Classifications

• • 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
  • C03B40/02—Preventing adhesion between glass and glass or between glass and the means used to shape it, hold it or support it by lubrication; Use of materials as release or lubricating compositions
• • 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

Definitions

• the present invention relates to a process for lubricating a surface such as a mould, a conveyor belt, etc., for the manufacture of a glass article such as a receptacle, in which there is periodically deposited a layer of lubricant on the surface.
• the manufacture of glass objects, in particular hollow glass objects such as bottles, flasks, etc. . . . is usually carried out in accordance with two methods:
• blown-blown in which a blank is formed by blowing in a first mould, this blank being then transferred to a second mould in which it is blown so as to assume its final shape.
• the second method termed, "pressed-blown", in which a blank is formed by pressing a drop of glass or parison issuing from a hopper in a mould, this blank being then transferred to a blowing mould in which the hollow blank is blown so as to assume its final shape.
• the internal walls of the moulds in which the blanks are formed are regularly lubricated to permit an improved penetration of the glass and avoid .[.cetain.]. .Iadd.certain .Iaddend.surface defects of the blank, which defects subsist on the finished receptacle.
• the technique still frequently employed at the present time in glassworks is a technique involving the manual lubrication of the moulds, which is not without danger for the handlers. This lubrication is usually carried out with an oil containing graphite in suspension.
• French Pat. No. 1,285,586 discloses an automatic lubricating process for a closed mould in which the moulding apparatus is provided with lubricating passageways through which oil is injected into the mould before introducing the parison in the latter.
• U.S. Pat. No. 4,409,010 discloses a process for lubricating moulds by a spaying of liquid oil onto the internal surfaces of the moulds, but the disclosed process does not avoid the drawbacks relating to the use of oil for the lubrication.
• Such a process which is particularly required when producing receptacles of high quality, for example in the perfumery field, necessarily increases the manufacturing costs and it is at the present time desired, for the manufacturer of glass bottles or receptacles in respect of which the surface quality requirements are less strict, to obtain directly from the mould, a receptacle whose surface state is acceptable to the client.
• U.S. Pat. No. 4,412,974 discloses a process for producing carbon black in which an acetylene jet is cracked in an air or oxy-fuel flame.
• This process has numerous applications.
• One consists in depositing a layer of carbon black on the walls of a mould, this layer having high lubricating and insulating qualities.
• Such a process is applicable in the glass-making field in particular for insulation against thermal and mechanical shocks of belts transferring glass objects issuing from the moulding machine and traveling for example to the machine for effecting a surface polishing with the flame mentioned above. In this way, harmful thermal and/or mechanical shocks of the glass receptacles leaving the moulds are avoided owing to the insulating properties of the produced carbon deposit.
• the process according to the invention permits in particular, when lubricating the moulds, the obtainment of a carbonaceous deposit which gives a skin quality to the glass which is very distinctly superior to that of the known processes and does not necessarily require a surface treatment of the receptacle when it leaves the mould.
• the process according to the invention is characterized in that the layer of lubricant is produced by means of a source of heat of a temperature exceeding 2000° K., through which there is injected for a predetermined period of time a gaseous .[.hydrocargon.].
• .Iadd.hydrocarbon .Iaddend.or mixture of a gaseous hydrocarbons comprising at least 15% of a constituent in respect of which the ratio of the number of carbon atoms to the number of hydrogen atoms C/H is higher than 0.75, the rate of injection of the hydrocarbon through the flame and the temperature of the latter being controlled in such manner as to obtain a porous layer of carbonaceous particles, which when they are deposited on the glass article whose external skin is at a temperature higher than about 500° C., are capable of burning in air.
• the source of heat is an oxygen-fuel flame having an oxygen factor of higher than 1.
• the carbonaceous deposit obtained is thus a porous layer which, after compression by the parison in the mould is slightly thermally insulating, which permits a uniform cooling of the skin of the glass receptacle by a cooling of the mould, but sufficiently thermally insulating to avoid a temperature gradient in the glass which would produce internal tension in the walls of the receptacle, thus rendering it more fragile.
• the quality of the skin of the receptacle obtained form the mould has an influence on the resistance of the receptacle to pressure. This parameter is very important for receptacles containing in particular gassy drinks.
• the process according to the invention permits, by the improvement in the quality of the skin of the receptacle directly issuing from the mould, an increase in the resistance to pressure of the receptacle of about 25% or even more, which is considerable. In some applications, this enables the thickness of the glass wall to be decreased for a given strength.
• the carbonaceous deposit obtained also has a very important feature in practice since it is found that it burns in the air when it is deposited on the glass blank: in this way, the finished receptacles have no traces of pollution, which considerably improves the manufacturing outputs. Further, the moulds may be simply cleaned with a cloth if this is necessary.
• a considerable advantage of the invention is that it permits the use of moulds which have been subjected to no polishing or lacquering on their internal surfaces, which operations are very expensive.
