CA1044478A - Non-stick cookware - Google Patents
Non-stick cookwareInfo
- Publication number
- CA1044478A CA1044478A CA273,298A CA273298A CA1044478A CA 1044478 A CA1044478 A CA 1044478A CA 273298 A CA273298 A CA 273298A CA 1044478 A CA1044478 A CA 1044478A
- Authority
- CA
- Canada
- Prior art keywords
- titanium
- article
- substrate
- layer
- base
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- A—HUMAN NECESSITIES
- A47—FURNITURE; DOMESTIC ARTICLES OR APPLIANCES; COFFEE MILLS; SPICE MILLS; SUCTION CLEANERS IN GENERAL
- A47J—KITCHEN EQUIPMENT; COFFEE MILLS; SPICE MILLS; APPARATUS FOR MAKING BEVERAGES
- A47J36/00—Parts, details or accessories of cooking-vessels
- A47J36/02—Selection of specific materials, e.g. heavy bottoms with copper inlay or with insulating inlay
Landscapes
- Engineering & Computer Science (AREA)
- Food Science & Technology (AREA)
- Cookers (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
Cookware with a cooking surface having the finish and corrosion resistance associated with stainless steel and the non-stick properties associated with polyflurocarbon coatings has a cooking surface which is continuously and uninterruptedly of titanium. Continuity of the titanium surface is maintained by fabricating the cooking surface using titanium welds for seams in the cooking surface or by explosively forming the cookware.
Preferably at least the base of the cookware is of steel clad with titanium on its upper surface.
Cookware with a cooking surface having the finish and corrosion resistance associated with stainless steel and the non-stick properties associated with polyflurocarbon coatings has a cooking surface which is continuously and uninterruptedly of titanium. Continuity of the titanium surface is maintained by fabricating the cooking surface using titanium welds for seams in the cooking surface or by explosively forming the cookware.
Preferably at least the base of the cookware is of steel clad with titanium on its upper surface.
Description
1~ 78 This invention relates to cookware of the non-stic~ type.
Cookware is well known in which the cooking surface i~
treated with various fluorocarbon polymer compositions, such as those sold under the trade marks DURON and TEPI~N, in order to inhibit the sticking to the ~urface of food being cooked;
more recently other organic polymeric coatings having similar properties have become available. In spite of continuing improve-ments, such surfaces are subject to wear or damage which limits their durability unless special care is taken in their use, and ~0 they have various other potential or actual disadvantages. Such a coating cannot provide the attractive appearance of polished metal finish and particularly if damaged can contain pits or roughness which can harbour contamination, and can allow corrosion of the substrate metal. Moreover the thicker and tougher coatings in particular have a significant resistance to heat transfer, and in certain cases there appears to be an increased tendency for liquid foods to burn in contact with the surface, possibly because of the lack of a polished surface.
Other materials for the cooking surfaces of cookware which -have found favour are stainless steel, because of its ability to retain a polished finish and resist corrosion, and cast iron - -or heavy gauge steel because of its high thermal capacity resulting ; in even heat transfer to the food. In order to co~bine these --properties, heavy gauge carbon steel clad with stainless ~teel has been u~ed in cookware.
It is known that titanium, like stDinless steelO has a hlgh corro~ion re~i~tance and will retain a polished finish, but ~ince it 1~ much more c08tl~ and mN¢h more difficult to work than ~tainlo~ ~teel, there ha~ b en no rea~on to employ this metal in cookware, ~
-We have found, most unexpectedly, that a titanium cooking surface provides non-stick properties similar to tho~e a~sociated with polyfluorocarbon fini~hes, but without the disaavantage~
of the latter and whilst at the same time providing the advantages associated with stainless steel sy utilizing a steel substrate Cos7 explosively clad with a surface layer of titanium, the ~t i~
reduced, and by using a substrate of suitable thickness, some of the advantageous properties of cast iron cookware can also be achieved.
