The key to the strength of Celgard’s base film is our unique dry-process manufacturing capability. This solvent-free process consists of extrusion, lamination, annealing, stretching, and slitting and results in thermally, chemically, and physically stable membranes that are designed to match customer needs.
Celgard machine direction (MD) only stretched base films are uniaxially-oriented in the machine direction (MD) with high strength and practically zero transverse direction (TD) shrinkage. As a battery separator, these features significantly improve cell manufacturability and safety.
Celgard MD + TD stretched base films are biaxially-oriented in the machine direction (MD) and transverse direction (TD) to add other unique and patented film and pore characteristics.
Our patented dry-process membranes are also lightweight and environmentally friendly. They feature a smooth and uniform pore structure that outperforms many other technologies in moisture vapor transfer, making them ideally suited for the technical textile and medical personal protective equipment (PPE) markets.
Celgard offers a wide range of high-performance base films, including:
- Monolayer Polypropylene (PP)
- Trilayer PP/Polyethylene(PE)/PP
- Co-extruded Monolayer or Multilayer Films
Chemical and dimensional stability are the most critical benefits provided by Celgard® monolayer polypropylene (PP) base films in battery separator and specialty membrane applications.
Base Films in Battery Applications
Celgard is the leading supplier of Monolayer PP separators to the primary (disposable) lithium battery market and our products are also widely used in rechargeable lithium-ion batteries.
Celgard® Monolayer PP separators are well-suited for these applications because they offer oxidation resistance and are stable across a wide thermal range.
- Certain battery separators in contact with electrodes and electrolyte are subjected to strong oxidation, which can cause changes to pore structure, reduced mechanical strength, and ultimately cell failure.
- Celgard® Monolayer PP films are chemically stable and may be used without protective coating layers – providing a cost-effective but stable separator solution in many primary lithium and rechargeable lithium-ion cells.
Monolayer PP separators available in thicknesses ranging from 5 to 25 microns and can also be coated and/or
laminated for specialty battery applications.
Monolayer PP Base Films in Specialty Membrane Applications
Select Celgard® Monolayer PP base films are available as waterproof/breathable membranes for outdoor apparel as well as viral protection membranes for medical PPE.
Contact Us to inquire about Celgard® biaxially stretched Mono PP membrane options, which are available in thicknesses ranging from 9 to 18 microns.