• the receptacles obtained from such non-polished moulds lubricated in accordance with the invention have indeed a skin quality higher than that of receptacles obtained from polished or lacquered moulds provided with a layer of lubricant according to the prior art.
• an oxyacetylene flame is preferably employed as a source of heat capable of producing a temperature higher than or equal to 2000° K.
• any source of heat having a temperature higher than 2000° K. is suitable, such as plasma.
• this lubrication can be carried out between the extraction of the blank and the pouring of a new drop of glass.
• hydrocarbons suitable for producing a powdered carbonaceous material by a thermal cracking there may be chosen, alone or in a mixture, acetylene, propyne, .[.propadiene,.]. benzene, acetylene-ethylene mixtures consisting of propyne,.[.propadiene,.]. benzene, acetylene-ethylene mixtures, the mixtures formed by propyne, propadiene, propylene, and other C 3 or C 4 hydrocarbons, such as butadiene, butene, propane.
• the mixtures containing at least 15% acetylene are suitable for carrying out the invention: there may be mentioned the acetylene-ethylene mixtures, in particular the mixtures sold under the commercial trademark, "Crylene” containing about 20% acetylene by volume and 80% ethylene by volume.
• the mixtures known under the trademark "Tetrene” consisting of propyne, propydiene, propylene, butadiene, butene, propane, in the proportion of 20 to 25% propyne by volume, 15 to 20% propydiene, 45 to 60% propylene by volume, 2 to 5% butadiene by volume, 2 to 5% butene by volume, 5 to 8% propane by volume, may also be suitable.
• Acetylene will preferably be used when the available period of time for lubricating the mold is less than about a second. Generally, tests may be carried out with different hydrocarbons so as to determine if the available period of time is sufficient to obtain a layer having good properties. When hydrocarbons of the "Crylene” or “Tetrene” type are used, it will be preferable to have a flame whose temperature is higher than 2200° K., and to slow down their rate of injection relative to the acetylene. One skilled in the art will determine the optimum conditions by simple routine measures.
• the carbonaceous material obtained on the walls before the dropping of the parison into the mould is constituted by .[.agregates.]. .Iadd.aggregates .Iaddend.of spherules of very small diameter, between 5 and 50 nm, and more generally between 10 and 25 nm. These particles are visibly disordered and are not like any known structure in carbonaceous materials such as graphite, etc.
• the macrostructures are of the type having filaments whose length is 0.5 to 5 ⁇ m, and whose diameter is 0.1 to 0.5 ⁇ m which appear in a haphazard manner.
• the whole forms an extremely powdered deposit having a very great apparent porosity (before the dropping of the parison) of 90 to 90% and preferably 95 to 98%.
• the thickness of the film in particular depends on the duration of the injection of the hydrocarbon and it is possible to obtain, for example on a metallic surface, deposits of 1 to 50 ⁇ m thickness.
• the spherical particles all have the characteristics of soot formed by carbonisation in a gaseous phase. They are therefore formed by solid carbon on which are more or less adsorbed various hydrocarbons, such as polyaromatic hydrocarbons which may or may not contain heteroatoms--O,H, S . . . On the whole, the fraction of carbon by weight is higher than 0.99.
• the surface to be lubricated will be the conveyor belt for the glass object when the latter leaves the mould and is conveyed to another station of the machine for another manufacturing step (reheating, etc.).
• the glass object is still hot during this transfer (temperature usually higher than about 500° C.)
• the same improvements are obtained as in the region of the mould, i.e. the absence of a greasy deposit and the maintenance of an excellent surface state.
• the flame is produced with an oxygen-natural gas mixture whose oxygen factor is equal to 1.35.
• the flame is directed in a direction parallel to the axis of the moulds and the lubrication is carried out when the mould is closed, between the ejection of the preceding blank and the introduction of a new drop of glass.
• the ventilation is stopped during the lubrication.
• An impulsion of acetylene occurs every n cycles of manufacture with 5 ⁇ n ⁇ 10; the duration of each impulsion is 0.8 second, the corresponding rate of flow is equal to about 600 ml with a rate of injection of the acetylene into the flame on the order of 240 m/s.
• An oxygen-propane mixture is used whose oxygen factor is equal to 1.2.
• the impulsion of acetylene occurs every n cycles of manufacture: with 5 ⁇ n ⁇ 10; the duration of each impulsion is 0.75 second, the corresponding rate of flow is equal to about 450 ml, the rate of injection of the acetylene is on the order of 170 m/s.
• the lubrication is carried out when the mould is open in accordance with the teaching of French Pat. No. 25 70 364.
• the ventilation for cooling the moulds is preferably cut off during the lubrication.
• This example shows the improvement obtained in respect of the transferring conveyor located on the output side of the I.S. machine.
• An oxygen-.[.ntural.]..Iadd.natural .Iaddend.gas flame is .[.sused.]. .Iadd.used .Iaddend.whose oxygen factor is equal to 1.1.
• a curtain of flames (one flame about every 8 mm) evenly spaced apart, perpendicular to the conveyor (about 170 mm above the latter) and about throughout the width of the latter is employed with an injection of acetylene through openings halfway between the flames (also every 8 mm).
• the conveyor belt to be treated measures 120 mm in width and travels through one complete path every 40 seconds. It is located at the entrance of the reheating arch and receives the bottles from a "machine" conveyor belt disposed at 90° and travelling slightly faster.
• the invention is generally applicable to the lubrication of any surface, such as a mould, a conveyor belt, etc. for contact with hollow or flat glass objects whose temperature is still sufficiently high to cause abrasions, scratching, or deformation under the conditions (in particular mechanical conditions) under which the glass object comes in contact with said surface.

