JPS5858212B2 - Method for manufacturing synthetic resin sheet with seam-like design - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a synthetic resin sheet having a group of seam-like small protrusions.

BACKGROUND ART Conventionally, the following processing technology has been used as one of the means for manufacturing footwear covering materials.

This can be obtained by first cutting the base material, such as a base material, into the shape of a toe, using commonly known cloth materials, leather materials, etc., and then sewing it together with parts such as bias tape, toe reinforcement pieces, and heel reinforcement pieces. The outer shape of this original lace is molded into a high-frequency processing mold made of silicone resin, etc., and the synthetic resin leather cut into the lace shape is loaded into the mold, and a high frequency is applied to the mold to form the synthetic resin leather. At the same time, the resin is thermally melted, and the concave-convex pattern of the mold, which is a copy of the external shape of the original hemlock as a base material, is transferred and engraved onto the resin surface of the synthetic resin leather, making the synthetic resin leather look just like the original hemlock. The necessary parts are processed to have an appearance similar to those made by sewing.

According to this means, the seams formed by sewing parts on the resin surface of the synthetic resin leather in the original form also appear as irregularities made of the resin of the synthetic resin leather.

However, since this seam-like unevenness is formed from the resin itself of the synthetic resin leather, it will be the same color as the base part and parts of the cover that are also formed from the resin.
Not only is it impossible to express the unusual stitches for decoration on the base material of the base material, but also the seam-like unevenness that is expressed is the same as the resin that represents the base and parts of the material. Since it is made of resin, it is difficult to express the difference in texture between them.

An attempt was made to apply paint to the seam-like unevenness in order to create a unique color, but since the seam-like unevenness was minute, the paint easily adhered to other parts. The painting process was difficult.

In order to overcome this, the present inventors filled the small concave part of the mold for forming seams with a material such as paste resin or powdered resin, and then layered a synthetic resin leather cut into a cover shape on top of it and applied high frequency. discovered a means of integrally forming small seam-like protrusions of a different color on the resin surface of synthetic resin leather, but this was not possible because the small recesses for seam formation were extremely minute and numerous. Not only is the filling operation of the material to be filled complicated and inconveniences such as filling defects likely to occur, but it also has the fatal drawback of being completely unsuitable for mass production.

The present invention provides a method for manufacturing a synthetic resin sheet having a seam-like design that overcomes the above-mentioned drawbacks, and the scope of application of the present invention is to overcome the above-mentioned drawbacks. It is used in a wide range of applications, including footwear materials, bag materials such as bags, floor materials, wall materials, clothing materials, and desk covering materials.

To explain the present invention in detail based on the drawings, a large number of small protrusions 2 having a seam-like appearance are formed on the resin surface of a synthetic resin base sheet 1, and the small protrusions 2 are formed from a brittle film 3. The present invention relates to a method for manufacturing a synthetic resin sheet having a seam-like design, which is made of a synthetic resin and is thermally welded to the resin surface of a base sheet 1.

That is, the present invention provides a method for forming an embrittlement film 3 in a high-frequency processing mold 5 having a large number of small recesses 2a formed by carving the outer shape of seams (this is done by inserting an embrittlement film 3 to cover these small recesses 2a).
is loaded, this embrittlement film 3 is compressed by the suppressing means 4 and the mold 5, and high frequency is applied to thermally melt the embrittlement film 3, and a part of it is press-fitted into the small recess 2a, And due to its squeezing action, the small recess 2a
A weakened part 3a having a shape that follows the outer shape of the peripheral edge 6 is formed in the embrittled film 3 in contact with the open peripheral edge 6, and the embrittled film is removed by removing the pinching action between the suppressing means 4 and the mold 5. 3 is peeled off and the fragile portion 3a is cracked so that the portion surrounded by the fragile portion 3a and press-fitted into the small recess 2a remains in the small recess 2a, and then the synthetic resin base sheet 1 is peeled off. The resin is loaded into the bottom mold 5 so that the surface of the resin faces toward the small recess 2a, and high frequency is applied to integrate the resin of the base sheet 1 and the portion 3b of the embrittled film 3 remaining in the small recess 2a. The present invention relates to a method for producing a synthetic resin sheet having a seam-like design characterized by heat welding.

