JPH01154727A - Manufacture of germ-and dust-free film - Google Patents

Abstract

PURPOSE:To make it possible to remove foreign matters entering from the outside and fine particles developing in a bubble by a method wherein a compact gas circulating and circulating gas purifying mechanism, which is realized by arranging a fan and a filter in the bubble so as to suck the gas in the bubble with the fan in order to pass it through the filter and blow it in the bubble for circulation, is added to the inflation method. CONSTITUTION:A bubble 7 is formed by extruding resin from an annular die lip 5 and folded by guide plate 8 and wound up to a winder 10. At the same time, a fan 15 is driven in order to circulate the gas in the bubble. In this case, since molten resin has high temperature, the interior of the bubble 7 becomes germ-free condition. Further, fine particles come from molten resin at the lower part of the bubble 7 are born by the gas circulated with a fan 15 and passed through gas passages 11 so as to be separated with a filter 16. As a result, since only the gas is sent back into the bubble, the interior of the bubble 7 is kept at germand dust-free conditions. By the way, at starting, the outside air is introduced through the flow passages 11 in the bubble. After the interior of the bubble stabilizes, the fan 15 is started.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is applicable to packaging of sterilized medical instruments, high-precision mechanical parts that are required to be dust-free, and high-density electrical and electronic parts. The present invention relates to a method for producing a sterile and dust-free film suitable for

(Prior technology) Conventionally, in the field of aseptic packaging, when using inflation molding, a filtered clean gas is introduced into the tube to keep the tube sterile and free of dust, and dust particles are introduced into the tube from the outside. A method for manufacturing packaging materials that prevents bacteria from entering is known (Japanese Patent Application No. 58-206884). Furthermore, in industrial applications, various attempts have been made to maintain a clean atmosphere in which films are molded to reduce dust and the like that adhere to the films. Furthermore, due to the problem of film formability, when forming the film by the inflation method, a bubble stabilizer that circulates the gas inside the bubble (Japanese Patent Publication No. 55-12367) and a method that adjusts the circulation air volume (Japanese Patent Application Laid-Open No. 59-123624) Publications), bubble cooling devices (Japanese Unexamined Patent Publication No. 154825/1983), etc. have been announced.

[Problem that the invention seeks to solve]

However, the above conventional methods are aimed at preventing foreign matter from entering the bubble or dust from adhering to the outer surface, and improving the formability of the bubble. Therefore, no consideration is given to fine particles and volatile matter generated within the bubble during molding. This is because there is no established method for evaluating the cleanliness of films, and generally only the intrusion of foreign matter from the outside is viewed as a problem.

In the present invention, polyA reflex resin was used and a well-known inflation method was used to perform blow molding by blowing clean gas passed through a high-performance filter into a bubble.

In this case, the resin humidity is approximately 150° C., resulting in a sterile state. However, for example, M F R: '3.53/10
After molding at 150°C for 40 minutes using low density polyethylene (LDPE) with density: 0.923SF/CT11', the concentration of fine particles inside the bubble was measured with an airborne particle counter, and the diameter was 0.5 μm. There were 103 to 10' particles/ft3. Furthermore, we investigated the cause and found that resin particles were separated from the molten resin during molding. In normal molding,
Molding is performed with the inside of the bubble in contact with the atmosphere of the fine particles Qa. Furthermore, it was also found that the fine particle concentration within the bubble was highly dependent on the molding temperature and less dependent on the molding time.

The reason for this is thought to be that after a certain period of time has elapsed after the start of molding, the fine particles within the bubble adhere to the film and are wound up, so that the fine particles within the bubble reach an equilibrium state.

The present invention has been made based on the above findings, and by adding a compact gas circulation and circulating gas cleaning mechanism to the normal inflation method or coextrusion inflation method, it is possible to eliminate not only foreign substances entering from the outside but also a compact gas circulation and circulating gas cleaning mechanism. , even removes fine particles generated within the bubble, allowing it to be used for pharmaceuticals, medical equipment,
Suitable for packaging precision mechanical parts, electrical, electronic parts, etc. The inner surface is sterile and dust-free single layer or laminated noilum, or these are subjected to surface treatment and V4 layer to impart the desired characteristics. The purpose is to provide a method for producing sterile and dust-free films.