Landscapes

• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Organic Chemistry (AREA)
• Re-Forming, After-Treatment, Cutting And Transporting Of Glass Products (AREA)
• Moulds For Moulding Plastics Or The Like (AREA)
• Containers Having Bodies Formed In One Piece (AREA)
• Lubricants (AREA)
• Blow-Moulding Or Thermoforming Of Plastics Or The Like (AREA)

Priority Applications (1)

Applications Claiming Priority (5)

Related Parent Applications (1)

Publications (1)

Family

ID=9333165

Family Applications (2)

Family Applications After (1)

Country Status (14)

Cited By (5)

Families Citing this family (18)

Citations (9)

Family Cites Families (1)

• 1986
  • 1986-03-17 FR FR8603733A patent/FR2595684B1/fr not_active Expired - Lifetime
• 1987
  • 1987-03-13 WO PCT/FR1987/000071 patent/WO1987005595A1/fr unknown
  • 1987-03-13 US US07/652,579 patent/USRE34785E/en not_active Expired - Lifetime
  • 1987-03-13 KR KR1019870701058A patent/KR950007699B1/ko not_active IP Right Cessation
  • 1987-03-13 DE DE198787400560T patent/DE238403T1/de active Pending
  • 1987-03-13 AU AU71641/87A patent/AU597351B2/en not_active Ceased
  • 1987-03-13 AT AT87400560T patent/ATE50973T1/de not_active IP Right Cessation
  • 1987-03-13 BR BR8706211A patent/BR8706211A/pt not_active IP Right Cessation
  • 1987-03-13 EP EP87400560A patent/EP0238403B1/fr not_active Expired - Lifetime
  • 1987-03-13 JP JP62501897A patent/JP2736065B2/ja not_active Expired - Fee Related
  • 1987-03-13 ES ES87400560T patent/ES2015305B3/es not_active Expired - Lifetime
  • 1987-03-13 US US07/110,214 patent/US4806137A/en not_active Ceased
  • 1987-03-13 DE DE8787400560T patent/DE3761902D1/de not_active Expired - Lifetime
  • 1987-03-16 CA CA000532121A patent/CA1298084C/fr not_active Expired - Lifetime
  • 1987-03-16 AR AR307025A patent/AR240894A1/es active
• 1990
  • 1990-03-15 GR GR90400002T patent/GR3001001T3/el unknown

Patent Citations (12)

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