LOW-E Glass Processing Instruction

Morn offers all kinds of low e coated glass:Single silver low e,double silver low e and triple silver low e,to be your turnkey building glass supplier,here is a low e coated glass processing instruction to help insulated glass manufacturers decreasing defective ratio and save costs during processing low e glass.

INDEX

1.Packaging,Transportation,Storage
1.1 Packaging
1.2 Transportation
1.3 Storage
2.Basic processing requirement
3.Processing instructions
3.1 Unloading
3.2 Unpacking
3.3 Cutting
3.4 Edging,Drilling
3.5 Washing
3.6 Tempering&Heat Strengthening
3.7 Insulating
4.FAQ &Matters Need Attention
4.1 White lines During Tempering
4.2 Dew in DGU Space
4.3Thermal Breakage (Annealed glass)
4.4 Glass breakage inside tempering furnace
4.5 Fingerprints

Introduction

Soft coated low-E glass is made by coating multi-layer of metal or oxide films onto the original glass sheet by sputtering process in a vacuum chamber.The Ag layer can effectively reduce the absorption of solar energy or control the energy loss in order to largely lower the heat transfer coefficient.Low-E glass can eliminate 50-80% heat transferred by clear glass,especially the far infrared radiation,meanwhile,it permits the all or part of the visible light to pass the coated glass,has great thermal insulation and solar shading performance.To guarantee the tempered low-E quality and performance,avoid non-conforming products,insulated glass manufacturer are advised to follow below processing instructions.

1.Packaging,transportation,storage

1.1 Packaging

1.1.1.Each package is about 2.8-3MT,including several pieces coated glass.

1.1.2 Coated glass are separated with special protective coatings or powders.

1.1.3 Desiccants are placed at glass top,glass were sealed with special adhesive tapes and plastic films,some with wooden crate packages.

1.1.4 Glass details can be seen on the sticker at side,including:
name,glass models,sizes,thickness,quantity,weight,production time,bar-codes and inspection marks.

1.2 Transportation

1.2.1 Reliable water-proof measures should be taken during transportation.

1.2.2 Avoid Package breakage and desiccant invalidation.

1.3 Storage

Mainly avoid chemically & Mechanically damage to the coating

1.3.1 Warehouse should be dry& ventilated to ensure no dew at glass surface.

1.3.2 Avoid rain&Direct sunshine,no leaky roofs,no outdoor storage.

1.3.3 No corrosive gas nearby.

1.3.4 Crates to be placed on shelves with 6-7 degrees lean.

1.3.5 Ensure the complete package of packing materials,avoid damages on glass.

1.3.6 Same size glass to be placed in the same shelves,crates to be separated with

foam boards.

1.3.7 Storage time:

Storage time based on above storage condition is:

Low-E (LT≥80%):6 months after initial packing.

Repackaging: 1 month.(change desiccant)

Low-E( LT<80%):8 months after initial packing.

Repackaging: 2 month.(change desiccant)

2.Basic processing requirement

2.1 Keep coating clear ,don’t touch the coating directly during processing and carriage.Operators should wear dry&clean gloves and breathing mask to avoid sweat/saliva or other materials which are easy to damage the coating.

2.2 Low-E coating has electrical conductivity,please justify with Ohmmeter,the test should be done in areas where need coating removing to avoid potential damage.

2.3 Low-E coating should be upwards or outwards during process to avoid coating contact machines directly.

2.4 Sucking low-E coating side is forbidden.

2.5 Direct contact of 2pcs coating sides or coating-glass side is forbidden,please use cord pads,soft papers or soft cotton ropes to separate glass.

2.6 Clean coating with unproved chemical solvents is forbidden ,nor normal textile or papers.

2.7 Please arrange the process properly from unpacking to DGU process.Please shorten the exposed time of low-E coating.After unpacking,Tempering process should be finished within 48 hours,DGU process to be finished within 72 hours.

2.8 Please process assorted glass firstly before processing low-E glass.And avoid cutting too many low-E glass over production capability within required processing time.

2.9 Try process is suggested for the clients who process our products the 1 st time,or any processing machines changes.

Because high transmittance products (LT>70%) have high processing requirement,please try at least 3-5 pieces before production for every lot glass in case of large scale production accident.

