CN220961176U

CN220961176U - Peel strength test specimen

Info

Publication number: CN220961176U
Application number: CN202322735048.4U
Authority: CN
Inventors: 孙虎; 郭钇伟; 丁常林
Original assignee: Tongwei Solar Hefei Co Ltd
Current assignee: Tongwei Solar Hefei Co Ltd
Priority date: 2023-10-11
Filing date: 2023-10-11
Publication date: 2024-05-14
Anticipated expiration: 2033-10-11

Abstract

The application relates to a peel strength test sample, which comprises a glass substrate, a packaging adhesive film, a back plate and a supporting sheet, wherein the packaging adhesive film is attached to the glass substrate, the back plate is laminated and attached to one side of the packaging adhesive film, which is opposite to the glass substrate, the supporting sheet is connected with one side of the back plate, which is opposite to the packaging adhesive film, and the shear modulus of the supporting sheet is larger than that of the back plate. According to the peel strength test sample, the shear modulus of the supporting sheet is larger than that of the backboard, and the backboard is supported, so that the backboard is not easy to deform under the supporting action of the supporting sheet in the peel strength test process, and the accuracy of the peel strength measurement result is improved.

Description

Peel strength test specimen

Technical Field

The application relates to the technical field of photovoltaic module testing, in particular to a test sample for peel strength.

Background

The national standard of the photovoltaic backboard clearly specifies that the peel strength of the backboard and the adhesive film after lamination is more than or equal to 50N/cm. In the related art, a polyolefin co-extrusion back sheet is used as a back sheet commonly used for a single glass assembly. In the test of the peeling strength of the laminated back plate and the adhesive film by using the tension machine clamp, the back plate can be obviously stretched and deformed along with the movement of the clamp, so that the measured data have great errors, and the peeling strength of the back plate and the adhesive film cannot be faithfully reflected.

Disclosure of Invention

Based on the above, a peel strength test specimen is provided to solve the problem of how to improve the accuracy of peel strength test.

The present application provides a peel strength test specimen comprising:

A glass substrate;

the packaging adhesive film is attached to the glass substrate;

A back plate laminated and attached to one side of the packaging adhesive film, which is opposite to the glass substrate; and

And the supporting sheet is connected with one side of the backboard, which is opposite to the packaging adhesive film, and the shear modulus of the supporting sheet is larger than that of the backboard.

In one embodiment, the backsheet is a polyolefin co-extruded backsheet.

In one embodiment, the backsheet is a fluorine-free PET-free, full polyolefin backsheet, a fluorine-containing PET-free polyolefin backsheet, a fluorine-free PET-containing polyolefin backsheet, or a fluorine-containing PET-containing polyolefin backsheet.

In one embodiment, the back sheet is a three-layer all-polyolefin solar back sheet, the back sheet comprises an upper layer, a lower layer and a core layer sandwiched between the upper layer and the lower layer, the upper layer and the lower layer are made of a polyolefin resin composition, and the core layer is made of a polyethylene resin composition.

In one embodiment, the material of the supporting sheet is polyethylene terephthalate.

In one embodiment, the packaging film is made of ethylene-polyvinyl acetate copolymer.

In one embodiment, the thickness of the supporting sheet is greater than the thickness of the packaging adhesive film, and the thickness of the supporting sheet is less than the thickness of the back plate.

In one embodiment, the thickness of the support sheet is 1mm to 3mm.

In one embodiment, the supporting sheet covers the whole surface of the back plate on the side facing away from the packaging adhesive film.

In one embodiment, the support sheet is laminated to the back sheet.

The peel strength test sample comprises a glass substrate, a packaging adhesive film, a back plate and a supporting plate, wherein the packaging adhesive film is attached to the glass substrate, the back plate is laminated and attached to one side of the packaging adhesive film, which is opposite to the glass substrate, the supporting plate is connected with one side of the back plate, which is opposite to the packaging adhesive film, the shear modulus of the supporting plate is greater than that of the back plate, so that when the supporting plate and the glass substrate move relatively along the shear direction, the supporting plate is linked with the back plate to form the packaging adhesive film glass, and the back plate is not easy to deform under the supporting action of the supporting plate, thereby being beneficial to improving the accuracy of the peel strength measurement result.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the related art, the drawings that are required to be used in the embodiments or the related technical descriptions will be briefly described, and it is apparent that the drawings in the following description are only some embodiments of the present application, and other embodiments of the drawings may be obtained according to the drawings without inventive effort to those of ordinary skill in the art.

