The adhesive is not made by melting rubber. A special material is added to the melted rubber so that it is adhesive. This material is called tackifier. Rubber is a high molecular substance of which the molecular weight is normally several tens of thousands up to several million, whereas the tackifiers are made of materials in which the molecular weight is mostly several hundreds up to 3 or 4 thousand. Most tackifiers are made of compound materials. They are, sometimes, made of pine resin.
This is usually called a curing agent or cross linking agent. It is used mainly to minimize the symptoms that the adhesive sticks to the work-piece by making the linear particles link with each other in a cross-linking formation.
This is an organic solvent that melts the rubber. The rubber is not melted by the solvent but it turns soft in the solvent, so that it looks melted. We usually use Toluene. We, however, use ethyl acetate (EA) to make the acrylic adhesive.
Anticorrosive and AntioxidantCore
When the adhesive is exposed to sunlight, heat or oxygen, it chemically reacts and is oxidized.
When it is oxidized, its rubber molecule chains are cut from each other and it hardens or becomes sticky.
This is used to finally roll the tape. It is like a spool.
Usually, its size is 3 inches (76~77mm) at diameter. Sometimes, 5 inches or 6 inches are also used.
It is usually made of paper. It can also be made of plastic to minimize alien matter.