GB/T 7123.1-2015 Determination of the working life of multi-component adhesives
1 Scope
This part of GB/T 7123 specifies methods for determining the working life of multi-component adhesives.
This part is applicable to the determination of the working life of multi-component adhesives.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 2790 Adhesives specimen assembly , 180° peel strength test method for a flexible-bonded-to-rigid test (GB/T 2790-1995; ISO 8510-2: 1990, EQV)
GB/T 2791 Adhesives - T peel strength test method for a flexible-to-flexible test specimen assembly
GB/T 2794-2013 Determination for viscosity of adhesives - Single cylinder rotational viscometer method
GB/T 2943 Terms of adhesive
GB/T 7124 Adhesives - Determination of tensile lap-shear strength of rigid-to-rigid bonded assemblies (GB/T 7124-2008; ISO 4587: 2003, IDT)
GB/T 20740 Adhesive - Sampling (GB/T 20740-2006; ISO 15605: 2000, IDT)
3 Terms and definitions
For the purposes of this document, the terms and definitions given in GB/T 2943 and the following apply.
3.1
working life
period of time during which a multi-component adhesive can be used after its component parts have been mixed
4 Method classification
The types of test methods for determining the working life of multi-component adhesives and the instructions for use are shown in Table 1.
Table 1 Types of test methods for determining working life of multi-component adhesives and instructions for use
Method No. Method abbreviation Instructions for use
Method I Method by rotational viscometer Not suitable for determination of adhesives with working life less than 5min
Method II Extrusion method Not suitable for determination of adhesives with working life less than 5min
Method III Spreading method Suitable for the determination of multi-component adhesives
Method IV Viscous method Suitable for the determination of multi-component adhesives
Method V Reaction temperature method Suitable for the determination of multi-component adhesives with changes in reaction temperature
Method VI Bonding strength method Not suitable for determination of adhesives with working life less than 5min
5 Principle
Method I Method by rotational viscometer: the working life is determined from the increase in viscosity of the adhesive as it reacts. This method is not suitable for the determination of working lives that are shorter than 5 min.
Method II Extrusion method: the working life is determined from the decrease in the mass of extruded adhesive mixed under standard conditions and within specified period. This method is not suitable for the determination of working lives that are shorter than 5 min.
Method III Spreading method: the working life is determined as the time taken to reach a point when the mixed adhesive can no longer be spread by hand.
Method IV Viscous method: the working life is determined as the time taken to reach a point when the surface of the mixed adhesive is no longer tacky, i.e. it is dry to the touch.
Method V Reaction temperature method: the working life is determined as the time taken by the mixed adhesive to reach the maximum temperature.
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Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 Method classification
5 Principle
6 Apparatus
7 Test environment
8 Procedure
9 Expression of results
10 Test report
