This article introduce brifely to improve the dimensional stability of CEM-3CCL by adjusting the proportions of the different length of the glass fiber glass fiber paper.
A conventional fiber glass paper is typically adhesive bonded by fiber glass material with diameter 9-10μm and length of about 13mm. This kind of fiber glass paper (CEM-3CCL), will warping deformation in the process, especially when heat.
Thermal expansion coefficient of the resin (60-90 * 10-6cm / cm.0C) is larger than glass fiber (5 * 10-6cm / cm.0C). Conventional glass fiber paper, due to the smaller density and larger gap, there will be fill of more plastic resin content. which caused the dimensional change inevitably large during the heat treatment when processing.
Filling the voids by the 7mm below short glass fiber to improve the density of fiberglass paper. When the fiberglass paper glued, the amount of resin will be reduced and the content will be uniformity. Therefore improved the dimensional stability of CEM-3CCL.
In the glass fiber paper, the short glass fiber 7mm or less, should account for more than 20%, while more than 8mm glass fiber, should account for more than 40%. If 7mm below short fiber glass less than 20% short glass fiber, glass fiber paper does not meet the requirements of density improvement, CCL dimensional stability, the effect is not obvious. If more than 8mm glass fibers of less than 40%, the tensile strength of the nonwoven fabric decreased, CEM-3the glass sheet is prone to break in the manufacturing process.
According to the requirements of Table 1, and adjust the ratio of glass fiber paper with different length of the glass fibers. Through the papermaking machine, epoxy resin as a binder, the binder content of 10% is made of glass fiber paper. Fiberglass resin content of the above-mentioned paper carried on the glue, the adhesive sheet are shown in Table 1.
Fiberglass paper with adhesive sheet as a core material, fiberglass cloth for fabric adhesive sheet having a thickness of 1.6mm CEM-3. Characteristics of the product are shown in Table 1. (author: Wendy)
Tabal 1 CEM-3 CCL Features Comparison
Example
|
1
|
2
|
3
| |
Fiber glass ratio in the paper
|
13mm
|
40
|
85
|
100
|
6mm
|
60
|
15
|
0
| |
Resin Content（％）
|
86.5
|
90.4
|
92.2
| |
Board Feature
|
Thermal Expanding（*10-6）
|
14
|
24
|
27
|
Dimension Shrinkage（％）
|
0.04
|
0.06
|
0.07
| |
warpage（mm)
|
0.7
|
1.6
|
1.8
| |
