Each punty scar was analyzed for different characteristics of the punty and vein. They include the transfer of the container to the punt and the subsequent separation of the finished container from the punt. The temperature at which the container was separated from the punty did not affect the height, diameter, or shape of the punty scar.
Also identified is a correlation between the size of the pointy and the scar height and height. An increase in the thickness of the bottom of the vessel correlated with a smaller diameter of the pointed scar, but was not related to the height of the scar. The greater the mass of the vessel correlated with an additional height to the pointed scar.
Introduction
The Glassblowing Process
The glassblower then removes the piece from the blowpipe by breaking it off at the auger line of the pipe. When the vessel is ready, it is broken off the punty and placed in an annealer to be slowly cooled to room temperature. Once all the steps below are completed, the barrel of the punty is broken off and placed in an annealer.
Although subject to personal preference in many ways, three main aspects of the pointed shape serve a purpose for the glassblower.
Overview of the “Break-off” Process
The tip on the tip allows the glassblower to precisely control how much punty he wants to grip his piece when attaching the punty. The viscosity of the tip as attached can also serve as a temperature gauge. Or, if the punty is attached too tightly to the container, the container will break before the punty breaks.
To break off a piece of punt, cool the junction between the punt and the piece (1), then hit (2) with the stick.
The Punty Scar
Each glassblower makes their own variety of pointy and, when asked, can point out different features they look for to ensure their piece doesn't fail. Obvious failure is when a piece breaks, either falls to the ground or cracks, when the punty is broken off. But often if a piece does not break in formation, the punty is considered successful.
This definition of success is too broad to draw conclusions from, so a more restrictive definition of success must be defined. The focus of this work is to identify the characteristics of an ideal dome: one that holds the piece until it breaks off and leaves minimal scarring.
What the Glassblowing Community Has to Say
- Attachment Temperature
- Jackline Area
- Vessel Bottom Thickness
- Mass of Vessel
- Comparative Punty Size
- Break-off Temperature
Many beginners ruin their pieces by spending too much time dipping and cooling the jackline while the punty gets cold. Once that happens, you're doomed.”1 The piece (and pointy) could otherwise be cooled by the extended delay, and the introduction of the gloryholeE heat could cause it to thermally shock and break. It is also difficult to introduce heat specifically to the punty, "The main source of heat for the punty is the gloryhole.
Advanced Glass lists jacklines as one of the physical features of the boat that has a great influence on how the boat transfers and is released from the runway.4 The jackline is the clamp located on the bubble near the blowpipe where the boat detaches from the blowpipe (after it is attached to the jacket.) Jackline cools and narrows the glass where it is placed, so that, by adding a drop of water (or applying a cold medium) to the jacket and a hard tap on the blowpipe, a crack will start that runs through jacket line. The important thing to remember is that the boat is broken on the jacket line after the punt is set, if the jacket line does not break easily, the jackline may break instead. More than anything else, temperature affects how your part separates from the pipe.
Advanced Glass claims that the geometry of the piece of glass itself may have the most influence on its successful transfer to and subsequent release from the punty.4 One of the characteristics mentioned is the thickness of the bottom of the vessel. Art of Fire claims that the size of a punty can be adjusted to the needs of the ship: a punty with a smaller mass will both heat up and cool down more quickly, which is ideal if the piece has a bottom that can't absorb much heat without burning. distort.1 . Advanced Glass indicates that the weight of the vessel is one of the physical characteristics of the vessel that affects the transfer and subsequent release of the punty.4 The mass of the vessel translates into the stress placed on the punty exerted; the entire weight of the piece is held by the small connection to the punty.
According to Beginning Glass, the size of the barrel determines the size of the punty to be used.2 The use of a blow mold was intended to remove the size and shape of the barrel as a variable; so minimize variations in the size and shape of the points. If the only challenge was keeping the punty firmly attached to the piece, you would simply make a giant punty and keep it warm all the time.
Literature Review: What the Science Says
In glassblowing, puntying is performed above the minimum temperature at which the glass can deform and flow, as puntying requires a semi-permanent interface to be formed between the punty and the container. In this case, the fracture may occur further along the tip (resulting in a protrusion at the base of the vessel) or in the bulk of the vessel (resulting in splintering of the vessel) depending on the stress present. . Viscous flow behavior therefore suggests that puntying occurs at just the right temperature above the glass transition region to allow viscous flow of the punty and limited cohesion.
The application of the cold tool or the water causes rapid cooling in thermal shock, which concentrates stress at the point of application. The process of attaching the frit cooled the glass where it touched the marver, so the frit indicators were added to the sides of the bubble and not the bottom where the punty could be affected. To break the vessel off the tip, apply a cold to the junction between the tip and vessel (1).
According to Beginning Glass, the size of the vessel determines the size of the punty to be used.2 The use of a blow mold was therefore theorized to minimize variations in the size and shape of the punty. Both the temperature of the mold and the length of time the glass was in the mold were not controlled. JacksH were used to secure the neck of the vessel in a jackline to ensure that it would break at that point.
A video recording was made of the temperatures of both the punty and the vessel when secured. Once "pointed" the barrel was reheated to equalize the temperature before being broken off the punty and placed in an annealer.
Punty Shape
Visual Idendification of Glass Temperature
Fracture Features
- General Ranking System
- Average Diameter Ranking System
- Greatest Height Ranking System
They have less material to buff and therefore aren't as bad as the level 4 punty. Rating 4, the worst punts broke off on the patterns and created a bump that would need to be sanded down to allow the vessel to lay flat. More experienced glassblowers tend to throw out vessels that are punty broken this way because it will take them less time to make a new vessel from scratch than it would be to polish it.
The largest and smallest dimension of each pointy scar was measured with calipers, the average of which provided an average pointy scar diameter. A large pointy scar implies that the pointy-to-vessel connection was stronger and more stable, although it is more so than. An ideal pointy will hold the vessel firmly but release easily and leave a smaller diameter scar, causing less damage to the vessel.
Amateur punty broke in countless ways, too varied to draw any specific trends from them. The height of each punty scar was measured using depth gauges, finding the sum of the height of the punty scar that penetrated and protruded from the vessel.
Analysis
- Attachment Temperature (ΔT)
- Jackline Area
- Vessel Bottom Thickness
- Mass of Vessel
The jackline is where the vessel breaks off the pipe while remaining attached to the punty. As the jackline area increased, the height of the scar of the scar decreased, as suggested in Figure 19. There were no apparent trends in the shape of the scar relative to the jackline of the specimen.
There was no clear relationship between the thickness of the base and the height of the pointed scar. The thickness of the bottom of the barrel can have an effect on the thermal experiences of the punty. There is no clear relationship between the size of the base of the vessel and the pointed scar.
The mass of the vessel also provides a shear stress when the vessel breaks away from the tip itself. There are no obvious trends in the diameter of the point scar and vessel mass, as shown in Figure 24. There are no discernible trends in the contour of the point scar in the vessel mass, as shown in Figure 26.
A positive trend in mean scar diameter relative to comparative spot size is shown. punty scar height increased with increasing punty size.
However, to ensure the safety of the connection to the vessel, the jackline is thermally shocked.
