Machining Hgw 2372.4

Fabric-based laminates (HGW) belong to the industrial laminates: fabric layers are impregnated with a thermosetting resin and pressed under heat and pressure into sheets, round bars or tubes. For Hgw 2372.4 (EP GC 203), the reinforcing fabric is glass fabric and the binding resin is a specially formulated epoxy resin with an elevated temperature limit of 155 °C (thermal class F) compared with the standard grade EP GC 202 (Hgw 2372.1, "FR-4"), combined with higher mechanical values. Compared with cotton-fabric laminates such as HGW 2282.5, the combination of glass fabric and epoxy resin yields significantly higher strength, lower water absorption and better electrical insulation; the colour is characteristically green.

Hgw 2372.4 (EP GC 203) machines well – sawing, milling, drilling and turning produce clean, dimensionally accurate results with sharp, carbide-tipped or diamond-coated tools, and we allow for the increased tool wear caused by the glass fabric. During machining we ensure adequate dust extraction. This allows us to reliably manufacture high-strength, temperature-resistant insulating parts, from single items to series production.

Hgw 2372.4 (EP GC 203) is worthwhile whenever high mechanical strength, good electrical insulation and an elevated continuous thermal load capacity are required together – for example:

• High-strength insulating parts requiring an elevated continuous-use temperature (up to 155 °C)
• Medium-voltage switchgear and transformer construction
• Components located near heat sources in mechanical engineering
• Applications where the standard grade (130 °C class) is thermally insufficient

Hgw 2372.4 (EP GC 203) is an engineering laminate; the price depends on the semi-finished shape (sheet, round bar, tube), dimension, material utilisation (offcut), machining effort and lot size. Due to the adapted resin formulation for the elevated temperature limit, Hgw 2372.4 (EP GC 203) is priced above the standard grade EP GC 202 (Hgw 2372.1). We are happy to quote binding prices on request based on your drawing.

Equally important are the limits of the material:

• Direct food contact – Hgw 2372.4 (EP GC 203) is not declared for this
• Pure cost optimisation without an elevated temperature requirement – the standard grade EP GC 202 (Hgw 2372.1) is sufficient here
• Continuous use well above 155 °C – the 180 °C special grades of the series are more suitable here
• Reshaping or welding – not possible as a thermoset (machining only)

An honest assessment – and how the disadvantages can be mitigated in practice: Advantages:

Disadvantages:

Practical tip: Hgw 2372.4 (EP GC 203) is the right choice when high strength, low water absorption and an elevated continuous-use temperature up to 155 °C are required. If 130 °C is sufficient, the standard grade EP GC 202 (Hgw 2372.1) is the more economical choice; for requirements up to 180 °C, the corresponding high-temperature special grades of the series are more suitable.

• Very high mechanical strength
• Elevated temperature limit (155 °C) compared with the standard grade
• Low water absorption
• Very good electrical insulation properties
• Dimensionally stable thermoset laminate
• Not declared for direct food contact
• Higher tool wear during machining (glass fabric)
• Higher price than the standard grade EP GC 202