Specification

Transcription

1 Specification Class: Test Instruction, Conditions of delivery Class No.:61 Technical conditions of delivery for elastomer parts JED 220 Previous Edition Part name (for databases) Elastomer, technical conditions of delivery Contents Page 1 Scope Materials Part-specific indications Avoiding hazardous substances Material testing Material requirements for finished parts Design Rules Dimensions Free size tolerances Geometrical tolerances Form errors Tolerance of flatness for sealing surfaces Part Structure General structure Surface quality Definition of parting line, flash, sprues and ejector pin marks Combinations of materials Bonded Parts Diaphragms with fabric Marking of components Time of delivery... 4 Compiler Approved Product Group: 3201 Continuation page 2 to 5 Olaf Hilla Andrzej Kozłowski JED.dot Template version 03 Stephan Eisfelder Doc. Code Language Rev en - F

2 JED-220 : Page 2 1 Scope The specification defines the quality requirements and technical conditions of delivery for elastomer and thermoplastic elastomer parts (both referred to as elastomers in this specification) and compound parts of these materials with metals, plastic materials or fabric as long as not otherwise stated on the drawing or other part specific documents. 2 Materials 2.1 Part-specific indications For parts that do not have a part-specific release of materials, the designations of the released materials shall be taken from the indication of the relevant JED specification on the drawing and the document Release of Materials belonging to that JED specification. For parts including a Release of Materials, the exact designation of the material shall be taken from the document Release of Materials relating to the part. The WABCO drawings of these parts shall be identified by the following text: "First production parts, parts from new or modified moulds and changes of any kind require the approval by the product engineering department". 2.2 Avoiding hazardous substances In addition to the part-specific rules, the specification JED-762 Avoiding hazardous substances has to be observed. 2.3 Material testing Test panels and standard specimens according to JED specification have to be made available for testing the technological data according to the pertaining JED specification. The supplier will be informed on the test result. A positive result of the test is the precondition for the sampling of parts. A material will be released, if the tests of parts are positive as well. 2.4 Material requirements for finished parts The requirements for materials as defined in the JED specifications apply to the finished parts as well. The assessment of tests done on finished parts has to take into account the geometrical and process related restrictions of the finished parts. Measurement positions and method have to be agreed in the course of Component Quality Planning. 3 Design Rules 3.1 Dimensions Free size tolerances Prior to production and making of moulds, the manufacturer generally has to verify whether the dimensional tolerances prescribed can be achieved by molding only or if subsequent processes are required, for instance removal of the parting line flash on sealing surfaces. If the drawing does not contain any indications, the following general tolerances apply: For O-rings the dimensional tolerances according to ISO For fabric reinforced diaphragms according to ISO class M3 For all other elastomer parts the tolerances according to ISO class M Geometrical tolerances Form errors In general the geometrical tolerances acc. ISO class M are valid. This does not apply for fabric reinforced diaphragms.

