PVC cake: The first step starts with the preparation of a PVC cake, heated to 140°C and weighing 175 gr. It's this cake that will be transformed into a vinyl disc.
Press loading: The PVC cake is placed at the center of the two halves of the mold, each equipped with a matrix (one for side A and the other for side B of the disc). The disc labels are placed in the mold on top and bottom of the PVC cake.
Pressing: The two halves of the mold are then pressed together under high pressure of 100 tons and a high temperature of 170°C. This melts the PVC which spreads to fill the mold, taking the shape of the grooves present on the matrix. During the pressing process, the labels are pressed into the vinyl. This means that the labels are an integral part of the disc itself, they are not simply glued afterwards.
Cooling: After pressing, the molds remain closed and the disc is surface cooled to 25°C. This is a crucial step to ensure the correct shape and stability of the disc.
Finishing: Once the disc is cooled, the molds open and the vinyl is recovered to cut the excess PVC around the edges of the disc, in order to give it its final shape. The vinyl disc is then inserted into a sub-pocket and regular inspections are carried out to ensure there are no defects.
Simple representation of a setup for operating a vinyl press
The production of vinyl discs is a precise and meticulous process. The tiniest details that are contained in the grooves which carry the sound information are much smaller than the width of the groove itself. To give you an idea, this is equivalent to the thickness of a human hair. Even though these details are invisible to the naked eye, they are nevertheless read very precisely by high quality playback needles.
The quality of the vinyl is also of paramount importance. Nowadays, it is imperative that vinyl discs have low background noise so that audiophiles can fully appreciate their favorite music. For this, it is crucial that the PVC used is of high quality.
The raw material of vinyls, commonly known as PVC or Compound in our professional environment, has evolved a lot since the birth of the microgroove. The challenges of this raw material lie mainly in its future scarcity, its ecological impact and its cost.
The "compound" in plastic material, also called "compound" in English, is a specific formulation of different types of raw materials. These are mixed together to create a new material with specific characteristics, a process often used in the plastic molding industry.
In the case of vinyls, the compound is based on PVC (polymerized salt), vinyl acetate, plasticizers, stabilizers, dyes, a release agent and an additive. These elements serve to not damage the playback needle of the turntable during playback.
It is interesting to note that the stabilizer has greatly evolved over time, moving from lead and tin to the current use of calcium zinc.
Because of their composition, the properties of vinyl discs come from chemistry and petroleum. Aware of the current ecological issues, we have implemented initiatives to mitigate this impact.
We found a recycling channel in 2018: production waste, unsuitable for manufacturing, is transformed into PVC pipes in the construction sector. However, vinyl recycling requires special attention: the raw material must be of the same formulation and free of any impurity.
If environmental impact is integral to your philosophy, you can make wise choices when buying vinyls. Prefer a light and black disc, as colored discs contain more plasticizers and are difficult to mix with each other.
In 2016, we manufactured the world's first algae disc with a Breton company. Despite the challenges encountered, this initiative underlines our commitment to continue to innovate and research more environmentally friendly alternatives.
The entire sector has a long way to go. We are doing our part by limiting our energy impact and constantly seeking to innovate. The more discs are passed down from generation to generation, the more the carbon impact of vinyl discs will be reduced. The effort must be - and is already starting to be - collective.