JP6867910B2 - Resin film regeneration method and resin film manufacturing method - Google Patents

Description

The present invention relates to a method for regenerating a resin film and a method for producing a resin film, which obtains a regenerated molded material by using a removed ear piece removed as a removal target during the production of the resin film.

Conventionally, when a resin film 1 for a diaphragm of a speaker of a portable device is manufactured using a crystalline resin of a thermoplastic resin, for example, a polyetheretherketone (PEEK) resin representing a super engineering plastic, FIG. 3 shows. As partially shown, pelleted polyetheretherketone resin is put into an extrusion molding machine and melt-kneaded, and a strip-shaped thin resin film 1 is continuously extruded from the die of this extrusion molding machine to cool rolls. The resin film 1 is cooled by the cooling roll, and then the resin film 1 having a predetermined length is wound around the winder.

At this time, since the thickness of both sides of the resin film 1 becomes non-uniform, the quality of the resin film 1 may be adversely affected as it is. Therefore, both side portions of the cooled resin film 1 are cut and removed as the removal ear pieces 2 to be removed (see FIG. 5).

By the way, although polyetheretherketone resin is extremely excellent in heat resistance and chemical resistance, it is a very expensive crystalline resin. Therefore, the removed earpiece 2 is removed as it is during the production of the resin film 1, and the removed earpiece is removed. Disposing of 2 as dust is problematic from the viewpoint of cost reduction and reuse. Therefore, conventionally, a regenerated pellet is produced by collecting the removed ear piece 2 removed during the production of the resin film 1 and melting it with a large kneader or a molding machine, and the resin film 1 is produced by the regenerated pellet. A method of manufacturing has been proposed and implemented (see, for example, Patent Documents 1 and 2).

However, in the case of this method, although the recycled pellets can be obtained, there is a new problem that the manufacturing process of the recycled pellets becomes complicated and complicated, and the cost increases. In view of this point, conventionally, a plurality of removed ear pieces 2 cut and removed during the production of the resin film 1 are twisted to form a string material, and this string material is stretched to form a compressed string material, and then , A method of cutting this compressed string material to a predetermined length to obtain recycled pellets has been proposed (see Patent Documents 3 and 4).

Japanese Unexamined Patent Publication No. 2012-081605 Japanese Unexamined Patent Publication No. 2011-20413 Japanese Unexamined Patent Publication No. 2006-021519 Japanese Unexamined Patent Publication No. 2013-091187

However, in the case of the method of obtaining the regenerated pellet by cutting the compression cord material to a predetermined length, although the regenerated pellet can be obtained relatively easily, it is twisted because the plurality of removed ear pieces 2 are simply twisted together. Air may be present between the plurality of removed ear pieces 2 at the time of alignment, and the recycled pellets may not be properly charged into the extrusion molding machine. In addition, since the recycled pellets contain air and have a light bulk specific gravity, even if the recycled pellets are put into the extrusion molding machine, the recycled pellets float inside the extrusion molding machine, and as a result, the timing of resin melting shifts. A new major problem will arise that the production of the resin film 1 will be seriously hindered.

The present invention has been made in view of the above, and it is possible to appropriately put the regenerated molding material into a molding machine or the like by suppressing the intervention of air in the ear pieces, and the regenerated molding material floats on the molding machine or the like to form a resin. It is an object of the present invention to provide a method for regenerating a resin film and a method for producing a resin film, which can reduce the timing of melting.

In the present invention, in order to solve the above problems, a method for regenerating a resin film, which obtains a regenerated molded material by using a removed ear piece removed from a crystalline resin film.
Approximately band-shaped removal removed from the side of a continuous resin film with a thickness of 1 μm or more and less than 20 μm A plurality of ear pieces are twisted to spot heat the vicinity of the twisting start portion, and the temperature at the time of this heating. It is characterized in that a string ear piece is formed by setting the temperature in the range of the glass transition point or more and less than the melting point, and the string ear piece is cut to a predetermined length to produce a regenerated molded material.

The crystalline resin film can be a resin film made of engineering plastic.
Further, the crystalline resin film can be a resin film made of polyetheretherketone resin or polyethylene terephthalate resin.
In addition, the removed ear piece can be stretched and twisted while applying tension.

