Heat-calendaring process

US patent 4790815 (1988) to Baxter, Heat sterilizable plastic container with non-stick internal surfaces, describes the need to prevent sticking when two layers of plasticised PVC are left in contact during sterilisation. A texture of crosshatched lines is given to one surface of the film in the calendaring process, as a result of the surface of one steel roll being textured. If polyethylene blown film is used, texturing is achieved by the use of embossing rollers, but the polymer is less likely to block than plasticised PVC. 

Lidding. Whatever the forming process, the end result, partway down the machine, is that of a pocket containing product that needs sealing. In both cases the lidding material is roll fed and sealed by heat and pressure to the filled formed pocket in the substrate. The printed sealing layer may need to be very accurately placed (e.g., calendar packs). 

Coran, 1978). During this test, fully mixed but unvulcanized rubber is contained in a heated cavity. Imbedded in the rubber is a rotating disc. Viscosity is continuously measured (by the torque required to keep the rotor rotating at a constant rate) as a function of time. The temperature is selected to be characteristic of rather severe processing (extrusion, calendaring, etc.). 

Mechanical finishing processes such as compacting, calendaring, raising, polishing, etc., are performed to alter fabrics appearance or function like fabric luster, smoothness, softness, residual shrinkage, etc., by using mechanical means alone or accompanied by application of heat, steam pressure, etc [96]. 

Calendar n. (1) To produce or process sheets of material by pressing between a series of revolving heated rolls. (2) The machine performing the process of calendering. 

In the case of nonwoven geotextiles made from continuous filaments, a heat process using calendering is most often used. The filament web spread on the feed apron is directed to a calendar where it will be compressed at a high temperature by two heated metal rollers. The heat and pressure cause the filaments to fuse together where they touch in this way, they form a cohesive filament stmcture. Depending on the product required, the calendar can be smooth or have a surface embossing pattern which... 

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