JPH04148927A - Method of forming a lamination layer and its product - Google Patents

Abstract

PURPOSE: To obtain a method for forming a laminate without releasing the laminate by giving a sealing agent along a longitudinal edge of at least one opposed surface of a plurality of sheets to form continuous barriers to prevent leaching of a liquid adhesive along the edge of the formed laminate to form the laminate by using the liquid adhesive. CONSTITUTION: A was applicator 7 has a heater 19, a supply tube 21, and a plurality of nozzles 23 for giving sealing agents 34 along a longitudinal edge of the opposed surface of a sheet 12. An oil roller 18 gives a thin coating of the adhesive on the opposed surface of the sheet 16. Since the sheets 12, 16 are passed between a pair of seals or integrated rollers 22 and 24 for operating sufficient pressure to the sheets 12, 16, adjacent opposed surfaces of the sheets 12, 16 are brought into close contact with one another. The continuous film of the adhesive and the agent excludes all the air between the opposed surfaces of the seals to form a laminate 26. As a result, the excess liquid adhesive is removed, and leaching of the adhesive along the longitudinal edge of the laminate is minimized.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention This invention relates to an improved laminate and a method of manufacturing a laminated core formed from the laminate. especially,
The present invention applies a liquid adhesive and a sealant to opposite sides of a sheet and applies a pressure force of -1- to the sheet by eliminating excess liquid adhesive and expelling air from between the opposite sides of the sheet. works and prevents air from re-entering7.
The invention relates to spreading the sealant to prevent leaching of liquid adhesive along the edges of the sheet.

BACKGROUND OF THE INVENTION There are several applications such as power transformers, electric motors, and electronic catalytic converters that use thin gauge sheets.

Thin gauge electrical steel sheets or amorphous metal sheets for electrical applications reduce electrically induced eddy currents by reducing the cross-sectional area through which current flows. Grain-oriented steel sheet is less than 0.5mm, typically 0.18m
It has a thickness within the range of 0.35 m to 0.35 m. Amorphous metal sheets typically have a thickness of about 0.02'+z to 0.02'+z.
It has a thickness of 0.05 mm.

It is known that the electrical device described above is more effective when the thickness of the sheet is reduced with a low limit of the seal thickness determined by the manufacturing conditions.

However, the reduction in sheet thickness has a detrimental effect on handling and manufacturing productivity. Handling of tissue-like thin sheets is a 65° problem because the sheets are easily torn and damaged during handling. The very thinness of the sheet reduces processing and productivity during manufacturing, making the product highly labor intensive to use.

The prior art describes adhesives, varnishes, oxides and mixtures that can be applied to the surface of the sheets so that several sheets can be bonded together (or laminated) for simultaneous processing. Processes such as lamination greatly increase productivity and reduce handling problems, since the laminations are thicker and stronger than a single sheet.

Nevertheless, U.S. Patent Application No. 071, filed April 27, 1987, assigned to the applicant and referenced here.
There are several disadvantages when using adhesives, varnishes or oxides to adhere sheets of length as discussed in the '043077 patent.

For example, in order to develop good adhesion between sheets, it is necessary that the adhesive be applied so that relatively thick layers create gaps between adjacent sheets. This is disadvantageous for bonded laminates used in electrical applications where increased gaps between sheets are rolled or laminated to reduce gap factors. Thin<(=J) Even a given adhesive is disadvantageous because it tends to shrink when it cures.Such shrinkage, especially in thin metal sheets, strains the sheet and causes distortion.Chemical adhesives Another disadvantage is that increased temperatures are required to cure the adhesive when using chemical adhesives. Such increased temperatures reduce the effectiveness of the area cleaning treatment of electrical steel sheets. Another disadvantage is that the sheets are tightly connected when used.When winding the tightly formed electrical steel layer around the core, distortion occurs, thereby increasing the core loss of the laminate.Chemical adhesives or Another drawback with ceramic adhesives is that the adhesive layer can be destroyed. Cutting, punching, or corrugating can destroy the fragile adhesive laminate so as to break the sheet laminate.

U.S. Pat. pushing air out between surfaces (7,
It is described that a layer can be clearly formed that resists separation. The remaining liquid between the opposing surfaces forms a seal that prevents the re-entry of air so that the lamination resists separation during continuous processing and manufacturing. The formed laminate does not create distortion in the sheets which increases the gap between the sheets.

