Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B27/00—Layered products comprising a layer of synthetic resin
  • B32B27/18—Layered products comprising a layer of synthetic resin characterised by the use of special additives
  • B32B27/20—Layered products comprising a layer of synthetic resin characterised by the use of special additives using fillers, pigments, thixotroping agents
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B27/00—Layered products comprising a layer of synthetic resin
  • B32B27/06—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B3/00—Layered products comprising a layer with external or internal discontinuities or unevennesses, or a layer of non-planar shape; Layered products comprising a layer having particular features of form
  • B32B3/02—Layered products comprising a layer with external or internal discontinuities or unevennesses, or a layer of non-planar shape; Layered products comprising a layer having particular features of form characterised by features of form at particular places, e.g. in edge regions
  • B32B3/04—Layered products comprising a layer with external or internal discontinuities or unevennesses, or a layer of non-planar shape; Layered products comprising a layer having particular features of form characterised by features of form at particular places, e.g. in edge regions characterised by at least one layer folded at the edge, e.g. over another layer ; characterised by at least one layer enveloping or enclosing a material
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25D—REFRIGERATORS; COLD ROOMS; ICE-BOXES; COOLING OR FREEZING APPARATUS NOT OTHERWISE PROVIDED FOR
  • F25D2201/00—Insulation
  • F25D2201/10—Insulation with respect to heat
  • F25D2201/14—Insulation with respect to heat using subatmospheric pressure

Definitions

• the present invention relates to evacuated jackets for thermal insulation, and in particular it relates to an evacuated jacket comprising an improved envelope, as well as to a process for manufacturing the same.
• Evacuated jackets are being increasingly used in a number of fields wherein thermal insulation at temperatures lower than about 100°C is required.
• an evacuated jacket is formed of an envelope inside which a filling material is provided.
• the envelope has the purpose of preventing (or reducing as much as possible) the entrance of atmospheric gases into the jacket, so as to maintain a vacuum level compatible with the degree of thermal insulation required by the application.
• the filling material has mainly the function of spacing apart the two opposite sides of the envelope when the jacket is evacuated, and must have a porous or discontinuous internal structure, so that its porosities or interstices can be evacuated in order to perform the thermally insulating function.
• This material can be inorganic, such as for example silica powder, glass fibers, aerogels, diatomaceous earths, etc.; or organic, such as rigid polyurethane or polystyrene foams, both in the form of boards and of powders.
• the envelope is made with so-called "barrier" sheets, which are characterized by their gas permeability being as low as possible and can be made of a single component but more frequently are multi-layers of different components.
• the "barrier" effect is conferred by one of the component layers, or barrier layer, which can be formed of polymeric materials, such as ethylene-vinyl alcohol copolymers (known in the literature with the abbreviation EVOH); of polymeric layers on which a thin layer (generally less than 0,5 ⁇ m) of aluminum or of an inorganic oxide is deposited; or of a metal sheet, mainly aluminum, having a thickness generally comprised between 4 and 10 ⁇ m.
• the multi-layer barrier sheet comprises at least one support layer of a polymeric material having good mechanical features, particularly plasticity; said layer can be formed for example of polyacrylonitrile (PAN) or a polyolefine.
• PAN polyacrylonitrile
• the barrier layer is covered with at least one protection layer, also polymeric.
• the polymeric protection layers are commonly made of polyesters (for example polyethylene terephtalate, normally abbreviated in PET) or polyamides (for example, Nylon ® ). Multi-layers comprising five, six or even more superimposed layers are also common.
• the envelope is generally formed of two barrier sheets having rectangular shape, reciprocally joined along the margins thereof by means of perimetrical weldings.
• the so joined margins of the barrier sheets form four flanges arranged at the sides of the resulting envelope.
• the main drawback of the envelopes of this kind consists exactly in the presence of these flanges, which are very fragile and their possible fracturing can easily propagate beyond the perimetrical weldings, causing the permeation of atmospheric gases into the jacket and thus compromising the thermal insulating features thereof.
• the barrier sheet hardly forms sharp corners and can be only curved; a slot (indicated with L in figure 5c) remains in the intersection area between flange F and the seals transversal thereto, which enables the passage of atmospheric gases towards the inside of the jacket, although in a reduced quantity.
• the smallest gas infiltrations resulting from this imperfections, which would be acceptable in other technical fields, are not acceptable in the case of the envelopes for evacuated jackets.
• Object of the present invention is therefore providing an evacuated jacket free from said drawbacks and a process for manufacturing the same. Said object is achieved by means of an evacuated jacket whose main features are specified in the first claim and other features are specified in the subsequent claims. The features of the process are specified in claim 7.
• a first advantage of the evacuated jacket according to the present invention consists in that its envelope has a very good gas tightness also at the end seals, although it is made starting from a single barrier sheet.
• said support layer and said protecting layer being formed of mutually heat- sealable materials having a similar melting temperature, it is possible that the opposite layers which are joined together by means of said longitudinal welding belong to opposite sides of the sheet, so that the resulting envelope is flat in the welding area and does not comprise a longitudinal flange.
• An advantage of the process for manufacturing the evacuated jacket according to the present invention consists in that, simultaneously to the sealing of the envelope ends, the thickness of the transversal flanges is made uniform by the welding bars. As a matter of fact, while said bars are nearing each other, the exceeding material is discharged form the sides because of the pressure of said bars and can be removed.
• said support layer and said protection layer are made of the same material.
• FIG. 1 shows an enlarged cross-sectional view of a barrier sheet that can be used for manufacturing an evacuated jacket according to said embodiment
• FIG. 2 shows a step of the manufacturing of the evacuated jacket according to said embodiment
• FIG. 3 shows a complete evacuated jacket according to said embodiment
• - figure 4 shows an enlarged cross-sectional view of a lateral flange of the jacket of figure 3 taken along line IV -IV of the same figure; and - figures 5a, 5b and 5c, the last being an enlarged partial sectional view, schematically show three steps of the manufacturing of a known jacket.
• barrier sheet 1 which forms the envelope of the evacuated jacket according to the present embodiment of the invention is a multi-layer comprising a central layer 2 provided with barrier properties towards atmospheric gases and consisting for example of a metal sheet, e.g. aluminum, having a thickness between 4 and 10 ⁇ m.
• a metal sheet e.g. aluminum
• said multi-layer comprises a lower layer 3 and an upper layer 4 suitable for providing support and protection for the central layer 2, and to enable the heat-sealing of the sheet.
• the materials which form said layers are mutually heat-sealable.
• Said materials can be selected in the group consisting of polyacrylonitrile (PAN), polyolefines, such as polyethylene, and polyvinylchloride, as well as mixtures and copolymers thereof.
• PAN polyacrylonitrile
• the lower layer 3 and the upper layer 4 suitably have a thickness between 20 and 100 ⁇ m, preferably of about 50 ⁇ m.
• the lower layer 3 and the upper layer 4 are made of the same material.
• Particularly suitable for this purpose is high density polyethylene (known as HDPE).
• the envelope of the evacuated jacket according to the present invention is made rolling up said barrier sheet 1 so as to superimpose two opposite margins 5 and 6 thereof.
• the superimposition is earned out so as to contact the lower layer 3 at margin 5 with the upper layer 4 at the other margin 6.
• a porous or discontinuous, organic or inorganic filling material of any known kind, and optionally a getter material or device are inserted inside the envelope.
• getter materials or devices suitable for chemically sorbing moisture or other atmospheric gases, are known in the field and therefore do not need a detailed description.
• Figure 4 shows an enlarged partial view in cross-section of one of said lateral flanges 8.
• it shows the portion of said flange which comprises the linear zone 7 of the longitudinal welding.
• the thickness of each lateral flange 8 is uniform all over its length, in spite of the threefold superimposition of the banner sheet 1, in the linear zone 7 of the longitudinal welding. This can be explained considering that in said linear zone 7 the lower layer 3 and upper layer 4 of the barrier sheet have become thinner.
• the heat of the welding bars causes said layers to be melted and to become soft, so that some of the polymeric material of which they are formed is discharged form the sides because of the pressure of said bars and can be removed.

