A stencil wiper roll (also called stencil wiping paper) is the rolled wiping material fitted to a solder paste printer’s automatic wiping mechanism to wipe residual solder paste off the underside of the stencil. It is the consumable for the printer’s under-stencil cleaning system. Its spec sheet may be only a few lines long, but every item directly affects cleaning results and fit. This page breaks down each term you’ll see on a spec sheet (two-layer structure, basis weight in GSM, spunlace process, core inner diameter), explains what each means and what to ask when purchasing.
1. Why stencil cleaning is worth the effort
When stencil apertures clog with residual solder paste, too little or too much paste is printed, leading to defects such as cold joints, shorts, solder bridges and open joints, which lower yield and add rework and repair costs.
A figure often quoted in the industry is that “60% to 70% of soldering defects originate in the solder paste printing environment.” Note that different sources give different numbers; both 60% and 70% have appeared in the same technical article. This shows it is an order-of-magnitude rule of thumb, not a precise statistic. When citing it, say “most defects originate at the printing stage” rather than treating a specific percentage as settled, or you’ll struggle to answer when asked for the source.
2. Two-layer structure: wood pulp and polyester layers each do their own job
The “two-layer” structure described in this section is from JIAHON’s product description. The spec sheet (TDS) for JIAHON-brand plain-weave wiper only states the composition (55% wood pulp + 45% polyester) and does not state a layered structure.
This is a key and often misunderstood design point for stencil wipers. It is not wood pulp and polyester blended evenly into one sheet; the spunlace process bonds two fiber layers into a two-layer structure, and the two layers do completely different jobs:
| Layer | Material | What it does |
|---|---|---|
| Friction side | Polyester layer | Provides friction to scrape off solder paste and red adhesive residue from the stencil; also provides structural strength and abrasion resistance |
| Absorbent layer | Natural wood pulp layer | Absorbs cleaning fluid, solder paste and flux; highly hydrophilic and absorbs quickly |
The overall composition is about 55% wood pulp and 45% polyester, but the point is that they are layered, not blended: scraping and absorbing are handled by different layers, which is why it can both wipe residue off and soak it up.
The manufacturing process: raw material preparation (wood pulp and polyester fiber) → spunlace processing (high-pressure water jets entangle the fibers) → layer forming (wood pulp and polyester layers combined) → cutting, stacking and packing.
3. Process: why spunlace matters
Nonwovens can be formed in several ways; the difference is what holds the fibers together:
| Process | How fibers are bonded | Effect on cleaning applications |
|---|---|---|
| Spunlace | High-pressure water jets entangle the fibers; no chemical binder | No binder means no extractable residue, which is key for precision cleaning |
| Chemical bonding | Binder sprayed on or impregnated | Binder may be extracted by solvent and transferred to the stencil or PCB |
| Thermal bonding | Heat-fusible fibers melt and bond to each other | No chemical residue, but stiffer to the touch and usually less absorbent |
| Needle punching | Mechanical needles entangle the fibers | Bulkier structure; surface flatness and low linting not as good as spunlace |
The key point about spunlace is that it contains no binder. Stencil cleaning often uses solvent (IPA or cleaning fluid). If the wiper contains a chemical binder, the solvent extracts it and leaves a residue film on the stencil underside: you contaminate while you wipe. That’s why asking a supplier “what process do you use” gets to the point faster than asking “what material is it.”
4. Basis weight: what 55 g/m² means
GSM means grams per square meter: basis weight. It is not thickness, but it relates to thickness, strength and absorbency.
- Higher basis weight: better dry and wet strength and more absorption per unit area, but a larger roll diameter for the same length and a higher unit cost.
- Lower basis weight: more length on the same roll diameter and less frequent changes, but tears more easily when wet; the risk of tearing is especially high in vacuum mode.
JIAHON-brand plain-weave wiper measures 55 g/m² and PP wiper 40 g/m² (JIAHON TDS). Spec sheets often state “excellent dry and wet strength, suitable for vacuum cleaning,” and that is exactly what basis weight does in this application.
