In continuous production of polyurethane (PU) sandwich panels using pentane as the blowing agent, the foam density is never perfectly uniform across the width. The core (middle) and the edges (near the metal conveyor belts) naturally differ. Under normal conditions, an edgetocore density ratio of 1.1 – 1.2 is acceptable. However, when this ratio exceeds 1.3 (i.e., edges are 30% heavier than the core), serious quality issues arise – warping, waviness, edge delamination, and poor adhesion. So, why does this higherthannormal density differential occur, and what can we do about it?

Nowadays, there’s a growing demand for polyurethane sandwich panels in the industrial system. They have excellent insulation performance when used in cold storage projects. Today, let’s talk about the differences between PIR and PUR polyurethane sandwich panels.

For many manufacturers and consumers, lingering, pungent odors in flexible polyurethane foam products are a persistent frustration. Standard practices like ventilation and sun-drying often fail to eliminate these smells, leading to widespread misperceptions that it is simply an unavoidable, slow evaporation process.In reality, over 90% of flexible foam odor issues stem from inadequate control during production. The root causes are overwhelmingly concentrated in three core processes: raw material selection and formulation, the foaming reaction itself, and post-curing treatment. By implementing targeted corrective measures in these areas, manufacturers can dramatically improve product quality and odor compliance.

Starting from July 1, 2026, HCFC-141b blowing agent will be completely banned for spray polyurethane foam. As HFC-245fa/water become the mainstream blowing system, new technical challenges have emerged. Based on the practical experience of our construction technical team, we have summarized the 10 most common defects of spray polyol systems formulated with HFC-245fa, along with corresponding solutions:

With the gradual phase-out of HCFC-141b, pentane has gradually become a mainstream blowing agent in the continuous panel industry.What problems will be encountered during the production of continuous PUR panel using pentane as the blowing agent?Let us take a look at the common defects and corresponding solutions.

In polyurethane foam production, the mixing effect directly determines the quality and performance of the foam. Just like in traditional Chinese medicine, where diagnosis involves 'looking, listening, questioning, and palpating,' experienced operators can quickly assess the mixing state of the foaming machine through sensory perception and basic tests, preventing problems before they occur.  

HFO-1233zd(LBA) is currently the most environmentally friendly, safe, and efficient blowing agent due to its extremely low global warming potential of ≈ 1, zero ozone depletion potential, and excellent foaming performance, making it the best alternative to HFC-245fa. Therefore, it has received significant attention.

In recent years, polyurethane products have been widely used in areas such as refrigerator insulation layers, mattresses, and automotive components, and their environmentally friendly and recyclable characteristics are also highly valued.

With the accelerated phase-out of HCFC-141b, the Center for Environmental Protection External Cooperation of the Ministry of Ecology and Environment recommends that the selection of HCFCs phase-out replacement technologies should be environmentally friendly, low-carbon, safe, and economical. This means no damage to the ozone layer; low global warming potential (GWP), good insulation performance, and high energy efficiency; production that meets safety standards; and a high cost-performance ratio, with raw material and production costs that are acceptable to the market.

Slow rebound sponge, affectionately called memory foam, has made a significant impact in fields such as pillows, mattresses, and car seats due to its magical "slow recovery" characteristic, providing users with a unique zero-pressure experience.