FIG. 1 is a schematic diagram showing the structure of a peel strength test specimen according to an embodiment of the present application.

Fig. 2 is a schematic diagram of a peel strength test sample according to an embodiment.

Fig. 3 is a schematic view showing another state in the case of performing a peel test on a peel strength test sample according to an embodiment.

Reference numerals illustrate:

10. a glass substrate; 20. packaging the adhesive film; 30. a back plate; 40. and a support sheet.

Detailed Description

In order that the above objects, features and advantages of the application will be readily understood, a more particular description of the application will be rendered by reference to the appended drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. The present application may be embodied in many other forms than described herein and similarly modified by those skilled in the art without departing from the spirit of the application, whereby the application is not limited to the specific embodiments disclosed below.

It will be understood that when an element is referred to as being "fixed" or "disposed" on another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present.

The terms "vertical," "horizontal," "upper," "lower," "left," "right," and the like are used for illustration purposes only and are not meant to be the only embodiment.

It is to be understood that the terms "center," "longitudinal," "transverse," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," and the like are used in an orientation or positional relationship based on that shown in the drawings, merely to facilitate describing the application and to simplify the description, and do not indicate or imply that the devices or elements being referred to must have a particular orientation, be configured and operated in a particular orientation, and thus should not be construed as limiting the application.

In embodiments of the present application, the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In the description of the present application, the meaning of "plurality" means at least two, for example, two, three, etc., unless specifically defined otherwise.

Referring to fig. 1, the peel strength test specimen provided by the present application includes a glass substrate 10, a packaging film 20, a back plate 30 and a supporting sheet 40. The packaging adhesive film 20 is attached to the glass substrate 10, the back plate 30 is laminated and attached to one side of the packaging adhesive film 20 facing away from the glass substrate 10, and the supporting sheet 40 is connected with one side of the back plate 30 facing away from the packaging adhesive film 20. In this embodiment, the shear modulus of the support sheet 40 is greater than the shear modulus of the back sheet 30.

As shown in connection with fig. 2 and 3, the peel strength test may be a 180 ° peel strength test method such that the supporting sheet 40 and the glass substrate 10 are relatively moved in the shear direction (see the direction indicated by the arrow in fig. 2 and 3). Since the supporting sheet 40 is connected to the side of the back plate 30 facing away from the packaging adhesive film 20, when the supporting sheet 40 and the peeling substrate move relatively along the shearing direction, the supporting sheet 40 links the back plate 30 to peel from the packaging adhesive film 20. Because the shear modulus of the supporting sheet 40 is greater than that of the back plate 30, the back plate 30 is not easy to deform under the supporting action of the supporting sheet 40, so that the accuracy of the peeling strength measurement result is improved.

It should be noted that, the shear modulus is also called shear modulus or rigidity modulus, and is the ratio of shear stress to shear strain, specifically, the ratio of shear stress to shear strain is the shearing of the material within the limit range of elastic deformation proportion under the action of shear stress. It characterizes the ability of a material to resist shear strain, with a greater shear modulus indicating a stiffer material, which in turn is less prone to deformation. Therefore, in the embodiment of the application, since the supporting sheet 40 connected to the back plate 30 has a larger shear modulus than the back plate 30, a good supporting effect can be achieved on the back plate 30, so that when the peeling strength test sample is subjected to peeling strength test, the supporting sheet 40 and the glass substrate 10 are pulled in opposite directions along the shearing direction, at this time, the supporting sheet 40 is linked with the back plate 30 to move relative to the glass substrate 10, so that the back plate 30 and the supporting sheet 40 have consistent displacement, the test error caused by the deformation of the back plate 30 is reduced, and the accuracy of the peeling strength test result is improved.

The supporting sheet 40 may be adhered to the back plate 30 by glue, and it is understood that the adhesive force of the glue connected to the supporting sheet 40 and the support of the back plate 30 is greater than the adhesive force of the packaging adhesive film 20 to the back plate 30, so that the supporting sheet 40 and the back plate 30 are linked, when the peeling strength test is performed, the back plate 30 can be peeled from the packaging adhesive film 20 by pulling the supporting sheet 40 and the glass substrate 10 along the shearing force direction in opposite directions, and the corresponding pulling force when peeling is measured. In some embodiments, the support sheet 40 is laminated to the backsheet 30 such that the overall structure of the peel strength test specimen is stable, consistent with the laminate structure in the photovoltaic module, so that the test results clearly reflect the peel strength between the backsheet 30 and the encapsulating film 20 in the photovoltaic module.