The high-frequency processing mold 5 used in the present invention has a large number of rows or groups of small recesses 2a in which the contours of stitches formed by sewing thread are engraved in the molding wall 5a.

The mold 5 is made of a base material sheet made of cloth, leather, etc., cut into the shape of a sheath or sheath material, if necessary, and parts made of other materials such as cloth or leather, if desired. A seam is formed using a sewing thread, and the surface of the resulting original sheet where the seam appears is molded using an insulating material with low high-frequency dielectric loss such as silicone resin, and the outline of the seam is transferred and engraved. .

Examples of such insulating materials with low high-frequency dielectric loss that are suitable as materials for the mold 5 include epoxy resins, urethane resins, melamine resins, furan resins, etc. in addition to silicone resins.

The pressing means 4, 4a consisting of the lid mold shown in FIG. 7 or the lid mold shown in FIG.
It is formed from each of the materials listed above.

In the mold 5 formed by molding the outer shape of the original sheet, the irregularities formed on the surface of the original sheet, even minute ones, become reverse pattern irregularities in the mold 5a of the mold 5. Transcribed and engraved.

A large number of small recesses 2a formed in rows or groups carved in the bottom mold 5 each have an open peripheral edge 6 at an angle of 90° with respect to a flat surface 5b within the molding wall 5a of the mold 5.
It stands steeply at an angle α close to 90°.

The embrittled film 3 is loaded into the mold 5a and placed on the flat surface 5b so as to cover the small recesses 2a, and a high frequency wave is applied thereon to be pressed by the suppressing means 4. Then, the brittle film 3 is thermally melted and a part thereof is press-fitted into each small recess 2a, and the pressing means 4 and the steep peripheral edge 6 of each small recess 2a sandwich the brittle film 3, and the peripheral edge Due to the nature of the brittle film 3, the part of the brittle film 3 that the part 6 is pressed against becomes a brittle part 3a which is weakened along the outer shape of the peripheral edge part 6, and the eyelid weak part 3a is a small concave part 2a of the brittle film 3. It is formed in a state surrounding the portion 3b press-fitted into.

As a result, the pinching action performed on the embrittled film 3 is removed by removing the pressing means 4 consisting of the lid mold that pressed the embrittlement film 3, and the embrittlement film extends on the flat surface 5b in the mold 5a. When the film 3 is peeled off, a portion 3b of the fragile film 3 surrounded by the weakened portion 3a and press-fitted into each small recess 2a is removed.
Since the weakened portions 3a are brittle and crack easily, they remain press-fitted into each of the small recesses 2a even though the weakened film 3 is peeled off.

The exfoliation of the brittle film 3 is caused by applying pressure and high frequency to the brittle film 3 by the suppressing means 4 and the mold 5, thereby causing the flat surface in the mold 5a of the mold 5 to peel off.
It is temporarily attached on top b with some adhesive force, so flip it up and peel it off.

Note that the flat surface 5 inside the mold 5a of the mold 5 described above
b refers to a relatively flat surface with an expanse that can have irregularities 2b of a certain size.

The embrittlement film 3 can be configured to have a different color from the resin of the synthetic resin base sheet 1 to which the seam-like design is to be applied, or it may be colored but transparent.

The synthetic resin base sheet 1 is made of synthetic resin leather such as synthetic resin leather with a synthetic resin layer 1b bonded to one side of the fabric 1a, or synthetic resin tarpaulin leather with a synthetic resin layer bonded to the other side of the fabric. Can be applied as a material.

This leather can be manufactured by a common leather manufacturing method such as a calendaring method.

In addition to woven fabrics, knitted fabrics and non-woven fabrics can be used as the fabric 1a.

The synthetic resin base sheet 1 can also be a single layer sheet made only of synthetic resin or a synthetic resin composite sheet laminated in multiple layers made only of synthetic resin.

Further, for example, as the synthetic resin base sheet 1, a sheet material in which a synthetic resin layer is bonded to paper made of vegetable fibers such as pulp, or paper made of inorganic fibers such as asbestos or glass fibers can be used.

