Smart Microporous Filtration: Blocking Rain, Venting Moisture

Jinbo® Waterproof Breathable Membrane, or commonly called "breather paper", is produced by Xiashi Packing Co., Ltd. It is an innovative polymer composite waterproof material. The core functional layer uses e-PTFE or PE breathable polymer film. We laminate high-density spunbond polypropylene (PP) non-woven fabric onto both sides with a full heat lamination method. No hot melt glue or solvent residue is left in the finished product, making it a dedicated protective material for building envelopes. Its performance meets architectural membrane industry specifications as well as requirements stated in national standard design atlas 06J925-2.

What sets our waterproof breathable membrane apart from others?

It comes down to our practical dual protection design: it keeps rainwater out while letting trapped moisture escape.

The key lies in its fine microporous structure, with pore dimensions between 0.1 and 1 micron. Thanks to surface tension, these tiny pores can hold back liquid water, yet they are big enough for water vapor to pass through without obstruction.

Here is a simple way to understand it. Raindrops are clusters of liquid water, far too large to pass through these micro pores. Our standard lightweight membrane can handle water pressure above 1.5 meters, while our heavy-duty variant can withstand more than 2 meters of water pressure. Real tests confirm it stays intact even under heavy typhoon rains, delivering dependable Class A waterproof performance.

Water vapor is a different story. Those molecules are hundreds of times smaller than liquid water clusters, so when humidity builds up inside a roof or curtain wall assembly, vapor simply migrates outward through the membrane along the concentration gradient. With a transmission rate of up to 1,500 g/m²·24h, trapped moisture keeps leaving steadily. Condensation never gets a chance to form, insulation holds up, and steel stays free of rust caused by lasting dampness.

Weather Resistance & Advantages Over Glued Alternatives

Simply put, it keeps buildings dry and structurally stable no matter windy or rainy conditions. The material has outstanding weather resistance. Products made by our pure heat lamination process work reliably from -40°C to 110°C. They pass more than 120 days of UV aging testing; no peeling or performance drop occurs after long-term outdoor exposure. It outperforms cheaper alternatives bonded with hot melt adhesive. Those glued products have poor vapor permeability and can only tolerate temperatures up to 60°C. When summer heat rises, the glue tends to soften and fail, separating the non-woven fabric from the membrane core. They cannot sustain long-term engineering use and bring extra high maintenance expenses to construction projects.

Physical Strength & Environmental Performance

Jinbo® waterproof breathable membranes maintain consistent mechanical strength. The PP spunbond non-woven layers on both sides shield the middle breathable film, delivering minimum longitudinal tensile strength of 130 N/50 mm and transverse tensile strength of 80 N/50 mm. The material resists tearing during on-site installation. It satisfies EU Class E fire classification. Certain grades adopt 100% recyclable raw materials and meet green building material standards.

System Installation & Energy Saving Benefits

For building envelope assemblies, this membrane is usually fitted outside insulation layers and used together with an internal vapor barrier. This setup improves the building’s air and water tightness, cuts heat loss from air convection and brings obvious energy-saving and insulation effects.

Application Scenarios

Jinbo® waterproof breathable membranes are widely adopted in steel structures, metal roofing, timber frame houses, curtain walls, stadiums, high-speed rail stations, airport terminals and many other large public and industrial projects. It has become a go-to functional material to avoid condensation inside building envelopes and extend building service life.