Unfortunately, some liquid remaining between the sheets leaches out from between the sheets along the sheet edges. This kind of leaching is
Bunching to form a deposited laminate creates a number of physical problems in sequential processing of the laminate. Where transformer oil is used as a bonding fluid to form the laminated electrical steel sheets, the oil is built up in an oil press and allowed to slide through the laminated or drive gear to form the transformer from the electrical steel sheets. It becomes difficult to obtain the precisely defined cuts needed to form the core. Also, since leaching is due to the adhesive liquid being transferred to the outer surface of the laminated sheets, the stacked and cut laminated sheets should be properly aligned within the core pile and the stacks together. ). When handling laminated sheets: When re-punching, lamination failure may occur.

Accordingly, there remains a need for improved techniques for forming laminates using liquid adhesives in which leaching of liquid adhesive between opposing surfaces of the formed laminate is minimized or inhibited.

SUMMARY OF THE INVENTION This invention relates to an improved method of forming laminates and a laminated core made from the laminates. A liquid adhesive and a sealant are applied to at least one opposing surface of the plurality of sheets. Pressure is applied to the sheets to remove excess liquid adhesive and force air from between opposing surfaces of the sheets to minimize leaching of liquid adhesive along the longitudinal edges of the laminate. Spread the sealant to form a continuous barrier along each longitudinal edge.

The main object of this invention is to form laminates using a liquid adhesive that resists separation, has no reduction in spacing factors, and can be produced without laminate fall separation.

A feature of this invention is that a laminate is formed from two or more sheets using a liquid adhesive and a sealant.

Another feature of the invention is that the laminate is applied along the longitudinal edges of at least one opposing side of the plurality of sheets to form a continuous barrier to prevent leaching of liquid adhesive along the width edges of the formed laminate. The method involves removing the sealant and forming a laminate using a liquid adhesive.

Another feature of the invention is that along the longitudinal edge and at a plurality of
A sealant is applied at a position intermediate the longitudinal edge to at least one opposite surface of ~ to form a continuous barrier at an intermediate position along the longitudinal edge, and laminated along the intermediate position. The purpose of the present invention is to form a laminate with a liquid adhesive that is divided into narrow laminates, thereby preventing leaching of the liquid adhesive along the longitudinal edges where the sealant is formed.

Another feature of the present invention is to form the laminate using a low viscosity liquid adhesive and a high viscosity sealant to prevent leaching of the liquid adhesive along the longitudinal edges of the formed laminate.

Another feature of the invention is the formation of a laminate using a liquid adhesive having a viscosity of less than about 80 cP at 24°C and a sealant having a viscosity of less than about 2500 cP at 2/1°C.

A further feature of the invention is to provide at least two sheets each having opposing surfaces, applying a liquid adhesive to one of the opposing surfaces of the sheets and applying a sealant along the longitudinal edge of one of the opposing surfaces. the sealant between the surfaces to form a continuous barrier by applying pressure to the sheet, removing excess liquid adhesive from between the surfaces, and spreading the sealant between the surfaces so that the surfaces come into contact with each other. By forming a laminate, the air between the surfaces is excluded by the liquid adhesive and the sealant prevents the re-entry of air and minimizes leaching of the liquid adhesive along the edges of the formed laminate. be.

Yet another feature of the invention is to feed a plurality of grain-oriented steel sheets, each having opposite surfaces and having a thickness of about 0.5 iz or less, along a feed path at a predetermined rate so that the opposite surfaces are Apply a liquid adhesive having a viscosity of not more than about 80 cP at 2/1°C to one side, and apply a liquid adhesive having a viscosity of not more than 2500 cF at 24°C to one vertical edge of the opposite side (17-). -) apply the sealant, pass the sheet between a pair of rollers, apply pressure to the sheet with the rollers to remove excess liquid adhesive from between the surfaces, and the opposite surfaces are brought into contact with each other; Sometimes the sealant forms a continuous barrier between opposing surfaces such that air between the surfaces is excluded by the liquid adhesive and the sealant prevents air from re-entering along the edges of the formed laminate. The goal is to form a volume from the sheet that minimizes the ingress of liquid adhesive.

