A Complete Guide to the Glass Pressing Process

There are several methods of making glass that result in different types of glass wares. Pressing is one of the methods used to produce glass. This mechanical method has greatly contributed to mainstreaming and making glass production more accessible.

What is the Glass Pressing Process?

This is a production method utilized in the glass-making industry that involves mechanically pressing the molten glass. This method is essential in creating complex designs with uniform thickness. The glass is melted to the desired temperature and then pressed into a mold of your choosing.

Glass Pressing Process
Glass Pressing Process

Benefits of Pressing Glass

There are numerous advantages of using the pressing glass procedure for creating your ideal glassware. These advantages include;

  • This method is essential when it comes to minimizing the production time as well as the labor required to carry out the procedure. This in turn will help reduce your cost of production while maximizing the efficiency of your production
  • The production method is especially ideal if you have a large-scale enterprise that requires mass production. This mechanical procedure has increased access to the production of glass expanding the glassware market
  • The resulting products from this method have even thicknesses complete with a flat surface. This allows you to manufacture products of various designs that can be used for different applications.
  • This process can also be utilized for the processing of laminated glass. Laminated glasses have the advantage of having enhanced protection that allows them to remain in one piece when shattered.

Step-by-step Process of Pressing Glass

The process of pressing glass involves the following steps;

Making Glass Parts Through Pressing Technique
Making Glass Parts Through Pressing Technique
  1. The first step in this process is preparing the raw materials. The raw materials may differ depending on the type of glass you are aiming to produce. Some of the commonly used materials include soda, sand, clarifying agents, limestone, and coloring agents.
  2. The next step is to put the materials into a furnace that has high temperatures until the materials melt. The melted materials should have a highly viscous consistency to allow you to properly manipulate it.
  3. After achieving the desired consistency, the molten glass is poured into a metal mold. The metal mold comes in different designs and can be customized to suit your preference. This is what determines the shape the glass is going to take
  4. This is followed by using a metal plunger to physically press the molten glass forcing it to take the shape of the metal mold. The interior of the glass will therefore be smooth while the exterior of the glass will take the shape of the mold.
  5. Once it has cooled down, the pieces are taken through quality control testing to ensure that the pieces are up to standard.
  6. The last step is finishing and this can be done using several methods including flaming. The aim is to smoothen out the glass products and in some cases introduce texture.

Surface Finishing on Pressed Glass

Surface finishing for this method of glass production is carried out using various methods. These methods include;

  • Sand-blasting; this method involves using fine and or hard grit with similar texture and forcing a jet of this material on the surface of the glass. The jetted material smoothens the surface resulting in a matte surface finish.
  • Fire finishing; this method involves subjecting the pieces to direct flames which glazes the material giving it a shiny finish.
  • Acid etching; in this method, acids are used to create a smooth finish for the glass. The type of acid commonly used for this method is hydrofluoric acid.
  • Mold; Molds can be used to finish glass wares that require a textured or patterned finish. This results in unique and aesthetic pieces.

Comparing Cut Glass vs Pressed Glass

Although both pressed and cut glass are designed using a mold, the types of molds used are distinctly different and result in glasses that are also different. The difference between these two types of glass include;

The mold used for pressed glass can be a combination of up to four different parts that directly imprint onto the molten glass giving it its shape. On the other hand, the mold used for cut glass does not imprint on the molten glass, the patterns are hand-curved after cooling down using a diamond wheel

Given that the patterns are hand-curved the cut glass details are much sharper and have more definition and are crisp to the touch. On the other hand, the pressed glass will have a rounder and overall smoother finish. Cut glass also tends to be more expensive than pressed glass.

Comparing Patterned Glass vs Pressed Glass

Pressed glass is designed using molds in which molten glass is poured and pressure is applied mechanically to imprint the shape of the mold into the resulting product once it is cooled. This often results in a smoother finish. On the other hand, patterned glass is designed using compression and the resulting product is a lot more textured.

Uses of Presses Glass

Glass Press Blowing Parts
Glass Press Blowing Parts

This method of production can be used to make various types of glass products. Its applications include;

  • Decorative glassware
  • Laminated glass
  • Jars
  • Tapered narrow-neck containers
  • Glass containers

FAQs

How do you know if Glass was Pressed?

Pressed glass can easily be set apart by its physical attributes. The characteristics include blunt facet edges, mold seams as well as regular faceting. The presence of chill markings which are a result of the hot glass interacting with the cold metal mold is another indicator.

Conclusion

There are different types of glass-making methods. However, if you are looking for a method of producing textured glass that is patterned, the pressed process is an ideal choice. This method is quick and simple and results in products that are aesthetically pleasing.

More resources:

Glass Manufacturing Process – Source: WIKIPEDIA

Glass Cutting Process – Source: WEPROFAB

Melting Point of Glass – Source: WEPROFAB

Pressed Glass – Source: BRITANNICA

Glass Annealing – Source: WEPROFAB

Glass Tempering Process – Source: WEPROFAB

Request An Instant Quote

We have a strong and efficient team which can offer you and instant and professional quote.

Our product manager will give you a quick demand portrait according to your design, drawing, standard, testing methods and other requirements. And we have a strong supporting team to fulfill your demand with our deep technology and know-how base. We can offer you a solution or a few options. And you will decide which one you prefer.

Upload File
Update cookies preferences
Scroll to Top