However, we have found that it is not possible to use the normal fabrication methods used for cookware upon titanium and titanium-clad ~ubstrates, and our initial attempts to produce acceptable cookware were unsuccessful. We have found that it is essential to maintain a continuous and uninterrupted layer of ~--titanium over the cooking surface, and thus unless the cooking surface is ~L~ u~b~planar, as in a griddleO there are difficult- ~ -ies in fabrication. For manufacturing hollow cookware, we have found the satisfactory techniques to be either to build up the cookware from separate parts~J welding the seams in the cooking surface with pure titanium so as to maintain continuity of the -~
titanium surface, or explosively forming of a titanium clad .
~substrate ~L sheet to the desired configuration. The former technique i8 preferred where deep cooking vessels are to be ~-produced, or where the base of the cooking vessel is to be -~
~ub~tantially thicker than the sidewalls, a~ is desirable when the cookware i8 to incorporate integral electric heating elements~ -Further feature~ o the invention will be apparent from the following de~cript~on of exemplary embodim~nts of the invention ~ith reference to the accompanying arawings, in which:
Cookware is well known in which the cooking surface i~
treated with various fluorocarbon polymer compositions, such as those sold under the trade marks DURON and TEPI~N, in order to inhibit the sticking to the ~urface of food being cooked;
more recently other organic polymeric coatings having similar properties have become available. In spite of continuing improve-ments, such surfaces are subject to wear or damage which limits their durability unless special care is taken in their use, and ~0 they have various other potential or actual disadvantages. Such a coating cannot provide the attractive appearance of polished metal finish and particularly if damaged can contain pits or roughness which can harbour contamination, and can allow corrosion of the substrate metal. Moreover the thicker and tougher coatings in particular have a significant resistance to heat transfer, and in certain cases there appears to be an increased tendency for liquid foods to burn in contact with the surface, possibly because of the lack of a polished surface.
Other materials for the cooking surfaces of cookware which -have found favour are stainless steel, because of its ability to retain a polished finish and resist corrosion, and cast iron - -or heavy gauge steel because of its high thermal capacity resulting ; in even heat transfer to the food. In order to co~bine these --properties, heavy gauge carbon steel clad with stainless ~teel has been u~ed in cookware.
It is known that titanium, like stDinless steelO has a hlgh corro~ion re~i~tance and will retain a polished finish, but ~ince it 1~ much more c08tl~ and mN¢h more difficult to work than ~tainlo~ ~teel, there ha~ b en no rea~on to employ this metal in cookware, ~
-We have found, most unexpectedly, that a titanium cooking surface provides non-stick properties similar to tho~e a~sociated with polyfluorocarbon fini~hes, but without the disaavantage~
of the latter and whilst at the same time providing the advantages associated with stainless steel sy utilizing a steel substrate Cos7 explosively clad with a surface layer of titanium, the ~t i~
reduced, and by using a substrate of suitable thickness, some of the advantageous properties of cast iron cookware can also be achieved.
However, we have found that it is not possible to use the normal fabrication methods used for cookware upon titanium and titanium-clad ~ubstrates, and our initial attempts to produce acceptable cookware were unsuccessful. We have found that it is essential to maintain a continuous and uninterrupted layer of ~--titanium over the cooking surface, and thus unless the cooking surface is ~L~ u~b~planar, as in a griddleO there are difficult- ~ -ies in fabrication. For manufacturing hollow cookware, we have found the satisfactory techniques to be either to build up the cookware from separate parts~J welding the seams in the cooking surface with pure titanium so as to maintain continuity of the -~
titanium surface, or explosively forming of a titanium clad .
~substrate ~L sheet to the desired configuration. The former technique i8 preferred where deep cooking vessels are to be ~-produced, or where the base of the cooking vessel is to be -~
~ub~tantially thicker than the sidewalls, a~ is desirable when the cookware i8 to incorporate integral electric heating elements~ -Further feature~ o the invention will be apparent from the following de~cript~on of exemplary embodim~nts of the invention ~ith reference to the accompanying arawings, in which:
- 2 -~.0~49t78 Eigure 1 is an isometric view of the pan portion of an electric frying pan of the tilting type, Figure 2 is a fragmentary vertical section on the line 2-2 in Figure 1, and Figure 3 is a fragmentary vertical section l:hrough a side wall and pa~t of the base of a skillet.
Referring to Figures 1 and 2, the pan shown is of the known type in which a pan 2 with electrical elements 4 encased beneath the pan is mounted by trunnions 6 upon a base (not shown) so that the pan may be tilted to pour off excess fat or liquid or solid food being cooked from lips 8 with a spout 10. The construction of the pan is also largely conventional, except for the materials and fabrication techniques employed.