Advantages of the invention include reduced manufacturing costs of laminates that can be slotted, cut or punched without any leaching of liquid adhesive, production of manufactured cores using sheet laminates with no distortion or stress; Contains.

The above and other objects, features and advantages of the invention will become apparent from consideration of the following detailed description taken in conjunction with the accompanying drawings.

[Example] Referring to FIG. 1, reference numeral 12 indicates that the coil 10 is unwound and moved along the supply passage 13 at a constant speed. Another sea 1□ ], 6 is oil roller 1
The coil 14 is fed under the coil 7 at the same speed. C
I-1, 6 are brought together with the sheets 12 by a redirection D-ruler 20.

In this invention, the seal l~ can be a continuous strip, foil, ribbon,
It will be understood that the term is meant to include the like, or the like, such as strips cut into individual lengths. Preferably, the sheet comprises cold worked or cast steel and an amorphous base metal having a thickness of about 0.5 cm or less. More suitable C-1~ is,
It has a glass insulation coating on both sides of the sheet i~, and the total thickness of the sheet and the coating layer is about 0.35xx 1'! 7 end direction f
[Contains steel.] Evans, U.S. Pat. No. 3,948, referenced here.

No. 786 describes a Mg-PO, grain oriented steel with a glass insulation coating.

The wax applicator 17 may include conventional mechanical equipment such as atomizers, capillary applicators, wiper rollers, extruders, and similar equipment.
It can be done. For example, the wax applicator 17 includes a heater 9, a supply tube 21, and a plurality of nozzles 23 for dispensing a sealant 34 along the longitudinal edges of the opposing surfaces of the waxes 1 and 12. are doing. Oil [7-La 18 applies a thin coating of liquid adhesive to the opposite sides of sheet 16 (
= 1 given 1, S -1 - I + 2 and sheet 16 act on sheet 12.16 with sufficient J1 - - As it passes between the pair of seals or combinations 22.24, G.
Adjacent opposite sound surfaces of 12 and 16 are brought into close contact with each other. A continuous film of liquid adhesive or sealant removes all air between the opposite sides of the seal to form a laminate 26. Laminations 26 form a mantle sill 28 forming core 30
wrapped around.

The gap between one cola 22 and 24 is not thinner than the combined thickness of the sheets 12, ]6. In particle oriented sheets, rollers 22.24 apply sufficient pressure to remove excess liquid adhesive and force air out to spread the sealant to induce stress in sheet 12.16. This results in the formation of a continuous barrier or seal along both edges of the laminate that is formed without the need for a laminate.

FIG. 1 shows that sealant is applied by wax applicator 17 to the lower opposing sides of sheet 12 and liquid adhesive is applied by roller 18 to the lower opposing sides of sheet 16 -L. Also, the wax applicator] 7 applies sealant to the opposite surfaces of the sheet 16.
The openings 18 can be used to apply liquid adhesive (-J) to the lower, opposite sides of the sheet 12. The adhesive and sealant can also be applied to opposite sides of the sheet 12.16. As long as a continuous barrier is formed along the longitudinal edges when stacking the sheets, the sealant can be applied in continuous lines, double lines, squares, diagonal parallel stripes, sinusoidal F lines, etc. It will be appreciated that a number of shapes may be applied to opposite sides of the sheet, such as extruded beads or the like.

The liquid adhesive can be applied as a fine mist or sprayed.

Depending on the equipment available, a number of sea or supply channels 13 can be installed.
The type of material to be laminated is supplied simultaneously with i, l =:, which is in liquid contact with the sheet during the processing steps, such as k (n It is suitable for sipping.

Even in the case of 1'l'' liquid adhesive and sealant are applied only to opposing sheet surfaces when the sheets are combined into one laminate.

Figure 12 shows line 2 in Figure 1 before G 1 to 12.16 is combined to roller 22.24, I, to H26.
A cross-section of 12.16 along 2) is shown.

The small beat of sealant 34 is the opposite sound of sheet] 2. 3
Along each longitudinal edge 36. Once the J is slit, additional sealant is applied lengthwise along opposing surfaces 32 at the location where the J is slit. In the electrical steel layer, the additional sealant, which is preferably subdivided into 1-1 loaves, is added to the slits and the sealant extending continuously along the longitudinal and lateral edges of the cut layer. A square, diagonal parallel striped pattern, or a sinusoidal pattern is used to ensure the J.