Further, in order to solve the above problems in the present invention, the regenerated molding material obtained by the resin film regeneration method according to claim 1 or 2 is put into a molding machine, and the resin film is extruded from the die of the molding machine. It is characterized in that the resin film is sandwiched between a cooling roll and a pressure welding roll to be cooled, the side portion of the cooled resin film is removed, and then the resin film is wound on a winder.

Here, the side portion of the resin film in the claims includes one side portion, the other side portion, and both side portions. Also, the term twisting of the removed earpiece includes at least twisting, twisting, twisting, twisting and knitting. When there are a plurality of removed ear pieces, after twisting each removed ear piece, the plurality of removed ear pieces may be twisted in the opposite direction, or the plurality of removed ear pieces may be twisted together. .. Moreover, you may knit while entwining a plurality of removal ear pieces.

The heating temperature of the removed ear piece is in the range of the glass transition point or more and less than the melting point of the crystalline resin of the twisted removed ear piece. The vicinity of the twisting start portion of the removed ear piece includes the twisting start portion and its vicinity. Further, the molding machine includes at least various extrusion molding machines, melt extrusion molding machines and the like. When the regenerated molding material is charged into the molding machine, a new molding material containing a crystalline resin may be charged together with the molding machine.

According to the present invention, when a regenerated molded material is obtained by using a removed ear piece removed from a crystalline resin film, a substantially band-shaped removed ear piece removed from the side portion of the resin film is prepared. A string ear piece is formed by twisting the removed ear piece and heating the twisting start portion and its vicinity to contract the removed ear piece. After forming the string ear piece, if the string ear piece is divided into a predetermined length, a remolded material for molding can be obtained.

According to the present invention, there is an effect that air can be suppressed from intervening in the ear piece and the regenerated molding material can be appropriately charged into a molding machine or the like. Further, by increasing the bulk specific gravity of the remolded material, there is an effect that it is possible to reduce the fact that the remolded material floats in a molding machine or the like and the timing of resin melting shifts. Further, since the removed ear pieces removed from the crystalline resin film rather than the amorphous one are targeted, the temperature control during heating becomes easy. Further, since the thickness of the resin film is less than 20 μm, a regenerated molded material can be obtained by using a removed ear piece that is difficult to crush. Further, since a plurality of removed ear pieces are twisted and heated, the bulk specific gravity of the regenerated molding material can be increased heavily and can be appropriately put into a kneading machine, a molding machine or the like. Further, since the vicinity of the twisting start portion of the removed ear piece is spot-heated and both sides of the removed ear piece at the beginning of twisting are point-heated, the removed ear piece can be rapidly contracted. Further, it is possible to release the air to the outside from the vicinity of the twisted portion where the air easily intervenes, and prevent the air from intervening in the string ear piece.

According to the invention of claim 2 , since the removed ear piece is stretched and twisted while applying tension, the width of the string ear piece can be made substantially constant, or the bulk specific gravity of the regenerated molded material can be increased. It will be possible.

According to the invention of claim 3, it is possible to inexpensively produce a crystalline resin film by effectively utilizing the removed ear pieces that are disposed of as dust. Further, since the resin film can be produced by adopting the melt extrusion molding method, the thickness accuracy, productivity, and handleability of the resin film can be improved, and the equipment can be simplified.

A state in which a plurality of removed ear pieces are twisted in the embodiment of the method for regenerating the resin film according to the present invention and the twisting start portion of the plurality of removed ear pieces is spot-heated to form a string ear piece is schematically shown. It is explanatory drawing. It is explanatory drawing which shows typically the state which cuts the string ear piece to a predetermined length by the cutter in embodiment of the method of regenerating the resin film which concerns on this invention. It is an overall explanatory view which shows typically the embodiment of the manufacturing method of the resin film which concerns on this invention. A state in which a plurality of removed ear pieces are twisted in the second embodiment of the method for regenerating a resin film according to the present invention, and the twisting start portion of the plurality of removed ear pieces is spot-heated to form a string ear piece. It is explanatory drawing which shows. It is a plane explanatory view which shows the extrusion-molded resin film.