[Failure to solve the problem]

The present invention has been made to achieve the above object, and its gist is that when manufacturing a film by the inflation method, a fan and a filter are provided inside the bubble, the gas inside the bubble is sucked by the fan, and the gas inside the bubble is sucked through the filter. The first invention is the @A manufacturing method of sterile and dust-free film that is blown and circulated inside the bubble.When manufacturing the film by the inflation method, a fan and a filter are provided inside the bubble, and the gas inside the bubble is sucked by the fan and the filter The second invention is a method for producing a sterile and dust-free film, in which the outer surface of a film formed by blowing and circulating it into a bubble is subjected to surface treatment or a VI layer.
l! A third invention, which is a method for producing a sterile and dust-free film, in which a fan and a filter are provided in a bubble, gas in the bubble is sucked by the fan, and the gas is blown out and circulated into the bubble through the filter, and By the extrusion inflation method (when manufacturing a 9A laminated film, a fan and a filter are installed inside the bubble, the gas inside the bubble is sucked by the fan, and the gas is blown out and circulated inside the bubble through a noil cooler. The fourth invention is a method for producing a sterile and dust-free film by subjecting it to surface treatment or further lamination.

[For production]

The device used in the method of the present invention has a fan that circulates gas and a filter that cleans the circulating gas installed inside the bubble, so it is compact and particles generated inside the bubble are absorbed into the gas sucked in by the fan. During the IW process, the gas is separated from the gas by a filter, and the inside of the bubble is kept clean.

In addition, if the film is cylindrical and both ends are heat-sealed,
By applying surface treatment and V4 layer to the outer surface of the film, a film with excellent properties and a sterile inner surface can be obtained without the invasion of bacteria or fine powder.

(Example) Fig. 1 shows an example of an apparatus for carrying out the method of the present invention. In Fig. 1, reference numeral 1 indicates a resin extrusion system.

The resin melt-kneaded and extruded by the extruder 1 passes through the die 1 inlet 2, enters the die 3, passes through the molten resin passage 4 provided in the die 3, and passes through the annular die slip 5.
It is extruded into a cylindrical shape. The resin extruded into a cylindrical shape is cooled from the outside by the air blown out from the air ring 6, crystallizes, forms bubbles 7, bends upward, is folded flat by the guide plate 8, and is taken up at the take-up station. : taken up by the winder 10 and taken up by the winder 10. At this time, the molten resin extruded from the annular die slip 5 cools and solidifies into a film while dissipating fine particles, but as the resin temperature decreases, the generation of fine particles gradually decreases and eventually ceases to be generated.

In addition to the molten resin passage 4 and the annular die slip 5, the die 3 is provided with a gas passage 11 that opens to a surface near the inner circumference of the annular die slip 5 of the die 3 and to a central surface. In addition, on the center upper surface of the die 3, there is a blowout pipe 1 at the top.
The base of the gas guide 13 to which the gas guide 2 is attached surrounds and is fixed to the central opening of the gas passage 11. A guide plate 14 is attached to the outer periphery of the gas guide 13 and the lower outer periphery of the blow-off pipe 12 to rectify the flow of gas. Inside the gas guide 13, there is a fan 1 that sucks the gas inside the bubble from the central opening through the gas passage 11.
5 is provided. The gas sucked by this fan 15 passes through a filter 16 and is released and circulated into the bubble 7 from the blow-off pipe 12.

To produce a sterile, dust-free film using the apparatus described in , F, first, resin is extruded from an annular die slip 5 to form a bubble 7, folded by a guide plate 8, and taken up by a pull-out roll 9 and placed in a winder. 10. At the same time, the fan 15 is driven to circulate the gas inside the bubble. In this case, since the temperature of the molten resin is high, the inside of the bubble 7 is in a sterile state, and the fine particles generated from the molten resin at the bottom of the bubble 7 are carried by the gas circulated by the fan 15 and are carried through the gas passage 11. As a result, fine particles are separated by the filter 16 and only gas is returned to the bubble, so the inside of the bubble 7 is kept sterile and dust-free. In addition, at the time of starting, external air is introduced through the flow path 11, and after stabilization, the fan 15 is started.

The apparatus shown in FIG. 1 is the most effective method for producing a sterile and dust-free film, but as shown in FIG. At the same time, if the filter 16 is provided below the fan 15 and the gas inside the bubble 7 is reversed so that it flows from bottom to top, the effect of removing particulates will be reduced to some extent, but the formability of the film will be improved. In this case, the shape of the gas guide 13 that houses the fan 15 and filter 16, the shape of the gas passage 1
By adjusting the shape of the injection port into the bubble 7 in No. 1 to match the characteristics of the resin used, both moldability and dust-free property can be improved.

The above-mentioned sterile and dust-free film is a long piece of cylindrical bubble that is folded and wound up in a winder.If both ends of the film are heat-sealed, the interior will remain sterile and dust-free, and the surface will be treated. Lamination can be applied to impart individual properties.

Examples of the surface treatment include vacuum evaporation treatment, sputtering treatment, and four-person coating.

Vacuum deposition treatment and sputtering treatment are performed by known methods.
A metal film is formed on the outer surface of the film. At that time, surface 3? P
AI Zrl to provide electrical function.

