PVC Seal Strip Extrusion Line
Product Overview
The PVC Seal Strip Extrusion Line produces flexible sealing profiles used in doors, windows, automotive, and industrial applications. These strips provide weatherproofing, sound insulation, and thermal sealing by compressing between mating surfaces to prevent air, water, and dust infiltration.
This compact line uses a single-screw extruder (SJ-45/25 or SJ-65/25) with a multi-cavity precision die, hot air heating/cooling tunnel, and automatic winding system. Production speeds of 10-25 m/min make this one of the most efficient PVC extrusion lines in terms of output-to-investment ratio.
PVC seal strips are formulated with plasticizers (DOP, DOTP, or DINP) to achieve Shore A hardness of 60-90, providing the flexibility needed for compression sealing while maintaining sufficient rigidity for retention in mounting grooves. The formulation also includes UV stabilizers for outdoor applications and flame retardants for building products.
The multi-cavity die design enables production of complex seal profiles including bulb seals, flap seals, combination seals with metal or fabric inserts, and multi-durometer co-extruded seals where a soft bulb is bonded to a rigid base — all from the same extrusion platform.
Key Features
Single-screw extruder (45mm-65mm)
Multi-cavity precision die
Hot air heating and cooling tunnel
Automatic winding with tension control
Online printing capability
Production Process
From raw material to finished product — each step is engineered for quality and efficiency.
Flexible Compound Preparation
PVC compound with 30-60 parts plasticizer, stabilizers, UV inhibitors, and pigments. Shore A hardness is controlled by plasticizer content — more plasticizer means softer seal.
Extrusion & Die Forming
The single-screw extruder processes the compound at 150-175°C. The precision die creates the seal cross-section — bulb, flap, U-channel, or custom profiles.
Hot Air Heating Tunnel
The extruded seal passes through a hot air tunnel that controls cooling rate. Slow, controlled cooling prevents internal stress and ensures dimensional stability.
Cooling & Haul-off
Water spray or air cooling finalizes the solidification. A caterpillar haul-off pulls the seal at controlled speed, maintaining consistent dimensions.
Online Printing (Optional)
Brand logos, measurement marks, or color stripes can be printed online using inkjet or hot stamping systems.
Winding & Packaging
The finished seal strip is wound onto spools with automatic tension control. Roll lengths of 50m, 100m, or 200m are standard for different market segments.
Technical Specifications
| Extruder Model | SJ-45/25 or SJ-65/25 |
|---|---|
| Strip Width | 5mm - 50mm |
| Strip Thickness | 1mm - 8mm |
| Production Speed | 10-25 m/min |
| Total Power | ~15-35 kW |
| Line Length | ~12m |
Why Choose Wings Plastic
Multi-Cavity Die Design
Precision dies produce complex seal profiles — bulb, flap, U-channel, or custom designs — with tight dimensional tolerances essential for sealing performance.
High-Speed Production
At 10-25 m/min, this line delivers high output from a compact, affordable machine — making seal strips one of the most profitable PVC extrusion products per investment dollar.
Co-Extrusion Capability
Optional co-extrusion system produces multi-durometer seals (soft bulb + rigid base) or seals with metal/fabric inserts — premium products with higher market value.
Controlled Cooling
Hot air heating tunnel provides slow, controlled cooling that prevents internal stress and shrinkage — critical for seals that must maintain precise dimensions for long-term sealing performance.
Compact Footprint
Total line length of only 12m makes this one of the smallest PVC extrusion lines, ideal for small factories or as an additional product line in existing facilities.
Quality Assurance
Every production line undergoes rigorous quality verification before delivery:
- Shore A hardness tested at multiple points along the seal length
- Cross-section dimensions verified under optical comparator
- Compression set tested per ASTM D395 to verify long-term sealing performance
- UV resistance tested for outdoor grades using QUV accelerated weathering
Typical Applications
Frequently Asked Questions
For window/door seals: 60-70 Shore A (soft bulb for compression sealing). For automotive: 70-80 Shore A (balance of flexibility and durability). For industrial: 80-90 Shore A (rigid seals for heavy-duty applications).
DOTP is recommended for its low migration, non-toxicity, and compliance with REACH/RoHS. DINP is a cost-effective alternative for non-sensitive applications. DEHP is being phased out due to regulatory restrictions in most markets.
Yes, with an optional co-extrusion adapter, the line can produce two-material seals (e.g., soft PVC bulb + rigid PVC base) in a single pass. This is a high-value product for premium window and automotive markets.
Bulb seals (P-bulb, D-bulb) for doors/windows, U-channel seals for glass retention, flap seals for sliding applications, and co-extruded multi-functional seals for automotive and premium building products.
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