Plastics9 min read
Multi-cavity mould first article checklist
A cavity by cavity sequence for proving a multi-cavity tool, from the run state and the sample plan to the spread across cavities and the records to keep.
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Topic hub
Plastics and assemblies
Electrical housings carry three jobs at once: structure, insulation and assembly. These guides cover wall sections, ribs, draft, material choice and the tolerances that keep a moulded part fitting.
Guides in this topic
Plastics10 min read
Injection moulding design guide for electrical housings
Wall sections, ribs, bosses, draft and material choice for MCB, MCCB and equipment housings that must insulate, locate and assemble.
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Plastics9 min read
CTI and dielectric strength of moulding materials
Tracking and breakdown are different failures with different tests. Here is how to read the numbers and turn them into creepage, clearance and a material call.
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Plastics9 min read
Glow wire testing for electrical plastics
GWFI, GWIT and the glow wire test explained: what each one measures, how the results are reported and which requirement belongs on the drawing.
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Plastics9 min read
Packaging and kitting for assemblies: damage, presentation and cost
How to pack an assembly so it arrives undamaged, present it at the line without extra handling, and stop packaging from quietly becoming the largest cost per unit.
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Plastics9 min read
Plastic housing FAI and PPAP: the evidence pack for a moulded part
What a first article inspection and a production part approval pack should contain for a moulded housing, including the plastic-specific evidence that a generic checklist misses.
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Plastics8 min read
Welded assemblies: resistance, ultrasonic and laser
Three welding methods, three different material and joint rules. The method has to match the material, the access and the joint you can actually design.
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Plastics9 min read
Design for assembly: 10 rules that cut build cost
Ten rules for parts that go together without a fight, and the assembly cost each one attacks.
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Plastics9 min read
Flame retardant plastics and UL 94
What the UL 94 ratings actually measure, how thickness and colour change the result, and how to specify a flame retardant grade without paying for a rating you cannot use.
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Plastics9 min read
Plastic part measurement and GD&T: fixtures, temperature and datums
Why a moulded part measured like a machined part gives the wrong answer, and how to set the condition, the fixture and the datum scheme before the first article.
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Plastics8 min read
Riveted assemblies: design and inspection
A rivet is a joint made in one stroke, and a poor joint is often made in the same stroke. Here is how hole, edge, grip and set force decide whether the assembly holds.
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Plastics9 min read
Screwed and clinched assemblies: thread, insert and serviceability
How to choose between a screw, a threaded insert, a clinch and a rivet, and the joint details that decide whether the assembly can be opened again.
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