Cu, sn, AQ, Cr, N1-Cr, ITO (indium, oxide of 8), Pd, etc. are used for capacitors, flexible printed circuit boards, various electrodes, antistatic,
It has applications such as transparent conductive films. For imparting electromagnetic wave shielding function, Δj, Cu.

Cr and N1-Cr are used. AJ, Cr, N1-Cr, and Cu are used to impart optical properties, and have applications such as decoration, stamping foil, and packaging materials. Aj, AQ for imparting heat shielding function.

ITO and Ti are used for solar control films, insulation packaging materials, building materials, etc. Gaspari V AJ is used to impart functional properties and is used for packaging foods, electrical and electronic parts, and precision mechanical parts.

Co, Go-Ni, Go-Cr are used to impart magnetic properties.
It has applications such as magnetic tape and recording media.

In addition, various types of resin and chemical coatings are used as coating removal methods.

For example, resistance! A: To impart scratch resistance, after coating with melamine, urethane, or silane paint,
A method of increasing crosslinking density and forming a cured film through a thermosetting reaction, by irradiating monomers and oligomers such as multisensitized acrylate with electron beams, or by adding a photosensitizer and then irradiating ultraviolet rays to initiate the crosslinking reaction. Methods of initiating and forming cured films are known. By these methods, the FQ resistance of the surface
In addition to improving the JJ property, the inner surface is made sterile and non-sterile, making it possible to apply it to optical materials such as plastic films and electrical parts. To impart a conductive function, a conductive paint is applied to the outer surface, and conductive +/I fillers include metal powder, metal oxide powder, carbon powder, and carbon IIM.
Examples include metal-plated short fibers and fine particles.

Binders used in this case include epoxy resins, acrylic resins, phenolic resins, alkyd resins, urethane resins, and rubber. These treatments lower the surface electrical resistance, prevent problems caused by dust adhesion due to charging, and static electricity problems, and provide electromagnetic shielding and transparent f
It can be a f1lG film. It also has applications in semiconductor packaging materials, transparent conductive films, electromagnetic wave shielding precision parts, and optical property films.

Furthermore, although films can be laminated by dry lamination, the functions of water vapor permeability, heat insulation, and light blocking properties can be imparted by selecting the type of film to be laminated.

Thus, the sterile,
The dust-free film is sterile on the inside, NO! Since the outer surface can be freely subjected to surface treatment and lamination without any damage, it is possible to produce sterile and dust-free films with characteristics that meet each purpose.

Although the above explanation is based on a single-layer film produced by the inflation method, the coextrusion inflation method yields a laminate film whose interior is sterile and dust-free. This laminated film can easily maintain its respective characteristics by selecting the films to be laminated. Naturally, it is also possible to keep the inner surface sterile and dust-free by surface treatment similar to that of a single-layer film or by laminating the vI layer, thereby enhancing the respective characteristics.

[Example 1] A single-layer sterile and dust-free film was produced using the 5A machine shown in FIG.

The resin used was low-density polyethylene (Shorex L130 manufactured by Showa Denf Co., Ltd.) with an MFR of 3.5 g/Io and a density of 0.9239/d, and the extruder used had a screw diameter of 40 mm. L/D: 26, rotation speed 66 rflll, annular die rib diameter: 50 mm
Extrusion, blow-out ratio (BtJR):
2.3, take-up speed E [: 9.7 m/sec
A cylindrical film with a width of 180 m when a film with a thickness of 50 μγ was folded with a guide plate was obtained. In addition, the filter for air purification is 0.3μ of dioquidyl phthalate.
An ultra-high performance filter with a collection rate of 99.97% using myL standard particles was used.

The resin was extruded at 150° C.), clean air that had passed through a filter was blown into the bubble, the air was discharged, and the air was blown through the filter into the bubble again for circulation. After running for 40 minutes, the extruder and take-up roll were stopped at the same time, the gas inside the bubble was sucked out, and measured with a light scattering airborne particle counter (Rion Co., Ltd. KC-01). Number of particles is 100/ft3
It was below.

In addition, after injecting ultrapure water with a specific resistance of 18 MΩ-cm that had been filtered through a 0.2 μm filter into the produced duplex film, a dimple bag with both ends heat-sealed was placed in a shaker (manufactured by Iwaki Glass Co., Ltd.). -8 type) with 40 #1 IIX
4.17 fL+! The inner surface was cleaned for 1 minute with horizontal vibration.

Next, the particles in the cleaning solution were measured using a light-blocking type submerged particle counter (High 7T, manufactured by Leuco Corporation, 4100).

As a result, it was confirmed that the fine particles having a diameter of 2 μm rL or more had a film inner area conversion of O11 cells/cI11 or less.

