BS 3691:1990 pdf download.E glass fibre rovings for reinforcement of polyester and epoxy resin systems.
4 Manufacture
4.1 Construction The rovings shall be constructed, either directly or indirectly, from glass strands of the same filament diameter designation. The filament diameter designation used shall be as given in Table 1, with filament diameter determined in accordance with Appendix B.
4.2 Size The glass strands used in the manufacture of the rovings shall have been treated with a size that is compatible with the specified resin system.
5 Property requirements The rovings as supplied shall be continuous about their length and shall comply with the property requirements given in table 2 when tested by the appropriate methods. NOTE Rovings should normally be supplied uniform in colour and free from contaminants, fuzz balls and foreign bodies.
6 Packaging and marking
6.1 Rovings shall be packed in containers in such a manner as to provide protection against damage during transportation.
6.2 Each container shall be clearly marked with the following information: a) the name or trade mark of the supplier; b) the designation as specified in clause 3; c) the designated tex value of the roving; d) the supplier’s identification of the roving, including size code and resin compatibility; e) the number and date of this British Standard, i.e BS 3691:1990 1) ; f) a statement as to whether the roving is normal or selected grade.
B.3 Calibration of the microscope scale Place the micrometer scale (B.2.2) on the microscope stage (B.2.1) and, using low magnification, centre the micrometer scale image on the screen. Increase the magnification until one micron of the image is approximately equivalent to one millimetre on the screen scale. Align the image by means of the stage sliding mechanism with the screen scale and record how many millimetres, A, on the screen scale correspond to 50 µm on the micrometer scale. Example. If 50 µm of the micrometer scale image are 60 mm wide on the screen scale, A = 60.
B.5 Method Place the slide on the microscope stage and focus on the filaments. Using the screen scale, measure and record the width of the image of the filament to the nearest millimetre. Traverse the slide by means of the stage sliding mechanism until another filament is encountered and then measure and record the image width. To avoid repeated measurements of the same filaments, start at one edge of the slide and traverse in one direction only. Repeat the process until 100 measurements have been made. If an insufficient number of measurements have been made from one slide, prepare a second and so on until 100 filaments have been measured.BS 3691 pdf download.