PPGI: The Ideal Material for Cold Rooms and Refrigerated Transport

PPGI: The Ideal Material for Cold Rooms and Refrigerated Transport

BlogDate: 07-08-2023 by: Ngoc Cam

Pre-painted Galvanized, also known as pre-coated steel, coil-coated steel, and color steel, is widely used in construction, such as round pipe production, square tube, factory manufacturing, automobile equipment manufacturing, household appliances, civil engineering,... In particular, the world also utilized PPGI for cold room and refrigerated transportation. Let’s get deeper into the outstanding features of PPGI with MRS Steel.

1. What is PPGI? 

Pre-painted Galvanized (PPGI) is a type of galvanized steel coil that is surface treated and coated with a high-grade color layer, acting as a protective and strengthening layer.  

Similar to zinc/aluminum alloy or zinc/aluminum/magnesium alloy coated coil products, color-coated corrugated sheet is also produced by hot dipped metallic coated technique.


Hot-dip continuous galvalume/ galvanizing (CGL) produces all kinds of zinc-aluminum and zinc-plated steel. First, an annealing furnace is used to change the mechanical properties of surface-treated cold-rolled steel in accordance with order requirements and improve adhesion to the plating layer. The steel tape is then coated with a protective layer (anti-finger, oil, chromium) by the hot-dip galvanizing principle to increase durability and prevent surface oxidation.

2. PPGI used for cold room and refrigerated transport

2.1. Cold room application

A cold room is designed and installed with a cooling or freezing system for the purpose of preserving and storing goods to keep the best quality. The particular structure of cold storage is heat and sound insulation to keep the temperature in the warehouse lower than room temperature. Cold storage is classified according to many uses or different types of goods, but all have the same structure of two parts: insulation and refrigeration. 

Two panels commonly used as cold storage covers are EPS Panels and PU Panels. Panel Polyurethane Sandwich is a high-grade material consisting of 3 layers of polyurethane foam sandwiched between two metal side skins. This material is highly durable, lightweight, and resistant to extreme weather conditions, so it is genuinely appropriate for cold room applications:

  1. Polyurethane Sandwich Panel is easy to assemble, transport and dismantle, suitable for mobile cold storage.
  2. The outer and inner shell of the PU Panel is made of galvanized steel with a plastic coating, and the panels are bonded together by a quick-action eccentric device.
  3. The panels are capable of bearing loads up to 2000 kg/m2
  4. Cold storage fully equipped with electric lighting system, refrigerant Freon 22 and 404A.



2.2. Refrigerated transport application

Refrigerated Freight Transportation is a particular industry in today’s globalized world, with constant temperature control, enabling the goods to remain at the desired temperature throughout their journey.

The basic idea behind cold transport, which uses salt and ice to keep temperature-sensitive goods cool, dates back to the 1800s. 

Currently, refrigerated transport vehicles are usually made from Polyurethane Sandwich Panels. PU panels can improve storage efficiency, reduce fuel consumption, and reduce the vehicle's overall weight due to their durability and lightweight. The bodywork is comprised of PPGI sandwich boards with a thickness of 50mm for freight and 100mm for refrigerated vans/trucks.


Besides PU Panels, mild steel is manufactured to specialized specifications to make refrigerated truck bed floors. The structure of mild steel contains about 0.05 - 0.3% carbon, so it is very malleable and ductile as required. When mild steel plates are galvanized, they will have an additional layer of protection against rust, oxidation, high strength, and good heat retention.

All refrigerated trucks are equipped with the best refrigeration units - DANA WATER HEATERS & COOLERS. The temperature monitoring system in the driver's cab can easily adjust the proper temperature. 

3. Vietnam's production capacity of color-coated galvanized steel

According to a report by the Vietnam Steel Association, coil, galvanized steel, and PPGI are the most exported steel products in 2022, with galvanized steel exports reaching 1.4 million tons, equivalent to 1.5 billion USD.


Vietnam's galvanized/aluminum/color steel products are aimed at exporting to world markets such as Europe, the United States, ASEAN,..., so they must meet the following standards: JIS 3321: 2010 of Japan; BS EN 10346: 2009 of Europe; AS 1397:2001; ASTM A792 of the United States… Zinc-aluminum alloy plating/galvanizing lines are imported from leading corporations specializing in metallurgical and steel-rolling equipment, such as Danieli, Tenova, and G7 countries with the best-advanced technology.

For details on importing PPGI used for cold rooms and refrigerated transport from Vietnam, please contact MRS Steel via Email: