Glass fiber board inspection method In the manufacturing process of the adhesive sheet, in order to ensure the quality, it is necessary to regularly test various technical requirements. The detection method is as follows:
1) Resin content: 1 The edge of the bonding sheet is at least 25 mm, and three samples are cut out in the width direction, left, center and right. The sample size is 100 mm × 100 mm, and the diagonal is parallel to the latitude and longitude. 2 Weighing one by one (W1), accurate to 0.001g. 3 Place the sample in 524-593 (muffle furnace, burn for more than 15min, or burn until the carbide is completely removed. 4 Move the sample to the desiccator, cool to room temperature. 5 weigh one by one (W2), Accurate to 0.001 g. 6 Calculation: Resin content = [(W1-W2) / W1] × 100%.
2) Gel time: 1 A sample of about 20 cm × 20 cm was cut out from the center of the bonding sheet, and the sample was placed so that the resin powder fell in the metal sieve and then sieved onto a clean white paper. 2 Take about 20mg of resin powder, put it in the center of the detector hot plate beforehand to 171 (±0.5 °C). Start the stopwatch when the resin powder melts, and stir the resin with a wooden toothpick. 3 Stop the stopwatch when the resin thickens until the drawing is interrupted. The elapsed time is the gel time.
3) Resin fluidity: 1 Cut 4 samples from the edge of the bonding sheet not less than 5 cm. The sample size is 100 mm × 100 mm, and the diagonal is parallel to the latitude and longitude. 2 Weighing (W1), accurate to 0.005 grams. 3 The sample is aligned and laminated, plus a release film, and then placed between two stainless steel plates. 4 Place the steel plate and the sample in a press at 170 ° C ± 2.8 ° C, press once, the unit pressure is 1.4 MPa ± 0.2 MPa, and keep it for 10 min. 5 Remove the sample and cool to room temperature. 6 Punch the φ80mm wafer from the center of the sample. 7 Weigh the wafer (W2) to the nearest 0.005g. 8 Calculation: Fluidity = [(Wl - 2W2) / W1] × 100%.
4) Volatile content: 1 At least 25 mm from the edge of the bonded sheet, 3 samples were cut in the left, middle and right width directions. The sample size is 100 mm × 100 mm, and the diagonal is parallel to the latitude and longitude. 2 At the corner of each sample, wear a small hole. 3 Place the sample in a desiccator for 1 h. 4 Weighing one by one (W1), accurate to 0.001g. 5 Hang the sample in an oven and bake at 163 ° C ± 2 ° C for 15 min. 6 Transfer the sample to a desiccator and cool for 10 min. 7 Weighing by piece (W2), accurate to 0.001g. 8 calculation: volatile content = [(W1 - W2) / W1] × 100%
(3) After the storage of the bonded sheet is tested by the appearance and various technical indicators, the bonded sheets should be stacked neatly and stored and managed as required. The epoxy resin in the bonding sheet is in a semi-cured state, and the quality of the bonding sheet changes with storage conditions and storage time during storage. The change in moisture absorption rate of the bonding sheet under various relative humidity conditions shows that the moisture absorption rate of the bonding sheet is remarkably increased in the case of a large relative humidity. The moisture absorption of the bonding sheet will seriously affect the quality of the product, especially the dip resistance. Fiberglass board
It can be seen that in the storage process of the bonding sheet, the moisture-proof problem must be given full attention! In order to ensure the quality of the product, it is necessary to emphasize that the bonding sheet should be stored under the conditions of temperature below 25 ° C and relative humidity below 50%.