Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
  • B29D30/00—Producing pneumatic or solid tyres or parts thereof
  • B29D30/06—Pneumatic tyres or parts thereof (e.g. produced by casting, moulding, compression moulding, injection moulding, centrifugal casting)
  • B29D30/52—Unvulcanised treads, e.g. on used tyres; Retreading
  • B29D30/54—Retreading
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
  • B29C48/03—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor characterised by the shape of the extruded material at extrusion
  • B29C48/07—Flat, e.g. panels
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
  • B29C48/03—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor characterised by the shape of the extruded material at extrusion
  • B29C48/07—Flat, e.g. panels
  • B29C48/08—Flat, e.g. panels flexible, e.g. films
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
  • B29C48/25—Component parts, details or accessories; Auxiliary operations
  • B29C48/30—Extrusion nozzles or dies
  • B29C48/32—Extrusion nozzles or dies with annular openings, e.g. for forming tubular articles
  • B29C48/33—Extrusion nozzles or dies with annular openings, e.g. for forming tubular articles with parts rotatable relative to each other
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
  • B29D30/00—Producing pneumatic or solid tyres or parts thereof
  • B29D30/06—Pneumatic tyres or parts thereof (e.g. produced by casting, moulding, compression moulding, injection moulding, centrifugal casting)
  • B29D30/52—Unvulcanised treads, e.g. on used tyres; Retreading
  • B29D30/58—Applying bands of rubber treads, i.e. applying camel backs
  • B29D30/60—Applying bands of rubber treads, i.e. applying camel backs by winding narrow strips
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
  • B29C48/25—Component parts, details or accessories; Auxiliary operations
  • B29C48/30—Extrusion nozzles or dies
  • B29C48/35—Extrusion nozzles or dies with rollers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
  • B29D30/00—Producing pneumatic or solid tyres or parts thereof
  • B29D30/06—Pneumatic tyres or parts thereof (e.g. produced by casting, moulding, compression moulding, injection moulding, centrifugal casting)
  • B29D30/52—Unvulcanised treads, e.g. on used tyres; Retreading
  • B29D30/54—Retreading
  • B29D2030/544—Applying an intermediate adhesive layer, e.g. cement or cushioning element between carcass and tread
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
  • B29D30/00—Producing pneumatic or solid tyres or parts thereof
  • B29D30/06—Pneumatic tyres or parts thereof (e.g. produced by casting, moulding, compression moulding, injection moulding, centrifugal casting)
  • B29D30/52—Unvulcanised treads, e.g. on used tyres; Retreading
  • B29D30/54—Retreading
  • B29D2030/546—Measuring, detecting, monitoring, inspecting, controlling
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
  • B29K2019/00—Use of rubber not provided for in a single one of main groups B29K2007/00 - B29K2011/00, as moulding material
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
  • B29K2021/00—Use of unspecified rubbers as moulding material
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
  • B29K2105/00—Condition, form or state of moulded material or of the material to be shaped
  • B29K2105/24—Condition, form or state of moulded material or of the material to be shaped crosslinked or vulcanised
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
  • B29K2105/00—Condition, form or state of moulded material or of the material to be shaped
  • B29K2105/24—Condition, form or state of moulded material or of the material to be shaped crosslinked or vulcanised
  • B29K2105/246—Uncured, e.g. green
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29L—INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES
  • B29L2030/00—Pneumatic or solid tyres or parts thereof
  • B29L2030/002—Treads
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29L—INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES
  • B29L2030/00—Pneumatic or solid tyres or parts thereof
  • B29L2030/003—Plies; Breakers
  • B29L2030/004—Carcasses