FIG. 13 shows the sheet 12.1 [-11] shown in FIG.
1! 2 shows an enlarged schematic cross-sectional view of a portion of layer 26 formed from FIG. Some of the planes of the metal sheets are not completely flat and are somewhat rough. The facing surface 32 of this sheet 12
are not in continuous contact with adjacent opposing surfaces 40 of sheet 16. Opposing surfaces 32.40 touch each other at a point 44
I will be in charge. Sea l-], 2.16 is the roller 22.
When brought into contact with each other by 24, the void portion 4G representing the point of non-contact between surfaces 32, 40 is filled with liquid adhesive 42.

Sealant 34 is spread along the longitudinal edges of layer 26 to form a thin continuous barrier or dam. FIG. 3 shows a thin barrier 34a formed by rollers 22.24 with sealant 34 extending along longitudinal edges 38. The separation or void portion 46 between surfaces 32, 40 at the point of non-contact is less than about 0.005 az. Excess liquid adhesive
．． Air is removed as it is squeezed out of the 40 ml. A continuous film of saw sealant 34a formed along the longitudinal edges 36.38 between the surfaces 32, 40 of the sheet 12.16 prevents the re-entry of air and is applied along the longitudinal edges 32, 40 of the layer 26, opposite to each other. The liquid adhesive 42 is prevented from penetrating between .40 and 1-. Therefore, G1 to 12.16 is held firmly together. No barrier 3/1a along the longitudinal edge, liquid adhesive 42
As shown by the permeation portion 42εt, the water oozes out between the sheets facing each other.

FIG. 2 shows a sealant layer 34 provided along the longitudinal edge 36.38. If layer 26, as shown in FIG. Face 32.
Can be leached between 4 o's. In this condition, it is necessary to provide additional sealant 34 along the opposing sides so that both edges of each layer have a continuous sealing barrier 34. Contains a.

In one layer, which is subdivided into two equally wide layers, sealant 34 is applied to the opposing surfaces midway between the edges 36,38.

Without being distinguished by theory, a cavity 4 filled with liquid adhesive or sealant and atmospheric pressure surrounding R26.
It is understood that the pressure differential that exists between the layers holds the layers tightly together. In other words, sheet 12.1
6 resists delamination because the internal layer pressure at separation is reduced below the atmospheric pressure pressing against the outer surface of layer 26, as shown by arrow 48 in FIG. Opposing surfaces 32.40 of sheet 12.16 carry thin layers of sealant 34 and liquid adhesive 42, respectively. Sea l-]
, 2.16 are fed from left to right through the engagement of rollers 22.24. As rollers 22.24 bring surfaces 32.40 into close contact with one another, a concave-convex lens 50 is formed to exchange air with sealant 34 and expel excess liquid adhesive 42 from between opposing surfaces 32.40.

The liquid adhesive preferably has a viscosity not greater than about 80 cP at 24°C when applied to the sea I-1! ! It can be a low viscosity liquid with a The use of highly viscous adhesives makes it difficult to obtain good spacing factors and tends to prevent conversion of the laminated sheets. Acceptable adhesives include water, Al'': l-/l-5 oil and the like. For high viscosity adhesives, it is possible to heat the adhesive above ambient temperature for application to the sheet. Suitable. For cutting electrical steel sheets, the adhesive is formed into a continuous film to provide continuous internal insulation to maintain magnetic properties. Natural or synthetic converted oils are suitable for this. Important The important thing is that the adhesive that adequately wets the surface of the sheet has the necessary viscosity to be compatible with the environment in which the lamination will be used.

In sealants, relatively high viscosity liquids or solids such as waxes may be used that have a viscosity preferably greater than about 250 cP at 24°C. Approximately 2500 at 24℃
Waxes with viscosities higher than cP are difficult to extrude. The additional force required to extrude the thick resinous wax can create microplastic distortions in the sheet that impair core losses in electrical steel.

Sealants that solidify at ambient temperatures, such as hard beeswax, induce core cera 1 - 2 and impair the stress state of the electrical steel. In the case of liquid adhesives, it may be necessary to heat the high viscosity sealant to a temperature above the ambient temperature of 1.t'7 for the sheet. and further have a 1-minute viscosity to retard or prevent penetration of liquid adhesive through the continuous barrier formed along the longitudinal edges of the laminate.

