d in the present embodiment Portion is also nested with aperture 22d, constitutes the porous membrane 2d of three-decker, when porous membrane 2d is used for the water conservancy diversion of absorbent article When layer, body fluid can infiltrate into absorbed layer, and body finally by aperture 22d with stepped diversion to the 21d that is recessed, the second recess 23d Liquid not easily passs through aperture 22d, the second recess 23d and recess 21d and is bled back again to surface layer after being absorbed by the absorption layer, reduce body fluid The amount of bleeding back, improve dry-ness.Three-decker facilitates the holding of porous membrane 2d high thickness simultaneously, is winding and is actually answering In, high three-dimensional thickness can be effectively kept, prevents film pass from collapsing, to lose desired effect.

Embodiment five:

As shown in Figure 14 and Figure 15, having with a thickness of 1.8mm, porous membrane 2e for the porous membrane 2e runs through its table Continuously distributed hexagon recess 21e, the circular aperture 22e there are two nestings in the bottom recess 21e of layer and bottom, institute State aperture 22e open surface area be greater than aperture bottom area, and it is described recess 21e with a thickness of the 1.5 of aperture 22e thickness Times, the upper surface equivalent diameter of the recess 21e is 5mm, and the upper surface equivalent diameter of aperture 22e is 1.5mm, the recess The percent opening of 21e is 45%, and the percent opening of aperture 22e is 20%, and the bottom equivalent diameter of the recess 21e is greater than aperture 22e's Upper surface equivalent diameter, the gap on the porous membrane 2e between adjacent recessed are 3mm, have point strip convex on the gap 23e is played, the protrusion 23e height is 0.06mm.

It as shown in figure 16, is a kind of molding machine 1e for manufacturing Figure 14 and porous membrane 2e shown in figure 15, the molding Device 1e is integral type seamless circular cylindricality netting gear, and solid thickness >=0.8mm, the netting gear surface has six continuously distributed sides Shape is recessed 11e, the bottom recess 11e nesting there are two circular aperture 12e, the 11e that is recessed with a thickness of aperture 12e thickness 1.5 times, there are a point strip projected parts 13, raised 13 height is 0.06mm, described on the gap between adjacent recessed 11e Molding machine 1e manufactures the mode that the mode that the porous membrane 2e is used is punched for vacuum.

Due to having point strip projected parts 23 on the gap between adjacent recessed 21e in the present embodiment, disappear to a certain extent In addition to the plastic sense of plastic film, reduce the glossiness of plastic film, give cotton sense, is used for disposable sanitary product In be more easier to be esthetically acceptable to the consumers, while protrusion 23 also increases the contact area of plastic film and body fluid, for absorbing When the guide layer of product, it is more conducive to the infiltration and diffusion of body fluid.

As shown in figure 17, the application of porous membrane 2 described in the utility model, a kind of absorbent article 3 are disclosed comprising Superficial layer 31, guide layer 32, absorbed layer 33 and bottom membrane 34, wherein guide layer 32 is the porous membrane 2, the absorbent article 3 It can be sanitary napkin, panty liner, baby paper diaper, baby diaper, adult diaper etc..

In practical applications, body fluid reaches 2 guide layer 32 of porous membrane through superficial layer 31, due to 2 water conservancy diversion of porous membrane Layer 32 has continuous recess 21 and is nested in the aperture 22 of concave bottom, and thickness compared with and recess 21 equivalent diameter it is larger, So both can by body fluid it is of short duration be stored in recess 21 in, also effectively prevent instantaneously reaching absorbent article 3 due to a large amount of body fluid When there is having little time to absorb generation so as to cause body fluid back leak and side leakage phenomenon.The thickness of 2 guide layer 32 of porous membrane simultaneously It is higher to prevent body fluid from again returning to superficial layer 31.

The product form and style of above-described embodiment and schema and non-limiting the utility model, any technical field The appropriate changes or modifications that those of ordinary skill does it all should be regarded as the patent category for not departing from the utility model.

Claims (21)

1. a kind of porous membrane, it is characterised in that: thickness >=0.8mm of the porous membrane has on the porous membrane and passes through The continuously distributed recess of its surface layer and bottom is worn, and the concave bottom has at least one aperture nesting wherein, it is described small The aperture upper surface area in hole is greater than aperture bottom area, and the recess thickness is at least one times of aperture thickness.

2. a kind of porous membrane as described in claim 1, it is characterised in that: the upper surface equivalent diameter of the recess is 1.1mm~10mm。

3. a kind of porous membrane as described in claim 1, it is characterised in that: the upper surface equivalent diameter of the aperture is 0.2mm~3.5mm。

4. a kind of porous membrane as described in claim 1, it is characterised in that: percent opening >=30% of the upper surface of the recess.

5. a kind of porous membrane as described in claim 1, it is characterised in that: percent opening >=10% of the aperture.

6. a kind of porous membrane as described in claim 1, it is characterised in that: the gap between the adjacent recessed be 0.5mm ~ 5mm。

7. a kind of porous membrane as described in claim 1, it is characterised in that: the bottom equivalent diameter of the recess is greater than or waits In the upper surface equivalent diameter of aperture.

8. a kind of porous membrane as described in claim 1, it is characterised in that: the hole shape of the recess and aperture is circle Or polygon.

9. a kind of porous membrane as described in claim 1, it is characterised in that: the recess is the first recess, and described first is recessed It is the second recess that sunken bottom, which also has a recess, and second concave bottom has at least one aperture nesting wherein.

10. a kind of porous membrane as described in claim 1 or 9, it is characterised in that: the gap between the recess has strip Or dot bulge.

11. a kind of porous membrane as claimed in claim 10, it is characterised in that: the height of the protrusion for 0.02mm ~ 0.08mm。

12. a kind of molding machine of porous membrane, it is characterised in that: the molding machine is the seamless column netting gear of integral type, institute Three-dimensional thickness >=0.8mm of netting gear is stated, the netting gear surface has continuously distributed recess, at least one aperture is nested in institute Concave bottom is stated, the thickness of the recess is at least one times of aperture thickness.

13. a kind of molding machine of porous membrane as claimed in claim 12, it is characterised in that: work as the upper surface of the recess Amount diameter is 1.1mm ~ 10mm.

14. a kind of molding machine of porous membrane as claimed in claim 12, it is characterised in that: work as the upper surface of the aperture Amount diameter is 0.2 ~ 3.5mm.

15. a kind of molding machine of porous membrane as claimed in claim 12, it is characterised in that: between the adjacent recessed Gap is 0.5mm ~ 5mm.

16. a kind of molding machine of porous membrane as claimed in claim 12, it is characterised in that: the bottom equivalent of the recess Diameter is greater than or equal to the upper surface equivalent diameter of aperture.

17. a kind of molding machine of porous membrane as claimed in claim 12, it is characterised in that: the integrated seamless column The bottom shape of netting gear is round or polygon.

18. a kind of molding machine of porous membrane as claimed in claim 12, it is characterised in that: the water of the recess and aperture Plane section shape is round or polygon.

19. a kind of molding machine of porous membrane as claimed in claim 12, it is characterised in that: the recess is recessed for first It falls into, it is the second recess that first concave bottom, which also has a recess, and second concave bottom has at least one aperture embedding Set is wherein.

20. a kind of molding machine of porous membrane as described in claim 12 or 19, it is characterised in that: between the recess Gap has strip or dot bulge.

21. a kind of molding machine of porous membrane as claimed in claim 20, it is characterised in that: the height of the protrusion is 0.02mm~0.08mm。