Classifications

• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
  • C03B9/00—Blowing glass; Production of hollow glass articles
  • C03B9/30—Details of blowing glass; Use of materials for the moulds
  • C03B9/38—Means for cooling, heating, or insulating glass-blowing machines or for cooling the glass moulded by the machine
  • C03B9/3825—Details thereof relating to plungers
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
  • C03B40/00—Preventing adhesion between glass and glass or between glass and the means used to shape it, hold it or support it
  • C03B40/04—Preventing adhesion between glass and glass or between glass and the means used to shape it, hold it or support it using gas
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
  • C03B9/00—Blowing glass; Production of hollow glass articles
  • C03B9/13—Blowing glass; Production of hollow glass articles in gob feeder machines
  • C03B9/193—Blowing glass; Production of hollow glass articles in gob feeder machines in "press-and-blow" machines
  • C03B9/1932—Details of such machines, e.g. plungers or plunger mechanisms for the press-and-blow machine, cooling of plungers

Definitions

• the invention relates to a device for pressing hollow moldings made of glass between a mold which has an inner wall which is complementary to the outside of a molding, and a plunger which has an open-pore plunger head with a surface which is complementary to the inside of the molding and an internal cavity , which can be filled with a liquid, a portion of which evaporates by heat transfer from the glass to the plunger head during each working cycle, forms a separating vapor layer between its surface and the glass and is replaced by further liquid introduced into the plunger head.
• the flow rates of the liquid which usually consists of water which is as pure as possible, between the cavity of the plunger head and the outer surface thereof are locally changed greatly.
• the pressure drop in the steam area becomes significantly greater than in the water area, due to the significantly larger volume of the vapor compared to the liquid volume.
• the invention is based on the object of developing a device for pressing hollow moldings made of glass in such a way that the cooling of the moldings takes place more uniformly than before under the influence of the steam emerging from the plunger head and the resulting moldings are thereby largely free of internal stresses and unwanted differences in wall thickness.
• the object is achieved in a device of the type described above in that the porosity of the plunger head increases from its inner cavity to its surface. In other words, the flow resistance of the plunger head is reduced from the water side to the glass side. It has been established, and can also be demonstrated by calculation, that this results in a more uniform flow through the plunger head.
• the plunger head has two concentric layers of different porosity.
• the plunger head is expediently fastened to a liquid-tight support body and has an inner layer of lower porosity and an outer layer of greater porosity, of which the inner layer has its greatest thickness in an area adjacent to the support body. It is thereby achieved that, when the flow through the plunger head is generally more uniform compared to the prior art, a minimum flow occurs in the area adjacent to the support body. This has the advantage that an excessively abrupt cooling of the molding in its mouth area is avoided.
• the embodiment of the invention described above can be developed with the same aim in that the outer layer has its smallest thickness in the region adjoining the supporting body.
• the flow resistance of the plunger head can also decrease continuously from the inside to the outside, ie from the water side to the glass side.
• the device shown is used for pressing hollow molded articles 10 made of glass, which are then blown into beer bottles or the like. are further processed. Such a formation 10 is partially shown in the drawing.
• the device has a hollow shape 12 with an inner wall 14 which is complementary to the outside of the molded article 10, a support ring 16 and a two-part neck ring 18 for forming an opening 20 of the molded article 10.
• a plunger 22 is associated with the mold 12 and has a supporting body 24 and a plunger head 26 attached to it.
• the plunger head 26 consists of open-pore sintered metal and has a surface 28 which is complementary to the inside of the molded article 10 and an inner cavity 30 and is welded to the supporting body 24, for example.
• the drawing shows the mold 12 in the closed state and the plunger 22 in an end position which it has reached by immersing it in the mold 12, into which a glass drop has previously been introduced.
• the plunger head 26 consists of two concentric layers 32 and 34 of open-pore sintered metal.
• the inner layer 32 which delimits the cavity 30, has a lower porosity and thus a greater flow resistance than the outer layer 34.
• the wall of the plunger head 26 has approximately the same overall thickness wherever it has a shaping effect on the shaping 10.
• each of the layers 32 and 34 has a thickness that varies with increasing distance from the support body 24.
• the inner layer 32 has its greatest thickness in the area radially inside the neck ring 18.
• its outer layer 34 has its smallest thickness.
• the total flow resistance of the wall of the plunger head 26 is greater in the area radially inside the neck ring 18 than in the other areas of the plunger head 26.
• the plunger 22 also includes an inner tube 36 which extends axially through the support body 24 and into the plunger head 26 and is sealed with an annular seal 38 against the inner wall of the support body 24.
• a piston-cylinder unit is provided in the usual way, of which only one end of a hollow piston rod 40 is shown.
• the support body 24 is fastened to the piston rod 40 and sealed against it with a further ring seal 42.
• the plunger is "fed _ ⁇ ser 22 of the hollow piston rod 40 forth through the inner tube 36 V, the 30 of the plunger 26 as well as the pores in the wall of the plunger head 26 fills the cavity ur.c evaporated ver ⁇ in the pores, so that between the surface 28 and the glass from which the ling 10 is formed, a vapor layer forms.
• This also applies to the neck area 32 of the plunger head 26, which, however, because of the relatively large thickness of the inner layer 32, emits less water vapor than the other areas of the plunger head 26.
• the molding 10 is also in the area of its mouth 20 by a Vapor layer kept separate from plunger 22. At the same time it is avoided that the molding 10 cools too suddenly in the region of its mouth 20.

Landscapes

• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Organic Chemistry (AREA)
• Manufacturing & Machinery (AREA)
• Moulds For Moulding Plastics Or The Like (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=6413568

Family Applications (1)

Country Status (3)

Cited By (1)

Families Citing this family (1)

Citations (4)

• 1990
  • 1990-09-04 DE DE19904028028 patent/DE4028028C1/de not_active Expired - Fee Related
• 1991
  • 1991-09-03 AU AU84042/91A patent/AU8404291A/en not_active Abandoned
  • 1991-09-03 WO PCT/EP1991/001667 patent/WO1992004288A1/de unknown

Patent Citations (4)

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