[knowledge] The advantages of TPU soft rubber material on the gas mask

Gas masks come in a wide variety of styles and designs. Most structures are composed of hard plastic and soft rubber materials. Hard plastic is mainly used to support the mask cover, so that the air circulation, soft rubber material is mainly taken into account people wear on the face, the comfort of contact with the human body. At present, hard plastic is usually made of PP, an environmentally friendly food grade material. The choice of soft material seems to have a lot of space, such as soft PVC, silicone, rubber, elastomer, PU. However, after thorough consideration of the manufacturer, the current production of the respirator mask uses two materials—silica gel and TPU/TPU compound.

Why did the gas mask finally choose silicone and TPU as raw materials for the soft part? This is mainly based on the following three considerations:

1, non-toxic environmental protection

Silicone is an environmentally friendly material that we all agree with. Food grade silicone can provide FDA 177.2600 test, which is a kind of food contact material. In addition, silicone does not smell, and it does not smell uncomfortable. In addition, silica gel is a chemically stable material, and human skin does not have any discomfort or allergies to silicone.

As for TPU. This is a kind of soft material that has been increasingly used in the rubber and plastics industry in the past 10 years. TPU is environmentally friendly and non-toxic. It has been tested by a third-party agency of SGS. TPU|TPU meets ROHS, REACH (SVHC) and does not contain toxic o-benzene plasticizers, does not contain bisphenol A, does not contain nonylphenol NP, does not contain much PAHs. They do not emit odors that make people feel uncomfortable. The TPU is mild in nature, and the skin is in contact with it without any allergic effects; the TPU meets the ISO 10993 biocompatibility test.

2, soft touch

Both silica gel and TPU can provide materials suitable for hardness, and find a balance between facial contact comfort and material strength. At present, the soft rubber TPU and silicone used in gas masks usually have a hardness of 45 to 50 A. Both TPU and silicone have Good low temperature resistance (all can maintain -50 °C soft and elastic).

3, one forming

The TPU can be directly bonded with the PP material mask by injection molding, without the need of adhesives for assembly. This will undoubtedly increase production efficiency. However, in recent years, modified silicone gels can also be used without surface pretreatment of PP pieces, and injection bonding of the two materials can be directly realized.

General silicone is suitable for high-grade gas masks. TPU is used for low-end products. Due to the superior stretch resilience of the silica gel relative to the TPU, the TPU has less resistance to tensile deformation than the silica gel. Of course, TPU materials can be recycled 100%, but also beyond the silicone.