Landscapes

• Thermal Insulation (AREA)
• Laminated Bodies (AREA)
• Muffle Furnaces And Rotary Kilns (AREA)
• Building Environments (AREA)
• Application Of Or Painting With Fluid Materials (AREA)

Priority Applications (11)

Applications Claiming Priority (2)

Related Child Applications (1)

Publications (2)

Family

ID=11444077

Family Applications (1)

Country Status (17)

Cited By (39)

Families Citing this family (19)

Family Cites Families (9)

• 2000
  • 2000-02-18 IT IT2000MI000287A patent/IT1316769B1/it active
• 2001
  • 2001-02-07 CA CA002398890A patent/CA2398890A1/en not_active Abandoned
  • 2001-02-07 AT AT01906113T patent/ATE252452T1/de not_active IP Right Cessation
  • 2001-02-07 DE DE60101050T patent/DE60101050T2/de not_active Expired - Fee Related
  • 2001-02-07 DK DK01906113T patent/DK1265746T3/da active
  • 2001-02-07 TR TR2003/01897T patent/TR200301897T4/xx unknown
  • 2001-02-07 AU AU2001234076A patent/AU2001234076A1/en not_active Abandoned
  • 2001-02-07 HK HK03104909.9A patent/HK1052482A1/zh unknown
  • 2001-02-07 MX MXPA02007904A patent/MXPA02007904A/es active IP Right Grant
  • 2001-02-07 EP EP01906113A patent/EP1265746B1/en not_active Expired - Lifetime
  • 2001-02-07 ES ES01906113T patent/ES2208559T3/es not_active Expired - Lifetime
  • 2001-02-07 KR KR1020027010606A patent/KR100548674B1/ko not_active Expired - Fee Related
  • 2001-02-07 JP JP2001559676A patent/JP2003522918A/ja active Pending
  • 2001-02-07 BR BR0108392-9A patent/BR0108392A/pt not_active Application Discontinuation
  • 2001-02-07 RU RU2002124775/06A patent/RU2253792C2/ru not_active IP Right Cessation
  • 2001-02-07 WO PCT/IT2001/000053 patent/WO2001060598A2/en not_active Ceased
  • 2001-02-07 DE DE20121944U patent/DE20121944U1/de not_active Expired - Lifetime
• 2002
  • 2002-08-19 US US10/223,140 patent/US20030006025A1/en not_active Abandoned

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