Rebond Foam Density Guide: What 50–300 kg/m³ Means for Buyers

Rebonded PU foam is often bought by density. Density is the weight of foam per cubic meter, written as kg/m3. Fungbillion supplies rebonded PU foam made with recycled PU foam and 100% recyclable. Foam scrap, Grade AA foam scrap and Hi-Poly shoe foam scrap are listed at different densities. These numbers describe different products at different stages of the foam supply chain, so they should not be compared as if they were the same material. This guide explains what the numbers mean for furniture padding, mattresses, carpet underlay and other foam purchases.

What density means in practice

Density is weight per unit volume. A higher-density foam contains more foam material in the same cubic meter than a lower-density foam. A block of the same size weighs more. Lower density means less material per cubic meter and a lighter part for the same dimensions.

Density is not firmness rating, compression grade, thickness, skin content, color or scrap grade. Two foams with the same density can behave differently if they use different scrap, different skin percentages, or a different binder and production method. For rebonded foam, read density with the grade and the finished part requirements.

Higher density usually means the finished part contains more material. It is generally heavier and can be specified where the part needs more support or better resistance to compression. Lower density is lighter and can be specified where weight or material usage is the main concern. Higher density is not always correct. The right density meets the load, shape, thickness and service condition.

Density ranges buyers see

Rebonded PU foam is listed from 50 kg/m3 to 300 kg/m3. It is made with recycled PU foam, is 100% recyclable, and shape cutting is supported. It is designed for replacement of virgin foam, furniture padding, farming mattress, domestic mattress and modular autoparts.

Foam scrap is a separate product group. The listed density for foam scrap is 15-30 kg/m3. Bales are listed at 200-300 kg per bale. Alibaba-listed supply ability of 5000 Ton/Tons per Month. Ports are Shenzhen or Guangzhou, China. A 40ft container loads 18000-22000 kg, and one 40HQ loads 20-22 tons of AA-grade compression bales.

Within foam scrap, Grade AA is listed at around 5% skin or 0-skin versions, with density 20-30 kg/m3. The Grade AA description says its 'quality is super good and price is also expensive'. Grade A is available in 5% skin and 15% skin versions. Grade B is around 15% skin. Colors are black, white or mixed. Other listed products include shredded foam, PU binder, 10mm thick foam carpet underlay, filter foam scrap, Dali skin foam, Hi-Poly shoe foam scrap at 50-60 density, and old used foam.

Rebonded foam density

At the lower end, 50 kg/m3 uses less material per cubic meter than a higher density product. For the same cut shape, the part is lighter. A buyer may choose a lower density when the part is not heavily loaded, when weight needs to be controlled, or when the foam is used as a filler or backing layer rather than a primary support layer.

At the higher end, 300 kg/m3 contains more material per cubic meter. A part of the same dimensions is heavier and can be specified where the application calls for more support or more resistance to compression. In furniture and mattress builds, higher density is often considered for load-bearing layers and parts that must hold their shape. Density is only one input. The grade of scrap, skin content, binder, thickness and cut shape also affect the finished part.

Do not convert density into a firmness rating. Density by itself does not give a comfort number or a hardness scale. If firmness is critical, specify the test or performance requirement you need and ask us for the relevant material data.

Furniture padding, mattresses and carpet underlay

For furniture padding, use density to separate light-duty and heavier-duty parts. Back panels, armrest wraps and non-load-bearing padding may use lower densities within the rebonded foam density range. Seat cushions and other parts that take repeated load may be specified at higher densities. Shape cutting is supported, so confirm density with the drawing or sample, not in isolation.

For domestic mattress and farming mattress, density can define the role of a foam layer. A higher density layer can be specified for support or base layers where more material and load resistance are needed. A lower density layer may be used where the mattress needs less weight or where the layer is not the main support. Density does not equal comfort. Two mattresses with the same foam density can feel different because of layer thickness, other materials, quilting and construction. The mattress foam buying guide covers how to compare these points before ordering.

For carpet underlay, the listed product is 10mm thick foam carpet underlay.

Other foam products use different density scales. Hi-Poly shoe foam scrap is listed at 50-60 density. That is a shoe foam scrap specification, not a rebonded foam density range. Do not compare a Grade AA scrap density with a rebonded foam density as if they describe the same finished product.

How to read a density offer

When a supplier quotes density, ask us these questions before you compare offers:

• Which product? Is the density for rebonded PU foam, foam scrap, shredded foam, PU binder, carpet underlay or shoe foam scrap?
• Which unit? Confirm the density is in kg/m3. If a quote uses another unit, ask for the conversion.
• Which grade? For foam scrap, is it Grade AA, Grade A or Grade B? What is the skin percentage: around 5%, 0-skin, 15% skin or another listed version?
• Is it bale density or finished part density? Confirm what the density number refers to.
• What is the thickness and shape? For rebonded foam, shape cutting is supported.
• What other performance data is available? Density alone does not define firmness, compression or rebound. Ask us for the material data that matches your application.
• What are the loading and shipping terms? Confirm port, bale weight, container load and payment terms. Payment methods listed are T/T, L/C, D/P D/A, MoneyGram, Credit Card, Western Union and Cash.

What to tell us when you inquire

Send your application, required density in kg/m3, grade and skin preference if you are buying scrap, color, thickness, cut shape, estimated quantity, destination port and payment method. If you are comparing rebonded foam with scrap or another foam product, state that clearly so the quote is based on the correct material. Contact us at Fungbillion, ChaoLang Industrial Zone, Chashan Town, Dongguan City, Guangdong, China. Office tel: 0086-0769-81805003; Mobile and WhatsApp: 0086-15875576145 / 15875576145; Email: [email protected]. Ms. Vicky Chen, Sales Manager, can review your specification. Use the contact page to send us your inquiry.

Keep reading: mattress foam buying guide · Rebonded PU Foam.