JP2006281683A - Manufacturing method of regenerated tire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a regenerated tire capable of enhancing productivity of the regenerated tire by an effective working method replacing an envelope-related work. <P>SOLUTION: The manufacturing method of the regenerated tire comprises a tread plastering process P5 of plastering a tread 2 on a base tire 1, a film plastering process P6 of plastering a heat-shrinkable film 5 on the outer circumference of the tread 2 plastered on the base tire 1, and a heat treatment process P7 of conducting a heat treatment. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a retread tire.

A conventional method for manufacturing a retread tire, for example, according to the precure retreading system disclosed in Patent Document 1, generally has the following steps.
For the base tire formed by scraping the outer peripheral surface of the tread in the buffing process, a vulcanized tread with a pattern is wrapped around where the cement is applied to the outer peripheral surface and the cushion sheet is applied. Join the ends with cushion rubber (tread application process), cover the tire with the tread wrapped around it (envelope covering process), and attach the rim to the bead part to deaerate the inside of the envelope (Vacuum process), put in a vulcanizing can and vulcanize (vulcanization process), remove the envelope (envelope removal process), and manufacture retreaded tires.

JP 2002-086587 A

  Covering the tire with the tread wound around the base tire and degassing the inside of the envelope is done by pressurizing the adhesive interface between the base tire and the tread to strengthen the adhesion, and at the shoulder and side of the tire This is to spread the repair rubber of the department and play an important role.

  However, since it involves a vacuum process, a considerable amount of work time is required at a minimum. The work time related to the envelope including this vacuum process accounts for a maximum of 25% of the total process including the preparation work for manufacturing the regenerated tire. It occupies a fairly large share.

  SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and the object of the present invention is a method for manufacturing a retread tire that can improve the productivity of the retread tire by an efficient work method that replaces the work related to the envelope. It is in the point to offer.

  To achieve the above object, the invention described in claim 1 includes a tread application step of attaching a tread to a buffed base tire, and a film application of attaching a heat shrinkable film to the outer periphery of the tread attached to the base tire. A retreaded tire manufacturing method comprising a process and a heat treatment process for performing a heat treatment was adopted.

  According to a second aspect of the present invention, in the method for manufacturing a retread tire according to the first aspect, in the film pasting step, the heat-shrinkable film is pasted so as to widely cover a peripheral edge of the joint surface of the tread to the base tire. It is characterized by attaching.

  According to a third aspect of the present invention, in the method for manufacturing a retread tire according to the first or second aspect, the thickness of the heat-shrinkable film applied in the film application step is 0.15 to 1.00 mm. It is characterized by.

  According to a fourth aspect of the present invention, in the method for producing a retreaded tire according to the first to third aspects, the temperature heated in the heat treatment step is 80 to 130 ° C.

  According to a fifth aspect of the present invention, in the method for producing a retread tire according to any one of the first to fourth aspects, the production of the retreaded tire is completed by leaving the heat-shrinkable film shrunk in the heat treatment step as it is. And

  According to the method for manufacturing a retread tire according to claim 1, the heat-shrinkable film is contracted by heat-treating the heat-shrinkable film attached to the outer periphery of the tread attached to the base tire, thereby the base tire. The adhesion interface between the tire and the tread can be pressurized to strengthen the adhesion, and the repair rubber for the shoulder portion and side portion of the tire can be extended.

In other words, the role of the conventional envelope has been replaced by a heat-shrinkable film. By using the heat-shrinkable film, there is no need for the removal of the envelope, the vacuum process, and the operations associated therewith. Work can improve productivity of rehabilitated tires.
Moreover, a vacuum apparatus etc. are unnecessary and an installation can be simplified.

  According to the method for manufacturing a retread tire according to claim 2, in the film sticking step, the heat-shrinkable film is stuck so as to cover a wide periphery of the joint surface of the tread to the base tire. While preventing peeling due to warping, the repair rubber for the shoulder and side portions can be reliably extended.

  According to the method for manufacturing a retreaded tire according to claim 3, the thickness of the heat-shrinkable film attached in the film sticking step is set to 0.15 to 1.00 mm so that the heat-shrinkable film is not used more than necessary. Thus, the necessary interfacial adhesive force between the base tire and the tread can be obtained.

  According to the method for producing a retread tire according to claim 4, by setting the temperature to be heated in the heat treatment step to 80 to 130 ° C., the maximum shrinkage force of the heat-shrinkable film is drawn, and the base tire and the tread are effectively removed. Can be glued.