How to choose basis weight in practice: check whether your printer’s cleaning mode uses vacuum. Machines with vacuum demand high wet strength; too low a basis weight gets sucked through and torn, and the fragments left under the stencil cause a bigger problem. Machines that only dry wipe or wet wipe can consider a lower basis weight in exchange for longer roll length.
5. Core inner diameter: the common “it won’t fit” problem
The inner diameter of the wiper roll’s core must match the printer’s spindle. This is a spec that’s easy to get wrong and easy to overlook when purchasing: material and basis weight can be right, and a 2 mm difference in inner diameter means it won’t mount. Inner diameters differ by brand and model; contact us with your printer model to confirm the right core size.
When requesting a quote, always state four things together: material width, roll length, core length and core inner diameter, plus whether you need a paper or PVC core and whether it needs a slot. If you only say “stencil wiper roll” or only give the width, there is a good chance the delivered rolls won’t fit. If you are replacing an existing consumable, the fastest way is to measure the inner diameter and length of the core you use now, or photograph the old core’s spec label and send it to the supplier.
6. How to confirm core specs for each printer brand
The length and diameter of the core (paper or plastic tube) must match the printer’s spindle; if either is wrong, it won’t mount. Sizes differ by brand, model and generation; contact us with your printer model to confirm the right core size. To check yourself, the fastest way is to measure the inner diameter and length of the core you use now.
Cores also differ in material and slotting: paper cores and PVC plastic cores are both available, with or without a slot, chosen by printer model.
Paper cores versus PVC cores
- Paper core: lower cost, but in wet wipe mode it absorbs water, softens and loses its roundness, causing tracking drift or jams.
- PVC plastic core: does not deform when damp; for wet wipe or solvent cleaning modes.
- Slotted or not: some printers’ spindles have locating keys and need a matching slotted core to mount and drive. This is often left out of catalogs, so ask about it when requesting a quote.
7. Other spec items, and one number to question
| Item | Common spec sheet wording | How to read it |
|---|---|---|
| Absorbency | Strongly absorbs solder paste, flux and residue; absorption rate above 50% | See below |
| Static | Meets ESD standards, reduces static risk | Ask which standard it follows and what surface resistance or resistivity was measured |
| Environment | Recyclable material; RoHS compliant | RoHS restricts hazardous substances and has nothing to do with linting or residue; don’t confuse the two |
| Quality system | ISO 9001 | This certifies the manufacturer’s quality management system, meaning process control and batch consistency; it is not product performance verification |
| Reference standard | IPC-7526 | The stencil and misprinted board cleaning handbook; the relevant standard for cleaning methods and verifying cleaning results |
Ask the supplier to explain “absorption rate above 50%.” Nonwoven absorbency is usually expressed as grams of liquid absorbed per gram of material (g/g) or milliliters absorbed per square meter (mL/m²); “50%” is not a standard expression in this field, and you can’t tell whether it is a weight ratio, a volume ratio or relative to some reference product. When purchasing, ask for figures in g/g or mL/m², with the test liquid stated (water and IPA absorption differ noticeably); otherwise the number can’t be used to compare brands. Likewise, statements such as “absorbs cleaning fluid more than four times faster than ordinary cotton rags” only mean something with the matching test conditions.
8. Seven things to confirm before purchasing
- Core inner diameter and length match the printer spindle (measuring the current core is fastest).
- Core material (paper or PVC) and whether a slot is needed.
- Material width and roll length, converted into usable hours per roll that fit your change schedule.
- Whether it is a two-layer structure (JIAHON product description).
- Process: whether it is spunlace (no binder), especially if it will be used with solvent.
- Basis weight, and whether the printer’s cleaning mode includes vacuum.
- Quantified absorbency data (g/g or mL/m²) and the test liquid; don’t accept a percentage alone.
