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
  • B29D35/00—Producing footwear
  • B29D35/12—Producing parts thereof, e.g. soles, heels, uppers, by a moulding technique
  • B29D35/122—Soles
• • 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
  • B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
  • B29C45/17—Component parts, details or accessories; Auxiliary operations
  • B29C45/1703—Introducing an auxiliary fluid into the mould
  • B29C45/1704—Introducing an auxiliary fluid into the mould the fluid being introduced into the interior of the injected material which is still in a molten state, e.g. for producing hollow articles
• • 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
  • B29D35/00—Producing footwear
  • B29D35/12—Producing parts thereof, e.g. soles, heels, uppers, by a moulding technique
  • B29D35/124—Heels
• • 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
  • B29D35/00—Producing footwear
  • B29D35/12—Producing parts thereof, e.g. soles, heels, uppers, by a moulding technique
  • B29D35/128—Moulds or apparatus therefor

Definitions

• the present invention relates to apparatus for and method of gas
• thermoplastic materials Injection moulding of thermoplastic materials is a well-known process.
• mouldings of comparatively thick sections over larger areas typically it is
• foam' in which the material has a closed cellular structure formed by mixing
• Gas Assisted injection Moulding is becoming well known and established as a version of injection moulding in which a fluid, normally gas,
• the gas may be injected into the flow of plastic at the moulding
• the process is based on the known principle that the plastic forms a
• the plastic flows into the mould cavity.
• the plastic is least viscous, i.e. it is most fluid or runny. It is also well
• each mould cavity or feed may be positioned at one or more locations within each mould cavity or feed
• the gas will form a randomly variable void which will be different in shape and contour moulding after moulding.
• moulding machine creates the pressure within the plastic whilst it cools and
• a further requirement of the gas assisted process is to release the gas
• variable voids in the moulded section are variable voids in the moulded section.
• apparatus for gas assisted injection moulding comprising a mould having
• first and second mould parts defining a moulding cavity, means extending
• mould into two or more linked sub-sections and supplying gas to the mould
• the invention also comprises moulded products made by the above
• External dividing channels are positioned so that the spaces between
• the external dividing channels may be formed by male, web-like
• moulding process and for the formation of moulded skins to be as
• dividing channels are used to prevent the formation of large, uncontrolled
• the connecting ribs will be sufficiently small in thickness to
• Figure 1A Illustrates a variable and uncontrolled void which would
• Figure 1 B Illustrates a section through the centre line X-X of
• FIGS 1C-1 E respectively illustrates sections A-A, B-B and C-C, taken
• FIGS 2A-2C respectively illustrate the likely effect of injecting gas
• FIGS 3A-3D Illustrate the application of the invention to a typical
• FIGS 4A-4D correspond to figures 3A to 3D and illustrate the
• FIGS 5A-5D correspond to figures 3A to 3D and illustrate the
• FIGS 6A-6D correspond to figures 3A to 3D and illustrate the
• FIG. 7A-7D correspond to figures 3A to 3D and illustrate the
• Figure 8A-8D correspond to figures 3A to 3D and illustrate the
• Figures 9A-9C illustrate a shoe heel with typical external dividing
• FIGS. 10A-10C illustrate a modification of the arrangement of figures
• Figure 1 1 A Illustrates a cross-section of an insulated container or drinking mug taken along the line B-B of figure 1 1 B,
• Figure 1 1 B is a cross-section taken along the line A-A of Figure
• Figure 12A illustrates the container or drinking mug of figures 1 1A
• Figure 12B is a cross-section taken along the line A-A of figure 12A
• Figure 13A illustrates the effect of injecting gas into a circular thick
• Figure 13B is a cross-section along the line A-A of figure 13 A
• FIG. 14A illustrates the application of the invention so that the
• Figure 14B is a cross-section along the line B-B of figure 14A.
• Figures 1A to 1 E show a possible
• the mould 1 comprises first and second mould parts 3 and 4
• mould cavity 6 in which the shape 2 is moulded.
• a moulding material inlet 7 and a gas inlet 8 lead into the mould cavity 6.
• Figures 2A to 2C show the problem described above in a moulded
• Figures 2B is the view in
• Figures 3A to 3D show the invention applied to a sole and heel shape
• Figure 3A is a plan view of the sole
• figure 3B is a cross-sectional view taken along the line C-C in