Products using such paper as a backing material can be used for many purposes such as wall materials and flooring materials.

The resin of the embrittled film 3 and the synthetic resin base sheet 1 is made of a thermoplastic soft synthetic resin that has a large high-frequency dielectric loss and can be heated and thermally melted by high-frequency application.

For example, examples of the resin for the synthetic resin base sheet 1 include polyvinyl chloride resin, polyurethane elastomer, polyethylene resin, vinyl chloride-vinyl acetate copolymer resin, and the like.

The brittle film 3 is melted and a part thereof is press-fitted into the small recess 2a carved in the mold 5a of the mold 5, and the brittle part 3a is formed by the peripheral edge 6 of the small recess 2a. When the brittle film 3 is peeled off from the flat surface 5b in the mold 5a, only the portion 3b that had been press-fitted into the small recess 2a cracks in the weakened portion 3a, so that it remains in the small recess 2a. The resin surface of the synthetic resin base sheet 1 is then thermally welded to the synthetic resin base sheet 1 loaded into the mold 5a by high-frequency heating. If the surface is treated with a thin hot-melt adhesive 1c, the portion 3b remaining in the small recess 2a of the fragile film 3 will be well welded to the resin surface of the synthetic resin base sheet 1.

This adhesive 1c may be applied to the entire resin surface of the synthetic resin base sheet 1, but when it is loaded into the mold 5a, the resin surface including the portion corresponding to the small recess 2a is treated with the adhesive 1c. The processing may be limited to a relatively small range.

This adhesive is preferably colorless and transparent, but if the entire resin surface is to be treated, it may be slightly colored as long as it is transparent.

High frequency processing is performed twice in the manufacturing method of the present invention, before and after.

In the first high-frequency processing, a part of the embrittled film 3 is press-fitted into a small recess 2a in a mold 5a of a mold 5, and the peripheral edge 6 of the small recess 2a is A fragile portion 3a is formed in the fragile film 3 in a shape that follows the outer shape.
In order to form a fragile part 3a in the fragile film 3 along the
It is necessary to apply pressure between a suppressing means 4 such as a lid mold and a forming mold 5.

This pinching pressure is applied by the upper electrode 7 and the lower electrode 8 placed above and below, and the suppressing means 4 such as the lid mold and the forming mold 5.
This may be done by sandwiching it between the two.

Alternatively, the pressing means 4 such as a lid mold may be placed in a mold 5.
Alternatively, or conversely, the forming mold 5 may be pressed against the suppressing means 4 such as a lid mold.

In other words, the brittle film 3 is attached to the lid mold 4 and the forming mold 5.
It suffices if the structure is such that it can be sandwiched between them with a pressing force in a relative relationship.

Next, in the high frequency application in FIG. 2, after the first high frequency application,
The brittle film 3 with the brittle portion 3a formed therein is molded into a mold 5.
The part 3b of the fragile film 3 surrounded by the fragile part 3a and press-fitted into the small recess 2a is left in the small recess 2a, and the synthetic resin base sheet 1 is loaded and placed on top of this. Then press the synthetic resin base sheet 1 if necessary using the pressing means 4a of the lid mold, which has a smoother inside than the lid mold 4 used in the first high-frequency impression process described above, and press the upper and lower parts of the sheet 1. A high frequency is applied to the upper electrode 7 and lower electrode 8 which are sandwiched between the two, and the heat-fused synthetic resin base sheet 1 and the portion 3b of the fragile film 3 remaining in the small recess 2a are integrated using the suppressing force. It is heat welded.

Therefore, if the material has a pressing force, the material that exerts a suppressing action is C shown in FIG. 8, which is placed on the synthetic resin base sheet 1.
Of course, the suppressing means 4a such as a lid mold as shown in FIG. Alternatively, the mold 5 may be pressed by pushing it up against the pressing means 4a such as a lid mold.

