1. Machine Setup and Operation Too much cooling wind used blowing sides of glass together before final blow starts-incorrect cooling nozzles provided Parison too soft-blank contact time too short Insufficient counterblow used Insufficient cooling wind applied on blank Wind gate may be too high   1. Machine Setup and Operation Ensure parison is not blown by cooling air before invert takes place-use cooling nozzles with larger slots Increase blank contact time Increase counterblow Increase blank mold cooling wind - check cooling setup Check deflector Check for dirty blank   2. Mold Equipment Insufficient venting of blank (increase depth of hollow scraping or slotting)   2. Mold Equipment Increase hollow scraping and venting or blank and mold faces   3. Vertiflow Caused by air leakage into mold cavity   3. Vertiflow Check mold venting - recut and increase if necessary Check mold fits Adjust height of bottom plate mechanism Check seals under distributor plate Check cooling air - is not connected to vents or vacuum Check vacuum system - is adequately vented Check vacuum passages - are clear in mechanism Check vacuum holes/vent holes - are clear in bottom plate Check cooling on time - is not too early Vertiflow on before revert on