Hereinafter, a preferred embodiment of the present invention will be described with reference to the drawings. As shown in FIGS. 1, 2, and 5, the method for regenerating the resin film in the present embodiment is on the side of the crystalline resin film 1. A plurality of the removed ear pieces 2 removed from the portion are twisted and heated, and the temperature at the time of heating is set in the range of the glass transition point of the crystalline resin or more and less than the melting point, so that the elongated string-shaped string ear pieces 4 Is formed, and the string ear piece 4 is cut to a predetermined length to obtain a regenerated molding material 7 for manufacturing the resin film 1.

The crystalline resin film 1 is a polyether ether ketone (PEEK) resin, a polyphenylene sulfide (PPS) resin, a polybutylene terephthalate (PBT) resin, a polyamide (PA) resin, and a polyethylene terephthalate (PET), which are at least excellent in strength and rigidity. It consists of a continuous long thin film made of resin, polypropylene (PP) resin, polyacetal (POM) resin, polyethylene (PE) resin, aromatic polyimide (PI) resin, and liquid crystal polymer (LCP).

The thickness of the resin film 1 is preferably 1 μm or more and less than 20 μm, preferably 1 μm or more and less than 15 μm, more preferably 1 μm or more and less than 12 μm, and further preferably 1 μm or more and less than 10 μm. This is because when the thickness of the resin film 1 exceeds 20 μm, the removed ear pieces 2 can be crushed to easily obtain recycled pellets. Therefore, a plurality of removed ear pieces 2 are twisted and heated. This is because there is little need to obtain the recycled molding material 7.

The crystalline resin has a large shrinkage rate, high rigidity and hardness, and has a specific melting point (Tm) unlike amorphous resins such as acrylic resin and polycarbonate resin. Temperature control during formation is really easy.

The plurality of removed ear pieces 2 are formed by cutting and removing both side portions of the resin film 1 into elongated strips (also substantially tape-shaped) as objects to be removed during the production of the resin film 1. The plurality of removed ear pieces 2 do not particularly ask for differences in width and length. The number of the removed ear pieces 2 is not particularly limited, but from the viewpoint of increasing the bulk specific gravity of the recycled molding material 7 to be heavy and convenient for handling, 2 or more and 6 or less, preferably 2 pieces. 5 or more, more preferably 2 or more and 4 or less. The width of each removed ear piece 2 is not particularly limited, but is, for example, 10 mm or more and 100 mm or less.

In the above, when the regenerated molded material 7 for manufacturing the resin film 1 is obtained by using the removed ear piece 2 removed from the resin film 1, first, the strip-shaped thin strips removed from both sides of the resin film 1 are thin. The removed ear pieces 2 are collected and a plurality of pieces are prepared, and the plurality of elongated removed ear pieces 2 are entwined and strongly twisted while being fed and supplied at a constant speed from the upper upstream to the lower downstream, and the plurality of removed ears are twisted strongly. By heating the twisting start portion 3 where the pieces 2 have begun to overlap with hot air jet and rapidly contracting the plurality of removed ear pieces 2, a plurality of removed ear pieces 2 are closely attached to each other, and a long and narrow string ear piece 4 (See FIG. 1).

These operations may be performed manually, but they can also be performed automatically using a dedicated device. In the case of automation, for example, the removal ear pieces 2 are fed out from a plurality of feeding rollers, and the plurality of removing ear pieces 2 are sandwiched between the plurality of drawing rollers, and the plurality of removing ears respectively fed out from the plurality of feeding rollers. A string ear piece 4 having a diameter of 5 mm, 10 mm, 20 mm, or the like can be formed by sandwiching the piece 2 between a plurality of focusing rollers and twisting the piece 2 by sliding a compression roller on the plurality of removal ear pieces 2. ..

During the above work, from the viewpoint of keeping the diameter of the string ear piece 4 substantially constant and increasing the bulk specific gravity of the recycled molding material 7, the plurality of removed ear pieces 2 are stretched in the vertical direction, and the plurality of removed ear pieces are extended. It is preferable that the tension in the feeding supply direction acts uniformly on 2. Further, the method of twisting the plurality of removed ear pieces 2 includes Z twist, S twist, normal twist, rung twist, twist twist and the like, but is not particularly limited. For example, when there are two removed ear pieces 2, the two removed ear pieces can be twisted to form a string ear piece 4, and when there are three removed ear pieces 2, three pieces are formed. The removed ear pieces can be braided to form the string ear pieces 4.