[Comparative Example 1] The number of particles was measured in the same manner as in Example 1, except that clean air was blown in to form a bubble, and a film was formed without evacuation. As a result, when measured using a light scattering airborne particle counter, 103 particles of 0.5μIrL or more were detected.
The number of particles of 2 μm or more was 1 when measured using a light blocking liquid submerged particle counter, which was 1.2 particles/ci when converted to the inner area of the film.

[Example 2] Both ends were sealed, packaged, and placed in a clean room (
Real jM 14111 stored in class 1000)
A sterile, dust-free film was taken out, and a conductive paint was applied to the outer surface by gravure coating. Conductive paint is Sn
Using O2, acrylic resin as a binder, film running speed 40TrL/nin, drying temperature 90°C]-
I did it. As a result, the surface resistance value was 106Ω.

The cleanliness of the inner surface of this surface-treated film was measured using the same method as in Example 1, in which the cleanliness was washed with ultrapure water and measured using a submerged particle counter.
The number of fine particles above was 0.11 particles/ctd.

[Example 3] MFR: 2. Og/10 min, density: 0.912
g/c+/.

Thickness: 20 μm linear low-density polyethylene film, thickness: 15 μm ethylene film (Soarnol DJ manufactured by Japan Synthetic Rubber Industry Co., Ltd.).

(429 mol% ethylene content) was used as a urethane adhesive (Art Coat main agent ΔD-300A manufactured by Toyo Morton Co., Ltd.).
Curing agent AD-300B, solvent BTS-500 100
: 100 : 116 ratio) in a laminator (Okazaki = [Gyo Co., Ltd. ¥JTDL-500
) Use shite adhesive application m: 4.1g/rd
, Lamination pressure: 5. OR3/cm, heating O-
Le onmaro: 65℃, drying temperature: 90-110℃, speed = 2
Dry lamination was performed under the condition of 0TrL/1n.

This was dry-laminated in the same manner as before, with the Soarnol DT side inside, on the opposite side of the sterile, dust-free film that was heat-sealed at both ends used in Example 2, and the other side was also dry-laminated. Laminated and 50μm/
15μm (barrier film) 720μm lI￥1
A layered film was created. When the inner surface cleanliness of this film was measured by the same method as in Example 1 in which ultrapure water was injected and cleaned, the number of particles of 2 μm or more was 0.12 particles/ci.

[Example 4] Various laminated films were made using the coextrusion inflation method, most of which were subjected to surface treatment, and the cleanliness of the inner surface was measured to be 0.1 to 0.12 cases/ci.

〔Effect of the invention〕

As described above, the method of the present invention has a compact device, and can easily produce a single-layer film or a laminated film whose inner surface is sterile and dust-free, and furthermore, these films are sterile and dust-free.
Since surface treatment and lamination can be performed without impairing the dust-free state, a sterile and dust-free film with characteristics suitable for each purpose can be obtained. Therefore, medical equipment,
It is a sterile and dust-free film with excellent properties that can be used suitably for packaging precision mechanical parts, electronic and electrical parts, etc., and is fully compatible with future advances in surface cleanliness evaluation technology. It is expected to have a wide range of applications.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an example of an apparatus for implementing the present invention, and FIG. 2 is a diagram showing an example of the apparatus. 1...Extruder, 2...Joint, 3...Dice, 4...
... Molten resin passage, 5... Annular die slip,
6...Air ring, 7...Bubble,
8... Guide root, 9... Take-up roll, 10... Winder, 11...
...Gas passage, 12...Blowout pipe,
12'... Suction pipe, 13... Gas guide, 14... Guide plate, 15.
...Fan 16...Filter.

Claims (4)

[Claims] (1) When producing a film by the inflation method, a fan and a filter are provided inside the bubble, and the gas inside the bubble is sucked by the fan and blown out and circulated inside the bubble through the filter, which is sterile and dust-free. Film manufacturing method. (2) When manufacturing a film by the inflation method, a fan and a filter are installed inside the bubble, and the gas inside the bubble is sucked by the fan, and the gas is blown out and circulated inside the bubble through the filter to form the outer surface of the film. A method for producing a sterile, dust-free film characterized by subjecting it to surface treatment or lamination. (3) When producing a laminated film by the coextrusion inflation method, a sterile method characterized in that a fan and a filter are provided inside the bubble, and the gas inside the bubble is sucked by the fan and blown out and circulated inside the bubble through the filter. , a method for producing dust-free films. (4) When manufacturing a laminated film by the coextrusion inflation method, a fan and a filter are provided inside the bubble, and the gas inside the bubble is sucked by the fan and then blown out and circulated inside the bubble through the filter to form a laminated film. A method for producing a sterile and dust-free film, characterized by subjecting the outer surface of the film to surface treatment or further lamination.