Sandwich panel production lines for polyurethane are divided into two types: continuous production lines and discontinuous (batch) production lines.

Continuous production lines are designed for manufacturing polyurethane sandwich panels in such a way that the top and bottom steel sheets of the panel are movable along the line. As the sheets move, polyurethane foam material is injected horizontally and transversely between the moving sheets.

In the polyurethane foam injection section, raw materials including continuous-grade polyol and isocyanate are combined with other components such as a blowing agent and a catalyst, and then injected between the steel sheets.

In continuous sandwich panel lines, the foam-coated steel sheets are mobile and are transferred beneath pressing rollers. The thickness determined between the rollers defines the thickness of the produced panel.
It is worth mentioning that the length of the pressing rollers in continuous sandwich panel machines ranges from 10 meters up to over 30 meters, and the thickness of the produced panels varies from 3 centimeters to over 15 centimeters. Therefore, the continuous-grade polyol materials must possess specific characteristics to ensure compatibility with various production lines and to deliver high-quality final products.
Below are the technical specifications of Razin Company's continuous-grade polyol.


Technical Features of Razin's Continuous-grade Polyol

  • The polyol materials must be adjustable to match the foam reaction time with the production line speed and panel thickness.
  • High adhesion between foam and steel sheets is a critical feature.
  • The polyol must be formulated to enable production of panels with a wide range of standard densities without causing stretching or shrinkage, while ensuring proper adhesion to the sheets.
  • The polyol must be designed so that, at the end of the production line, the foam is fully cured and suitable for cutting.
  • The standard shrinkage percentage after injection is a key characteristic; poor-quality polyols may cause issues like shrinkage and denting of the sheets into the foam.
  • Compatibility of the polyol with the blowing gas is another important feature.

As indicated by the technical features, producing this grade of polyol involves technical complexity. Razin Polyurethane Company, utilizing its experienced R&D team, has succeeded in manufacturing, stabilizing, and obtaining customer approvals for this product.


Applications of Polyurethane Foam Made from Continuous-grade Polyol

  • Construction of side walls for industrial halls
  • Roof construction for industrial halls
  • Building prefabricated structures and houses
  • Manufacturing of fixed and mobile cold storage units
  • Manufacturing of fixed and mobile containers
  • Internal partition walls and office rooms
  • Cleanroom construction in laboratories, pharmaceutical units, etc.


Razain Company's Continuous-grade Polyol Grades
In the panel products section, two grades, 300 and 302 Razapol, are offered in unfoamed form. Grade 300 Razapol meets B3 standards, while Razapol 302 meets B2 standards. These grades, containing 10% cyclopentane gas and an appropriate amount of catalyst DMCHA (depending on the length of production lines), are used to produce continuous panels with thicknesses of 4, 8, 10, and 15 centimeters.


Why Choose Razin's Polyol
High Quality:
Utilization of premium raw materials, advanced technical knowledge, and precise quality control systems.

High Compatibility:
The variety of grades and their technical features make Razin’s raw materials suitable for diverse production lines.

Technical Support:
Providing consultation and after-sales services to ensure the production of high-quality polyurethane foam.

Cost-Effectiveness:
Despite competitive pricing, the raw materials are designed to achieve high quality and suitable density with minimal raw material consumption.