PU Casting
Polyurethane casting involves the use of a versatile polymer known as polyurethane, which can be moulded into a myriad of shapes and forms. This process offers a unique set of properties that make it an attractive choice for manufacturers looking for durability, flexibility, and precision in their end products.
The rubber moulding and plastic moulding industries have witnessed a paradigm shift with the introduction of PU castings. Polyurethane’s ability to mimic the properties of rubber and plastic with added advantages such as increased durability and resistance to abrasion makes it an ideal material for creating long-lasting components. From seals and gaskets to custom-moulded parts, PU castings offer unparalleled versatility.
PRE-PROCESSING
Pre-processing in polyurethane (PU) casting is a critical step that determines the quality and performance of the final product. It begins with accurate weighing and proportioning of polyols, isocyanates, and additives to ensure chemical consistency.
The materials are then thoroughly mixed to achieve a uniform blend. Moisture control is essential, as water can cause bubbles and defects, so components are often dried or stored under controlled conditions.
Degassing under vacuum removes trapped air, preventing voids in the casting. Temperature conditioning of materials ensures proper flow and reaction rates. Careful pre-processing sets the stage for defect-free, high-performance PU components.
PROCESSING
Processing in polyurethane (PU) casting transforms prepared materials into precise, durable components.
During this stage, the mixed PU resin is carefully poured, injected, or dispensed into molds using methods like gravity casting, vacuum casting, or reaction injection molding (RIM). Vacuum or pressure techniques minimize air bubbles, ensuring smooth surfaces and dimensional accuracy. Temperature, humidity, and curing time are closely monitored to control reaction rates and achieve the desired mechanical properties.
Complex shapes, inserts, or over-molding can be integrated at this stage. Consistent process control ensures each part meets specifications, producing high-quality, reliable PU components ready for post-processing and final use.
POST-PROCESSING
Post-processing in polyurethane (PU) casting refines and prepares the parts for final use.
After demolding, excess material is trimmed, flash is removed, and edges are smoothed. Machining or cutting may be performed to achieve precise dimensions or custom features. Surface finishing techniques—such as polishing, sanding, or coating—enhance appearance, texture, and durability.
Additional curing or heat treatment may be applied to stabilize mechanical properties. Parts are inspected for defects, hardness, and dimensional accuracy to ensure quality. Post-processing transforms raw castings into functional, high-performance components, ready for industrial, automotive, consumer, or specialized applications while meeting all design specifications.
CUSTOMIZATION
Hardness, color, and finish per spec
Thickness & geometry per drawing
Branding/part-number embossing
PROCESS CONTROL
Moisture control & de-gassing for bubble-free parts
Controlled exotherm & post-cure for dimensional stability
Tolerances: Typically ±0.25–0.50 mm depending on size and geometry
Surface finishes: From as-cast textures to polished Class-A
Color management: Pantone/RAL matching; multi-shot & clear tints
WHY PU VS. RUBBER/PLASTIC
Outlasts rubber under abrasive load; better cut/tear resistance
Dampens vibration like rubber but holds tighter tolerances like plastics
Castable at low pressure → lower tooling cost, faster iterations
PRODUCTS
Automotive
Aerospace & Defence
Electrical & Electronics
Medical Devices
Construction
