What is a core?

Core is a platform on which a decorative surface is laminated.
The quality, finish, durability, and cost of a furniture depends on the quality of the core material.

Therefore, choosing the right core material is an extremely crucial decision for your furniture project.

Some of the commonly used core materials for furniture are:

1. Plywood
2. Medium Density Fiber (MDF) Board
3. Particle Board

These days because of advances in material science, polymer based core material like foamed olefins, and PVC are also used as furniture core material.

Here’s a quick summary of key attributes of each core material which should be considered before embarking upon a furniture project:

AttributesPlywoodMDF Particle Board Polymer
Structural Properties 500 – 600 600 – 800 450 – 600 450 – 700
Density (kg/m3) ExcellentExcellentGoodExcellent
Compression Strength PoorExcellentExcellentExcellent
Thickness Uniformity ExcellentGoodGoodGood
Screw Holding PoorExcellentPoorExcellent
Functional Properties     
Warping/Bending? PoorSatisfactorySatisfactorySatisfactory
Surface Finish of Furniture  Satisfactory Excellent Good Excellent
Water Resistance  Good  Satisfactory   Satisfactory  Excellent
  Termite/Borer Resistance  Satisfactory Satisfactory Satisfactory Excellent
  Fire Retardant  Satisfactory SatisfactorySatisfactory Excellent
  Environment Friendly  Satisfactory GoodGood Excellent
Cost ExpensiveEconomicalEconomical Economical

Let’s review each of the attributes in detail.

Density indicates the weight of the material. Dense material is ‘compact’. Thus, for long panels like wardrobe doors, tall kitchen units a denser material like MDF or polymer board is recommended because it will not warp or bend. For a given thickness, MDF has the highest density, followed by polymer boards, particle board, and plywood.

Compression Strength
Compressive strength is a measure of the ‘load’ bearing capacity of the material. This attribute is extremely important for horizontal applications like table tops, shelves etc. So a material having higher compressive strength should be chosen for horizontal applications. MDF, plywood have excellent compressive strength. The compressive strength of polymer boards can be increased by suitable additives. Particle board does not have good compressive strength.

Thickness Uniformity
Uniformity in thickness is a very important technical feature of a core material. A uniformly thick material is very easy to process, and thus results in a good quality furniture. In trade lingo, this feature is known as ‘calibration’. MDF, particle board, and polymer board are all made through sophisticated machines in controlled environment. Therefore, the thickness variation in these materials is extremelylow. However, plywood manufacturing still involves a lot of manual processes, therefore the thicknessvariation in plywood is very high. Although, there are some manufacturers of plywood which manufacture calibrated ply. The recommended maximum permissible variation in the thickness is ±0.5mm. The thickness variation in MDF, particle board, and polymer boards is in the range of ±0.1-0.2mm, where as in case of non-calibrated plywood it is generally greater than ±1 mm.

Screw Holding
Screw holding strength of a material is an important attribute because it would determine the life of the furniture. Plywood offers the best screw holding property followed by MDF, polymer board, and particle board. For a furniture which would not require frequent shifting, then MDF can be an excellent choice because of other strong structural attributes. 

Some applications require ‘curved’ shapes. In such instances, the flexible nature of the core material becomes an important attribute. Thin polymer boards are the most flexible material, followed by MDF. Plywood and particle boards are not flexible at all and therefore not suitable for curved furniture. 

Warping relates to ‘straightness’ of the panel. Warping is undesirable because of cosmetic and technical reasons. A warp panel may cause the hinges and other hardware to break because of uneven distribution of stresses. Warping can happen because of: 1 Moisture – if the material absorbs moistures then it will swell and if the material releases moisture it will shrink. This swelling and shrinking will cause the material to bend. 2 Improper Balancing – If the thickness of the front and the back laminate is not same or if they are of different materials, then the finished furniture may warp. 3 Glue – If different types of glue are used to bond the front and the back laminate the different bonding strength of the glue may cause the furniture to warp. 4 Homogenous Construction – If the core material is homogenous, then the warping would be less. Non homogenous materials tend to warp more because of different moisture retention property and thermal expansion/contraction rate.

Polymer boards have the least moisture absorption, where as plywood, MDF, and particle board absorb moisture. MDF, particle board and polymer boards are homogenous material. Therefore, they do not tend to warp. Plywood is a non-homogenous material and therefore has maximum warping.

Surface Finish
This is the MOST important attribute of a core material because ultimately, the customer only sees the surface of the finished furniture. Machine made materials like polymer boards, MDF, and particle boards give an exceptional surface finish because these materials are homogenous. The surface finish for plywood is satisfactory. The choice of the core material becomes all the more crucial if high gloss or mirror finish furniture is required. For high gloss finish, polymer boards, MDF would provide exceptional finish followed by particle board and plywood.

Water Resistance
Water resistant property is important for core materials ONLY when the furniture may be exposed to moisture/water; for example bathroom cabinets, or the shutters below the kitchen sink. Water resistance is NOT an important requirement for core material where the finished furniture would not have any contact with water. For example, living room furniture, wardrobes, bedrooms furniture can be made using a core material which is not water resistant. Polymer boards are the best choice of core material to make the furniture water proof, followed by plywood. Exterior grade MDF and particle boards offer good water resistant properties.

Termite/Borer Resistance
Natural materials are affected by termites and other pests. Polymer materials have the distinct advantage of being never affected by termites or borers where as all wood based core materials like plywood, MDF, and particle board may be affected by termites and borers. Therefore in areas where there is a risk of termite/borer attacks, then polymer boards should be the default option for core.

Fire Retardant
Certain applications may require the core material to be fire retardant for safety purpose. Polymer materials can offer excellent fire retardant properties compared to plywood, MDF, and particle boards.

Environment Friendly
Polymer boards can be recycled and can also be manufactured from recycled material. Therefore, polymer board is the most environment friendly core material. MDF and particle boards can be recycled and made using recycled raw material. Although plywood can be recycled, it cannot be made usingrecycled material. However, in India the resin used to bond MDF, particle board, and plywood emits volatile organic compounds (VOC) which is not environment friendly.

Cost is an important criteria to consider while choosing the core material. Particle board is the cheapest, followed by MDF, polymer board and plywood.

In conclusion, there is NO single size fits all solution for the core. Based on the requirements of the project, the suitable core material should be chosen. Therefore, OpuLuxTM – our range of super high gloss prelaminated boards are offered on plywood, MDF, particle board and polymer based boards, thus giving you a complete flexibility to choose the right core material to suit your specific requirements.