Polyester 1.5 Layer Forming Fabric | 5-Shed Extra-Weft Paper Machine Wire for Brown Paper, Liner Board & Corrugated Paper Machines — PFM Screen

Q1: What is a 1.5 layer forming fabric and how does it differ from single and double layer?

A 1.5 layer forming fabric is a modified 5-shed single layer structure with additional (extra) weft yarns inserted between the regular cross-direction yarns. The "1.5" designation reflects its position between a true single layer (1 weft layer) and a true double layer (2 independent weft layers). Unlike a double layer, the 1.5 layer has no separate machine-side weft system — it is still fundamentally a single-layer structure with enhanced sheet-side properties. The result is higher air permeability than a double layer (better drainage), better fiber support than a single layer, and easier cleaning than either — making it ideal for brown paper and board grades that need more than single layer performance without the complexity of double layer construction.

Q2: Which paper grades are best suited for the 1.5 layer forming fabric?

The 1.5 layer forming fabric is primarily designed for brown paper grades including liner board (test liner, kraft liner), corrugated medium (fluting medium), brown kraft paper and sack kraft. These grades typically run at 50–400 m/min on Fourdrinier machines and require a balance of rapid drainage (to handle recycled fiber furnishes with high water retention) and adequate fiber support (to produce uniform sheet formation). The 1.5 layer is not normally used for fine printing paper, tissue or newsprint — for those grades, double layer, 2.5 layer or triple layer forming fabrics are better suited.

Q3: What machine speed range is the 1.5 layer forming fabric designed for?

PFM Screen's 1.5 layer forming fabrics are designed for paper machines running at 50–400 m/min. This speed range covers most board and brown paper Fourdrinier machines. At this range, the 1.5 layer's open drainage structure (440–525 CFM) handles the dewatering demands without the additional drainage elements (vacuum foils, high-vacuum boxes) needed at higher speeds. For machines above 400 m/min on board grades, PFM Screen recommends upgrading to a double layer or 2.5 layer forming fabric for better dimensional stability and wear life. Contact our technical team with your machine speed for a definitive recommendation.

Q4: Does the 1.5 layer forming fabric clean more easily than a double layer?

Yes. The 1.5 layer's modified single-layer internal structure has fewer yarn interlocking points and less three-dimensional internal void space than a true double layer fabric. This means that fiber fines, fillers and pitch deposits are less likely to become trapped deep inside the fabric body where standard cleaning showers cannot reach. In practice, 1.5 layer fabrics on board machines typically require lower shower water pressure and shorter cleaning sequences than comparable double layer fabrics, reducing shower water consumption and energy costs. This characteristic is especially valuable on recycled fiber furnishes where pitch and stickies contamination is high.

Q5: What are the key dimensions and specifications of the two standard 1.5 layer models?

PFM Screen offers two standard 1.5 layer models: Model 254510 (warp 0.22 mm, top weft 0.13 mm / binder 0.45 mm, warp density 28 pcs/cm, weft density 26.8 pcs/cm, MD strength 700 N/cm, air permeability 443 CFM) and Model 254010 (warp 0.22 mm, top weft 0.22 mm / binder 0.40 mm, warp density 28 pcs/cm, weft density 32.2 pcs/cm, MD strength 700 N/cm, air permeability 525 CFM). Model 254010 offers higher air permeability (525 CFM) and is preferred for heavier basis weight grades or slower machines that need faster drainage. Model 254510, with its finer top weft (0.13 mm), provides better sheet-side fiber support for grades where smoothness matters more.

Q6: Can I replace a double layer forming fabric with a 1.5 layer to reduce cost?

In some cases, yes — but it depends entirely on your paper grade, machine speed and quality requirements. For board and corrugated grades at 50–400 m/min where the double layer's main benefit is fiber support (not extreme wear life or formation quality), switching to a 1.5 layer can reduce fabric cost while maintaining acceptable sheet quality. However, if your machine runs above 400 m/min, or your paper grade requires very low wire mark (printing paper, fine writing paper), a double layer or higher-order fabric is necessary. PFM Screen recommends a trial evaluation before committing to a full fabric change. Contact us to discuss your specific machine and grade requirements.

Q7: How do I specify the correct fabric width and perimeter for my machine?

The fabric width is determined by your machine width plus the required edge overhang on both sides — typically 50–100 mm per side beyond the paper web width, to cover the edge drainage strips. The fabric perimeter (running length) is determined by measuring the actual roll and table geometry with a measuring tape along the fabric path, from breast roll to couch roll and return. Always specify the minimum and maximum running length positions (accounting for tension adjustment range). Alternatively, send PFM Screen the worn-out fabric or its dimensions and we will match the replacement specification exactly. Custom dimensions are available for any machine width and table geometry.

Q8: What is the lead time and minimum order for a 1.5 layer forming fabric?

PFM Screen accepts orders for a single fabric with no minimum order quantity. Standard lead time for a 1.5 layer forming fabric is 2–4 weeks from order confirmation to shipment, depending on fabric dimensions and production scheduling. For mills that order regularly, PFM Screen can maintain a rolling production schedule to reduce lead times. Contact our team via WhatsApp (+86 153 6967 9157) or email (polyestermesh@pfmscreen.com) with your fabric dimensions and model preference — we will provide a formal quotation and confirmed lead time within 24 hours.

Get a Custom 1.5 Layer Forming Fabric Quote — 24-Hour Response

Send us your paper grade, machine type, forming table width, fabric perimeter and annual quantity — PFM Screen will respond with specifications and pricing within one business day.

WhatsApp: +86 153 6967 9157Email: polyestermesh@pfmscreen.com