Definitions

• the invention relates to an apparatus for applying a raw rubber mixture to a moving surface for the manufacture of tires and in particular retreaded tires.
• hot retreading involves placing a raw tread, in the form in particular of sheets, strips or profile, on a carcass ready to be retreaded. , then cook the whole in a mold;
• cold retreading consists in using a precooked tread which is placed on a carcass ready to be retreaded, then in vulcanizing the whole by using heating means such as an oven. .
• publication EP-0 528 683 describes an apparatus for applying a hot-bonding rubber by means of a laying head, the orifice for applying the rubber simultaneously covering the entire width of the carcass allowing it to be laid in a single carcass turn of the entire bonding rubber layer.
• a high pressure of application of this laying head on the carcass allows the filling of the holes likely to be on the carcass during the laying of the bonding rubber.
• this machine does not make it possible to produce thin bonding gums (the latter having a minimum thickness with said machine of 1.4 mm) or perfectly controlled since the dimensioning of the bonding gum simultaneously over the entire width of the carcass results in variations non-negligible thickness of this rubber depending on whether it is positioned at the top of the carcass or the sides of the latter.
• gums or rubber mixtures will be named: - "normal”: mixtures for which the time TO for the onset of vulcanization (commonly called “scortch time”) is greater than 15 minutes at a temperature of 105 ° C.,
• - “thin” for a strip will be defined as a thickness of mixture less than 2 mm, which can range up to 0.5 or even 0.1 mm, - “small width” for a strip, will be defined relative to the width of the surface to be covered, the width of the strip being less than one tenth of the width to be covered,
• the bonding rubber in a layer of minimum thickness so that the bond between carcass and tread has the least possible impact on the performance or properties of the tire so retreaded and also, for minimize the amount of product used. But we also want to have enough flexibility to, while respecting this constraint, be able to vary the thickness of this layer in order to allow it to plug if necessary the holes present on the surface of the carcass.
• the apparatus for applying hot and under pressure a rubber mixture on a receiving surface in relative movement relative to said apparatus, in the form of a strip of thin thickness and thinness. width comprises at least one extruder composed of a body and a main extrusion screw rotatably mounted in a chamber and intended to deliver a rubber mixture to a first intermediate extrusion orifice opening near the receiving surface and located at the entrance to the front area of a rubber mix recovery pad which cooperates with the receiving surface so as to form with the latter an extrusion orifice defining the profile of the strip of rubber mixture to be formed and delimited by a profiling wall of the recovery pad on the one hand and by the receiving surface on the other hand, characterized in that the front zone of the recovery pad has a front arch, which precedes the profiling wall and which forms an acute angle with the receiving surface so that the pressure of application of the mixture at the inlet of the extrusion orifice is generated essentially by the effect of this year gle
• This device proves capable of depositing strips of thin rubber continuously on a moving surface, and therefore meets the needs expressed by the retreading industry.
• FIG. 1 is a partial axial section of an application device in accordance with the invention
• FIG. 2 is a partial section along line II of the application device shown in FIG. 1,
• FIG. 3 is a perspective representation of a recovery shoe according to the invention
• - Figures 4B and 4A respectively represent a diagram showing the pressure measured in the recovery pad as a function of the distance of the mixture in said pad relative to the extrusion orifice and a partial axial section of the recovery pad in accordance with the diagram
• - Figure 5 shows a schematic view of a hole detection system attached to a recovery pad.
• the receiving surface can have a movement other than rotation, the important thing being that the latter is in relative movement relative to the application device to allow a drive of the mixture intended to be applied.
• the device 1 for applying a rubber mixture C on a receiving surface 2 comprises a body 10 comprising at least one extrusion screw 11 rotatably mounted in a chamber 13 and which opens into a intermediate extrusion orifice 14.
• the free end 110 of the screw 11 has a conical shape and stops directly at the border between the chamber 13 and the intermediate extrusion orifice 14 onto which this chamber 13 opens.
• the invention is not limited to this embodiment and that it can be envisaged for less reactive mixtures to have an extrusion screw which leads to a small intermediate chamber which can possibly for problems of 'congestion be bent, before leading to the extrusion orifice itself.
• the advantage of having a screw end which arrives low, that is to say close to the opening towards the outside of the chamber 13, is that there is no pressure at the end of the screw. which allows the latter to empty completely at the end of the operation.