In the embodiment of the present application, the measured tensile force is used to characterize the peeling strength, that is, the greater the tensile force when the back plate 30 is peeled from the packaging adhesive film 20, the harder the peeling, that is, the greater the peeling strength; accordingly, the smaller the pulling force at which the back sheet 30 is peeled from the encapsulating film 20, the easier the peeling, i.e., the smaller the peeling strength. Thus, the peel strength can be measured based on the corresponding tensile force at the time of peeling.

In some embodiments, the backsheet 30 is a polyolefin co-extruded backsheet, i.e., the backsheet 30 is formed by co-extrusion of a polyolefin material. Polyolefin materials include, but are not limited to, polyethylene octene copolymers and polyethylene butene copolymers. The weight average molecular weight of the polyolefin material is 11 to 17 tens of thousands, and at this time, the structural strength of the back sheet 30 is high. The polyolefin material may have a weight average molecular weight of 11 ten thousand, 12 ten thousand, 13 ten thousand, 14 ten thousand, 15 ten thousand, 16 ten thousand or 17 ten thousand, which is not limited herein.

It should be noted that the polyolefin co-extruded backsheet may comprise a multilayer co-extruded polyolefin heat-shrinkable film. The specific manufacturing process can comprise four steps: pretreatment, coextrusion, calendering and heat shrinkage. Wherein, the pretreatment step is to process the raw materials to meet the production requirement. The coextrusion step is to extrude three different polyolefin materials into the same die to form a three-layer structure. The calendaring step is to compress the coextruded three-layer film through a calendar so as to make the film smoother. Finally, the film is heat-shrunk to give it heat-shrinkable properties.

The backsheet 30 may also be a fluorine-free PET (Polyethylene terephthalate ) free full polyolefin backsheet, a fluorine-containing PET free polyolefin backsheet, a fluorine-free PET containing polyolefin backsheet, or a fluorine-containing PET containing polyolefin backsheet. The material of the back plate 30 is not limited herein.

The back sheet 30 may be a three-layer all-polyolefin solar back sheet, and specifically, the back sheet 30 includes an upper layer, a lower layer, and a core layer sandwiched between the upper layer and the lower layer, the upper layer and the lower layer being made of a polyolefin resin composition, and the core layer being made of a polyethylene resin composition. The polyethylene resin composition takes silane grafted and modified polyolefin as a main component, improves the heat-resistant temperature of the polyolefin through silane grafted and modified polyolefin, and obviously improves the heat-resistant and humidity-resistant performance while improving the low-temperature impact resistance, the adhesive performance, the water-resistant performance and the electrical insulation performance of the back plate.

In some embodiments, the material of the support sheet 40 is polyethylene terephthalate, i.e., PET.

In some embodiments, the packaging film 20 is made of ethylene-polyvinyl acetate (EVA) copolymer, and the packaging film 20 made of this material may be referred to as "EVA film". EVA adhesive film is a thermosetting adhesive film, and has advantages in adhesive force, durability, optical characteristics and the like, so that the EVA adhesive film is more and more widely applied to photovoltaic modules.

In the related art, the bonding strength of the back plate 30 and the EVA film after lamination is tested, which simulates the current production situation of the photovoltaic module, and the bonding strength between different back plates 30 and different EVA films has a certain gap, but the common standard is not less than 500N/cm. In a test, a piece of tempered glass having a length of about 300mm and a width of 150mm was generally taken, a back sheet 30 and an EVA film of the same size were laminated in this order on the tempered glass, and laminated in a laminator. After lamination and solidification, the cured product was left to cool at room temperature for 4 hours or more to obtain a cured product, and the cured product was cut into strips of 1mm by 300 mm. Taking a plurality of the strips, manually separating the backboard 30 from EVA by about 20mm, fixing the sample on a tensile testing machine, peeling 180 degrees at the speed of 100mm/min, peeling 100mm each time, recording data, and removing the median of the data from the test result. However, in the test specimen of the related art, the back plate 30 is easily deformed to cause inaccuracy in the measurement result.

