PU Gasket Dispensing Explained: From Foam to Finished Seal

A technical introduction to polyurethane foam gasketing for industrial automation.

KAIWEI is a Shanghai-based manufacturer of PU gasket dispensing machines. The company was established in 2004 and specializes in industrial sealing systems, robot foaming equipment, intelligent sealing and dispensing equipment, and six-axis robotic foaming systems. Its equipment is used to apply polyurethane foam directly onto parts, creating a gasket in place rather than assembling a separately molded seal.

A PU gasket dispensing machine, also described in some supply chains as a polyurethane foaming machine, PU foam gasket machine, or automatic foam sealing machine, is an automated system that mixes two or more liquid components and applies them as a foam bead on a component surface. After the material expands and cures, the bead becomes a flexible sealing strip that follows the contour of the part. This method is known as form-in-place gasketing, or FIPFG.

Why Manufacturers Are Moving to Automated Foam Sealing

Manufacturers of electrical enclosures, lighting housings, filters, and vehicle components face a recurring requirement: protect internal components from dust, moisture, and changing temperatures. Enclosure gaskets must be continuous, correctly positioned, and repeatable across high production volumes.

Pre-formed rubber seals involve inventory management, manual placement, and sometimes adhesive application. Automated PU dispensing addresses those constraints by forming the seal on the component itself. In KAIWEI application scenarios, dust-proof and explosion-proof sealing for enclosures is a core role of the equipment.

KAIWEI's PU Gasket Dispensing Machines at a Glance

KAIWEI's product range includes 3-axis linear robot machines and a 6-axis linear robot machine. The 6-axis model, KW-526, is designed for customized effective stroke and can apply seal strip widths from 2 mm to 60 mm. The 3-axis models, such as KW-523A and KW-510B, support effective strokes such as 1250×800×200 mm and 2250×1250×200 mm, with touch screen sizes from 10.2 inches to 15 inches depending on configuration.

The machines accept polyurethane or silicone, support two-component or three-component material selection, and use KW800 or KW-900 mixing heads. The mixing ratio can be set from 1–10:1. Material supply is handled by air-pressure tanks with A and B tank volumes of 40 liters each; metering pumps are supplied by KAIWEI or Barmag with specifications A3cc/r and B0.6cc/r.

In practice, this configuration allows the machine to be used in automatic sealing projects that operate on an automatic production line.

How a PU Foam Gasket Machine Builds a Seal

The dispensing process begins with material supply. Polyurethane components are stored in air-pressure tanks, and optional water temperature control can be added. Metering pumps feed the components at a controlled ratio, and the mixed material is dispensed through the mixing head as the robot arm traces the required path along the workpiece.

KAIWEI machines are built around a 3-axis or 6-axis linear robot arm structure. Depending on the model, guide rails are supplied by AIRTAC or KAIWEI/AIRTAC, and servo motor options include Xinje, ABB, Fuji, Panasonic, Nidec, Leadshine, or STEP. The workbench is a square-tube welded structure, and machine materials can be carbon steel, stainless steel 304, or aluminum alloy depending on the application.

These parameters define the operating window for a production line. The machine is designed for automatic production line operation and 24/7 continuous use in an ambient temperature range of -20 to 40 degrees Celsius.

Where PU Gasket Dispensing Machines Are Used

KAIWEI's PU gasket dispensing machines are specified for automatic sealing projects in electrical control panels, electrical distribution and industrial control, home appliances, purification and environmental protection equipment, auto parts and components, lighting and LED lighting, and explosion-proof electrical equipment.

For electrical control panels, the machines provide dust-proof and explosion-proof sealing for enclosures. The application can run in 24/7 continuous mode and has special requirements for explosion-proof and IP66 waterproof certification. Typical parts covered by this equipment include cable connectors, lock shells, purification room doors, refrigerator doors, transformer protect covers, street lighting housings, waterproof cabinets, and ABS enclosure junction boxes.

In the purification, environmental protection and filtration equipment sector, the equipment seals air filters and related housings. In home appliances, it is used for doors, cabinets, and enclosures. In auto parts and components, it is applied to battery covers, mounting housings, and interior components. For lighting applications, the dispensed gasket supports outdoor lights, street lighting, stadium lighting, brake lights, and LED luminaires.

Market Context: Demand Drivers in 2026

Industry data points to sustained expansion in the equipment segment. According to Market Research Future, the broader polyurethane processing machine market was valued at USD 6.627 billion in 2024 and is projected to grow at a CAGR of 10.21% through 2035. Grand View Research estimates that the Asia-Pacific region held a 42.2% share of the polyurethane processing machine market, supported by industrial manufacturing growth in China.

