Slit Tape Polypropylene Fabric: What Industrial Buyers Should Know

If you're specifying or sourcing woven polypropylene fabric — for containment, separation, frost fabric— there's a good chance slit tape construction has crossed your desk. It's lower in price than monofilament round/ oval polypropylene and has been a standard in the industry for decades. It's a reasonable choice for plenty of applications. But there are real performance considerations that are worth understanding before you write it into a spec.

What Is Slit Tape Polypropylene?

Slit tape fabric is made by extruding a flat sheet, that is simultaneously slit it into narrow, flat tape-like strands. those tapes that are then woven together; typically, in a plain weave pattern. It's the same basic construction used for many woven fabrics. It's essentially unchanged since it originated in the carpet industry more than 40 years ago.

Slit tape's low cost mainly comes from how the yarn itself is made: extruding a flat film and slitting it into tapes is a simpler, faster, less capital-intensive process than extruding and drawing  monofilament. Because the resulting "yarns" are flat tapes rather than round or oval monofilaments, the fabric also packs tightly — which is the source of its biggest limitation.

What is Monofilament Polypropylene?

Individual yarns are extruded, often in an oval or round shape. Each yarn enters is cooled and drawn to achieve desired strength.  Each extruded yarn is collected onto a bobbin for the machine direction yarn to be loaded onto the weaving loom where the cross direction yarns will be woven with the yarns from the bobbin.  The process to produce the yarns requires slower extrusion time, making monofilament based fabrics more expensive.

The Trade-Offs:

Strength:

Slit tape's tight weave gives it strong tensile performance for the cost — in fact, slit-film fabrics often test as strong as or stronger than some monofilament —Lighter weight and potential for higher strength are 2 helpful characteristics.

Monofilament fabric strength can be increased by changing the yarn denier, the weave pattern or using high tenacity yarns.  

Flow rates

Slit tape fabric can have  dramatically lower flow rates  than monofilament woven alternatives, since the flat tapes leave less open area between strands. Lower permeability/ air flow is helpful when heat retention as a crop cover is required.

Monofilament fabric supports any needed drainage and breathability (permeability). This is where filtration usually favors monofilament over slit tape.

The practical differences typically show up in three places:

Edge and seam durability

Slit tape tends to show its age faster at stress points; they are prone to splitting into fine strands, most visible along edges and seams, weakening the fabric over time.  Monofilament yarns resist splitting making them a better selection when need to cut edges, apply grommets, and high-flex points are present over time.  They also generally resist twisting while on loom, instead of lying flat. Twists can create creates uneven spots in the fabric that can be weaker, let more air, water, or light through than intended, and are more likely to split or tear over time.   Oval shaped monofilament yarns can twist in the same way as slit tape yarns, but often without the potential for fabric weakening

Consistent long-term performance

With UV-stabilized monofilament, there is less surface area for UV related fabric breakdown.

 Check out the comparison chart below for details. 

Questions Worth Asking Any Supplier

• What is the type of yarn? Round/ oval (monofilament) or flat/ slit tape?

• What is the tensile strength?  And what was the test method? So you know if all comparison fabrics were tested the same way.

• What's the water flow rate, if applicable?

• What is the UV warranty and what testing was done that supports the marketing language?

Where to Look Next

Acadian's woven fabric lines include monofilament polypropylene and slit tape yarn fabrics.  Depending on your application requirements, we may have that fabric in stock. 

Have questions about which construction fits your application? Request a sourcing consultation and we'll walk through the specs with you directly.