In addition, in this second high-frequency impression process, the above-mentioned pressing is not necessarily required, so that the portion 3b of the embrittled film 3 remaining in the small recess 2a and the synthetic resin base sheet 1
and are likely to be welded to each other by thermal melting, the upper electrode 7 may be placed directly on it without pressing, for example, without placing the suppressing means 4a such as a lid mold on it. A high frequency is applied together with the lower electrode 8 placed under the mold 5, and the embrittled film 3 inside the mold 5 is
It is sufficient to weld the portion 3b of the brittle film 3 and the synthetic resin base sheet 1 by thermally melting the portion 3b of the embrittlement film 3 and the resin of the synthetic resin base sheet 1.

However, in addition to the small recesses 2a, there are minute surface irregularities 2b that reflect the outer shape of the original sheet and recesses 2c for parts such as decorative tape, so these irregularities 2b. In order to better transfer the irregularities 2b and depressions 2c to the resin surface of the synthetic resin base sheet 1, high frequency is applied to melt the resin, and the resin surface of the synthetic resin base sheet 1 is transferred to such irregularities 2b and depressions 2c.
It is preferable to press it against the inner surface of the mold 5a in which the mold 5a is formed.

The small protrusions 2 forming a seam-like design formed on the synthetic resin sheet obtained by the present invention are formed from the embrittled film 3, and the seams of the design may be, for example, single needle lockstitch, double All kinds of stitches can be used, such as multi-needle lockstitch, zigzag stitch, or embroidery stitch.

Therefore, if these seams are formed on the original sheet and copied onto the original mold 5 to form the outer shape of the seams as small recesses 2a, each of the small recesses 2a will have the same shape as the thread of the seam. The small recesses 2a are expressed in the order of the stitch shapes described above, such as a single line, a parallel line consisting of multiple lines, a zigzag (the above is an example of a row of stitches), and an embroidery pattern (seams are arranged in a row). The eyes are formed in an intermittent or continuous shape (for example, eyes forming a group).

If the thread actually sewn onto the original sheet is relatively thick, the small recesses 2a will be formed relatively wide and deep accordingly, so the embrittlement film 3 covering the small recesses 2a will be A thick one is used, but this small recess 2a
This is preferable because it does not cause defects such as insufficient press-fitting of the embrittled film 3 into the film.

In the manufacturing method of the present invention, even if the small concave part with a seam-like outline carved in the mold is minute, an embrittlement film is placed on top of the concave part and then pressed, and a high frequency is applied. Not only can a part of the brittle film be easily press-fitted into the small recess, but also its suppressing action simultaneously causes the part of the brittle film around the press-fitted part to be compressed by the periphery of the small recess. A weak part is created by pressure welding, and by simply peeling off this brittle film, the brittle part can be cracked and the press-fitted part of the brittle film can remain in the small recess. The process of filling the brittle film resin is simple and accurate, even though the small recesses are minute, so that the parts of the brittle film press-fitted into the small recesses are not exposed to the surface of the synthetic resin base sheet. Similarly, if they are fused together using a high-frequency stamping process, minute seam-like designs can be faithfully and instantly expressed.

In addition, since the material press-fitted into the small recess is the resin of the embrittled film, it can be configured as a different material from the synthetic resin base sheet. By integrally welding the material sheet to the surface of the material sheet by applying high frequency, a unique seam-like design can be easily formed with the base material sheet.

Furthermore, by making the seam-like design a unique color, the minute seam-like design can be easily identified, making it possible to express a unique design.

In the present invention, since the seam-like outer shape is carved into the mold to form a small recess, the open peripheral edge of the small recess is close to 90° or 90' with respect to the flat surface inside the mold. Since the embrittlement film forms an angle, we placed the embrittlement film on this flat surface and applied suppression and high frequency, so the part of the embrittlement film that is in contact with the periphery of the small recess is easier to remove than other parts. However, since the weakened part does not extend to the part of the fragile film that is surrounded by the weakened part and is press-fitted into the small recess, this weakened part can be cracked. After that, the press-fitted part is integrally welded to the base sheet by applying a second high frequency, and there is no weak part in the seam-like design, and the seam-like design will crack or peel due to the weak part. It never gets easier.

Since the material that is press-fitted into the small recess is a brittle film made of thermoplastic synthetic resin with high high-frequency dielectric loss, it easily self-heats and melts when high-frequency is applied, and when simultaneously subjected to compression, a fine seam-like external shape is formed. The small recesses that were transferred are filled well, and the inner shape of the small recesses is transferred in the opposite direction.
This part of the brittle film can express fine seam-like designs well.

