Polyurethane adhesives (PU adhesives) feature excellent elasticity, wear resistance and low‑temperature resistance. They play a vital role in shoe‑material bonding, automotive interior parts, composite films, building sealing and other fields. Polyurethane systems are sensitive to moisture and bubbles. Moisture intrusion during stirring may trigger foaming reactions, whereas residual bubbles degrade the compactness and bonding strength of adhesive layers. SIENOX delivers mixing‑defoaming solutions optimized for polyurethane adhesives to effectively tackle the above‑mentioned challenges.

Material Properties and Defoaming Challenges

• Polyurethane systems are moisture‑sensitive. Ingress of atmospheric moisture during stirring may trigger side reactions and generate CO₂ bubbles.

• Inadequate mixing of two‑component polyurethane leads to incomplete curing, resulting in soft or brittle adhesive layers and deteriorated bonding strength.

• Solvent‑based polyurethane undergoes viscosity variation due to solvent evaporation, and bubbles generated during stirring are hard to eliminate.

• High‑solid‑content polyurethane adhesives feature high viscosity. Conventional stirring equipment delivers low mixing efficiency and brings difficulties for color‑change cleaning.

Core Solutions

Vacuum stirring for dehydration — An optional vacuum system enables stirring under negative‑pressure conditions. It not only removes bubbles but also lowers water content inside the system and mitigates side‑reaction risks induced by moisture.

Homogeneous planetary mixing — The combined revolution‑and‑rotation motion thoroughly mixes two‑component polyurethane adhesives with zero dead zones and no delamination for consistent and stable curing performance.

Contact‑free stirring for easy color switching — Paddle‑free design leaves minimal residues on container walls. Color and material change are achieved with simple cleaning, which reduces cross‑contamination and downtime.

Six Major Technical Advantages

• Planetary dual‑motion trajectory — Coordinated revolution and rotation produce three‑dimensional material mixing under centrifugal force. It ensures homogeneous blending of polyurethane A/B components and stable curing performance.

• High‑vacuum defoaming — Optional vacuum system makes bubbles expand and burst under negative pressure. Dehydration and defoaming under vacuum reduce the risk of CO₂ bubble formation caused by moisture.

• Precise temperature control — Optional temperature‑control module adjusts stirring temperature in real‑time. Gentle stirring prevents excessive solvent evaporation and shear‑induced heat generation for solvent‑based polyurethane.

• Contact‑free stirring — No stirring paddles are applied to avoid cross‑contamination. Minimal wall residues facilitate easy cleaning during color and material replacement.

• Multi‑segment program control — Support multi‑stage setting for rotation speed, duration and vacuum level. Flexible multi‑segment programming adapts to polyurethane formulas with different curing rates.

• Intelligent safety interlock — Safety sensor for the cover locks the lid during operation to protect operator safety.

Recommended Equipment and Model Parameters

Recommended Model: MIX90

Pilot‑to‑production unit｜Processing volume: 1000 mL｜Rotation speed: 0‑2000 rpm｜Optional vacuum / temperature control / MES system connection

Typical Application Fields

• Polyurethane hot‑melt adhesives for shoe‑material bonding

• Polyurethane sealants for automotive windshields

• Polyurethane adhesives for flexible‑packaging lamination

• Polyurethane waterproof coatings for construction

• Polyurethane potting adhesives for wind‑turbine blades

• Polyurethane foam adhesives for cold‑chain equipment

• Polyurethane adhesives for wood splicing

• Cast‑in‑place polyurethane for mining sieve plates