Zero Bubble Residue for Acrylic! Defoaming Test of 3 Systems

Solve bubble issues in acrylic UV adhesives, solvent-based coatings and structural adhesives, covering full viscosity range from 50 cps to 100,000 cps


Acrylic Resin is thermoplastic or thermosetting polymer formed by polymerization or copolymerization of acrylate or methacrylate monomers. It boasts excellent optical transparency, weather resistance, color stability and convenient processability. It can be categorized into UV-curable acrylate, solvent-based acrylic coating, two-component MMA structural adhesive, etc., widely used in optical lenses, automotive coatings, advertising signs, electronic potting, medical devices, 3D printing and other fields. Air is easily entrapped during coating, pouring and mixing of acrylic materials. Bubbles in UV-curable systems get locked permanently and cannot escape spontaneously; solvent-based systems generate secondary bubbles due to solvent volatilization, which seriously damages appearance and functional performance. SIENOX provides high-efficiency defoaming solutions for all types of acrylic resins through self-developed planetary mixing & defoaming technology.


◆ Material Properties

Common Resin Types

UV-curable acrylate, solvent-based PMMA, two-component MMA structural adhesive

Curing / Drying Method

UV photo-curing, solvent evaporation drying, free radical polymerization curing

Viscosity Range

50~100,000+ cps, from watery free-flowing liquid to high-viscosity paste

Solvent / Diluent System

Water-based / solvent-based / 100% solid content (solvent-free), reactive diluent for viscosity adjustment

Curing Conditions

Second-level curing under UV lamp / room-temperature solvent evaporation / heating at 60-80℃ for acceleration

Defoaming Challenges

Bubbles get locked irreversibly in UV systems; secondary bubbles generated by volatilization in solvent-based systems


◆ Mature Application Fields

🔍 Optical Lenses

PMMA/PC optical lenses, light guides, light guide films for LCDs, transparent windows (high-transparency acrylic systems)

🚗 Automotive Coatings

Automotive OEM coatings, refinish coatings, clear coats, base coats (solvent-based acrylic, viscosity 2,000~15,000 cps)

🔌 Electronic Potting & Conformal Coating

PCB conformal coating, electronic component potting, FPC reinforcement bonding (UV-curable or two-component systems)

🪧 Advertising Signs

Acrylic thermoformed letters, display racks, light box panels, acrylic crafts (cast / extruded PMMA sheets)

🔧 Structural Adhesive / MMA

Two-component MMA structural adhesive, rapid bonding of metal/composite materials, ship & vehicle manufacturing (medium-viscosity reactive type)

💅 Nail & Daily Chemical

UV/LED gel nail polish, nail art adhesive (low-viscosity free-flowing system)

🖨️ 3D Printing / Photocuring

SLA/DLP photoresin, post-processing coating for 3D printed models (low-viscosity photocurable system, high precision requirement)

🏥 Medical Devices

Medical catheter bonding, IVD equipment housing encapsulation, dental restorative materials (biocompatible grade acrylic)

🏠 Architectural Coatings

Exterior latex paint, waterproof coating, floor topcoat (water-based acrylic emulsion system, eco-friendly low VOC)


◆ Core Problems Caused by Bubbles

🔘 Surface Defects (Crater / Fish-eye)

Burst bubbles on coating/casting surface form craters, fish-eyes, orange peel and other appearance defects, requiring polishing rework or direct scrapping

💎 Reduced Transparency & Optical Performance

Bubbles are instantly locked in UV-curable systems, forming permanent light scattering spots, lowering transmittance and causing fogging & whitening of optical parts

📉 Insufficient Bonding & Structural Strength

Internal bubbles in MMA structural adhesive reduce bonding area and mechanical properties; shear strength drops by 30-50% with potential safety hazards

🎨 Poor Coating Uniformity

Solvent-based coatings generate secondary bubbles from solvent volatilization, leading to uneven film thickness, poor hiding power and obvious color difference


◆ Recommended Process — Planetary Mixing & Defoaming

Step 1 Material Preparation

Operate UV acrylate systems away from light to prevent pre-curing; seal solvent-based materials to avoid solvent loss; weigh A/B components of two-component MMA according to ratio

Step 2 Vacuum Mixing & Defoaming

Put mixture into mixing cup, set vacuum degree -95KPa and planetary mixing parameters. The machine completes mixing and vacuum defoaming synchronously in one cycle