  According to the method for producing a retread tire according to claim 5, productivity of the retreaded tire is improved by leaving the heat-shrinkable film shrunk in the heat treatment step as it is, thereby completing the production of the retreaded tire. The tire can be protected from adhesion of dirt and the like by the heat-shrinkable film, thereby improving the merchantability.

Hereinafter, an embodiment according to the present invention will be described with reference to FIGS.
A process for forming a retread tire by the precure retreading system according to the present embodiment is schematically shown in FIG.

First, in the inspection process, the tires for rehabilitation are inspected for appearance, nail holes, scratches, etc. (process P1), and whether or not they can be rehabilitated by retrending are excluded.
The rehabilitation tire that can be rehabilitated enters the next buffing process (process P2), and the outer peripheral surface of the tread is scraped to form the base diamond 1.
In addition, the base tire is partially polished or repaired such as filling a hole.

On the other hand, a tread with a pattern is vulcanized from a tread rubber material in a separate PC molding vulcanization step (process P3).
The vulcanized tread 2 with a pattern formed by vulcanization is continuous in a band shape, and is cut to a required length in the next cutting step (process P4).

Then, in the next tread winding step (process P5), the vulcanized tread 2 is wound around the base tire 1.
When winding the vulcanized tread 2, cement is applied to the outer peripheral surface of the base tire 1 and a cushion sheet is pasted, or cushioning is directly applied to the base tire 1 from an extruder.

Such a base tire 1 is rotatably supported, and is supplied to the base tire 1 on which the vulcanized tread 2 rotates by a feeding device, and is wound around the outer peripheral surface thereof.
The front end and the rear end of the vulcanized tread 2 wound around the base tire 1 are brought into contact with each other via a cushion rubber and joined with a stapler or the like.

  In the steps so far, as shown in an exploded sectional view in FIG. 2 (1), the cement sheet 3 is applied to the outer peripheral surface of the base tire 1, the cushion sheet 4 is pasted thereon, and the vulcanized tread 2 is wound thereon. Then, the front and rear ends are joined, and the vulcanized tread 2 is wound and pasted around the base tire 1 via the cushion sheet 3 as shown in FIG.

And it enters into the following film sticking process (process P6).
In the film sticking step, as shown in FIG. 3, a belt-shaped heat-shrinkable film 5 is wound in the circumferential direction on the outer peripheral surface of the vulcanized tread 2 wound around the base tire 1.

The heat-shrinkable film 5 is a belt-like film having a uniaxial shrinkage in the circumferential direction, a heat shrinkage rate of 60%, and a tensile strength of 1000 kg / cm ^2. Winding, thickness is 0.7mm.
As shown in FIG. 4 (1), the heat-shrinkable film 5 has a width W that is the maximum length of the vulcanized tread 2 so as to cover the periphery of the joint surface of the vulcanized tread 2 with respect to the base tire 1. It is significantly larger than the substantial length Wt and is 2 to 3 times the width length Wt.

In a state where the heat-shrinkable film 5 is wound around the outer peripheral surface of the vulcanized tread 2, the table tread 1 is put in a vulcanizing can and enters a vulcanization step (process P7).
In the vulcanization step, first, the heat-shrinkable film 5 is shrunk by heating at a vulcanization temperature of 100 to 115 ° C., and as shown in FIG. Then, vulcanized rubber such as the cushion sheet 3 is vulcanized and the vulcanized tread 2 is bonded to the table tread 1.

In this way, the heat-shrinkable film 5 may be shrunk and bonded to the side portion of the table tread 1 to vulcanize the unvulcanized rubber and bond the vulcanized tread 2 to the table tread 1 at the same time. For example, the heat-shrinkable film 5 may be shrunk after vulcanization molding to pressurize the adhesion interface between the base tire 1 and the vulcanized tread 2 to strengthen the adhesion.
The interfacial pressure at this time is about 0.9 kg / cm ² , which is comparable to the conventional interfacial pressure due to the tightening of the envelope by degassing of about 0.8 kg / cm ^2. It is high.

  Since the heat-shrinkable film 5 is attached so as to cover the peripheral edge of the joint surface of the vulcanized tread 2 with respect to the base tire 1, it is possible to prevent the edge of the vulcanized tread 2 from peeling off due to warping.

  The heat-shrinkable film 5 has a thickness of 0.7 mm so that the necessary interfacial adhesive force between the base tire 1 and the vulcanized tread 2 can be obtained without using a heat-shrinkable film more than necessary.

Although the adhesion interface pressure between the base tire 1 and the vulcanized tread 2 due to the shrinkage of the heat-shrinkable film 5 can be expected to have the same effect as that of the conventional envelope, the vacuum process and There is no work associated with it, and it is a simple work with few processes.
In fact, the process productivity was improved by 15%.