Therefore, the synthetic resin sheet obtained by the present invention gives the synthetic resin sheet an appearance as if it had been sewn with sewing thread, without the need for complicated sewing work, and can easily express any complicated seams. In addition, when the design is expressed using actually sewn threads, the threads break when they come into contact with other objects, and the threads tend to fray from the cut portions, and these frays cause the entire design and expression to break. However, in the present invention, the seam-like design expressed is not actually composed of sewing thread, but is made by welding a resin made of a brittle film. Therefore, even if a part of the design were to be damaged, there is no risk that the damage would spread to the entire design.

Examples will be shown next, but it goes without saying that the present invention is not limited to these examples.

〔Example〕

Leather for shoelaces is used as the main material for making the original sheet, and this leather is made into a U-shaped piece that is continuous at the toes, including the left and right laces and toes, and separated only at the heel. It is cut into a shape to form a lace, and two strips made of leather are sewn on the left and right sides of the lace by lock stitching from the vicinity of the eyelet attachment part at the front of the lace so as to have a shape inclined toward the heel.

Furthermore, a bias tape made by cutting a synthetic resin leather made by laminating a synthetic resin on one side of a woven fabric into a tape shape so that the weave direction of the woven fabric is biased is attached to the cuff of the lace part; A toe reinforcing piece made of leather is sewn to the toe part of the lace part, and an eyelet reinforcing piece made of leather is sewn to the eyelet attachment part at the front part of the lace part using a lock stitch with cotton thread.

The toe reinforcing piece is sewn using a two-needle lockstitch method, in which two threads are sewn in parallel along the semicircular shape of the edge of the toe reinforcing piece.

The outer shape of the original sheet formed as described above is copied onto a mold 5 made of silicone resin as a mold 5a having a concave shape as shown in FIG. 4.

Inside this mold 5a (this includes not only the fine irregularities on the leather surface of the main material's laces, but also the fine irregularities on the leather surface of the reinforcing tape, toe reinforcing pieces, and eyelet reinforcing pieces), as well as those of the pieces tape. The protrusions and the like protruding from the surface of the ribs are precisely engraved in the form of fine surface irregularities 2b and recesses 2c, and the stitches used to sew them together also form small recesses 2a, forming a matrix. It is engraved in the shape of

The mold 5 of the mold 5 in which these uneven shapes are engraved
As shown in FIG. 8A, there is a small recess 2a in the shape of a seam.
The thickness is 0.05 to 0.2 over a relatively small area where
3 cut pieces of a white synthetic resin brittle film with a size of about An upper electrode 7 and a lower electrode 8 were placed above and below, and high frequency was applied between them while being pressed.

Since the combination of the lid mold and the forming mold 5 as the suppressing means 4 was pressed between the upper electrode and the lower electrode, the lid mold acted as the pressing means 4 for the embrittled film 3 as a result.

Next, the upper electrode 7 and the lid mold as the pressing means 4 are removed, and when the cut piece of the embrittled film 3 is peeled off from inside the mold 5a, a small recess 2 corresponding to the seam is formed.
A crack 3c was generated in a portion 3a of the embrittlement film 3 along the peripheral edge 6 of the embrittlement film 3, and a portion 3b of the embrittlement film 3 press-fitted into the small recess 2a remained in the small recess 2a in a form that was pulled out through the crack 3c.

Next, a base sheet 1 made of a blue polyvinyl chloride resin sheet piece 1a is cut into a size that approximately matches the shape of the recess and is loaded into the recess 2c corresponding to the reinforcing tape in the mold 5a. A base sheet 1 made of polyvinyl chloride leather 1e, in which a synthetic resin layer 1b made of beige polyvinyl chloride resin is laminated and bonded to a fabric 1a made of woven fabric using a calendar method, is transferred into the mold 5a. U
The synthetic resin layer 1 is cut into a shape that almost matches the shape of the glyph.
A second pressing means '4a with a smooth inner surface is fitted and loaded into the mold 5a so that b is on the inside.
An upper electrode 7 and a lower electrode 8 were placed above and below the lid mold, and a high frequency was applied while being pressed.