Viscosity is a measure of a liquid's resistance to flow based on the attractive forces between molecules. A large value is an attractive force, and a slow value causes liquid to flow. The viscosity of the liquid adhesive and the sealant used are such that the 32.degree.
．． This is important for influencing the flow rate of meniscus 50 between 40 and 40.

It has been empirically determined that various low viscosity liquids are good as adhesives, as described in co-pending US patent application Ser. No. 0,710,3077.

Iron cores used as transformers for power conversion are often permanently immersed in transformer oil and cooled by the transformer oil. The use of this oil as a bonding fluid has the special advantage of being compatible with transformer oils. In some applications, the formed core can be subjected to a final heat treatment at the end of life. In heat-treated cores where carbon in hydrocarbon-based liquid adhesives can contaminate sheet metal, i.e., grain-oriented steel, synthetic non-carbon oils can be used as adhesives.

Example 1 As an example, the width is 7.65 ci, the length is 30.5 cm, and the thickness is 0.
．． 18 mm of conventional grain oriented electrical steel was covered with a 5-6 g turbidity 2/dust 2 insulation coating applied to a milk glass coating. In trials 1 to 3, liquid adhesive TJ was applied to the sheet. A silicon type transformer oil of nominal viscosity of 40 cP at 24° C. was applied by brush oil to one opposing side of each set of steel sheets. The two sheets were laminated through the sheets via a pair of 76-shoulder diameter neoprene rollers, and back pressure was applied to remove excess transformer oil and air was expelled from between the opposing surfaces. In tests 4-6, only sealant was used. 24℃
The organic wax has a viscosity of 500 cP, and the descending line of the ream is about 10 mm along the vertical and low link direction of the sheet.
was applied by contact wiping onto one opposing sheet surface when separated by a width of about 25 mm and about 25 mm apart. The wax sealant was spread into a thin film between the opposing sides of the sheet by applying sufficient pressure to the outer surface of the sheet.

All tests were examined immediately after lamination and after undergoing metal cutting. Tests 1-3 were based on laminations with good properties and maintained the essential magnetic properties of the grain-oriented electrical steel. The average iron loss at 15 kG and 1.7 kG was increased by 0.8% and 0.9%, respectively.

However, leaching of transformer oil from between the sheets along the edges is evident during sheet solidification and during stack cutting. Exam 4
As expected in ~6, no leaching occurs because only high viscosity sealant is used.

However, the produced laminates had poor properties, experiencing considerable deterioration in magnetic properties when cut. 1-
The average iron loss at 5kG and 17kG was increased by 51% and 52%, respectively. Tests 4 to 6 show that the use of a sealant without a liquid adhesive to form a continuous film between opposite surfaces of the seal does not prevent deterioration of the magnetic properties. Contact, or inner layer ``shorting'', occurs when the continuous inner layer insulation is poor, resulting in reflux or eddy currents during alternating current magnetization.
If the laminations formed when building the core are cut, this results in loss of insulation coating from the sheet surface.

When a continuous film of liquid adhesive is provided, the insulation coating flakes off, clearly retaining the powder insulation at the point of cut that holds the sheets together as the adhesive comes into contact with each other when cutting the metal sheet.

Example 2 A highly permeable grain-oriented electrical steel sheet with a width of 7.65 cm, a length of 30.5 CI, and a thickness of 0.23 mm was coated with a mill glass coating.
9], coated with Og I/w2 insulation coating. Test 7 ``'+,, at 1.0, the same liquid adhesive was applied in the same manner as in Tests 1-23 above.
, was done.

The same sealant and the same application force method as in Tests 4 to 0 were applied using the same sealant and the same application force method as in Tests 4 to 0.
The sealant was used in tests 11-14, except in tests 11 to 14, with each parallel band having a series of parallel bands (=1). Passed +/T I was immediately evaluated in a no-command manner.

The results for the laminates made in Tests 7-14 are substantially the same as reported above for Tests 1--0. Although the magnetic properties of the laminates made in Tests 7-10 using liquid adhesive C-F were good, leaching of the adhesive occurred during solidification of the sheet and after cutting the laminate. ] The average iron loss at 5 kG and 17 kG increased by -0.3% and 0.8%, respectively. Trial @11 to 1
Laminates made with 4 have inferior properties, 1.5 kG and 1
The average iron loss at 7kG was increased by 2.4% and 43%, respectively.

