Brushes for Glass Processing and Glass Washing Machines
Industry guide · 6 min read · updated 2026-10-24
Almost every flat glass process starts with a wash. Glass is washed after cutting and edging, before tempering, before insulating-glass assembly, and before laminating or coating. In a horizontal or vertical washer, pairs of rotating cylindrical brushes scrub both faces of the lite in heated detergent water, then further pairs scrub again in the rinse sections before air knives dry the glass.
The brushes decide whether cutting oil, glass fines and packing residue come off without scratching the surface or damaging a coating. This page covers how washer brushes work, which filaments suit coated and uncoated glass, the water and maintenance practices that protect them, and what to send for a replacement quote.
1. How a glass washer uses its brushes
A typical machine has one or two pairs of brushes in the wash section, where heated water and detergent remove oil and dirt, then pairs of brushes in the rinse sections. A washer equipment maker's guidance puts wash water at 110 to 140 °F (about 43 to 60 °C), depending on glass type and coating, with a non-foaming, easily rinsed detergent that does not attack the glass, the coating or the machine's nylon and rubber parts.
Brushes are usually long rollers spanning the machine width: nylon or polypropylene fill on a steel or stainless shaft. Our glass washing roller brushes, such as the nylon brush roller for glass washing machines, are built in lengths of 1 to 5 m on 45# steel or stainless shafts, and smaller rollers such as a 55 mm diameter roller with 0.2 mm nylon on a stainless shaft are used on compact machines.
2. Polypropylene vs nylon fill
Pilkington's technical bulletin on washing its pyrolytic low-E glass recommends polypropylene brush rolls for glass washing machines, noting that PP is usually softer, more flexible and lower-friction than nylon, and that nylon brushes must be set correctly to avoid coating damage. The same bulletin says its hard pyrolytic coatings can be washed with standard brushes, unlike softer sputtered low-E coatings, which typically need special soft brushes.
| Glass type | Typical brush choice | Notes |
|---|---|---|
| Uncoated float glass | Nylon or PP | Nylon gives more scrubbing action for oily cut glass |
| Hard-coat (pyrolytic) low-E | PP preferred; nylon if correctly adjusted | Run coated side up, away from support rolls |
| Soft-coat (sputtered) low-E | Special soft brushes | Follow the coater's washing instructions exactly |
| Glass before lamination or printing | Nylon or PP with treated rinse water | Surface residue affects adhesion |
3. Brush setting and operation
These points come from Pilkington's washing bulletin and a washer maker's maintenance guide, and they apply to almost any machine.
- Set brush height so only the bristle tips sweep the glass, evenly across the full width, rather than the sides of the bristles.
- Never let a lite stop under rotating brushes.
- Run a test lite before production and inspect it in transmission, in reflection and under a bright light close to the surface.
- Keep oil and grease off brushes and rolls; over-greased bearings drip into the tanks and are pumped onto the brushes.
- Abrasive particles trapped in the washer can scratch glass and coatings, so keep tanks and filters clean.
4. Water quality and its effect on brushes
Pilkington recommends a detergent wash in clean water at 50 to 60 °C (120 to 140 °F) and a final rinse with clean deionized water at no less than 43 °C (110 °F). The washer maker explains why: minerals in rinse water dry on the glass as streaks and can spoil sealant, interlayer or coating adhesion. Softened water does not solve this because softening only swaps hardness ions for sodium. Deionization removes dissolved solids completely; reverse osmosis removes about 95%.
Treated water has a downside for brushes: without chlorine, algae and bacterial slime grow in tanks and on brushes. Draining tanks daily, avoiding dead legs in the piping and periodic sanitising keep slime off the bristles.
5. Maintenance and replacement
One washer manufacturer recommends draining and cleaning tanks weekly (or every shift for coated glass), greasing brush bearings every 250 hours, and opening the machine at 500 hours to inspect brushes and rolls for damage or embedded glass chips and to check brush adjustment. When cleaning inside the machine with a low-pressure hot-water sprayer, never aim it straight at the bristles.
- Replace brushes with embedded glass chips; they will scratch every following lite.
- Replace when filament has worn so short that the brush can no longer be set to tip contact across the full width.
- Replace in pairs so upper and lower brushes clean evenly.
- Check shaft straightness and journal wear when a brush is removed.
6. What to send for a quote
Send the details through Request a Quote. For general roller design questions see how to choose a cylinder roller brush.
- Washer make and model, and brush position (wash or rinse, upper or lower).
- Overall length, brush face length, outside diameter and shaft details (journal diameters, keyways, bearing seats, drive end).
- Current fill material and filament diameter if known; otherwise a photo of the old brush with a ruler.
- Glass types washed (float, hard-coat or soft-coat low-E, laminated) and water treatment used.
- Quantity, including spares.
Frequently asked questions
- What brushes are best for a glass washing machine?
- Polypropylene or nylon cylindrical brush rollers. Pilkington recommends PP brush rolls for washing its pyrolytic low-E glass because PP is softer and lower-friction; nylon works if correctly adjusted and gives more scrubbing action on uncoated, oily glass.
- Can low-E glass go through a brush washer?
- Hard-coat (pyrolytic) low-E can be washed with standard washer brushes, coated side up. Soft-coat (sputtered) low-E usually needs special soft brushes, so follow the glass supplier's washing instructions.
- What water should be used in a glass washer?
- Heated detergent water in the wash section and treated water in the final rinse. Pilkington recommends deionized final rinse water at 43 °C or above. Softened water is not recommended for streak-free rinsing.
- How often should glass washer brushes be checked?
- One washer maker recommends a full inspection of brushes, rolls and brush adjustment every 500 operating hours, with weekly tank cleaning. Plants washing soft-coat glass often do the full inspection weekly.
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