Borosilicate glass stirring rod

Product overview
Molybdenum is used to manufacture stirrers and plungers for glass production. Stirrers provide homogenization of glass melts and plungers are used for portioning and dosing. These components are designed to withstand extremely high temperatures and corrosive glass melts in industrial glassmaking.

Your advantages at a glance

• High melting point (~2620 °C)
• Excellent creep resistance at elevated temperatures
• Good dimensional stability
• High corrosion resistance against glass melts
• Good electrical and thermal conductivity
• High material purity available for optical applications

Applications and product types

• Homogenization stirrers
• Spiral/stem-type stirrers
• Portioning and dosing plungers (including spiral plungers)
• Semi-finished products for stirrer manufacture and machining

Coatings and variants

• Al2O3 ceramic diffusion barrier coating for enhanced corrosion resistance
• Partially platinum-clad stirrers: platinum sleeve protects shaft outside the melt to reduce oxidation while retaining molybdenum core strength
• Fully platinum-clad stirrers: soft platinum cladding provides full corrosion protection where extreme purity or aggressive glass types require it

Advantages compared with ceramic stirrers

• Greater design flexibility enabling improved stirring action
• Small shaft diameters with large blade diameters for effective mixing
• Higher mechanical stability and better thermal-shock resistance
• No contamination of the glass melt
• Considerably longer service life in many applications

Products and options we provide

• Standard and customized homogenization, spiral and portioning stirrers
• Dosing plungers and spiral plungers
• Semi-finished molybdenum parts for further processing
• Optional coatings and claddings: Al2O3 diffusion barrier; partial or full platinum cladding

Technical characteristics / specifications

• Material: molybdenum (Mo); optional Al2O3 diffusion barrier; optional partial or full platinum cladding
• Melting point: approx. 2620 °C
• High creep resistance and high-temperature mechanical stability
• Excellent corrosion resistance to molten glass (e.g. borosilicate, opal glass)
• Good electrical and thermal conductivity
• High-purity grades available for optical glass applications
• Custom designs available to meet process requirements