What kind of board is a good density board?

With the development of my country's furniture, home decor, and other industries, density fiberboard (MDF) products are becoming increasingly integrated into people's daily lives. While MDF with acceptable performance can be used with confidence, substandard MDF can cause significant problems for consumers. Common MDF testing criteria include formaldehyde emissions, water absorption expansion rate, bond strength, static bending strength, and flame retardant rating. Only MDF that meets quality inspection requirements can be used with confidence.

Common plate testing items

01. Formaldehyde emission

Formaldehyde is a chemical gas that, at certain concentrations in the air, can be harmful to the human body. Living in an environment with excessive formaldehyde concentrations for long periods of time can negatively impact both physical and mental health.

The adhesives used in common artificial boards contain formaldehyde, but if formaldehyde emissions are kept within a certain range, they pose no threat to human health. The national standard GB18580-2017, "Limits of Formaldehyde Emissions from Artificial Boards and Their Products for Interior Decoration and Renovation Materials," stipulates a formaldehyde emission limit of 0.124 mg/m³, designated E1. Compared to the older standard GB18580-2001, these formaldehyde emission limits are more stringent.

02. Water absorption thickness expansion rate

The water absorption thickness expansion rate is a very important indicator in the actual use of density board products. It reflects the water resistance and dimensional stability of the product. The lower the value, the worse the performance.

While MDF rarely experiences direct water immersion during actual use, measuring this property can provide a rough estimate of its dimensional stability as humidity levels fluctuate. MDF with poor water resistance can significantly expand in humid environments if its edges are not tightly sealed, causing changes in size and strength, which can affect the board's usability.

03. Bonding strength

There are two types of bonding strength indicators for density boards, namely internal bonding strength and surface bonding strength.

Internal bond strength is one of the primary indicators of MDF's physical and chemical properties, reflecting the quality of the bonding between the board's fibers. Higher values ​​indicate a board's ability to withstand temperature fluctuations, resulting in higher-quality bonding and a lower risk of delamination and cracking.

Surface bond strength reflects the processing and use performance of MDF products. If this performance does not meet the standard, the board will be prone to problems such as loose structure, delamination, and detachment of decorative surfaces during use. If the surface of the MDF is rough and uneven, its surface bond strength will be weakened.

04. Static bending strength

Static flexure strength is the ratio of the bending moment to the bending section modulus of the board under maximum load. When MDF is subjected to stress, it will cause a certain degree of bending, which is called "static bending." "Static flexure strength" is the compressive strength that the board can withstand when it is bent to the point of breaking.

Static flexural strength reflects the product's ability to bear loads and resist deformation under load. The national standard for transverse static flexural strength is 15.0 MPa. Failure to meet this indicator indicates that the product is prone to breakage, deformation, and other phenomena during use.

05. Flame retardant fire rating

Flame-retardant density board is a common functional artificial board in public places because it has flame retardants added during the production process, which can suppress open flames, reduce heat, effectively control fire, and reduce smoke and toxicity.

Qualified flame-retardant density boards can slow the spread of fire, while inferior flame-retardant density boards produced by unscrupulous vendors pose a significant risk to people's lives and property. The existing GB8624-2012 "Classification of Combustion Performance of Building Materials and Products" is the primary standard for testing the flame retardancy and fire resistance of flame-retardant density boards.

▲ Combustion performance classification of building materials and products

▲ Classification criteria for flat-plate flame-retardant building materials and products

In our daily lives, furniture, cabinets, flooring, etc. all use density boards, and the quality of indoor air in our homes is also closely related to these boards. Evaluating the quality of a density board is inseparable from the above-mentioned board performance tests, so you should pay attention to them when purchasing.