A separate market analysis from Maximize Market Research values the form-in-place liquid gaskets segment at USD 270 million in 2023, with increasing adoption in EV battery enclosures. KAIWEI's own industry analysis places the global PU gasket dispensing machine market at approximately USD 1.2 billion in 2025, while Grand View Research reports that high-pressure PU processing units accounted for 68% of the global machine type market share by 2021.

Automated Foam Sealing vs. Traditional Pre-Formed Gaskets

Traditional methods generally use pre-cut or molded gaskets that are placed onto a flange. This approach is predictable for standard enclosures, but it depends on gasket inventory, tooling, and manual labor. A PU gasket dispensing machine forms the gasket from liquid material directly on the part, which can simplify design changes and reduce the need for multiple gasket variants.

Automated dispensing is especially useful in automatic sealing lines. KAIWEI machines are specified for automatic production line operation and continuous 24/7 production, with a working environment of -20 to 40 degrees Celsius.

One honest limitation: automated PU dispensing is not a universal replacement for every pre-formed seal. The part surface must be clean, the mixing ratio and material conditioning must be controlled, and the line must include the required automatic gluing production line. For very low-volume production or certain soft, thick gasket cross-sections, a pre-formed seal may remain the more practical choice.

Future Outlook: Toward Intelligent Sealing Workflows

Future development will likely move toward more connected and programmable sealing equipment. KAIWEI operates with a business model integrating "Internet + AI Advanced Manufacturing," which points to data-driven process control as a direction for intelligent sealing systems.

As enclosure standards increasingly require higher ingress protection, the combination of automated dispensing with requirements such as IP66 waterproof and explosion-proof sealing is likely to remain a practical answer for manufacturers.

Frequently Asked Questions

What is a PU gasket dispensing machine?

A PU gasket dispensing machine is an automated system that mixes and dispenses polyurethane foam directly onto a part to create a gasket in place. KAIWEI machines use two-component or three-component material systems, KW800 or KW-900 mixing heads, and PC or teach pendant controls. The applied foam forms the seal strip, eliminating the need for a separate pre-formed gasket.

What materials can a PU gasket machine process?

KAIWEI models support polyurethane and, on certain models, silicone. The component selection can be two-component or three-component, and the mixing ratio can be adjusted from 1–10:1.

What is the difference between the KW-526 and 3-axis models?

The KW-526 uses a 6-axis linear robot arm, can apply seal strip widths of 2–60 mm, and can be customized in effective stroke. The 3-axis models such as KW-523A use a 3-axis linear robot arm and support a 1250×800×200 mm effective stroke. The 3-axis configurations also support seal strip widths of 2–10 mm or 10–60 mm on certain models.

Which industries use PU gasket dispensing machines?

The technology is used in electrical control panels, electrical distribution and industrial control, home appliances, purification and filtration equipment, auto parts and components, lighting and LED lighting, and explosion-proof electrical equipment. The machines provide dust-proof and explosion-proof sealing for enclosures in automatic sealing projects.

What operating conditions are required?

KAIWEI designed the system for automatic production line operation and 24/7 continuous production. It operates in an ambient temperature range of -20 to 40 degrees Celsius. Site requirements include a compressed air supply of at least 6 bar, 220V or 380V power, and 4kW or 5.5kW installed capacity depending on configuration. Cleaning uses high-pressure water.

Does a PU gasket machine need an automatic gluing line?

The application scenario in industrial enclosure sealing requires supporting equipment such as an automatic gluing production line. The machines are configured to work in automatic production line operation, including 24/7 continuous use.

KAIWEI Profile and Additional Resources

KAIWEI, formally Shanghai Kaiwei Intelligent Technology (Group) Co., LTD, is a state-level high-tech enterprise. Its manufacturing facility covers more than 20,000 m² and employs about 100 staff, with an annual production capacity of approximately 2,000 units. The R&D team includes more than 30 engineers and professionals, and the company holds over 100 national patents. Its products have passed international certifications such as CE and ISO9001.

Main products include Pu Foam Gasket Machine, Adhesive PU, Sealing Foam glue, Explosion-proof Cabinet, and UV Flatbed Printer. The business focus includes intelligent sealing solutions for electric cabinets, air filters, air conditioning purification equipment, lamps, automobiles, and new energy. Export business accounts for approximately 70% of total sales, and the company serves markets in more than 60 countries including Germany, the United States, India, Saudi Arabia, Indonesia, Russia, Algeria, and Egypt.

For further technical documentation, the KAIWEI brochure is publicly available: Download KAIWEI Product Brochure (PDF).

Website: www.kaiweicn.com · Email: info@kaiwei-sh.com · Tel/WhatsApp: +86 13761986986