RED Matthews
Well-Known Member
This was a review of information for one of the ABM-FORUM people, that I thought might interest others. I have never got into Medical bottles a lot, but I have been exposed to a lot of the bottlemakers problems trying to make the rectangular type of med bottles - and my experiences were in the era of ABM's.
One problem that has plagued the world of making bottles is gravity, It is a force that requires concentrated counting experience on the part of the bottle maker. The most important knowledge of a bottlemaker, is knowing how to shape [the mold ready shape] of his formed [parison]. The parison shape is what determines the thickness of the glass when it is blown into the final mold for the bottle. In the case of making the rectangular meds, it is more important than it is for a plain round or square bottle form. There has to be enough glass in the wide sides of the parison glass, so it will blow out into the wider form of a med bottle. If it isn't right, the shoulders will be thin and even subject to a tapped breakage if there isn't enough glass there.
Now the next thing they have to consider and count are the seconds the parison is hanging in the closed final mold; before the make the final blow. Realize that the glass at this point is still in a very liquefied-viscous condition; so gravity is pulling it down after it gets in the mold. Maybe 5 or 6 seconds!! And this will vary from one type of bottle to another.
The important factor is having enough glass in the parison to fill out the shoulders of a bottle and enough glass to fill in the bottom corners of a rectangular med bottle. Both of these areas need to have enough glass to make a good bottle.
One must realize that the bottom of a bottle is usually the weakest part of a bottle, anyway. In your bottle the glass fill-out in the bottom corners is acceptable; but if the glass on those four corners was thin - just a light tap would cause a handling breakage. Likewise a thin shoulder corner can also be broken easily.
Another difficulty in rectangular bottles with sunken panels on all four sides is a tough bottle to blow in a mold when there are embossed letters in those sunken panels. "3-in One oil" and a lot of meds have trouble getting the air out of the space between the sunken panels and the mold cavity wall. This problem has to be helped with drilled vent holes to the back outside of the mold. The problem in early med was exacerbated by the fact that number 70 twist steel drills were not readily available - if at all.
This is a good time to point out that a Mr. Kelly of Eighty Four Pensulvania; developed a two headed horizontal drilling machine that drilled two holes facing each other. With depth control, one drill head could make a 1/8th inch hole within about 3/l6th of an inch of the cavity wall and then the mating spindle could drill a small hole into the center of the back up hole. These machines were an automatic need in almost every mold shop.
Information for bottle people that are curious. I will appreciate your comments and/or questions. RED Matthews
One problem that has plagued the world of making bottles is gravity, It is a force that requires concentrated counting experience on the part of the bottle maker. The most important knowledge of a bottlemaker, is knowing how to shape [the mold ready shape] of his formed [parison]. The parison shape is what determines the thickness of the glass when it is blown into the final mold for the bottle. In the case of making the rectangular meds, it is more important than it is for a plain round or square bottle form. There has to be enough glass in the wide sides of the parison glass, so it will blow out into the wider form of a med bottle. If it isn't right, the shoulders will be thin and even subject to a tapped breakage if there isn't enough glass there.
Now the next thing they have to consider and count are the seconds the parison is hanging in the closed final mold; before the make the final blow. Realize that the glass at this point is still in a very liquefied-viscous condition; so gravity is pulling it down after it gets in the mold. Maybe 5 or 6 seconds!! And this will vary from one type of bottle to another.
The important factor is having enough glass in the parison to fill out the shoulders of a bottle and enough glass to fill in the bottom corners of a rectangular med bottle. Both of these areas need to have enough glass to make a good bottle.
One must realize that the bottom of a bottle is usually the weakest part of a bottle, anyway. In your bottle the glass fill-out in the bottom corners is acceptable; but if the glass on those four corners was thin - just a light tap would cause a handling breakage. Likewise a thin shoulder corner can also be broken easily.
Another difficulty in rectangular bottles with sunken panels on all four sides is a tough bottle to blow in a mold when there are embossed letters in those sunken panels. "3-in One oil" and a lot of meds have trouble getting the air out of the space between the sunken panels and the mold cavity wall. This problem has to be helped with drilled vent holes to the back outside of the mold. The problem in early med was exacerbated by the fact that number 70 twist steel drills were not readily available - if at all.
This is a good time to point out that a Mr. Kelly of Eighty Four Pensulvania; developed a two headed horizontal drilling machine that drilled two holes facing each other. With depth control, one drill head could make a 1/8th inch hole within about 3/l6th of an inch of the cavity wall and then the mating spindle could drill a small hole into the center of the back up hole. These machines were an automatic need in almost every mold shop.
Information for bottle people that are curious. I will appreciate your comments and/or questions. RED Matthews