The heat-shrinkable film 5 that has been heat-treated and shrunk in this manner is left attached to the retreaded tire, and the retreaded tire is manufactured and shipped.
By doing in this way, while improving the productivity of a retreaded tire, a retreaded tire can be protected from adhesion of dirt etc. with a heat-shrinkable film, and merchantability can be improved.

  Next, an example in which a repair rubber 6 (for example, a silicon sponge sheet) that is a flexible annular material is applied to the shoulder portion of the base tire 1 around which the vulcanized tread 2 is wound will be described with reference to FIG.

  The repair rubber 6 is affixed to the shoulder portion from the end edge portion of the vulcanized tread 2 to the side portion of the base tire 1, and as described above, the heat-shrinkable film 5 is wound in the circumferential direction and vulcanized. Then, as shown in FIG. 5, the heat-shrinkable film 5 is shrunk from the outer peripheral surface of the vulcanized tread 2 so as to cover the repair rubber 6 on both shoulders, and vulcanized with the base tire 1. While pressurizing the adhesion interface with the finished tread 2 to strengthen the adhesion, the repair rubber 6 can be extended and pasted.

As the heat-shrinkable film, it is preferable to use a film having a heat shrinkage rate of 30 to 100% and a tensile strength of 250 to 1500 kg / cm ² with a thickness of 0.15 to 1.00 mm. In addition, not only one axis but also two axes can be used.

  Furthermore, the heat shrinkable film is wound around the base tire around which the vulcanized tread is wound. As described above, there are a method of winding in the circumferential direction of the base tire and a method of winding in the radial direction of the base tire.

FIG. 6 shows an example of winding the heat-shrinkable film 15 in the radial direction of the base tire 11 (and the vulcanized tread 12). The base tire 11 having an annular shape is wound spirally.
In addition, the heat-shrinkable film piece 25 cut to a length of about the width W of the heat-shrinkable film 5 shown in FIG. 4 is used as the diameter of the base tire 21 (and the vulcanized tread 22) as shown in FIG. Affix one piece in the direction over the entire circumference.

  After the heat-shrinkable film 15 (25) is applied in this way, heat treatment (or vulcanization) is performed to maximize the tightening due to heat shrinkage, and the base tire 11 (21) and the vulcanized tread 12 (22) are bonded. Pressurize the interface to strengthen the bond.

  In the above embodiment, the base tire and the vulcanized tread are bonded via the cushion sheet. However, if this is bonded only with the adhesive, the heat shrinkage is performed at a temperature lower than the vulcanization temperature. The heat-shrinkable conductive film can pressurize the adhesive interface between the base tire and the vulcanized tread to strengthen the adhesion, thereby further improving productivity.

It is a figure which shows roughly the procedure of the formation process of the retreaded tire by a precure retreading system. It is an exploded sectional view and an assembly sectional view of a base tire, a cushion sheet, and a vulcanized tread. It is a perspective view which shows a mode that the heat-shrinkable film was wound around the outer peripheral surface of the vulcanized tread wound around the base tire in the circumferential direction. It is the same sectional view before heat treatment, and a sectional view after heat treatment. It is the same sectional view after heat processing of another embodiment. It is a perspective view which shows the example which affixed the heat-shrinkable film to radial direction. It is a perspective view which shows another example which affixed the heat-shrinkable film to radial direction.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Base tire, 2 ... Vulcanized tread, 3 ... Cement, 4 ... Cushion sheet, 5 ... Heat-shrinkable film, 6 ... Repair rubber,
11 ... stand tire, 12 ... vulcanized tread, 15 ... heat shrinkable film,
21 ... stand tire, 22 ... vulcanized tread, 25 ... heat shrinkable film piece.

Claims (5)

A tread application process for attaching the tread to the buffed base tire;
A film sticking step of sticking a heat-shrinkable film to the outer periphery of the tread attached to the base tire;
A heat treatment step for performing heat treatment;
A method for producing a retread tire comprising the steps of: In the film sticking step,
The method for producing a retread tire according to claim 1, wherein the heat-shrinkable film is affixed so as to cover a wide periphery of a joint surface of the tread with respect to the base tire.   The method for producing a retread tire according to claim 1 or 2, wherein a thickness of the heat-shrinkable film attached in the film attaching step is 0.15 to 1.00 mm.   The method for producing a retread tire according to any one of claims 1 to 3, wherein a temperature to be heated in the heat treatment step is 80 to 130 ° C. 5. The method for producing a retread tire according to claim 1, wherein the production of the retread tire is completed by leaving the heat-shrinkable film shrunk in the heat treatment step as it is.

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