PE foaming one-time forming large-scale rotational molding packaging box and its manufacturing process

Abstract

The invention discloses a PE foaming once-molded large rotational molding packaging box. The PE foaming once-molded large rotational molding packaging box comprises a rotational molding packaging box body, a rotational molding packaging box cover, a bottom bracket, sealing rubber strips and hasp locks; shells of the rotational molding packaging box body and the rotational molding packaging box cover are polyethylene shells, the position between the inner layer and the outer layer of the shell of the rotational molding packaging box body is filled with a polyethylene foaming layer, and the position between the inner layer and the outer layer of the shell of the rotational molding packaging box cover is also filled with a polyethylene foaming layer; and the mesh number of granules of polyethylene foaming raw materials of the polyethylene foaming layers ranges from 20 to 40. By means of the PE foaming once-molded large rotational molding packaging box, the intensity, the toughness, the anti-shock resistance and the heat preservation airtight function of the rotational molding packaging box can be guaranteed to the maximum degree, and therefore the production efficiency and the product yield are improved.

Description

technical field [0001] The invention relates to the technical field of rotomolding, in particular to a large-scale rotomoulding packing box formed by PE foaming at one time and its manufacturing process. Background technique [0002] At present, in order to increase the strength, toughness and impact resistance of rotomolding packaging boxes, and at the same time have the function of airtight heat preservation, there are generally two manufacturing processes: one-time perfusion of PU foaming method and artificial secondary addition of PE (polyethylene) foaming One-shot molding method. The secondary perfusion PU foaming method is to first use the rotational molding process to produce a double-layer hollow rotationally molded packaging box shell, and then fill the double-layer hollow position of the rotationally molded packaging box with PU foaming equipment and special shaping fixtures. The method of foaming material, although this process method can also achieve the above-m...

AI Technical Summary

Problems solved by technology

The secondary perfusion PU foaming method is to first use the rotational molding process to produce a double-layer hollow rotationally molded packaging box shell, and then fill the double-layer hollow position of the rotationally molded packaging box with PU foaming equipment and special shaping fixtures. The method of foaming material, although this process method can also achieve the above-mentioned required properties and functions, but it has the disadvantages of cumbersome operation, large investment, and high requirements for the rotational molding process level, resulting in a high product scrap rate, because the rolling The molded double-layer hollow rotomolding box shell is put into the shaping fixture, so the requirements for the dimension matching of the formed rotomoulding box shell are very high, and this is precisely the place that is difficult to achieve in the rotomolding process. The manufacturing Another disadvantage of the process is that it is easy to produce delamination phenomenon in high and low temperature (-40 ~ 70 degrees Celsius) environment, that is, the phenomenon of separation between the perfused PU foam material and the shell of the rotationally molded packaging box due to different materials, thus affecting The strength, toughness, impact resistance and airtight heat preservation function of the rotomolded packaging box further increase the product scrap rate

Another manufacturing process is the operation method of artificially adding PE foam material twice and one-time molding method is to use the rotational molding process to produce the double-layer hollow rotationally molded packaging box shell, that is, when the rotationally molded packaging box shell is in a molten state (Mold temperature is about 220 degrees Celsius) Cool without blowing, then stop the machine, directly use the funnel to manually add PE foaming material (60-80 mesh fine particle powder or unground 5MM particle raw material through the feeding port reserved on the mold) ) and return to the furnace to bake and form at one time. The disadvantages of this manufacturing process are low work efficiency and high operational safety hazards. Because the mold temperature is high, it is easy to burn workers and cause accidents. At the same time, because this manufacturing process needs to be carried out under shutdown operation, and the shell of the rotomolded packaging box is in a molten state during the operation process, it is easy for the shell of the rotomolded packaging box to generate piles (flow) during the operation process, which in turn causes the finished product of the rotomolded packaging box to be produced. The phenomenon of uneven thickness and warping will eventually affect the strength, toughness, impact resistance and airtight insulation function of the rotomolded packaging box, resulting in product scrapping, especially when this manufacturing process is used to manufacture large rotomolded packaging boxes.

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