Whereas in a convention81 pan of this type the base of the pan would commonly be of carbon steel clad on its upper surface with itainless steel, in the present case the upper surface of the carbon steel layer 12 is explosively clade with a titanium layer 14. A suitable material is sold by E.I. du Pont de Nemours & Co.
lnc. under the trade mark DETACLAD. Typically, the titanium layer is 1/16 inch thick and the carbon steel substrate is of 3/8 -inch thickness. The su~strate may be tapped in conventional manner to recelve studs 16 for nuts 18 which tight~n clamps 20 by means of which the elements 4 are secured to the base. Stainless steel skirts 22 are welded at 24 to the substrate layer 12 so as to ; shroud the elements and support the trunnions ~, enclosure of the - - elements being completed by a base plate 26.
The side walls 34 and lips 8 of the pan are formed from a strip of 1/16 inch thick titanium sheet. The upper edge of the sheet i~ folded outwardly to form a bead 20~ except in the area of . ' - , ,, .
,, , . , , j , , -'', ' ,~, ,,' , ', ' , ' ' ,, '',', ' :
,~, ,, , ,~ , . . . .
, ", , , , ,:
,, ~, , ' , ,, ~ "
.. . ...
1~)444~
the lips 8 which are formed by outward bending of the strip material. The lower edge of the sheet is notched at the positions of the corners 30 of the pans and bent inwardly to form curved transitions 32 whose inner ends abut the edges of the layer 14.
The spout 10 is separately formed and the seams in the strip and between the strip and the spout and the strip and the layer 14 are ~oined by titanium welds 36 so as to maintain continuity of the titanium cooking surface. Although titanium welding is difficult and requires great skill, alternative methods of bonding such as silver soldering have not been found to work.
Where hollow cookware with a relative thin base is satisfactory, as in much stove-top cookware, a unitary sheet of steel explosively clade with titanium may be explosively formed to provide the body of an article of cookware. In accordance with conventional explosive forming techniques, the sheet to be formed is positioned so as to close the opening of a hollow mould, which is evacuated, and an appropriate explosive charge is applied to the titanium clad surface of the plate and detonated so as --plastically to deform the plate into a comp}ement of the mould cavity whilst maintaining the integrity and continuity of the titanium cladding. A section of part of a skillet formed in this manner is shown in Figure 3~ both the titanium layer 40 and the --steel layer 42 being continuous as between the base 44 and the side - wall 46 of the skillet.
Although both the welding of titanium and explosive forming are known techniques, it it not believed that they have previously -been used to form cookware. The added expense as compared with more conventional fabrication techniques is only ~ustified in the present instance by the advantageous properties thereby secured :, ,;. , ,, . , ' ~' ':,' ' ' in the product. 1~ 78 In some cases, neither welding nor explosive forming will be required. Thus a g~iddle may be formed from a plate of carbon steel explosively clad on its upper surface with titanium, the necessary fixtures and fittings required to complete or install the griddle being formed into ar attached to the steel plate without penetrating the cooking surface.
Stove-top ware could be explosively formed or titanium weld~d from titanium sheet throughbots, although clad material will usually be preferred 80 as to reduce the co~t of material and increase the thermal capacity of the cookwareO The substrate layer of the clad material could comprise metals other than steelt for example, the lower surface of the base of an article of cookware can sometimes advantageously be clad with copper to improve thermal conductivity~
~he term ~non-stick" is used as applied to cookware in this specification and the appended claims in its normal commercial sense to imply a ~ubstantially reduced tendancy for food to ~tick to the cooking surface as compared with the ~uraces of conventional metal cookware, and is noteto < be understood as a representation that no sticking will occur under aDy circum~tance~. :
. 5 ,, , , "",, ',, ', ,' ., . ,, ,:, .
.
,, , , , ', ' ,' ' '
Referring to Figures 1 and 2, the pan shown is of the known type in which a pan 2 with electrical elements 4 encased beneath the pan is mounted by trunnions 6 upon a base (not shown) so that the pan may be tilted to pour off excess fat or liquid or solid food being cooked from lips 8 with a spout 10. The construction of the pan is also largely conventional, except for the materials and fabrication techniques employed.
