PU sponge

一、Two basic classifications (by raw materials)

1. Polyether PU sponge (mainstream)
   • Resistant to hydrolysis, not prone to yellowing, good breathability, and stable rebound
   • Applicable: Mattresses, sofas, car seats, slow rebound memory foam
2. Polyester PU sponge
   • High density, strong oil absorption, better sound absorption effect, and low cost
   • Applicable: sound-absorbing cotton, cleaning sponge, industrial filtration, packaging lining

二、Common functions: PU sponge category

1. high resilience foam
   Rapid rebound under stress, even support, the main material for sofas, car seat cushions, and office chairs, with a rebound rate of over 60%.
2. Slow rebound (memory foam)
   Slowly sink, fit the body, disperse pressure, make pillows, waist protection, and anti bedsore mattresses.
3. Perforated sound-absorbing sponge
   Pore connectivity, sound insulation and noise reduction, soundproofing cotton for recording studios, computer rooms, and equipment.
4. Anti static/conductive PU sponge
   Electronic packaging to prevent electrostatic breakdown of chips and motherboards.
5. Flame retardant PU sponge
   Self extinguishing upon leaving the fire, used for fire prevention scenarios in automobiles, furniture, and computer rooms.
6. Self skinning PU
   The surface is dense and hard, with soft foam inside. It is an integrated molded part of car armrests, steering wheels, and seat armrests. 

   三、core advantages and disadvantages

   advantage

   1. Excellent cushioning, shock absorption, and elasticity, with adjustable softness and hardness
   2. Perforated design is breathable, absorbent, and sound-absorbing; Closed cell insulated floating water
   3. Easy to cut, die cut, and shape processing, suitable for backing glue and composite fabric
   4. Mild acid and alkali resistance, can be used for antibacterial and ROHS environmental modification
   5. Large density span: 18-120kg/m ³, suitable for both light and soft to high-density hard pads

   shortcoming

   1. Long term heavy pressure is prone to collapse and permanent deformation (more pronounced in low-density areas)
   2. Ordinary models absorb water, dry slowly, and are prone to mold when wet
   3. High temperature (>80 ℃) is prone to softening and aging, and ordinary models have a slight odor
   4. Large pores are prone to dust accumulation, and EVA is not as dust-proof as EVA

   四、Mainstream application scenarios

   1. Home bedding: mattress, sofa, pillow, memory pillow, bay window cushion
   2. Automotive interior: seats, headrests, roof, door sound insulation, armrests
   3. Electronic packaging: shock-absorbing lining for mobile phones, cameras, and instruments
   4. Acoustic sound insulation: machine room, audio-visual room, speaker sound-absorbing cotton
   5. Industrial consumables: cleaning sponge, filter cotton, mechanical equipment shock pad
   6. Shoe material medical: shock-absorbing insoles, correction pads, anti pressure ulcer seat cushions, surgical cushioning pads

   五、PU sponge vs EVA foam (quick differentiation)

   Comparison item	PU sponge	EVA foam
   feel	Porous, soft, breathable, and soft rebound	Dense, smooth, non breathable, and slightly stiff
   water resistance	Open cell water absorption, closed cell micro waterproofing	Completely non absorbent and moisture resistant
   Compressive durability	Long term heavy pressure can easily cause sagging	Anti compression, not easy to collapse
   core purpose	Cushion, mattress, sound-absorbing, precision cushioning	Yoga mat, floor mat, toolbox lining, shoe midsole
   processing	Can be finely shaped and have good sound absorption effect	Wear resistant, waterproof, and durable for outdoor use

   
   
   Foshan Zhiwei Adhesive Products Co., Ltd. has over 20 years of professional matching solution experience in the use of PU sponge industry. We welcome inquiries from major manufacturers and contact email：yang@fszw-tapes.com。