SIST EN 1842:1999
(Main)Plastics - Thermoset moulding compounds (SMC - BMC) - Determination of compression moulding shrinkage
Plastics - Thermoset moulding compounds (SMC - BMC) - Determination of compression moulding shrinkage
This European Standard specifies a method to determine the moulding shrinkage of compression moulded test specimens of thermosetting materials. It applies only to materials which exhibit no post-shrinkage after moulding such as polyester SMC and BMC. Knowledge of the shrinkage of these thermosetting materials is necessary for the construction of moulds and for establishing the suitability of the moulding material to produce parts with accurate dimensions.
Kunststoffe - Wärmehärtende Formmassen (SMC - BMC) - Bestimmung der Verarbeitungsschwindung
Diese Europäische Norm legt eine Methode zur Bestimmung der Verarbeitungsschwindung gepreßter Probekörper aus wärmehärtendem Material fest. Sie gilt nur für solche Materialien, die nach der Verarbeitung keine Nachschwindung aufweisen, wie z.B. Polyesterformmassen SMC und BMC. Die Kenntnis der Schwindung dieser wärmehärtenden Materialien ist notwendig sowohl für die Konstruktion von Werkzeugen als auch zum Nachweis der Eignung einer Formmasse zur Herstellung von Formteilen mit genauen Abmessungen.
Plastiques - Matieres a mouler thermodurcissables (SMC - BMC) - Détermination du retrait au moulage par compression
La présente Norme Européenne prescrit une méthode de détermination du retrait au moulage par compression d'éprouvettes de matières à mouler thermodurcissables. Elle s'applique uniquement aux matériaux qui ne présentent pas de post-retrait après moulage tels que les SMC et BMC polyester. La connaissance du retrait des matières thermodurcissables est nécessaire pour la construction des moules et pour la détermination de l'aptitude de ces matières à produire des pièces de dimensions précises.
Polimerni materiali – Duromerni materiali za oblikovanje (SMC – BMC) – Določevanje skrčka pri oblikovanju s stiskanjem
General Information
- Status
- Published
- Publication Date
- 30-Apr-1999
- Technical Committee
- IPMA - Polimer materials and products
- Current Stage
- 6060 - National Implementation/Publication (Adopted Project)
- Start Date
- 01-May-1999
- Due Date
- 01-May-1999
- Completion Date
- 01-May-1999
Overview
EN 1842:1997 is a CEN (European Committee for Standardization) standard titled Plastics - Thermoset moulding compounds (SMC - BMC) - Determination of compression moulding shrinkage. It specifies a laboratory method to determine the moulding shrinkage of compression-moulded test specimens made from thermosetting moulding compounds. The standard applies only to materials that do not exhibit post-shrinkage after moulding, for example typical polyester SMC and BMC formulations. Accurate shrinkage data is essential for mould construction and to verify that a chosen material can produce parts with the required dimensional accuracy.
Key Topics and Requirements
- Scope and applicability
- Method limited to compression-moulded thermosetting compounds with no post-shrinkage (e.g., polyester SMC/BMC).
- Test specimens and moulding
- Specifies the use of compression-moulded test specimens to measure dimensional change introduced during moulding.
- Measurement of shrinkage
- Defines how to determine shrinkage as a comparison between mould cavity dimensions and final part dimensions after cooling.
- Purpose and acceptance
- Enables assessment of material suitability for producing dimensionally accurate parts and informs mould tool design.
- National adoption note
- The standard is adopted nationally by CEN member bodies (the extract shows adoption as SIST EN 1842:1999 in Slovenia).
(Note: EN 1842:1997 describes the method and its limitations; consult the full published standard for detailed test procedures, sample preparation, and measurement tolerances.)
Applications
EN 1842:1997 has practical value across industries that mould thermosetting composites:
- Mould design and engineering
- Use shrinkage values to calculate tool dimensions, compensate for expected part contraction and ensure fit of mating components.
- Material selection and specification
- Compare different SMC/BMC grades for dimensional stability and suitability for particular parts.
- Quality control and incoming inspection
- Verify supplier supplied batches meet declared shrinkage performance as part of production acceptance testing.
- Automotive, electrical and consumer components
- Useful where SMC/BMC parts require tight dimensional tolerances (body panels, housings, structural parts).
Target users include materials engineers, mould/tool designers, quality managers, composite part manufacturers and suppliers of thermoset moulding compounds.
Related Standards
- EN 1842:1997 complements other CEN/ISO test methods for plastics and composite materials (refer to CEN and ISO catalogues for related dimensional stability and mechanical test standards). For full procedural and measurement details, obtain the official EN 1842:1997 document from your national standards body.
Frequently Asked Questions
SIST EN 1842:1999 is a standard published by the Slovenian Institute for Standardization (SIST). Its full title is "Plastics - Thermoset moulding compounds (SMC - BMC) - Determination of compression moulding shrinkage". This standard covers: This European Standard specifies a method to determine the moulding shrinkage of compression moulded test specimens of thermosetting materials. It applies only to materials which exhibit no post-shrinkage after moulding such as polyester SMC and BMC. Knowledge of the shrinkage of these thermosetting materials is necessary for the construction of moulds and for establishing the suitability of the moulding material to produce parts with accurate dimensions.
This European Standard specifies a method to determine the moulding shrinkage of compression moulded test specimens of thermosetting materials. It applies only to materials which exhibit no post-shrinkage after moulding such as polyester SMC and BMC. Knowledge of the shrinkage of these thermosetting materials is necessary for the construction of moulds and for establishing the suitability of the moulding material to produce parts with accurate dimensions.
SIST EN 1842:1999 is classified under the following ICS (International Classification for Standards) categories: 83.080.10 - Thermosetting materials. The ICS classification helps identify the subject area and facilitates finding related standards.
SIST EN 1842:1999 is available in PDF format for immediate download after purchase. The document can be added to your cart and obtained through the secure checkout process. Digital delivery ensures instant access to the complete standard document.
Standards Content (Sample)
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Kunststoffe - Wärmehärtende Formmassen (SMC - BMC) - Bestimmung der VerarbeitungsschwindungPlastiques - Matieres a mouler thermodurcissables (SMC - BMC) - Détermination du retrait au moulage par compressionPlastics - Thermoset moulding compounds (SMC - BMC) - De
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