• there is a self-emptying system that is to say that, if one stop feeding the screw with mixture, the latter will push all the rest of the mixture outside the screw.
• a part 20 in the form of a substantially parallelepipedal recovery pad 20, which cooperates with the receiving surface to create a sort of extrusion blade at the level of an orifice d extrusion 16 formed by the passage arranged between the receiving surface 2 and the profiling wall 211 of the recovery pad 20.
• a recovery shoe 20 according to the invention is shown in perspective in Figure 3.
• This recovery shoe 20 extends parallel to the direction of translation of the receiving surface 2 indicated by the arrow R in Figure 1, and has a front zone 201 and a rear zone 202 taking account of the direction of translation of the surface 2.
• the recovery pad also carries two lateral flanges 203 and 204 which delimit the width of the extrusion orifice 16 in a direction perpendicular to the direction of translation of the receiving surface 2.
• These flanges 203 and 204 extend in the direction longitudinal as shown in Figure 3, in order to also act as sealing lips ensuring close contact with the receiving surface 2, and thereby delimit the width of the strip S which will be formed in contact with said area.
• These edges 203 and 204 then constitute, with the front arch 205 of the recovery pad, a cavity 210 for pressurizing the mixture.
• these flanges 203 and 204 may consist of simple edges which are sufficient to ensure the lateral sealing of the cavity 210 of the recovery pad.
• the extrusion screw 11 opens into the intermediate extrusion orifice 14 located between the two zones 201 and 202.
• the rubber mixture is first deposited on the receiving surface 2 and then, in a second time, under the effect of the relative movement R of this the latter is brought to the level of the cavity 210 formed by the arch 205 of the front part 201 of the recovery pad 20 and is finally present in the extrusion orifice 16 to form a strip S of thin thickness deposited uniformly on the receiving area 2.
• the profile of the wall 205 placed upstream of the profiling wall 211 is adapted so as to force the mixture to a better distribution over the entire width of the profiling wall.
• this profile is designed to create, with the relative movement of the receiving surface, a "dynamic pressure" under the blade in order to form a strip S of constant thickness and width and to apply the mixture to the receiving surface 2 in the best possible conditions by impregnating with mixture all the irregularities of the surface such as the carding grains, the repair holes or else, the junctions of the turns of the strips.
• FIG. 4B illustrates this phenomenon since it represents the evolution of the pressure P (on the ordinate) as a function of the distance d
• FIG. 4A a mixture C is thus seen to appear in the cavity 210 of the front zone 201 of the recovery pad 20 comprised between the wall of the front arch 205 and the receiving surface 2.
• the front arch 205 created with the latter an effect of angle in the zone of exit of the mixture out of the pad of recovery, the arrow R representing the direction of translation of the surface 2.
• the pressure is substantially equal to zero without disturbing this phenomenon of dynamic pressurization whose action contributes to the profiling of the rubber C at the outlet of orifice 16.
• the value of the angle between the front arch 205 and the receiving surface 2 is not necessarily determined precisely but must be sufficiently small and less than 30 °, and preferably between 5 ° and 10 °, to create this dynamic effect.
• the speed of translation of the receiving surface 2 relative to the recovery pad is also a factor of first order to obtain the effect of dynamic pressurization. This speed, depending on the nature of the mixture, the angle of the front arch and the thickness of the strip, can vary between 0.2 and 3 m / s and more generally, is between 0.8 and 1 , 5 m / s.
• the front zone 201 has, at the level of the extrusion orifice 16, a profiling wall 211 which constitutes, as has been said, a kind of profiling blade with the rotary receiving surface 2, and which makes it possible to determining the profile and a substantially “constant” thickness of the strip S.
• the distance separating the profiling wall 211 from the receiving surface C is less than 1 mm and generally between 0.1 and 0.5 mm to obtain strips d '' a thickness of the order of 0.1 mm to 1 mm. This height of the strip S is thus always slightly greater than the height of the blade and considered to be constant with respect to the average profile of the receiving surface.
• a bead P In order to regulate the flow of mixture leaving the screw 13, it may be advisable, in the configuration illustrated in FIG. 1, to allow a bead P to form in the rear part 202 of the recovery pad, which will be able to satisfy consumption instantaneous mixing above average and linked for example to the presence of a hole.
• the regulation of this bead P can be carried out very simply using a probe 35 comprising two feelers 36 and 37 for acquiring the high position and the low position of the bead respectively.
• Those skilled in the art will be able to use other technologies to evaluate the size of the bead by using for example the incidence of a laser beam or even proximity detectors.
• the rear zone 202 does not have a rear edge or lip which would eventually close in the transverse direction the extrusion orifice in contact with the surface, the driving of the mixture towards the front of the recovery pad not necessitating closing the rear area.