1LJ1--Example J Additional laminates were prepared according to the invention from the same sheet as in Example 2. The sheets in Tests 15-17 had the same adhesive and f=1 method as described in Tests 1-3 of Example 1.

Sea 1. Example 1 after applying liquid adhesive of /\
In Test 15, the sealant described in Tests 4 to 6 was applied in the form of a bead of 1 oz width along the longitudinal and lateral edges of the sheet.
It was also given in ~17. The sheet was tested in Example 1, Test 4.
It was solidified into a laminate in the same manner as described in ~.6. No leaching of adhesive along any edges of the laminate occurred after setting of the Sea I- or after cutting the laminate. The magnetic properties of the stack were excellent before cutting. 15 i<
G and ],, 7 k The average core loss of G is the above-mentioned test results when liquid adhesive (゛) is used in Tests 1 to 3 of Example 1 or Tests 7 to ]0 of Example 2. Well within range.

A shaped vIN retains liquid adhesive between opposing surfaces of the sheets forming the laminate upon solidification of the sheets.
It was shown that the sealant was spread in a thin continuous film along the edges of the.

The results of a series of tests are summarized in Table 1.

Table---1- Lamination properties after cutting Good Good Poor 6 Poor
No 7 Good
Good 8 good
Yes 9 Good
Yes10 Good
Yes 11
Inferior No 12
Inferior No 13
Poor No 14
Poor No 15
(Invention) Good No 16 (Invention)
Good No 17 (Invention) Good
Although only one embodiment of the invention has been described, it will be understood that various changes may be made without departing from the spirit and scope of the invention. For example, a variety of adhesives and sealants may be used, as long as they are compatible with the situation in which the laminate is used, having the necessary viscosity to form a seal when formed into very thin layers.

Two or more sheets can be laminated together using a variety of means simultaneously to apply a liquid contact agent to opposing surfaces of at least one sheet. One or both sides of the sheet can be pre-applied with a coating, such as a metal or glass insulation coating. The laminates are wound around a core formed into a laminated core of cut laminates or similar fabrics. Accordingly, the limitations of the invention should be determined from the scope of the appended claims.

[BRIEF DESCRIPTION OF THE DRAWINGS] Figure 1 is a schematic view of two sheets being laminated together by a pair of sealing rollers as they move along a supply path and the lamination is wound around an iron core. 3 is an enlarged schematic sectional view of the laminated sheet of the present invention, and FIG. 4 is an enlarged longitudinal sectional view of two seeds pressed together according to the invention. be. In the figure, 1o, 14
Coil, 12.16 Sheet, 13: Supply passage, 22
．． 24. Laura, 26. Laminated, 32.4o6 sides, 36.
38 vertical edge, 34 sealant, 42. Adhesive, 34 a
, : lTt wall.

Claims (22)