3.Processing instruction

3.1 Unloading

Please follow below principles:

3.1.1 Check if the crates and adhesive tapes are complete,if any damages,please take photos and contact us.

3.1.2.Glass shelves must be placed on flat ground.

3.1.3 Please use suitable loading equipment.

3.1.4 Please pay attention to the balance when hanging the glass.

3.2 Unpacking

3.2.1 All operators should wear clear,dry gloves and masks,it’s forbidden to contact the coating directly,or any saliva fall onto coating side.

3.2.2 Place the glass with 6-7 degrees lean.

3.2.3 Unpacking the crate according to the instruction,pay attention to coating side direction.

3.2.4 Before processing,please identify the coating side with detection pen,Ohmmeter,or lights.

3.2.5 Sucking glass with equipment with sucking discs,the discs contact the glass side,and keep balance when moving in case of glass breakage.

3.2.6 Suck coating side directly is forbidden.

3.2.7 Avoid rub and ensure glass edges don’t scratch another piece.

Remark:

A.Suspenders,clamps must be qualified and passed inspection.

B.Please ensure the operators’ safety during unloading and moving glass,all operators must be trained before handling glass.

3.3 Cutting

Please follow below items during cutting:

3.3.1. All operators should wear clear,dry gloves and masks,it’s forbidden to contact the coating directly,or any saliva fall onto coating side.

3.3.2 The coating side should be upwards,cannot contact cutting tables directly.

3.3.3 All cutting oils must be ensured don’t corrode the coating,the max length of oil dots should be controlled below 10mm.

When cutting glass with oils,the time between cutting&edging should not exceed 8 hours,for temperable low-E with powders,please don’t cut with oil.

3.3.4 All tools or machines that may contact coating side directly should be verified.

3.3.5 When placing glass on shelves,the 1st piece glass coating side should be outwards in case of damage.Each side of shelves is not suggested to load over 30 pieces glass.

3.3.6 All the glass should be separated with cord pads,papers or soft cotton ropes.

3.3.7 Avoid measuring tools damage the coating side when measuring.

3.3.8 Before removing coating,please adjust the wheels pressure and speed.

3.3.9 After cutting ,clean the cutting table with air and sweep the glass fragments.

3.4 Edging,drilling

3.4.1 All operators should wear clear,dry gloves and masks,it’s forbidden to contact the coating directly,or any saliva fall onto coating side.

3.4.2 Edging machines including double edging machine,single edging machine. Machines with splints to fix glass is note suggested.

3.4.3 Before large scale production,please try cleaning and tempering pieces,after confirming no scratches,no splints prints and clear coating,please start production.

3.4.4 Keep edging machines clean,all rollers,conveyor belts should be cleaned before edging,no oil or dusts allowed. The conveyor belts shall not be too tight,please adjust the pressure according to glass thickness,the upper belts is suggested to use special belts for low-E glass.

3.4.5 The suggested water PH value is 6-8,change water every 8 hours.

3.4.6 Wetting glass before edging,and during edging process,there should be enough water to wet the glass panels.

3.4.7 Please change the waters used to cool the edging wheels in case impurities inside damaging glass coating.

3.4.8 All glass must be washed after edging instantly.

3.4.9 When drilling holes,coating side should be upwards(flat drilling) or outwards(vertical drilling) .

3.5 Washing

3.5.1 All operators should wear clear,dry gloves and masks,it’s forbidden to contact the coating directly,or any saliva fall onto coating side.

3.5.2All glass must be washed after edging instantly, When cleaning glass,coating side should be upwards(flat washing) or outwards(vertical washing)

3.5.3 Low-E washing machine is suggested,avoid hard hairbrushes contact the coating,all hairbrushes,conveyor rollers must be cleaned.

3.5.4 Water quality requirement

Wash water: Tap water with 6-8 PH.

Rinsing water:Deionized water with PH value 6-8,electrical conductivity ＜30uS/cm.

For better washing,please heat the water to 40℃-50℃.

3.5.5 Please clean the washing machine.

A.No oil or dusts on upper cover plates.

B.No oils or dusts on all division plates,water pipes.

C.No oils,dusts ,on rollers,glue prints on all rollers.