• figure 3A and figures 3C and 3D are cross-sectional views taken along the
• the mould of the invention comprising a series of upstanding ribs extending from the surface of the
• T e gas injector for the mould is indicated
• FIG. 1E is replaced by a plurality of smaller controlled voids 34.
• Channels between the ribs split the ribs into sections and form subsidiary
• connecting ribs will provide lateral tensile and compressive strength to
• the connecting ribs are normally
• FIGS. 4A to 4D illustrate a modified form of the moulding shown in
• FIGS 5A to 5D illustrate another modified form of the moulding
• Figures 6A to 6D illustrate a modified form of the moulding shown in
• FIGS. 7A to 7D illustrate a modified form of the embodiment shown
• FIGS. 8A to 8D illustrate a modified form of the embodiment shown
• Figures 9A to 9C respectively correspond to figures 2A to 2C.
• FIGs 10A to IOC respectively correspond to figures 9 A to 9C but
• the gas and plastic feeds are from the bottom of the heel rather than the
• shoe sole or heel is preferably covered with an inner sole in order
• Such inner soles may be fixed or
• Inner soles are often used in shoe construction as illustrated in Figures 6A to 6D. Inner soles are often used in shoe construction as illustrated in Figures 6A to 6D. Inner soles are often used in shoe construction as illustrated in Figures 6A to 6D. Inner soles are often used in shoe construction as illustrated in Figures 6A to 6D. Inner soles are often used in shoe construction as illustrated in Figures 6A to 6D. Inner soles are often used in shoe construction as illustrated in Figures 6A to 6D. Inner soles are often used in shoe construction as illustrated in Figures 6A to 6D. Inner soles are often used in shoe construction as illustrated in Figures 6A to 6D. Inner soles are often used in shoe construction as illustrated in Figures 6A to 6D. Inner soles are often used in shoe construction as illustrated in Figures 6A to 6D. Inner soles are often used in shoe construction as illustrated in Figures 6A to 6D. Inner soles are often used in shoe construction as illustrated in Figures 6A to 6D. Inner soles are often used in shoe construction as illustrated in Figures
• channels or voids are formed with comparatively consistent cross-sections
• Th e hollow channels achieve reductions in production costs
• shoe sole or heel or another component is formed by
• the external dividing channels may be positioned so that the spaces
• channels are formed with comparatively controlled and predictable wall
• the external dividing channels are formed by the male, rib-like
• features in the mould tool may be designed and positioned to provide
• the invention has a wide variety and range of applications.
• hollow internal gas channels, and external dividing channels provide an
• One such application is the moulding of one-piece food or liquid or
• One example is a drinking cup or mug or tumbler a shown
• continuous hollow internal channels 1 14 partially cover the base 1 15 and
• a lid 127 which may be moulded in plastic, with or without the features of
• reduce resistance to compression may be provided by including a blowing
• the material may be fed directly into the component
• the gas may be injected either directly into the plastic in the mould
• configuration of the dividing channels may require the injection of gas
• the channels should be at a depth of between 90% and 60% of the total
• the thicknesses therefore vary, preferably between 1 and 4mm.
• the thickness of the rib also requires a generous draw taper to facilitate ejection of the moulding from the mould cavity.
• the thickness of the connecting ribs is dependent on the plastic
• the number of connecting ribs is dependent on the lateral rigidity or
• connecting ribs is therefore preferably between 10 and 30mm.
• thicker sections, in which hollow continuous gas channels are formed may be formed.
• channels are in the direction of the draw of the opening of the mould
• Figures 14A and 14B illustrate the addition of externally formed
• gas and plastic are fed through the same inlet 142.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Manufacturing & Machinery (AREA)
• Footwear And Its Accessory, Manufacturing Method And Apparatuses (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=10815829

Family Applications (1)

Country Status (4)

Families Citing this family (1)

Family Cites Families (9)

• 1997
  • 1997-07-15 GB GBGB9714807.6A patent/GB9714807D0/en active Pending
• 1998
  • 1998-07-14 AU AU84472/98A patent/AU8447298A/en not_active Abandoned
  • 1998-07-14 WO PCT/GB1998/001879 patent/WO1999003665A1/en not_active Application Discontinuation
  • 1998-07-14 EP EP98935110A patent/EP1005409A1/de not_active Withdrawn

Non-Patent Citations (1)

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