Spandex prepolymerization mixing device for easily-shaped polyurethane

Abstract

The utility model discloses a spandex prepolymerization mixing device for easy-to-shape polyurethane. The spandex prepolymerization mixing device comprises a PTMG (polytetramethylene glycol) inlet pipeline, an MDI (methylene diphenyl diisocyanate) inlet pipeline, a mixer and an outlet pipeline, a mixing gear is arranged in the mixer, and the gear is made of a PTFE (Polytetrafluoroethylene) material; the mixer is respectively connected with the PTMG inlet pipeline, the MDI inlet pipeline and the outlet pipeline in three different directions; a mixer upper cover and a mixer lower cover are arranged outside the mixer; and the mixer upper cover and the mixer lower cover are fastened through fastening bolts respectively arranged at four corners of the mixer upper cover and the mixer lower cover. The technical scheme of the utility model is adopted. The pre-mixing effect of PTMG and MDI can be effectively improved, the mixing reaction efficiency of the static pipeline reactor is enhanced, the generation of gel caused by poor pre-mixing effect is reduced, and the pre-polymerization process is optimized.

Description

Technical Field

[0001] This utility model belongs to the field of chemical fiber equipment, specifically referring to a device for prepolymerizing and mixing spandex in easily shaped polyurethane. Background Technology

[0002] In spandex production, the prepolymerization process involves thoroughly mixing MDI (diphenylmethane diisocyanate) and PTMG (polybutanediol), then heating the mixture in water at 90 degrees Celsius to produce large molecular segments with urethane groups. These segments are then reacted with amine chain extenders in the final polymerization stage to produce a dopant solution that meets process requirements. Currently, the commonly used MDI and PTMG mixing method in the prepolymerization stage suffers from low mixing efficiency, negatively impacting the prepolymerization reaction effect. For example, Chinese utility model patent (publication number CN207838777U) discloses a homogenizing and stirring device for spandex prepolymer, which includes a drive device, a stirring frame, a stirring main shaft, an upper ring connecting plate, a stirring sub-shaft, detachable stirring blades, and a lower ring connecting plate. The drive device is located at the top of the stirring frame, and the stirring main shaft is located inside the stirring frame. The lower end of the stirring main shaft is connected to the upper ring connecting plate, the upper end of the stirring sub-shaft is securely connected to the upper ring connecting plate, and the lower end of the stirring sub-shaft is securely connected to the lower ring connecting plate. Several detachable stirring blades are provided on the stirring sub-shaft, and these detachable stirring blades are inclined blades. This utility model ensures uniform viscosity and temperature of the prepolymer in the first reaction, reducing viscosity output fluctuations from thousands to hundreds, and almost eliminating fluctuations in the subsequent second reaction, greatly improving the yield of the final product. Summary of the Invention

[0003] The technical problem to be solved by this utility model is to provide a prepolymer mixing device for easily shaped polyurethane with high mixing efficiency.

[0004] This utility model is implemented as follows:

[0005] A prepolymer mixing device for easily shaped polyurethane spandex includes: a PTMG inlet pipe, an MDI inlet pipe, a mixer, and an outlet pipe;

[0006] The mixer is equipped with mixing gears inside, and the gears are made of PTFE (polytetrafluoroethylene).

[0007] The mixer is connected to the PTMG inlet pipe, the MDI inlet pipe, and the outlet pipe in three different directions, respectively.

[0008] The mixer is provided with an upper cover and a lower cover.

[0009] The upper cover and the lower cover of the mixer are fastened together by fastening bolts at the four corners.

[0010] Furthermore, a viewing mirror is provided near the side of the mixer cover.

[0011] The advantages of this invention are: by using this mixing device, the premixing effect of PTMG and MDI can be effectively improved, the mixing reaction efficiency of static pipeline reactor can be enhanced, the formation of gel due to poor premixing effect can be reduced, and the prepolymerization process can be optimized. Attached Figure Description

[0012] The present invention will now be further described with reference to the accompanying drawings and embodiments.

[0013] Figure 1 This is a top view of the present invention (with the top cover removed).

[0014] Figure 2 This is a top view of the entire utility model.

[0015] Reference numerals: 1. PTMG inlet pipe; 2. MDI inlet pipe; 3. Mixer; 4. Outlet pipe; 5. Mixing gear; 6. Mixer top cover; 7. Mixer bottom cover; 8. Fastening bolt; 9. Sight glass. Detailed Implementation

[0016] The details of this utility model can be more clearly understood by referring to the accompanying drawings and the description of specific embodiments. However, the specific embodiments of this utility model described herein are for illustrative purposes only and should not be construed as limiting the utility model in any way. Under the teachings of this utility model, those skilled in the art can conceive of any possible modifications based on this utility model, and these should all be considered to fall within the scope of this utility model.

[0017] refer to Figures 1 to 2 This utility model discloses a prepolymer mixing device for easily shaped polyurethane spandex, comprising: a PTMG inlet pipe 1, an MDI inlet pipe 2, a mixer 3, an outlet pipe 4, and a PTFE mixing gear 5 inside the mixer 3. The mixer 3 is connected to the PTMG inlet pipe 1, the MDI inlet pipe 2, and the PP outlet pipe 4 in three different directions. The mixer 3 is provided with a mixer upper cover 6 and a mixer lower cover 7. The mixer upper cover 6 and the mixer lower cover 7 are fastened by fastening bolts 8 at the four corners to prevent the prepolymer from leaking from the joint surface. A sight glass 9 is provided near the right side of the mixer upper cover 6, through which the mixing effect of PTMG and MDI can be observed.

[0018] The main workflow of this utility model is as follows:

[0019] The two main spandex raw materials, PTMG and MDI, enter the mixer 3 through PTMG inlet pipe 1 and MDI inlet pipe 2, respectively. The raw material flow rate in the mixer 3 is high enough to drive the mixing gear 5, causing it to rotate counterclockwise. The rotation speed varies with the raw material flow rate. When the flow rate increases, the speed of the mixing gear 5 increases accordingly, thus enhancing the mixing effect. The prepolymer mixture after mixing is sent out to the premixing section through outlet pipe 4. The mixing effect of PTMG and MDI can be observed through sight glass 9.

[0020] The technical solution of this utility model can effectively improve the premixing effect of PTMG and MDI, enhance the mixing reaction efficiency of static pipeline reactor, reduce the formation of gel due to poor premixing effect, and optimize the prepolymerization process.

[0021] The above embodiments and figures are not intended to limit the product form and style of this utility model. Any appropriate changes or modifications made by those skilled in the art should be considered as not departing from the patent scope of this utility model.

Claims

1. A spandex pre-polymer mixing device for easy set polyurethane characterized by: The utility model relates to a kind of PTMG and MDI mixing device, including: PTMG inlet pipe, MDI inlet pipe, mixer, outlet pipe; The mixer is internally provided with a mixing gear, and the gear is made of PTFE; The mixer is connected with the PTMG inlet pipe, the MDI inlet pipe and the outlet pipe in three different directions respectively; The mixer is externally provided with a mixer upper cover and a mixer lower cover; The mixer upper cover and the mixer lower cover are fastened by four corner fastening bolts respectively.

2. A device for pre-polymerization of spandex of easy-set polyurethane according to claim 1, characterized in that: The mixer upper cover is provided with a sight glass near the side edge.

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