ISO 15034 pdf download.Composites — Prepregs — Determination of resin flow
1 Scope
This International Standard specifies a procedure for the determination of the resin flow of prepregs made of continuous reinforcement impregnated with epoxy and/or unsaturated-polyester resin.
2 Normative references
The following normative documents contain provisions which, through reference in this text, constitute provisions of this International Standard. For dated references, subsequent amendments to, or revisions of, any of these publications do not apply. However, parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document referred to applies. Members of ISO and IEC maintain registers of currently valid International Standards. ISO 291 :1 997, Plastics — Standard atmospheres for conditioning and testing. ISO 472:1 999, Plastics — Vocabulary. ISO 8604:1 988, Plastics — Prepregs — Definitions of terms and symbols for designations. ISO 9782:1 993, Plastics — Reinforced moulding compounds and prepregs — Determination of apparent volatile- matter content.
3 Terms and definitions
For the purposes of this International Standard, the terms and definitions given in ISO 472 and ISO 8604 apply.
4 Principle
A test specimen is cut from a prepreg sample and placed between bleeder cloth and release film. This assembly is cured at the test temperature and pressure in a hot press. After curing, any resin which flowed beyond the original dimensions of the test specimen is removed. The resin flow is calculated as the percent difference between the mass of the test specimen before and after curing.
5 Apparatus
5.1 Cutting template, made of metal or ceramic material, measuring (1 00 1 ) mm by (1 00 1 ) mm and about 5 mm thick. Hard metals such as steel are recommended. 5.2 Knife, single-edge. 5.3 Analytical balance, capable of weighing to the nearest 1 mg.5.4 Glass bleeder cloth, 1 81 style or equivalent. 5.5 Release film (perforated), heat-resistant, for example polytetrafluoroethylene, with suitable perforations through which the resin can flow out. 5.6 Release film (unperforated), heat-resistant, for example a copolymer of tetrafluoroethylene and hexafluoroethylene (FEP). 5.7 Heated platen press, capable of raising the temperature to 200 °C and maintaining the pressure at up to 600 kPa over a 1 00 mm by 1 00 mm area.
6 Preparation of test specimens
6.1 A minimum of three specimens shall be tested from each sample. 6.2 Using the template, carefully cut pieces measuring 1 00 mm by 1 00 mm from the prepreg sample. Cut the pieces out across the width of the prepreg. Cut out sufficient pieces so that, when they are placed one on top of the other, they will give specimens 0,2 mm to 0,5 mm thick. If the necessary number of pieces cannot be cut out in the width direction (as with narrow tape, for example), they may be cut out in the longitudinal direction. The edges and selvedges of the prepreg shall not be included in any of the pieces. 6.3 In the case of unidirectional prepregs, lay up the plies with alternating plies perpendicular to each other. Using two or four plies for each specimen is recommended. If the recommended number of plies does not give a thickness in the required range, a different number of plies may be used, but this shall be noted in the test report.
7 Conditioning and test atmospheres
7.1 Conditioning Prepregs are usually stored at a low temperature, such as –1 8 °C. Before opening a sealed package of prepregs, allow it to warm up to the point where no condensation takes place on the outside of the package. Ensure that the prepregs do not absorb moisture from the atmosphere. 7.2 Test atmosphere Prepare the specimens and carry out the test in a room in which the atmosphere is one of the standard atmospheres defined in ISO 291 , unless otherwise specified. If the press is installed in an insufficiently conditioned atmosphere, the time during which the specimen is exposed to this atmosphere shall be kept as short as possible.