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Troubleshooting Guide |
Here are some typical problems with vacuum-formed shapes:
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Problem | Possible Causes | Problem Remedy |
Soft and Weak Pieces | ||
Starch + Colloidal Systems | ||
Too little starch | •Check weight or volume of starch used •Increase starch in formulation |
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Bacteria eating starch (you will smell this!) |
•Clean out system with Clorox to kill bacteria and treat water like swimming pool to keep bacteria-free | |
Increased fiber size: length and/or diameter |
•Chop fibers longer or add some chopped fibers to formulation •Consult with fiber supplier |
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Too high colloidal silica to starch ratio | •Optimize by using less small particle colloidal in formulations •Use larger particle size colloidal for greater strength |
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Starch inconsistency | •Try a different pallet and lot number | |
Filler content | •Check size and weight of filler used | |
Wesil Binder Systems | ||
Too little binder | •Check weight added; try 10% more and monitor forming time | |
Filler content | •Check weight, size, and quality of filler used | |
Errant Wesil Binder | •Try a different pallet or lot number | |
Longer Forming Time | ||
Smaller or shorter fiber | •Try fiber from different pallet/bag •Consult with fiber supplier |
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Filler too fine Too much filler |
•Check weights and filler anaylses •Use coarser filler, 100-120 mesh preferred •Try 48 or 35 mesh to open it up |
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Too much binder | •Check weights and silica:starch ratio •Reduce starch by 10% •If using Wesil binders, reduce by 10% |
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Clay in formulation | •In general clays like bentonite increasing forming time •Do not use clays with Wesil binders |
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Rough Back Side | ||
Over floccing slurry too concentrated |
•Reduce starch and/or
increase colloidal silica to increase the silica:starch ratio •Run lower fiber content in slurry •If using Wesil binders, reduce level by 10% |
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Slow Drying | ||
Poor de-watering | •Reduce starch and/or
increase collodial silica to increase the silica:starch ratio •If using Wesil binders, reduce level by 10% |
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Clay in formulation | •Clay tends to hold water •Check weight used and reduce level by 10% if possible |
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Oven conditions | •Dying above 250°F degrades starch •Low humidity gives fastest drying •Need more air circulation early in drying cycle |
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Poor floc, cloudy water | ||
Too little binder | •Check to ensure correct amount of colloidal silica was added •Increase colloidal silica by 10% to see if floc improves |
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Starch inconsistency | •Try a different pallet or
lot number •If pre-dissolved, make up a fresh batch |
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White water problems | •If using recycled white water, check for excess colloidal and starch in white water | |
High temperature shrinkage (reformulation) | ||
Wrong fiber | •Use a higher temperature fiber | |
Wrong binder | •Use larger particle size colloidal silica •Try a colloidal alumina binder |
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Wrong filler | •Use mullite (high alumina content) or alumina filler | |
If you still have a problem and would like expert technical assistance,
give us a call or follow this link and describe your problem. We'll
get back to you to help you determine a solution. Tech Help |
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WesBond Corporation 1135 East 7th Street Wilmington, DE 19801
phone (302) 655-7917 fax (302) 656-7885
e-mail the webmaster
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