Annex 2-8 Reinforced plastic materials

1. General

(1) Application

(A) This Guidance applies to the base materials such as thermosetting resins, fiber reinforce- ments and core materials (hereinafter refer to FRP materials) used in the construction or re- pair of FRP ships, composite vessels and other marine structures which are to be certified

or are intended for classification.

(B) FRP materials or hybrid materials other than those prescribed in this Guidance may be used where specially approved in connection with the design. In such cases, the detailed data re- lating to the manufacturing process and mechanical properties, etc. of the materials are to be

submitted for approval.

(2) Approval

(A) FRP materials such as thermosetting resins, fiber reinforcements, core materials, etc. are to

be type approved in accordance with this Guidance and the Guidance specially specified by the Society in advance

(B) The manufacturing process of of FRP ships, composite vessels or which are to be certified or are intended for classification is to be

with the Guidance specially specified by the Society in advance

(C) In order that a FRP materials can be approved, the manufacturer is

other marine structures approved in accordance

required to demonstrate

(3)

to the satisfaction of the Society that the necessary manufacturing and testing facilities are available and are supervised by qualified personnel.

Manufacturing control

(A) It is the manufacturer's responsibility to assure that effective process and production controls in operation are adhered to within the manufacturing specifications.

(B) Where control imperfection inducing possible inferior quality of FRP materials occurs,

manufacturer is to identify the cause and establish a countermeasure to prevent recurrence. Also, the complete investigation report is to be submitted to the Surveyor.

(C) For further use, each FRP material affected by previous (B) is to be tested to Surveyor's satisfaction. The frequency of testing for subsequent products offered may be creased to gain confidence in the quality at the discretion of the Society.

the

its

the in-

(4)

(5)

(6)

(D) The manufacturer is to provide the material producer with such information as is essential to ensure that the FRP materials to be used are in accordance with the approval require- ments and the product specification. This information is to include any survey requirements for the materials.

(E) Post-cure heating is to be carried out in properly constructed ovens which are efficiently maintained and have adequate means for control and recording of temperature. The oven is to be such as to allow the whole item to be uniformly heated to the necessary temperature.

In the case of very large components which require post-cure heating, alternative methods will be specially considered.

Retest procedure

(A) Where test material fails to meet the specified requirement, two additional tests of the same type may be made at the discretion of the Surveyor.

(B) Where an individual test result in a group (minimum five) deviates from the mean by more

than two standard deviations in either the higher or lower direction, the result is to be ex- cluded and a re-test made. Excluded results of tests are to be reported with confirmation

that they have been excluded. Only one exclusion is acceptable in any group of tests.

Quality

(A) FRP materials are to be free from surface or internal defects which would be prejudicial to their proper application in service.

(B) In the event of any material proving unsatisfactory during subsequent working or fabrication,

such material may be rejected, notwithstanding any previous satisfactory testing and/or certif- ication where the Surveyor considers necessary.

Identification and marking of materials

(A) The manufacturer of approved FRP materials is to identify each batch with an unique num- ber or code.

(B) The manufacturer of FRP products is to adopt a system of identification which will enable

all finished products to be traced to the original batches of base materials. Surveyors are to

Guidance Relating to the Rules for the Classification of Steel Ships 2015 95

be given full facilities for tracing any component or material when required.

(7) Certification

The manufacturer is to provide the purchaser with test reports or certificates of conformity for

each batch of FRP material supplied indicating the relevant values are to comply with this Guidance.

2. Thermosetting resins

(1) The test methods for thermosetting resin are to be in accordance with the Guidance specially specified by the Society.

(2) Minimum property values of gel coat resins are to comply with the values specified in Table 1.

Table 1 Minimum property values of gel coat resins

(3) Minimum property values of cast thermosetting resins are to comply with the values specified in

Table 2.

Table 2 Minimum property values of cast thermosetting resins

(4) The polyester containing wax or other material that deteriorate bonding are to be additionally carried out interlaminar shear strength test (KS M ISO 14130). Minimum property values are in accordance with Table 3.

96 Guidance Relating to the Rules for the Classification of Steel Ships 2015

3. Fiber reinforcements

(1) The following tests are to be made on each fiber reinforcement:

(A) Tensile strength (stress at maximum load).

(B) Tensile strain at break.

(C) Tensile secant modulus at 0,5 per cent and 0,25 per cent strain respectively.

(D) Compressive strength (stress at maximum load).

(E) Compressive modulus.

(F) Flexural strength (stress at maximum load).

(G) Modulus of elasticity in flexure.

(H) Apparent interlaminar shear.

(I) Fibre content.

(J) Determination of water absorption.

(2) The test methods for Fiber reinforcements are to be in accordance with the Guidance specially

specified by the Society

(3) Minimum property values of laminates are to comply with the values specified in Table 3.

Table 3 Minimum property values of laminates

4. Core materials

(1) Specific requirements for end-grain balsa

(A) The supplier is to provide a signed statement that the balsa (ochroma lozopus) is cut to end-grain, is of good quality, being free from unsound or loose knots, holes, splits, rot, pith and corcho, and that it has been treated against fungal and insect attack, shortly after fell- ing, followed by homogenization, sterilization and kiln drying to an average moisture content of no more than 12 per cent.

(B) The test methods for end-grain balsa are to be in accordance with the Guidance specially specified by the Society

(C) Minimum property values of end-grain balsa are to comply with the values specified in

Table 4.

Guidance Relating to the Rules for the Classification of Steel Ships 2015 97

Table 4 Minimum property values of end-grain balsa

(2) Specific requirements for rigid foams (PVC, Polyurethane and other types)

(A) The foam is to be of the closed cell type and compatible with the proposed resin

(e.g. polyester, epoxide, etc.).

(B) Foams are to be of uniform cell structure.

(C) Data is to be provided on the dimensional stability of the foam by measurement shrinkage.

(D) The following test data is to be submitted for each type of foam:

(a) Density.

(b) Tensile strength (stress at maximum load).

(c) Tensile modulus of elasticity.

(d) Compressive strength (stress at maximum load).

(e) Compressive modulus of elasticity.

(E) Additionally the compressive properties (see (D) (d) and (e)) are to be determined at imum of five points over the temperature range ambient to maximum recommended or 70 °C, whichever is the greater.

system of the

a min- service

(F) The test methods for rigid foams are to be in accordance with the Guidance specially speci- fied by the Society

(G) Minimum characteristics and mechanical properties of rigid expanded foams are to comply

with the values specified in Table 5.

Table 5 Minimum characteristics and mechanical properties of rigid expanded foams at 20 °C

(H) Other types of foam will be subjected to individual consideration. A minimum core strength of 0.5 is to be achieved.

shear

98 Guidance Relating to the Rules for the Classification of Steel Ships 2015