Heat before you heat...
21 November, 2009
In most things, preparation is everything. And so it never ceases to amaze me why many manufacturers risk a sensitive and costly production process without taking the time to start it off right. One area commonly neglected in the thermoforming of plastic products is the temperature and humidity of the sheet material feed before it is even loaded onto the line. Plastic is one of the least thermally conductive materials one could ever hope to work with. The materials typically take more time than you think to get to any decent operating or ambient temperature.
All thermoformers and users of infrared heaters, infrared ovens, quartz heaters, ceramic heaters, should therefore ensure, wherever possible, that their plastic materials are not just brought out from a cold store and deployed into production in a matter of minutes therefore reducing costs for thermoforming. It only takes a little planning and foresight to recognise this factor and to prepare the materials over a period of time on the factory floor in order to establish the materials at the room temperature of the production line. In typical thermoforming production, systems of preheating serve to even out temperature across the raw sheet feed before it enters the main heating system proper. Infrared preheating systems are preferred, owing to the greater degree of temperature control possible. The goal at preheating is the complete elimination of temperature variation later in the processing cycle. An effective heat ‘soak’ will also pre-empt flaws such as finished difficulties appearing in the form of pearlesence on the finished product or lack of gloss. At Ceramicx we are used to listening to processors and users pointing to the heating systems as a possible cause of part failure and deformation. But as a general rule, heating is very rarely a causal factor in these matters. Instead, the complexity of the part design; it’s dimensions, the depth of the thermoforming ‘draw’ and the characteristics of the material composition – these are the prime factors that must be calculated and overcome in order to thermoform quality plastics product. In fact, infrared heating techniques can be the best friend of the manufacturer who is trying to overcome the inherent difficulties of complex product parts. Make the most of the technology from the start of the process.
21 November, 2009
In most things, preparation is everything. And so it never ceases to amaze me why many manufacturers risk a sensitive and costly production process without taking the time to start it off right. One area commonly neglected in the thermoforming of plastic products is the temperature and humidity of the sheet material feed before it is even loaded onto the line. Plastic is one of the least thermally conductive materials one could ever hope to work with. The materials typically take more time than you think to get to any decent operating or ambient temperature.All thermoformers and users of infrared heaters, infrared ovens, quartz heaters, ceramic heaters, should therefore ensure, wherever possible, that their plastic materials are not just brought out from a cold store and deployed into production in a matter of minutes therefore reducing costs for thermoforming. It only takes a little planning and foresight to recognise this factor and to prepare the materials over a period of time on the factory floor in order to establish the materials at the room temperature of the production line. In typical thermoforming production, systems of preheating serve to even out temperature across the raw sheet feed before it enters the main heating system proper. Infrared preheating systems are preferred, owing to the greater degree of temperature control possible. The goal at preheating is the complete elimination of temperature variation later in the processing cycle. An effective heat ‘soak’ will also pre-empt flaws such as finished difficulties appearing in the form of pearlesence on the finished product or lack of gloss. At Ceramicx we are used to listening to processors and users pointing to the heating systems as a possible cause of part failure and deformation. But as a general rule, heating is very rarely a causal factor in these matters. Instead, the complexity of the part design; it’s dimensions, the depth of the thermoforming ‘draw’ and the characteristics of the material composition – these are the prime factors that must be calculated and overcome in order to thermoform quality plastics product. In fact, infrared heating techniques can be the best friend of the manufacturer who is trying to overcome the inherent difficulties of complex product parts. Make the most of the technology from the start of the process.
