The above diagram lists the most commonly used main materials and auxiliary materials in the die-cutting factory. Here we will talk about the foam in the main material:

Polyurethane foam is also known as polyurethane elastomer.

Polyurethane is a new kind of organic polymer material, known as the "fifth plastic", because of its excellent properties and widely used in many fields of national economy.

Polyurethane elastomer is also known as polyurethane rubber. It belongs to special synthetic rubber. It is an elastic polymer with more carbamic acid in the molecular chain (-- NHCOO --). The variety of raw materials, a variety of formulas, adjustable range is large, low hardness to Shao A10 low modulus rubber, high to Shao D85 high impact elastic materials (elastic modulus can be up to several hundred MPa, and the elastic modulus of rubber is 0.2~10MPa), so polyurethane elastomer is between rubber to plastic polymer materials.

Foam is a polymer with many small vesicles, the solid phase is the polymer matrix, the vesicles filled with gas.

Foam is divided into open and closed pore according to the structure of the bubble pore, the bubble pore and the bubble pore connected with each other is called the structure of the open pore, the bubble pore and the bubble pore are not connected with each other is called the structure of the closed pore.

Summary of the main uses of foam:

(1) Panel interlayer: function - no pollution, prevent loosening, prevent collision noise, prevent adhesion.

(2) around the LED: to prevent light leakage, absorb impact, high air tightness.

(3) PCB under the periphery: absorb impact, absorb vibration, fill gaps, heat insulation effect.

(4) keyboard gasket: counter-elastic, no pollution, good dimensional stability.

(5) around the battery: no pollution, absorb impact sound, improve air tightness.

(6) mat: good friction, no pollution, good dimensional stability.

(7) disk machine tail pad: absorb vibration, prevent collision noise, improve air tightness.

(8) friction gasket: good friction, no pollution, good dimensional stability.

(9) plate cover cushion: absorb vibration, block motor noise, shockproof, improve air tightness.

(10) around the speaker: to prevent noise and fill the gap.

(11) around LCD: dust proof, shock absorption, gap filling, improve shading.