3 JED-220 : Page Tolerance of flatness for sealing surfaces Generally for inherently stable areas of the product, which are in the drawing marked with sealing surface (in old drawings also valve seat, sealing edge etc.), the maximum acceptable tolerance of flatness is 0,05 mm. For inherently stable areas of diaphragms, which are in the drawing marked with sealing surface (in old drawings also valve seat, sealing edge etc.), the maximum acceptable tolerance of flatness is defined in accordance with ISO tolerance class P for parts without fabric and tolerance class M for parts with fabric reinforcement. 3.2 Part Structure General structure All supplied parts have to be without deformations and defects as for instance pores, bubbles, cracks, etc. The parts shall have a homogeneous structure. For O-rings, the requirements defined in ISO 3601 apply Surface quality Surface imperfections or burrs must not lead to any degradation of the part function (e.g. surface protection, flatness) or of any optical properties, which have been specified. 3.3 Definition of parting line, flash, sprues and ejector pin marks If the drawing does not contain any indications, the following determinations apply: The maximum permissible flash in functional areas is 0.1mm x 0.1mm. In other areas 0.3mm x 0.3mm are permitted. For fabric reinforced diaphragms max. 0.2mm thickness x 0.5mm length are permitted. The maximum permissible flash for O-rings is specified in ISO Prior to mould manufacture, the position of elements like parting line, flash, sprue and ejector pin marks shall be exactly determined together with WABCO. This determination shall be included into the WABCO drawing, except for O-Rings. Generally these elements must not be located at sealing surfaces. If the drawing does not contain any indications, the parting line, height and width of flash, sprue and ejector pin marks have to be agreed in writing with WABCO Product Engineering. 3.4 Combinations of materials Bonded Parts There are two independent methods to check the combination of two materials which are vulcanized to each other: Chemical connection: the resistance to chemicals of the bonding agent and the corrosion resistance underneath the elastomer shall meet the requirements defined in JED-780 for elastomer bonded to metals or plastics, Mechanical connection (dry peel off test): The bond between insert and elastomer should be tested by pulling the sample piece to destruction in a way, that the elastomer is forced to be removed from the insert. The test will be passed, if the crack runs within the elastomer. A separation in the rubber bonding is not permitted. The product specific test details have to be aligned with WABCO. Blisters and inclusions of foreign material which might affect the adhesion are not permitted. Elastomer overflow on the unvulcanized part is only permissible in the areas defined in the drawing. The firm adhesion is the precondition. Also firm adhesion of the bonding agent in not vulcanized part areas is required.

4 JED-220 : Page 4 Metallic components supplied must not exhibit any traces of corrosion. Sufficient temporary corrosion prevention must be ensured for the transport and storage of the parts. The corrosion prevention methods to be used shall be agreed with WABCO and may not damage the elastomer Diaphragms with fabric The position of fabric defined in the drawing has to be observed. It is decisive for the diaphragm s endurance and function. If the fabric is vulcanized as overlay, the fabric shall be on the correct side. In case of fabric is vulcanized as inlay, it shall not be visible at the surface (not protrusion). 3.5 Marking of components The components shall, if possible under the constraints of size, function and process, bear the following markings: a) manufacturer s monogram, b) cavity No and mould No, c) WABCO identification No, d) date of manufacture according to JED-226, e) WABCO monogram according to JED-369, f) symbol for the material For catalogue parts of manufacturers, the markings according to a) and b) are required. If the area is too small to bear a complete marking, the sequence mentioned above (a to f) shall be observed. The marking according to f) consists of the symbols according to ISO 1629 for elastomers and ISO for thermoplastic elastomers, the symbol is shown in square brackets. This marking is legally mandatory for parts with a weight of 200 g and more. Example: > EPDM < In case of vulcanized materials on the basis of rubber blends a maximum of two constituents are mentioned in the sequence of their percentage. Example: > CR + NBR < The marking shall be applied below or near the WABCO monogram or part number. It shall be applied in such a way that it can be easily read. This applies in particular to components mounted on the outside. The position of these markings shall be stipulated with the WABCO Product Engineering prior to manufacture of mould, it will be adapted into the drawing. The marking shall be applied only on surfaces which do not have sealing functions. Therefore, certain components (e.g. o-rings) shall not be marked. 4 Time of delivery In order to avoid changes of material properties, the time between manufacturing date and delivery date shall be limited. The storage time of parts at WABCO and supplier together should not exceed the limitations given by ISO Storage periods at suppliers are restricted to: For material group A acc. ISO 2230 to 2 year For material group B acc. ISO 2230 to 4 years

5 JED-220 : Page 5 For material group C acc. ISO 2230 to 6 years This enables WABCO to store the parts too. If parts are stored prior to delivery, this will have to be done under the conditions defined in ISO In case the above storage times are exceeded for low runner parts (aftermarket) or catalogue parts, WABCO Quality has to be asked for approval.