CN-122016789-A - Method for testing resin content of carbon fiber unidirectional prepreg surface

CN122016789ACN 122016789 ACN122016789 ACN 122016789ACN-122016789-A

Abstract

The invention discloses a method for testing the resin content of the surface of a carbon fiber unidirectional prepreg, which comprises the specific test procedures of cutting the prepreg and preparing a plurality of groups of material sheets, removing a prepreg surface isolation film, amplifying and shooting a photo under an optical instrument, and obtaining the total pixel value of the picture in the step S2 by using image software Acquiring the surface resin pixel value of the picture in the step S2 by using image software And calculating the resin content of the surface of the prepreg. The test method can simply, intuitively, safely and environmentally-friendly realize quantitative characterization of the resin content on the surface of the prepreg by combining with image processing software through application of simple instruments such as an optical imager or an optical microscope, reflects the degree of infiltration of the resin in the prepreg on the fibers, further guides formulation of the prepreg production process, and improves the manufacturability of the prepreg.

Inventors

KONG WEINA
LIU SIDA
GUI JIAJUN
WANG JIEYU
CHEN MANYU
Ban Zifa
ZHU KAI

Assignees

中航复合材料有限责任公司

Dates

Publication Date: 20260512
Application Date: 20260213
Priority Date: 20251222

Claims (7)

1. A method for testing the resin content of the surface of a carbon fiber unidirectional prepreg is characterized by comprising the following specific testing procedures: s1, cutting a prepreg sample and preparing a plurality of groups of tablets; s2, removing the isolation film on the surface of the prepreg, amplifying under an optical instrument and taking a picture; S3, obtaining the total pixel value of the picture in the step S2 by using image software ; S4, acquiring the pixel value of the surface resin of the picture in the step S2 by using image software ; S5, calculating the resin content on the surface of the prepreg, wherein the calculation formula is as follows: = 。
2. The method for testing the resin content of the surface of the unidirectional carbon fiber prepreg according to claim 1, wherein in the step S1, a plurality of observation webs are uniformly cut out of the prepreg within a width.
3. The method for testing the resin content of the unidirectional carbon fiber prepreg surface according to claim 1, wherein in the step S2, an optical instrument is selected from an optical imaging instrument or an optical microscope, the prepreg surface isolation film is removed and then is placed under a lens of the optical instrument smoothly, and the surface morphology of the material sheets is observed one by one and clear pictures are obtained.
4. The method for testing the resin content of the surface of the unidirectional prepreg of carbon fiber as claimed in claim 1, wherein in the step S2 and the step S3, photoshop is used for image software.
5. The method for testing the surface resin content of a unidirectional prepreg of carbon fibers as set forth in claim 4, wherein in step S2, a "source" is set as an "entire image" at a "histogram" interface to obtain a total pixel value of the photograph 。
6. The method for testing the surface resin content of the unidirectional carbon fiber prepreg according to claim 4, wherein in the step S3, "select", "color range" is clicked in sequence, a surface resin region is selected, and a "source" is set as a "selected layer" on a "histogram" interface to obtain a surface resin pixel value 。
7. The method for testing the surface resin content of the unidirectional carbon fiber prepreg according to claim 6, wherein the surface resin region is obtained in two ways, comprising: Setting a selection mode in a color range dialog box as a highlight mode, and setting color tolerance values and range values; Setting "select" in the "color range" dialog box to "sample color" mode, clicking the "straw tool" to take the resin color in the photograph, "add" or "subtract" the error color, and setting the "color tolerance" value.

Description

Method for testing resin content of carbon fiber unidirectional prepreg surface Technical Field The invention relates to the technical field of composite material characterization test, in particular to a method for testing the resin content of a carbon fiber unidirectional prepreg surface. Background Prepregs are intermediate products of resin-based composite materials, which are made by impregnating a matrix material (resin) with a reinforcing material (fibers, fabrics, etc.) under strict control. The resin content is one of the key physical properties of the prepreg, and directly influences the paving manufacturability, mechanical property and molding quality of the prepreg. Currently, for the uncured prepreg, the resin content of the prepreg is generally obtained by using a solvent which can completely dissolve a resin matrix and does not change the quality of reinforcing materials and fillers according to HB 7736.5 part 5 of a test method for the physical properties of the prepreg for the composite material, dissolving or extracting all the resin in a prepreg sample, calculating the percentage of the mass difference before and after the sample treatment, and for the cured prepreg composite material, the resin content is generally estimated by metallographic observation and picture treatment according to GB/T3365 test method for the pore content and the fiber volume content of carbon fiber reinforced plastics, and the resin content is obtained by dissolving or ablating at high temperature according to ASTM D3171 test for the component content of the composite material. The resin content of the prepreg surface affects the surface tackiness of the prepreg and reflects the degree of wetting of the prepreg to some extent. The current common test method can obtain the total resin content in the prepreg and the composite material, but the test result cannot obtain the resin content on the surface of the prepreg, and cannot reflect the distribution condition of the resin. Disclosure of Invention Aiming at the defects existing in the prior art, the invention provides a method for testing the resin content on the surface of the carbon fiber unidirectional prepreg, which can simply, intuitively, safely and environmentally-friendly realize quantitative characterization of the resin content on the surface of the prepreg by combining image processing software through application of simple instruments such as an optical imager or an optical microscope, reflects the degree of infiltration of the resin in the prepreg to the fiber, further guides formulation of the prepreg production process and improves the manufacturability of the prepreg. A method for testing the resin content of the surface of a carbon fiber unidirectional prepreg comprises the following specific testing procedures: s1, cutting a prepreg sample and preparing a plurality of groups of tablets; s2, removing the isolation film on the surface of the prepreg, amplifying under an optical instrument and taking a picture; S3, obtaining the total pixel value of the picture in the step S2 by using image software ; S4, acquiring the pixel value of the surface resin of the picture in the step S2 by using image software; S5, calculating the resin content on the surface of the prepreg, wherein the calculation formula is as follows: =。 as a preferable aspect of the present invention, in step S1, a plurality of observation webs are cut uniformly over one width of the prepreg. In step S2, the optical instrument is an optical imaging instrument or an optical microscope, the prepreg surface isolation film is removed and then the prepreg surface isolation film is placed under the lens of the optical instrument, and the surface morphology of the material sheet is observed one by one and a clear photo is obtained. As a preferable mode of the above-described aspects, in both step S2 and step S3, photoshop is used for the image software. As a preferable mode of the above technical solution, in step S2, setting "source" as "whole image" at "histogram" interface, obtaining the total pixel value of the photograph。 As the optimization of the technical scheme, in the step S3, clicking the 'select', 'color range', selecting the surface resin area, setting the 'source' as the 'selected layer' at the 'histogram' interface, obtaining the surface resin pixel value。 As preferable modes of the above technical means, there are two modes of obtaining the surface resin region, including: Setting a selection mode in a color range dialog box as a highlight mode, and setting color tolerance values and range values; Setting "select" in the "color range" dialog box to "sample color" mode, clicking the "straw tool" to take the resin color in the photograph, "add" or "subtract" the error color, and setting the "color tolerance" value. Compared with the prior art, the invention has the beneficial effects that: The method can simply, intuitively, safely and environment-friendly realize quantitativ