[Claims] (1) providing at least two sheets each having opposing surfaces, applying a liquid adhesive to one of the opposing surfaces, applying a sealant along a longitudinal edge to one of the surfaces, and applying pressure to the sheet; to remove excess liquid adhesive from between the surfaces to form a continuous barrier along the longitudinal edges such that the surfaces contact each other, thereby eliminating air between the surfaces. is driven out by the liquid adhesive so that the sealant prevents air re-entry to minimize liquid adhesive seepage along the longitudinal edges. (2) The laminate forming method according to claim 1, wherein the liquid adhesive is oil and the sealant is wax. 3. The method of claim 2, wherein each sheet is made of grain-oriented steel less than about 0.5 mm and the surface of the sheet is coated with an oil- and wax-impermeable glass insulating film. (4) The distance between the surfaces after pressure is applied is approximately 0.0
2. The method for forming a laminate according to claim 1, wherein the width is narrower than 0.05 mm. 5. The laminate forming method according to claim 1, further comprising the step of passing one of the sheets along the supply path at a predetermined speed and passing the other sheet along the supply path at a predetermined speed. 6. The method of forming a laminate according to claim 5, wherein the pressure is applied by passing the sheet between a pair of spaced rollers, and the gap between the rollers is greater than or equal to the combined thickness of the sheets. 7. The method of claim 6, wherein the sealant is applied to one side of the sheet and the liquid adhesive is applied to the other side of the sheet as the sheet passes along the feed path. 8. The method of claim 3, wherein each sheet has a thickness of about 0.5 mm or less, and the method includes the step of winding the laminate around an electrical transformer core. 9. The method of claim 3, wherein each sheet has a thickness of about 0.5 mm or less and includes the step of cutting the layers that are not to be laminated. (10) The laminate forming method according to claim 1, wherein the liquid adhesive has a viscosity of about 80 cP or less at 24°C, and the sealant has a viscosity of about 2500 cP or less at 24°C. (11) The laminate forming method according to claim 1, wherein the temperature of the liquid adhesive and sealant is higher than the ambient temperature when the liquid adhesive and sealant are applied to the surface of the sheet. 12. The method of claim 1, wherein the sealant is applied in the form of one of the group consisting of continuous lines, parallel lines, intersecting diagonal lines, sinusoidal lines, squares, and extruded beads. (13) providing at least two sheets each having opposing surfaces, applying a liquid adhesive to one of the opposing surfaces, and applying a sealant to one of the surfaces along a longitudinal edge and at a position midway between the longitudinal edges; applying pressure to the sheet to drive excess liquid adhesive from between the surfaces to form a continuous barrier along the longitudinal edges and at an intermediate location such that the surfaces contact each other; and slit the laminate along intermediate locations to form a continuous barrier along each slit edge between the sheets of the laminate so that air between the surfaces is forced out by the liquid adhesive and A method of forming a laminate in which the sealant prevents air re-entry to minimize leaching of liquid adhesive along the longitudinal edges of the laminate. (14) passing one of the sheets along the feed path at a predetermined speed and passing another sheet along the feed path at the predetermined speed;
A liquid adhesive having a viscosity of about 80 cP or less at 24°C is applied to one of the opposing faces, a sealant having a viscosity of about 2500 cP or less at 24°C is applied along the longitudinal edge of one of the faces; is passed between a pair of rollers, which apply pressure to the sheet to expel excess liquid adhesive from between the surfaces to create a continuous barrier between the surfaces with a sealant when the surfaces are brought into contact with each other. forming opposite surfaces so that air between the surfaces is forced out by the liquid adhesive and the sealant prevents air re-entry and minimizes leaching of the liquid adhesive along the edges. A method of forming a laminate from a plurality of grain-oriented steel sheets each having a surface and a thickness of about 0.5 mm or less. 15. The method of claim 14, wherein the liquid adhesive is applied to one of the sheets and the sealant is applied to another sheet as the sheet passes along the feed path. (16) at least two sheets each having opposing surfaces and in which the surfaces contact each other, a sealant along the longitudinal edges of the surfaces, an adhesive between the sealants on the surfaces, a liquid adhesive and a sealant; and the air between the surfaces excluded by
The laminate forms a continuous barrier with the sealant to prevent air re-entry and minimize liquid adhesive infiltration along the edges, thereby allowing the laminate to be handled without delamination. (17) The laminate according to claim 16, wherein the liquid adhesive is oil and the sealant is wax. 18. The surface of claim 16 having a glass insulating coating impermeable to liquid adhesives and sealants, each sheet being grain oriented steel having a thickness of about 0.5 mm or less. Laminated. 19. The laminate of claim 16, wherein the liquid adhesive has a viscosity of about 80 cP or less at 24°C and the sealant has a viscosity of about 2500 cP or less at 24°C. (20) at least one laminate of at least two sheets each having opposing surfaces and having a thickness of about 0.5 mm, the surfaces touching each other; a sealant along the longitudinal edges of the surfaces; It consists of an adhesive between the sealant on the surfaces and air between the surfaces that is excluded by the liquid adhesive and the sealant, and the sealant forms a continuous barrier to prevent air from re-entering. A metal core that minimizes the penetration of liquid adhesive along the edges, thereby allowing the metal core to be handled without lamination separation. (21) The metal core according to claim 20, wherein the core is a wire-wound transformer. (22) The metal core of claim 20, wherein the liquid adhesive has a viscosity of about 80 cP or less at 24°C, and the sealant has a viscosity of about 2500 cP or less at 24°C.