Whereas in a convention81 pan of this type the base of the pan would commonly be of carbon steel clad on its upper surface with itainless steel, in the present case the upper surface of the carbon steel layer 12 is explosively clade with a titanium layer 14. A suitable material is sold by E.I. du Pont de Nemours & Co.
lnc. under the trade mark DETACLAD. Typically, the titanium layer is 1/16 inch thick and the carbon steel substrate is of 3/8 -inch thickness. The su~strate may be tapped in conventional manner to recelve studs 16 for nuts 18 which tight~n clamps 20 by means of which the elements 4 are secured to the base. Stainless steel skirts 22 are welded at 24 to the substrate layer 12 so as to ; shroud the elements and support the trunnions ~, enclosure of the - - elements being completed by a base plate 26.
The side walls 34 and lips 8 of the pan are formed from a strip of 1/16 inch thick titanium sheet. The upper edge of the sheet i~ folded outwardly to form a bead 20~ except in the area of . ' - , ,, .
,, , . , , j , , -'', ' ,~, ,,' , ', ' , ' ' ,, '',', ' :
,~, ,, , ,~ , . . . .
, ", , , , ,:
,, ~, , ' , ,, ~ "
.. . ...
1~)444~
the lips 8 which are formed by outward bending of the strip material. The lower edge of the sheet is notched at the positions of the corners 30 of the pans and bent inwardly to form curved transitions 32 whose inner ends abut the edges of the layer 14.
The spout 10 is separately formed and the seams in the strip and between the strip and the spout and the strip and the layer 14 are ~oined by titanium welds 36 so as to maintain continuity of the titanium cooking surface. Although titanium welding is difficult and requires great skill, alternative methods of bonding such as silver soldering have not been found to work.
Where hollow cookware with a relative thin base is satisfactory, as in much stove-top cookware, a unitary sheet of steel explosively clade with titanium may be explosively formed to provide the body of an article of cookware. In accordance with conventional explosive forming techniques, the sheet to be formed is positioned so as to close the opening of a hollow mould, which is evacuated, and an appropriate explosive charge is applied to the titanium clad surface of the plate and detonated so as --plastically to deform the plate into a comp}ement of the mould cavity whilst maintaining the integrity and continuity of the titanium cladding. A section of part of a skillet formed in this manner is shown in Figure 3~ both the titanium layer 40 and the --steel layer 42 being continuous as between the base 44 and the side - wall 46 of the skillet.
Although both the welding of titanium and explosive forming are known techniques, it it not believed that they have previously -been used to form cookware. The added expense as compared with more conventional fabrication techniques is only ~ustified in the present instance by the advantageous properties thereby secured :, ,;. , ,, . , ' ~' ':,' ' ' in the product. 1~ 78 In some cases, neither welding nor explosive forming will be required. Thus a g~iddle may be formed from a plate of carbon steel explosively clad on its upper surface with titanium, the necessary fixtures and fittings required to complete or install the griddle being formed into ar attached to the steel plate without penetrating the cooking surface.
Stove-top ware could be explosively formed or titanium weld~d from titanium sheet throughbots, although clad material will usually be preferred 80 as to reduce the co~t of material and increase the thermal capacity of the cookwareO The substrate layer of the clad material could comprise metals other than steelt for example, the lower surface of the base of an article of cookware can sometimes advantageously be clad with copper to improve thermal conductivity~
~he term ~non-stick" is used as applied to cookware in this specification and the appended claims in its normal commercial sense to imply a ~ubstantially reduced tendancy for food to ~tick to the cooking surface as compared with the ~uraces of conventional metal cookware, and is noteto < be understood as a representation that no sticking will occur under aDy circum~tance~. :
. 5 ,, , , "",, ',, ', ,' ., . ,, ,:, .
.
,, , , , ', ' ,' ' '
Claims (8)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. An article of non-stick cookware comprising a continuous and uninterrupted layer of titanium sheet defining the entire cooking surface of the article, and a substrate of carbon steel metallurgically bonded to that part of the titanium layer defining the base of the article, the bottom of the base being configured to receive heat by thermal conduction from a source beneath the substrate.