When the twisting start portion 3 of the plurality of removed ear pieces 2 is heated to increase the bulk specific gravity, it is preferable to perform spot heating in a range of, for example, 10 mm, instead of simply heating. The temperature at the time of spot heating is equal to or more than the glass transition point (Tg) of the crystalline resin and less than the melting point (Tm) when measured at a position approximately 5 mm horizontally outward from the peripheral surface (surface) of the twisting start portion 3. The range is good. This is because if it is less than the glass transition point, the physical properties of the removed ear piece 2 cannot be changed or heat shrinkage cannot be expected. On the other hand, when the melting point is exceeded, the removed ear piece 2 melts and is significantly thermally deteriorated, making it difficult to form the string ear piece 4.

For example, when the removed ear piece 2 is made of polyetheretherketone resin, spot heating is carried out in a temperature range of 143 ° C. or higher and lower than 343 ° C., preferably 144 ° C. or higher and lower than 300 ° C., and more preferably 145 ° C. or higher and lower than 200 ° C. be able to. When the removed ear piece 2 is made of polyethylene terephthalate resin, it can be carried out in a temperature range of 69 ° C. or higher and lower than 260 ° C., preferably 144 ° C. or higher and lower than 200 ° C., more preferably 145 ° C. or higher and lower than 180 ° C. ..

The optimum spot heating range is 5 mm or more and 20 mm or less, preferably 7 mm or more and 15 mm or less, and more preferably about 10 mm in order to prevent deterioration of the removed ear piece 2 due to heat history. For this spot heating, a plurality of hot guns 5, dryers, heaters, etc., which are heating means, can be appropriately used.

After forming the elongated string ear piece 4, the string ear piece 4 is cut to a predetermined length with a cutter 6 or scissors (see FIG. 2), and the regenerated molding material 7 for manufacturing the resin film 1 similar to the recycled pellets 7 is formed. Can be manufactured. This cutting operation may be performed manually, but it can also be automatically performed using a dedicated device as described above. In the case of automation, after inserting the elongated string ear piece 4 into a hollow inverted conical vertically long supply path that gradually inclines downward and reduces the diameter, the string ear piece 4 is narrowed down. It can be cut to a predetermined length.

The string ear piece 4 preferably has substantially the same length as the new crystalline resin pellet (for example, 8 mm, 10 mm) so that the regenerated molding material 7 can be smoothly charged into the melt extrusion molding machine 10. , 12 mm, 20 mm, etc.). When the cutter 6 is used as a cutting means, it is preferable that the cutter 6 is arranged so as to be rotatable in the horizontal direction or reciprocating horizontally with respect to the cord ear piece 4.

Next, when a crystalline resin film 1 is newly manufactured using the manufactured regenerative molding material 7, the regenerated molding material 7 is melt-extruded together with the new crystalline resin as a molding material as shown in FIG. It is put into a molding machine 10 and melt-kneaded, and a strip-shaped thin resin film 1 is continuously extruded from the T die 13 of the melt extrusion molding machine 10 and sandwiched between the cooling roll 16 and the pair of pressure welding rolls 17. After cooling and removing both side portions of the cooled resin film 1, the resin film 1 is wound around the winder 18.

The melt extrusion molding machine 10 is composed of, for example, a single-screw extrusion molding machine, a twin-screw extrusion molding machine, or the like, and functions to melt-knead the charged recycled molding material 7 or the like. A raw material input port 11 for molding materials is installed behind the upper part of the melt extrusion molding machine 10, and the raw material input port 11 has helium gas, neon gas, argon gas, krypton gas, nitrogen gas, carbon dioxide gas, etc. An inert gas supply pipe 12 for supplying the inert gas of the above is connected, and the inflow of the inert gas through the inert gas supply pipe 12 effectively prevents oxidative deterioration and oxygen cross-linking of the molding material. To.