As a result, the resin surface of the polyvinyl chloride leather having a swollen shape has minute irregularities, toe reinforcing pieces, and eyelet reinforcing pieces that mirror the leather surface in the mold 5a of the mold 5, as shown in FIG. , each convex portion 9 corresponding to each of the bias tapes was clearly expressed in beige color, while the reinforcing tape was clearly expressed as a convex portion 10 in blue color.

In addition, a seam-like design is formed on the convex portions 9 and 10 of the small protrusions 2.
The convex parts 9 and 10 are clearly expressed in white.
It was clearly distinguished from the other colors.

[Brief explanation of drawings]

Fig. 1 is a developed plan view of the cover material showing the implementation side obtained by the present invention, Fig. 2 is an enlarged partial sectional view taken along line C-C of Fig. 4, and Fig. 3 is a cross-sectional view of Fig. 4 C-C. Line enlarged partial sectional view, No. 4
The figure is a plan view of the mold for obtaining the cover material shown in Fig. 1, Fig. 5 is an enlarged partial partial view taken along line C-C in Fig. 4, and Fig. 6 is taken on line C-C in Fig. 4. Enlarged partial cross-sectional view, Figure 7 is the 5th
A cross-sectional explanatory diagram of the first high-frequency impression process at the part of the mold shown in the figure, and FIG. 8 A, B, and C are enlarged explanatory diagrams showing the order of the manufacturing process of the present invention product in part X of FIG. 7. , FIG. 9 is a perspective view showing how the brittle film is peeled off from the mold. 1...Synthetic resin base sheet, 2...
Small protrusion, 2a... Small recess, 3... Brittle film, 3a... Weak part, 3b...
Press-fitted part of the embrittled film, 3c...Crack,
4, 4a...pressing means, 5...molding mold, 5a...molding die, 6...peripheral portion, 7...upper Electrode, 8...lower electrode.

Claims (1)

[Claims] 1. An embrittlement film is loaded into a high-frequency processing mold having a large number of small recesses formed by carving out the outline of seams so as to cover these small recesses, and the embrittlement film is The film is compressed by the suppressing means and the mold, and a high frequency is applied to thermally melt the embrittled film, a part of which is press-fitted into the small recess, and the small recess is opened by the pressing action. A fragile portion having a shape that follows the outer shape of the peripheral edge is created in the embrittled film in contact with the peripheral edge, and the embrittled film is peeled off by removing the pressing action between the pressing means and the mold, and the weakened portion is cracked. The part surrounded by the fragile part and press-fitted into the small recess remains in the small recess, and then the synthetic resin base sheet is placed in the mold with the resin surface facing the small recess. A method for producing a synthetic resin sheet having a seam-like design, which comprises loading the base sheet and applying high frequency to thermally weld the resin of the base sheet and the portion of the brittle film remaining in the small recesses together. 2. The method for producing a synthetic resin sheet according to claim 1, wherein the brittle film has a different color from the synthetic resin base sheet. 3 Claim 1 in which the embrittlement film is colored and transparent
A method for producing a synthetic resin sheet according to item 1 or 2. 4. The composition according to any one of claims 1 to 3, wherein the portion of the brittle film remaining in the small recess is thermally welded to the resin surface of a synthetic resin sheet coated with an adhesive. Method for manufacturing resin sheets. 5. The method for producing a synthetic resin according to any one of claims 1 to 4, wherein the synthetic resin base sheet is synthetic resin leather in which a synthetic resin layer is integrally bonded to a cloth. 6. The method for producing a synthetic resin sheet according to any one of claims 1 to 4, wherein the synthetic resin base sheet is a single-layer or multi-layer sheet made only of synthetic resin materials. 7. Any one of claims 1 to 4, wherein the synthetic resin base sheet is a composite sheet in which a synthetic resin layer is integrally bonded to paper (method for producing a synthetic resin sheet as described above). 8. The method for producing a synthetic resin sheet according to any one of claims 1 to 7, wherein the pressing means is a lid mold.