• This force is relatively modest, of the order of 500 to 1000 N, which limits the mechanical stresses applied to the system.
• a hole detector as shown in Figure 5
• This detector can be composed for example of one or more feelers 206, 207, 208 which will activate when the real circumferential profile 2 ′ of the reception surface is located below the mean profile 2 of this same surface. The average profile given with reference to the position of the probes relative to the position of the recovery pad.
• the advantage of using several feelers lies in the greater precision brought to the location of the holes.
• the control system registers its azimuth on the circumference of the receiving surface and anticipates the increase in the speed of the screw during the next turn, so as to make a larger quantity of rubber available at the recovery pad when the latter passes over the hole to be filled.
• the apparatus according to the invention can be used to allow the laying of mixtures whose reactivity is such that the vulcanization system of the mixture is divided into two products A and B which, a when combined, react extremely quickly and can vulcanize in a few minutes (less than 7 minutes for temperatures around 100 ° C).
• the invention makes it possible to provide a solution to these problems through the use of the recovery shoe cooperating with the supply system by using at least, in addition to the screw 11, two other extrusion screws 26 and 27 that one can see in figures let 2.
• These extrusion screws 26 and 27 supplied respectively with products A and B, are arranged for example perpendicular to the extrusion screw 11 and diametrically opposite or, on the contrary, with a small angle between the two arrivals.
• These screws 26 and 27 lead to the extrusion screw 11 which will perform a rapid mixing of A and B before discharging the mixture thus produced towards the intermediate extrusion orifice 14.
• the extrusion screws 26 and 27 may have conical ends opening as close as possible to the extrusion screw 11 in order to facilitate mixing and emptying of the installation.
• the products A and B therefore open directly into the conical part of the extrusion screw 11 where they are simultaneously mixed and discharged towards the intermediate extrusion orifice 14. In this way it is possible to place extremely reactive products without the vulcanization taking place. occur in the extruder.
• the screw 11 empties completely because it opens into the intermediate extrusion orifice 14, where the pressure is substantially equal to zero.
• the emptying of the recovery pad is also complete thanks to the small volume contained in the bead and in the cavity 210. In this way, the mixture of products A and B is deposited on the receiving surface 2 a few fractions of a second after have been realized.
• Another application of the invention proves to be particularly advantageous and relates to all of the situations encountered during the manufacture of tire casings, when it is necessary to improve the quality of the interfaces between two layers of rubber of different nature or even when it is essential to improve the raw tights of a profile.
• it is traditionally used dissolving on the basis of rubber mixture and solvent.
• the toxicity of the vapors from these solvents causes nuisances that we seek to reduce by all means.
• a device, as proposed in the invention is particularly suitable for carrying out the deposition of a strip S of very thin rubber mixture on the surface of an envelope during manufacture. .
• This layer of gum a few hundredths of a millimeter thick advantageously replaces any solvent-based dissolution and represents an amount of material equivalent to that deposited in the previous situation.
• Such an apparatus therefore makes it possible to deposit a strip on a receiving surface in relative displacement relative to a recovery pad. It can be easily mounted on a robot to control the movements of the device in a direction transverse to the movement of the receiving surface and to obtain products of very different shapes.
• the pressure for applying the mixture is, moreover, quite sufficient for producing good quality junctions between the strips laid during the various turns of a rotating receiving surface such as a tire carcass to be retreaded.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Manufacturing & Machinery (AREA)
• Extrusion Moulding Of Plastics Or The Like (AREA)
• Tyre Moulding (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=32039553

Family Applications (1)

Country Status (7)

Families Citing this family (9)

Family Cites Families (12)

• 2003
  • 2003-09-19 WO PCT/EP2003/010455 patent/WO2004028779A1/fr active Application Filing
  • 2003-09-19 EP EP03769292A patent/EP1545859A1/de not_active Withdrawn
  • 2003-09-19 JP JP2004538957A patent/JP2006500250A/ja active Pending
  • 2003-09-19 BR BR0314691-0A patent/BR0314691A/pt not_active IP Right Cessation
  • 2003-09-19 CN CNA038225336A patent/CN1684812A/zh active Pending
  • 2003-09-19 AU AU2003277875A patent/AU2003277875A1/en not_active Abandoned
• 2005
  • 2005-03-21 US US11/084,258 patent/US20050230031A1/en not_active Abandoned
• 2008
  • 2008-02-05 US US12/068,338 patent/US20080202666A1/en not_active Abandoned

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events