A T-die 13 is attached to the tip of the melt extrusion molding machine 10 via a connecting pipe 14, and the T-die 13 functions to continuously push the thin strip-shaped resin film 1 downward. A gear pump 15 mounted on the connecting pipe 14 is located upstream of the T-die 13, and the gear pump 15 transfers the molding material to the T-die 13 at a constant speed and with high accuracy.

The cooling roll 16 and the pair of pressure welding rolls 17 are rotatably supported below the T-die 13, and the cooling rolls 16 are arranged so as to be sandwiched between the pair of pressure welding rolls 17, and the resin film 1 Is in sliding contact with the cooling roll 16 and is pressed against the cooling roll 16. As the cooling roll 16, for example, a metal roll having a diameter larger than that of the pressure welding roll 17 is used.

For each pressure welding roll 17, a metal elastic roll having a metal surface is used when molding a resin film 1 having excellent smoothness. Further, if it is desired to improve the adhesion between the resin film 1 and the cooling roll 16 on the peripheral surface of each pressure welding roll 17, an elastic layer that repels the resin film 1 is covered as necessary, and this elasticity Inorganic compounds such as silica and alumina are selectively added to the layer. As the material of the elastic layer, at least natural rubber, isoprene rubber, butadiene rubber, norbornene rubber, acrylonitrile butadiene rubber, nitrile rubber, urethane rubber, silicone rubber, fluororubber and the like are adopted. Among these, it is preferable to use silicone rubber or fluororubber having excellent heat resistance.

A winder 18 for winding the resin film 1 on a rotatable winding roll 19 is installed downstream of the pair of pressure welding rolls 17, and a resin film is placed between the pair of pressure welding rolls 17 and the winder 18. A plurality of slit blades 20 for cutting and removing both side portions of 1 as unnecessary removal ear pieces 2 are arranged so as to be able to move up and down, and a resin film is formed between the plurality of slit blades 20 and the winder 18. A required number of rotatable tension rolls 21 are supported by applying tension to 1 to smoothly wind the film.

In the above, when the crystalline resin film 1 is newly produced, as shown in FIG. 3, a remolding material 7 and a new crystalline resin are mixed to prepare a molding material, and then a melt extrusion molding machine is used. The molding material is charged into the raw material charging port 11 of 10 while supplying the inert gas indicated by the arrow in the figure, and the molding material is melt-kneaded by the melt extrusion molding machine 10 in a heated and pressurized state from the T die 13. The strip-shaped thin resin film 1 is continuously extruded. At this time, the water content of the molding material before melt-kneading is adjusted to 5000 ppm or less, preferably 2000 ppm or less, and more preferably 250 to 2000 ppm or less. This is because if the water content exceeds 5000 ppm, the molding material may foam.

After extruding the resin film 1, the resin film 1 is sequentially wound on the cooling roll 16, the pair of pressure welding rolls 17, the tension roll 21, and the winding roll 19 of the winding machine 18, and the resin film 1 is cooled by the cooling roll 16 to cool the resin. After cutting and removing each of both sides of the film 1 as a strip-shaped removing ear piece 2 with a slit blade 20, the film 1 is sequentially wound on a winding roll 19 of a winding machine 18, and the molding material containing the regenerative molding material 7 is used. An expensive resin film 1 for a diaphragm of a speaker or a film capacitor can be manufactured at low cost. If the thickness of each of the removed ear pieces 2 cut and removed is less than 20 μm, the cut / removed ear pieces 2 are reused for producing the regenerated molded material 7 as needed.

According to the above, the plurality of removed ear pieces 2 are heated while being strongly twisted, and the plurality of removed ear pieces 2 are rapidly compressed and the air between the removed ear pieces 2 is exhausted to the outside, so that the plurality of removed ear pieces 2 are removed. It is possible to effectively prevent air from intervening between the ear pieces 2. Therefore, when the resin film 1 is manufactured later, the regenerated molding material 7 can be appropriately charged into the melt extrusion molding machine 10. Further, since the bulk specific gravity of the regenerated molding material 7 is heavy and high, even if the regenerated molding material 7 is put into the melt extrusion molding machine 10, the regenerated molding material 7 does not float inside the melt extrusion molding machine 10. Therefore, it is possible to effectively prevent the timing of resin melting from shifting and causing a serious hindrance to the production of the resin film 1.