According to the peel strength test sample provided by the embodiment of the application, the supporting sheet 40 with the shear modulus larger than that of the backboard 30 is utilized, so that the supporting sheet 40 plays a supporting role on the backboard 30 in the peel strength test process. Therefore, the back plate 30 and the supporting sheet 40 are linked and are not easy to deform, errors caused by the formation of the back plate 30 are reduced, and the accuracy of a test result is improved.

The tensile testing machine can be a TSL-1002 electronic tensile testing machine provided by Jinan Sike testing technology Co., ltd, and is not limited herein.

In some embodiments, the thickness of the supporting sheet 40 is greater than the thickness of the packaging adhesive film 20, and the thickness of the supporting sheet 40 is less than the thickness of the back sheet 30, so that the overall thickness of the peel strength test sample can be reduced while the supporting sheet 40 provides a sufficient supporting force for the back sheet 30, so as to more truly simulate the peel strength between the back sheet 30 and the packaging adhesive film 20 in the photovoltaic module.

In some embodiments, the thickness of the support sheet 40 is 1mm to 3mm, for example, the thickness of the support sheet 40 is 1mm, 1.5mm, 2mm, 2.5mm, or 3mm. The later the thickness of the support sheet 40, the greater the corresponding shear modulus. Through the test, when the thickness of the supporting sheet 40 is 1mm to 3mm, the back plate 30 can be prevented from being deformed in the peeling strength test process, and meanwhile, the waste of materials caused by the thickness is avoided.

It should be noted that the supporting sheet 40 may cover a part of the surface of the back plate 30. In some embodiments, the support sheet 40 has a plurality, and the plurality of support sheets 40 are connected to the back plate 30 at intervals, and the back plate 30 is peeled from the packaging film 20 by synchronously pulling the plurality of support sheets 40 when the peel strength test is performed. In some embodiments, the supporting sheet 40 covers the entire surface of the back plate 30 facing away from the packaging film 20, so that when the peel strength test is performed, the tensile force applied by the supporting sheet 40 to each position of the back plate 30 is relatively uniform, which is more beneficial to reducing the deformation of the back plate 30 and improving the accuracy of the test result.

The technical features of the above embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

The foregoing examples illustrate only a few embodiments of the invention, which are described in detail and are not to be construed as limiting the scope of the invention. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the invention, which are all within the scope of the invention. Accordingly, the scope of protection of the present invention is to be determined by the appended claims.

Claims

1. A peel strength test specimen comprising:

a glass substrate (10);

A packaging adhesive film (20) attached to the glass substrate (10);

A back plate (30) laminated on one side of the packaging adhesive film (20) facing away from the glass substrate (10); and

And the supporting sheet (40) is connected with one side of the back plate (30) which is opposite to the packaging adhesive film (20), and the shear modulus of the supporting sheet (40) is larger than that of the back plate (30).

2. The peel strength test specimen according to claim 1, characterized in that the backsheet (30) is a polyolefin co-extruded backsheet.

3. The peel strength test specimen according to claim 1 or 2, characterized in that the back sheet (30) is a fluorine-free PET-free full polyolefin back sheet, a fluorine-containing PET-free polyolefin back sheet, a fluorine-free PET-containing polyolefin back sheet or a fluorine-containing PET-containing polyolefin back sheet.

4. The peel strength test specimen according to claim 1, wherein the back sheet (30) is a three-layer all-polyolefin solar back sheet, the back sheet (30) comprising an upper layer, a lower layer, and a core layer sandwiched between the upper layer and the lower layer, the upper layer and the lower layer being a polyolefin resin composition, and the core layer being a polyethylene resin composition.

5. The peel strength test specimen according to claim 1, wherein the material of the supporting sheet (40) is polyethylene terephthalate.

6. The peel strength test specimen according to claim 1, wherein the material of the encapsulation film (20) is ethylene-polyvinyl acetate copolymer.

7. The peel strength test specimen according to claim 1, characterized in that the thickness of the supporting sheet (40) is greater than the thickness of the encapsulation film (20), and the thickness of the supporting sheet (40) is less than the thickness of the back plate (30).

8. The peel strength test specimen according to claim 7, characterized in that the thickness of the supporting sheet (40) is 1mm to 3mm.

9. The peel strength test specimen according to claim 7, characterized in that the support sheet (40) covers the entire surface of the back plate (30) on the side facing away from the encapsulating film (20).

10. The peel strength test specimen according to claim 1, characterized in that the support sheet (40) is laminated to the back sheet (30).