Step 3 Coating / Pouring

Apply or pour material immediately after defoaming, pour slowly along container wall; keep UV systems protected from light until coating finished before photo-curing

Step 4 Curing / Drying

Cure UV systems under specified wavelength & energy; apply gradient drying temperature for solvent-based systems to avoid fast surface skin locking residual bubbles


◆ Recommended Equipment

  1. MIX60 — Capacity 5~60g, suitable for lab R&D and small-batch UV acrylate defoaming; excellent effect for low-viscosity photocurable systems (50~2,000 cps)

  2. MIX90 — Capacity 20~500g, suitable for medium-batch production and defoaming of medium-viscosity solvent-based acrylic coatings / MMA structural adhesives (2,000~30,000 cps)

  3. MIX1000PLUS — Capacity 100~1,000g, suitable for mass production and defoaming of high-viscosity acrylic structural adhesives / heavy-bodied coatings (30,000~100,000+ cps)

  4. MIX2000 — Capacity 500~2,000g, suitable for industrial continuous production and batch defoaming of large castings


◆ Test Cases

▶ Case 1: Low-viscosity UV Acrylate Defoaming

Test Material

UV-curable acrylate optical adhesive (for PCB/FPC protective coating, 100% solid content, colorless transparent free-flowing liquid)

Initial Viscosity

800 cps (25℃)

Test Model

MIX60

Vacuum Level

-95 KPa

Rotation Speed

1,500 rpm

Defoaming Time

3 min

Material Temp.

25℃ (Room temperature, light-shielded operation)

✅ Defoaming Result: Mixing + defoaming finished in 3 minutes. No bubbles or craters after UV curing, transmittance＞98%, coating thickness uniformity ±2%, meeting optical-grade appearance standards for PCB conformal coating.


▶ Case 2: Medium-viscosity Solvent-based Acrylic Coating Defoaming

Test Material

Solvent-based thermoplastic acrylic topcoat (for automotive refinish, containing pigments and UV absorbers, moderate viscosity)

Initial Viscosity

8,000 cps (25℃)

Test Model

MIX90

Vacuum Level

-95 KPa

Rotation Speed

2,000 rpm

Defoaming Time

5 min

Material Temp.

25℃ (Room temperature sealed operation)

✅ Defoaming Result: Mixing + defoaming finished in 5 minutes. Sprayed film free of craters, fish-eyes and orange peel, 60° gloss＞92%, film thickness uniformity ±3%, meeting appearance standards for automotive refinish coatings.


▶ Case 3: High-viscosity MMA Structural Adhesive Defoaming

Test Material

Two-component MMA structural adhesive (for metal-composite bonding in ships & transportation vehicles, A/B=10:1, high-thixotropy paste)

Initial Viscosity

45,000 cps (25℃)

Test Model

MIX1000PLUS

Vacuum Level

-95 KPa

Rotation Speed

2,500 rpm

Defoaming Time

8 min

Material Temp.

40℃ (preheat for viscosity reduction)

✅ Defoaming Result: Mixing + defoaming finished in 8 minutes. A/B components homogeneously mixed without bubbles. Lap shear strength of metal-carbon fiber bonding increased by 35%, no pores on adhesive cross-section, meeting structural bonding strength requirements for ship applications.


◆ Before & After Comparison

Comparison Item

Before Defoaming

After Defoaming

Surface Quality

Surface defects such as craters, fish-eyes and orange peel

Smooth surface free of defects, gloss＞90

Transmittance / Optical Property

Light scattering spots caused by bubbles, fogging & whitening

Transmittance＞98%, optically clear and uniform

Bonding Strength

Bubbles reduce bonding area with scattered strength data

Lap shear strength increased by 35%, consistent test data

Coating Uniformity

Large film thickness fluctuation, obvious color difference

Film thickness uniformity ±2%, color difference ΔE＜0.5

Curing Integrity

Bubbles locked in UV systems, uneven local curing

Fully and evenly cured, stable hardness/elasticity data

Yield Rate

High rework rate, poor batch appearance consistency

Yield＞99%, stable and controllable batches


🎯 Free Sample Testing    
      Send us your acrylic resin samples. We will test defoaming parameters and issue test reports.