Further, instead of simply heating the twisted end portion of the plurality of removed earpieces 2, the twisting start portion 3 of the plurality of removed earpieces 2 is spot-heated, and both the inner and outer surfaces of the removed earpieces 2 that have begun to overlap and become entangled. Since the point heating is performed, the plurality of removed ear pieces 2 can be rapidly contracted, reduced in diameter, and integrated. Further, when the resin film 1 is amorphous, since the amorphous resin does not have a clear melting boundary, it is not practically easy to set a temperature range above the glass transition point and below the melting point, but it is crystallized. Since the removed ear piece 2 removed from the amorphous resin film 1 is the target of the regenerated molding material 7, the temperature control at the time of spot heating becomes really easy. Therefore, it can greatly contribute to the automation and mass production of the recycled molding material 7.

Next, FIG. 4 shows a second embodiment of the present invention. In this case, a plurality of removed ear pieces 2 are entwined and strongly entwined while being fed and supplied from the upstream to the downstream in the horizontal lateral direction at a constant speed. Along with twisting, the twisting start portion 3 where the plurality of removed ear pieces 2 began to overlap was spot-heated to rapidly heat-shrink the plurality of removed ear pieces 2, so that the plurality of removed ear pieces 2 came into close contact with each other. The elongated string ear piece 4 is formed. Since the other parts are the same as those in the above embodiment, the description thereof will be omitted.

Also in this embodiment, the same action and effect as those in the above embodiment can be expected, and even when a plurality of removed ear pieces 2 cannot be fed from above to below at a constant speed, the elongated string ear pieces 4 are formed. It is clear that you can.

In the above embodiment, the remolded material 7 for the resin film 1 is manufactured, but the present invention is not limited to this. For example, the reclaimed molding material 7 for medical products, automobiles, liquid crystal manufacturing equipment, and semiconductor manufacturing equipment may be used. In addition to the regenerated molding material 7, colorants (titanium oxide, carbon black, etc.) and antioxidants (hindered phenol-based) are used as molding materials to be charged into the raw material input port 11 of the melt extrusion molding machine 10. , Hindered amine type, thio type, phosphorus type, etc.), antistatic agent, flame retardant (antimonium oxide, metal hydroxide, etc.), plasticizer, mold release agent, lubricant (silicone type, fluorine type, etc.), inorganic filler, Additives such as organic fillers, inorganic fibers, and organic fibers may be added. Further, fine irregularities may be formed on the peripheral surface of the cooling roll 16 and fine irregularities may be formed at the same time when the resin film 1 is molded to reduce the friction coefficient.

The method for regenerating a resin film and the method for producing a resin film according to the present invention are used in the field of producing a resin film used for portable devices, information devices, audio devices, precision parts, electronic parts, and the like.

1 Resin film 2 Removal ear piece 3 Twisting start (twisting start)
4 String ear piece 5 Hot gun 6 Cutter 7 Recycled molding material 10 Melt extrusion molding machine (molding machine)
13 T die (die)
16 Cooling roll 17 Pressure welding roll 18 Winding machine 20 Slit blade

Claims (3)

A method for regenerating a resin film in which a regenerated molded material is obtained by using a removed ear piece removed from a crystalline resin film.
Approximately band-shaped removal removed from the side of a continuous resin film with a thickness of 1 μm or more and less than 20 μm A plurality of earpieces are twisted to spot heat the vicinity of the twisting start portion, and the temperature at the time of this heating. A method for regenerating a resin film, which comprises forming a string ear piece by setting the temperature in the range of the glass transition point or more and lower than the melting point, and cutting the string ear piece to a predetermined length to produce a remolded material. The method for regenerating a resin film according to claim 1, wherein the removed ear piece is stretched and twisted while applying tension. The regenerated molding material obtained by the resin film regeneration method according to claim 1 or 2 is put into a molding machine, and the resin film is extruded from the die of the molding machine and sandwiched between a cooling roll and a pressure welding roll for cooling. A method for producing a resin film, which comprises removing the side portion of the cooled resin film and then winding the resin film on a winder.

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