2. An article according to claim 1, wherein the titanium layer is explosively bonded to the carbon steel substrate .
3. An article according to claim 2, wherein the article comprises a bottom having a titanium layer explosively bonded to a much thicker carbon steel substrate, and a sepa-rately formed rim of titanium, titanium welded to the titanium layer of the base.
4. An article according to claim 3, further incorpor-ating an electrical heating assembly attached beneath the steel substrate in heat conducting relationship thereto.
5. An article according to claim 3 or 4, wherein the titanium layer is about 1/16 inch thick and the carbon steel substrate is about 3/8 inch thick.
6. An article according to claim 1, wherein the lower surface of the base is clad with copper.
7. An article of non-stick cookware comprising a continuous and uninterrupted layer of titanium whose upper surface defines the entire cooking surface of the article, a substrate of carbon steel much thicker than the titanium layer and explosively bonded to the lower surface of the titanium layer, and an electrical heating assembly attached beneath the steel substrate in heat conducting relationship thereto.
8. A method of producing an article of non-stick cookware, comprising fabricating a base, comprising an upper layer of titanium explosively bonded to a considerably thicker substrate of carbon steel adapted to receive heat by conduction from a source beneath the substrate, and titanium welding side walls of titanium to said titanium layer of said base to provide a vessel with an inner cooking surface which is continuously and uninterruptedly of titanium.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA273,298A CA1044478A (en) | 1977-03-07 | 1977-03-07 | Non-stick cookware |
| JP9407777A JPS53109772A (en) | 1977-03-07 | 1977-08-04 | Cooking instrument |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA273,298A CA1044478A (en) | 1977-03-07 | 1977-03-07 | Non-stick cookware |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1044478A true CA1044478A (en) | 1978-12-19 |
Family
ID=4108085
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA273,298A Expired CA1044478A (en) | 1977-03-07 | 1977-03-07 | Non-stick cookware |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JPS53109772A (en) |
| CA (1) | CA1044478A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5440973A (en) * | 1993-04-30 | 1995-08-15 | Anchor Hocking Corporation | Low-fat non-stick frying device |
| WO2005089599A1 (en) | 2004-03-10 | 2005-09-29 | Kärcher Futuretech GmbH | Cooking receptacle, particularly for a modular field kitchen, and method for the production thereof |
| WO2005089052A2 (en) * | 2004-03-19 | 2005-09-29 | Meyer Intellectual Properties Limited | Titanium based composite cookware |
| WO2012022651A1 (en) | 2010-08-19 | 2012-02-23 | Rational Ag | Container for foodstuffs, and method for producing such a container |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6419294U (en) * | 1987-07-27 | 1989-01-31 |
-
1977
- 1977-03-07 CA CA273,298A patent/CA1044478A/en not_active Expired
- 1977-08-04 JP JP9407777A patent/JPS53109772A/en active Pending
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5440973A (en) * | 1993-04-30 | 1995-08-15 | Anchor Hocking Corporation | Low-fat non-stick frying device |
| WO2005089599A1 (en) | 2004-03-10 | 2005-09-29 | Kärcher Futuretech GmbH | Cooking receptacle, particularly for a modular field kitchen, and method for the production thereof |
| WO2005089052A2 (en) * | 2004-03-19 | 2005-09-29 | Meyer Intellectual Properties Limited | Titanium based composite cookware |
| WO2005089052A3 (en) * | 2004-03-19 | 2006-04-27 | Meyer Intellectual Properties | Titanium based composite cookware |
| GB2427997A (en) * | 2004-03-19 | 2007-01-17 | Meyer Intellectual Properties | Titanium based composite cookware |
| GB2427997B (en) * | 2004-03-19 | 2007-11-14 | Meyer Intellectual Properties | Titanium based composite cookware |
| WO2012022651A1 (en) | 2010-08-19 | 2012-02-23 | Rational Ag | Container for foodstuffs, and method for producing such a container |
| FR2963928A1 (en) * | 2010-08-19 | 2012-02-24 | Rational Ag | CONTAINER FOR FOODSTUFFS AND PROCESS FOR MANUFACTURING SUCH A CONTAINER |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS53109772A (en) | 1978-09-25 |
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