Maturation control: maturation is also called curing, is the process of putting the film that has been compounded into the oven (ripening room), so that the main agent of the polyurethane adhesive, curing agent reaction crosslinking and be compounded with the substrate surface interaction. The main purpose of curing is to make the main agent and curing agent in a certain period of time to fully react to achieve the best composite strength; secondly, to remove the low boiling point of the solvent residue, such as ethyl acetate, etc..
Maturation control is mainly the control of maturation temperature and maturation time. The maturation time of maturation temperature is determined by the performance of the used adhesive and the final performance requirements of the product. Different binder varieties have different ripening temperatures and times. Maturation temperature is too low, below 50 ℃, the reaction of the adhesive is extremely slow; maturation temperature is too high, the substrate film additives precipitation, affect the composite film performance and increase the odor, such as maturation time is too long will also affect the composite film performance and increase the odor, which is mainly caused by the precipitation of processing aids in polyethylene film.
The function of ripening room: It is to put the film that has been compounded into the baking room (ripening room), so that the main agent of polyurethane adhesive, curing agent reaction cross-linking and be compounded by the process of substrate surface interaction. The main purpose of maturation is to make the main agent and curing agent fully react within a certain period of time to achieve the best composite strength; secondly, to remove the residual solvents with low boiling point, such as ethyl acetate, etc., to reduce the amount of solvent residue and reduce odor.
Maturation conditions also depend on the following factors.
1, PET, BOPA, AL, CPP and other films due to good heat resistance, high shrinkage temperature, maturation temperature can be increased. And LDPE, BOPP, EVA and other maturation temperature can not be too high; general situation 50 ℃ - 65 ℃ between.
2, The maturing time of products with high glue amount is longer.
3, The maturing time of products in the form of film rolls can be reduced appropriately.
4, The maturing time of products with longitudinal convex tendons can be lengthened.
5, the film thickness, film roll diameter when appropriate to extend the maturation time.
6, in order to reduce the amount of residual solvent can be appropriately extended maturation time.
7, according to the use of the product appropriate adjustment of maturation time.
There is also an accelerated ripening for control in production. Take the composite film just produced about 1 meter long, full width, placed in the oven at 80 degrees for 30 minutes, in checking its appearance and initial viscosity peeling situation, timely detection of problems and measures. This is also an indispensable part of the dry lamination process management.
There are the following requirements for the maturation room.
1, the size and location of the maturation room should be built according to the convenience of turnover storage, to facilitate the entry and exit of the film roll, the door should be opened easily.
2, the height of the maturing room is generally in 2-2.5 meters, the top into a tower, leaving 5-10 cm up the air holes, can be directly outside, or add a small exhaust window regularly exhaust, the role is to discharge the smell of maturing room.
3, the shelves of the maturing room can be placed flat or three-dimensional shelf type, depending on the transport conditions of each enterprise, but not the film roll directly upright or lying on the ground.
4, the four walls of the maturing room, doors, roof and other insulation, generally using perlite, foam board, etc., the effect is to increase the time of insulation, save electricity, reduce costs and the temperature around the same.
5, Heating control. Maturing room can be heated by electricity, steam, heating, etc., regardless of what kind of heating, should be equipped with temperature self-control devices, in the room should be mercury thermometer to test whether the temperature and set the same.
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Post time: Jul-04-2023