Acrylic foam SOFRYL™

What is Acrylic foam SOFRYL™ ?

It is the foam body of acrylic emulsion obtained by mechanical foaming, coating, and drying.

  • Photo “Foamed Emulsion”

  • SEM photo “Dried Foam Sheet”

Product outline

  • Excellent sound absorbency due to its open-cell structure, which bubbles are connected continuously.
  • High cushioning performance to protect the materials from impact shock.
  • Self-adhesiveness, “easy to peel off but yet difficult to slip”, results excellent workability for binding.

Expansion of applications

SOFRYL™ is expanding for the following applications by using ① to ③ properties listed below.

  • Pressure sensitive adhesive for mats, toilet seat sheet, advertisement poster.
  • Sound absorbing layer for automotive interior materials.
  • Ventilation control membrane for automobile sound absorber.
  • Damping material for musical instruments.
  • Sealing material for Woven/Non-woven fabric.
  • Internal cushion sheet for mobile devices. Types of lower compression set after heating are also available.

Property ① Sound absorption

Sound absorption mechanism

Sound is transmitted by the vibration of air. When the sound wave enters the open cell structure such as acrylic foam body, the vibration of the incident sound wave causes friction between the air molecules in the cell and the skeleton of its structure. This friction converts sound energy into thermal energy, so the sound passed through the material becomes smaller than before passing. Furthermore, the skeleton parts also vibrate due to the vibration of the incident sound(“skeletal vibration”). Energy is required to vibrate objects, therefore, the sound energy is consumed to vibrate the skeleton. In this way, since the sound energy becomes smaller (being absorbed) while the sound passes through the material, the sound we hear is reduced.

  • Sound absorption mechanism

  • Sound absorption demo video

Sound absorption coefficient

The sound absorption coefficient is a numerical value of the sound absorbed by a material. The closer the value to 1, the better the absorption performance. Comparing the materials’ vertical incident sound absorption coefficient, SOFRYL™(red line) performs decisively higher than urethane foam (green) which also is a porous sound absorbing material, and even excels compared to non-woven sound absorbing material(blue). (See graph below left) Moreover, SOFRYL™ exhibits excellent sound absorption performance in the reverberation chamber method, of which experiment environment is closer to an actual use environment than that of vertical incidence sound absorption.(below right)

  • Measurement results of vertical incidence sound absorption coefficient

  • Measurement results of reverberant sound absorption coefficient

Property② Cushioning

In spite of its low density, urethane foam has characteristics of high elastic modulus and strong repulsion, that possibly be the disadvantage of damaging materials against shocks such as bumping and dropping. On the other hand, acrylic emulsion foam is overwhelmingly soft, low in elastic modulus, and low rebound even though it has higher density than urethane foam. Therefore, it shows excellent cushioning and can protect materials from impact shocks.

  • Cushioning performance test of acrylic emulsion foam

Property③ Adsorption (Pressure sensitive adhesive)

SOFRYL™ has a property of sticking to adherends despite having almost no surface tack. We call this property “Adsorption (self-adhesiveness)” The video below left shows characteristics of the foam: weak peeling force and strong shearing force. Accordingly, it is easy to peel off but difficult to slip and that results excellent workability for binding. Besides, when putting an adhesive sheet to the adherend, typical adhesives usually require certain skills to stick together because air entrapment can easily be in between. On the other hand, since the foam sheet has an open-cell structure, air can be released through open-cells easily by pressing the air entrapment even after sticking to the adherend. This air venting mechanism makes it easy for anyone to stick up without specific skills.

  • Adsorption test of acrylic emulsion foam

  • Air venting mechanism

Catalog / Technical data


Functional Chemicals Dept., Functional Chemicals Division

Phone number +81-3-6218-3841

Emulsion Technology Co., Ltd.