CH466122A - Method for forming blister-shaped packages, apparatus for carrying out this method, packaging resulting from this method - Google Patents

Description

       

  
 



  A method of forming blister-shaped packages, apparatus for placing
 implementation of this process, packaging resulting from this process
 A blister-shaped product package includes a sheet of thermoplastic material which is formed with a depressed portion which contains product, and a cover sheet which is adhered to the thermoplastic sheet all around the depression to 'enclose the product.



   The object of the present invention is a method for forming blister-shaped packaging, it is also an apparatus for implementing this method, it is also the packaging resulting from this method.



   The method according to the invention is characterized in that a forming roll with a horizontal axis is used, the surface of which comprises a cavity forming a matrix, in that a sheet of thermoplastic material is brought onto the surface of the roll, in that vacuum suction is applied to the die-forming cavity in order to attract a portion of the sheet into said cavity thereby producing a vacuum in said sheet, in that a product is deposited in said vacuum portion which is located in said cavity, in that a cover sheet is made to adhere to said thermoplastic sheet all around the depressed part in order to enclose the product, and in that the product in the enclosed state is removed from said cavity forming matrix,

   said roller performing a rotational movement about its axis at least to remove the product in the enclosed state from said die cavity.



   In one embodiment of the particularly advantageous process, the thermoplastic material is heated beforehand, and, after the product has been deposited in the part under reduced pressure, it is subjected to cooling such that the material which forms this part under reduced pressure is subjected to cooling. tightens on the product.



   The apparatus for implementing the method according to the invention is characterized in that it comprises a forming roll, at least one cavity forming a matrix in the surface of this forming roll, means for depositing a thermoplastic sheet on said cavity forming a matrix, means for making a vacuum suction on this cavity forming a matrix in order to produce a part in depression in the sheet, means for depositing a product in said part in depression, means for making a cover sheet adhere to said thermoplastic sheet all around the part in depression so as to enclose the product, and means for rotating said roller about its axis at least during the removal of the packaged product from said cavity forming a die.



   An embodiment of the method according to the invention, as well as the apparatus used for this implementation, is now described in conjunction with the appended drawing in which:
 fig. 1 is an elevational view of a forming machine having a blister roll, which shows in section the forming roll of the machine, and
 fig. 2 is an elevational view similar to FIG. 1 which shows in section the fixed suction pipe intended for the forming roller.



   Referring to the drawings, a forming roll 4 works in conjunction on one side with a preheating roll 3 which supplies a thermoplastic sheet material I to the forming roll, and on the other side with a sealing roll. S which provides the cover material. The forming roll carries on its surface at the periphery a series of die-forming cavities 10, each of these cavities having an axially extending communication duct 11, this duct extending to one end of the roll with a view to 'a further communication with a fixed system 9 intended to apply the vacuum during the rotation of the forming roll.

   A tablet feeder 6 is provided between the forming and sealing rolls, likewise
 that tension rollers 7 are provided to maintain the tension on the sheets, and that a guillotine device 8 is also provided.



   The preheating roller is kept running
 operation at a temperature high enough to plasticize the thermoplastic sheet and the forming roll is maintained at a temperature low enough to prevent adhesion of the thermoplastic material to the sealing surface, but the temperature being however kept high enough to prevent frosting of the sheet during forming. The sealing roll 5 is maintained at a temperature sufficient to effect a hot pressure sealing of the thermoplastic sheet on the cover sheet, which may for example be a metal sheet.



   The rotation of the rollers in the direction of the arrows causes the sheets to be drawn through the machine. As a die-forming cavity moves while engaging the preheating roll it is covered with the thermoplastic sheet and rotation of the forming roll continuing to place the die-forming cavity in communication with the coating system 9. empty, through its pipe 1 1 which extends axially. Thus the thermoplastic material is drawn into the cavity in order to form a re-entrant part in the thermoplastic sheet, and then, while the re-entrant part is still under the action of vacuum, a tablet is deposited there from the supply device 6. .