FAQ
How is spunlace different from ordinary nonwovens? The difference is how the fibers are bonded. Spunlace uses high-pressure water jets to entangle the fibers, with no chemical binder; chemical bonding relies on sprayed or impregnated binder. Stencil cleaning often uses solvent, and a wiper containing binder will have residue extracted by the solvent and transferred to the stencil underside: you contaminate while you wipe.
Is 55 g/m² a thickness? No. GSM is grams per square meter (basis weight); it relates to thickness but is not thickness. Higher basis weight gives better dry and wet strength and more absorption per unit area, but less length on the same roll diameter. Choose by whether the printer’s cleaning mode uses vacuum: vacuum machines need high wet strength, and too low a basis weight gets sucked through and torn.
Why does core inner diameter matter so much? Because it decides whether the roll mounts at all. Material and basis weight can be right, and a 2 mm difference in inner diameter keeps it off the spindle. When requesting a quote, state material width, roll length, core length and inner diameter together, plus paper or PVC core and whether a slot is needed. When replacing an existing consumable, measuring the current core is fastest.
What’s the difference between paper cores and PVC plastic cores? Whether they deform when damp. In wet wipe mode a paper core absorbs water, softens and loses roundness, causing tracking drift or jams; a PVC core doesn’t deform when damp. If the cleaning mode includes wet wiping or solvent, choose PVC. Some printers’ spindles also have locating keys and need a matching slotted core to mount and drive.
The spec says “absorption rate above 50%.” What does that mean? That wording can’t be interpreted; ask the supplier. The standard expressions for nonwoven absorbency are g/g (grams of liquid per gram of material) or mL/m² (milliliters per square meter). “50%” doesn’t tell you whether it’s a weight ratio, a volume ratio or relative to a reference product. Always ask for the test liquid too: water and IPA absorption differ noticeably.
Does ISO 9001 mean product performance is fine? No. ISO 9001 certifies the manufacturer’s quality management system, meaning process control and batch-to-batch consistency, but it does not verify any product performance metric. Likewise, RoHS restricts hazardous substances and has nothing to do with linting or residue performance. These are basic process and regulatory thresholds; product performance still depends on test data.
How often should the roll be changed? It depends on roll length, cleaning frequency and paper advance per cleaning. Divide roll length by the paper advance per cleaning to get cleanings per roll, convert that to hours using the line’s cleaning frequency, and put it in the maintenance schedule. Don’t find out you’re out of stock when the roll runs out: without wiper rolls the stencil cleaning system means stopping the line or cleaning by hand.
Standards cited
Refer to the current version from each issuing body for the standards cited here.
- IPC-7526 Stencil and Misprinted Board Cleaning Handbook. Issued by IPC / electronics.org.
- IPC-7527 Requirements for Solder Paste Printing. Issued by IPC / electronics.org.
- IPC-A-610 Acceptability of Electronic Assemblies. Issued by the Global Electronics Association (formerly IPC).
- RoHS Directive 2011/65/EU Restriction of Hazardous Substances in EEE. Issued by the European Commission.
Further reading: on stencil cleaning standards, cleaning equipment and print quality measurement: an SMT stencil cleaning and squeegee implementation case (five test results and standards cross-reference); a full guide to IPC-7526 stencil and misprinted board cleaning; white light structured light thickness and deformation measurement (non-contact inspection of carrier warpage, board warpage and solder paste thickness); JH64 stencil and flux cleaner (RoHS, halogen-free, PFOA/PFOS reports and SDS highlights).
Related products: JIAHON supplies all the items mentioned: JIAHON-brand industrial wipers (cleanroom rolls); stencil cleaner / flux cleaner; squeegee blades and accessories compatible with DEK printers; squeegees and solder blocking blades compatible with GKG GSE printers; P3 electric stencil cleaning machine JHPBT-1000X.
DEK and GKG are trademarks of their respective owners; JIAHON is not the authorized distributor of DEK or GKG in Taiwan, and compatible parts are not made by those brands.
From: JIAHON Engineering Department
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