D.No sundries such as wool,glass fragments on hairbrushes.Please use Low-E glass soft hairbrushes and interference between glass&brushes should be below 1mm.

E.Water box:No oils,no sundries such as wool,glass fragments,no floater when filled with water,no oil in water,keep the water filter board unobstructed.

F.No oil,dusts in air ducts,pipes ,dash plates.

G.The washing machine set height should be same as glass actual thickness,please pay attention that the height showed in instrument panel maybe not accurate,please measure the actual height.

3.5.6 Please ensure sufficient water during washing process.

3.5.7 Glass should not stay inside the machines whether the brushes working or not.

3.5.8 The glass placement after washing,please refer to 3.3.5 and 3.3.6. It’s suggested to install a light at exit to inspect the washing quality.

3.5.10 Please temper the glass timely after washing.

3.6 Tempering and heat strengthening

3.6.1 Recommended furnaces

Forced convection tempering furnaces,convection assisted radiant tempering furnaces

3.6.2 Processing requirement:

3.6.2.1 All operators should wear clear,dry gloves and masks,it’s forbidden to contact the coating directly,or any saliva fall onto coating side which will easily pollute the coating.

3.6.2.2 Tempering process is suggested to be finished within 48 hours after unpacking.

3.6.2.3 Coating side should be upwards,check the glass cleanness before tempering,double washing is required is glass not clean,there should be no water-drops on glass.

3.6.2.4 No corrosive gas inside tempering machines.

3.6.2.5 Keep continuous tempering,when placing glass on furnaces,avoid potential problems such as partial temperature too high or low,rollers too hot or too cool.

3.6.2.6 When placing glass on shelves,the1st piece glass coating side should be outwards in case of damage.Each side of shelves is not suggested to load over 30 pieces glass.

3.6.3 Parameters

The parameters are different from glass types,furnace models,sizes,thickness,loading percentages,but low temperature&long time process is prefered.General parameters are as below:

Forced convection tempering furnaces: 660-680℃，40-45s/mm

convection assisted radiant tempering furnace:670-690℃，50-55s/mm

3.6.4 Please make glass into DGU timely after tempering process.

3.7 Insulating

3.7.1 All operators should wear clear,dry gloves and masks,it’s forbidden to contact the coating directly,or any saliva fall onto coating side which will easily pollute the coating.

3.7.2 When removing coating at glass edge,please pay attention to below:

A.Glass edge coating should be eliminated before DGU process.

B.The removing width to be decided by the clients’ requirement.

C.Leftovers on the wheels should be cleaned.

3.7.3 Cleaning requirement please refer to 3.5.

3.7.4 Before cleaning glass,please verify the actual washing effect of the machines.

3.7.5 Check the coating quality before fitting,avoid contact coating surface.

3.7.6 Avoid butyl,sealants polluting the coating.

4.FAQ &Matters Need Attention

4.1 White lines During Tempering

White lines are caused by too high bottom temperature,E.g the too high temperature rollers caused the glass upturned,the glass bottom rub the rollers.The solution is as below:

A.Decrease the bottom temperature or the rollers’ temperature.

B.Increase the upper wind pressure to make glass flat.

In which decreasing temperature is the most important.

4.2 Dew inside double glazed units

The main reasons are as below:

A.Invalid desiccant before insulating.Check the desiccant storage&sealing&filling conditions,and the times between filling&insulation.

B.Discontiguous butyl.Check the pressing effect,butyl continuity,second sealing,glass bow,etc.

C.Materials quality is also important.

4.3.Thermal Breakage (annealed glass)

Thermal Breakage are caused by maybe many reasons,should prevent this problem from processing,installation,storage,and using aspects.

A.Glass should be at least seamed edge or machine grind edge.

B.Finished DGU should be separated with cord pads to keep good ventilation.

C.The glass packing should not be too tight,add extra materials between belts&glass.

D.Don’t keep glass under sunlight before installation.

4.4 Glass breakage inside tempering furnace

For radiant furnaces,the rollers temperature is high,glass are easy to break because of too low temperature in continuous production.Please adjust the production rhythm to keep rollers’ temperature stable.

4.5 Fingerprints

The reason is operators contact the glass directly ,improper handling motion can also cause this.

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