   The die-forming cavity continues its travel and ceases to be in communication with the suction system, and contacts the cover sheet which is sealed to the thermoplastic sheet as a result of the action on each other. forming and sealing rolls. After sealing, the entire wrapped part is taken out of the die cavity, when cooling begins so that the material of the re-entrant part tightens on the tablet. The separation of the packaged parts from each other is carried out by the guillotine system.



   According to the above arrangement, the product is deposited in the corresponding re-entrant part before the material of the re-entrant part cools, and the deposition and covering operations are carried out almost simultaneously with the forming operation of the re-entrant part.



   It has also been found that by using the above apparatus with a metal foil as the covering foil, the action of the pressure between the forming roll and the sealing roll causes the formation of a weakening line on the cover. the part of the sheet which forms a right angle all the way around the periphery of the depressed part. This is useful in order to facilitate the eventual removal of the product from the packaging by applying pressure through the cover sheet. Thus, the blister package described above can advantageously have a metal foil as the cover foil, which creates a line of weakness all along the periphery of the depressed portion.



   This process has been described by way of example with reference to the packaging of tablets, but it should be understood that it is also very well applicable to the packaging of other products including small quantities of powder by means of. slight rearrangement of the shape roll position during filling.
  


    

Claims (1)

CLAIM I A method of forming a blister-shaped package, characterized in that a forming roll with a horizontal axis and the surface of which comprises at least one die cavity is used, in that a sheet of thermoplastic material is brought onto the surface of the roller, in that vacuum suction is applied to the die-forming cavity in order to attract a part of the sheet into said cavity, thereby producing a vacuum in said sheet, in that a product is deposited in said part in depression which is in said cavity, in that a cover sheet is made to adhere to said thermoplastic sheet all around the part in depression in order to enclose the product, and in that the product is removed from there. 'enclosed state of said die-forming cavity, said roller performing a rotational movement about its axis at least to remove the product in the enclosed state from said die cavity. SUB-CLAIMS 1. Method according to claim I, characterized in that said roller is driven in continuous rotation around its axis while said suction is applied, said product is deposited, and said sheet is adhered to. cover. 2. Method according to claim I, characterized in that the thermoplastic material is heated before bringing it onto the surface of the roll. 3. Method according to sub-claim 2, characterized in that said heated material is subjected to cooling such that the thermoplastic material forming the part under reduced pressure on the product as a result of this cooling. 4. Method according to claim I, characterized in that one causes the formation of a line of weakness in the cover sheet all around the part in depression. CLAIM II Apparatus for carrying out the method according to claim I, characterized in that it comprises a forming roll, at least one cavity forming a matrix in the surface of this forming roll, means for depositing a thermoplastic sheet on said cavity forming a matrix , means for making a vacuum suction on this cavity forming a matrix in order to produce a part in depression in the sheet, means for depositing a product in said part in depression, means for making a cover sheet adhere to said sheet thermoplastic all around the depressed part so as to enclose the product, and means for rotating said roller about its axis at least when removing the packaged product from said cavity forming a die. SUB-CLAIMS 5. Apparatus according to claim II, characterized in that said means for depositing the sheet, said suction means for establishing a vacuum, said means for depositing product and said means for making the cover sheet adhere are arranged to enter into a vacuum. acting successively during movement of the die cavity during continuous rotation of said forming roll. 6. Apparatus according to claim II, characterized in that it comprises a rotating sealing roller which works in clamping connection with said forming roller for supplying the cover sheet, and for the operation of adhering said said forming roller. cover sheet by pressure on the sheet of thermoplastic material all around said depressed part by means of the passage of this sheet of thermoplastic material and of this cover sheet at the place where the clamping occurs between said rollers. 7. Apparatus according to claim II, characterized in that it comprises a heating roll, and means for passing the thermoplastic material around this heating roll and from there on the surface of the forming roll. 8. Apparatus according to sub-claim 5, characterized in that the forming roll carries, extending over its periphery, a series of die-forming cavities, and in that the suction means for producing the vacuum comprise a fixed system. valve designed to ensure, during the rotation of said forming roller, a precise successive engagement of said die-forming cavities, by means of means of communication by conduits located in the forming roller. CLAIM III Blister-shaped package resulting from the process according to claim I.