Preparation process of adhesive-free expanded block

A production process and a binder-free technology, applied in the field of medical material manufacturing, can solve the problems of the emulsifier being difficult to volatilize, impossible to remove the emulsifier cleanly, and the product is not pure, and achieve the effect of improving safety.

Active Publication Date: 2018-11-20
SHANGHAI KANGNING MEDICAL DEVICE
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

There are following disadvantages in the existing bulk block manufacturing process with binder: the product containing binder is not a pure expanded polytetrafluoroethylene product, and FEP emulsion is introduced to remove moisture and emulsifier by high temperature, but this It is impossible to remove all emulsifiers in one process, resulting in impure products
In terms of technology, if the coating adhesive is too thin, gaps will cause the product to crack, and there will be a certain percentage of defective products; if the coating adhesive is too thick, it will be difficult for the emulsifier to volatilize, resulting in yellowing of the product at high temperature. There will also be defective products

Method used

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  • Preparation process of adhesive-free expanded block
  • Preparation process of adhesive-free expanded block
  • Preparation process of adhesive-free expanded block

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0043] A kind of non-binding agent bulk block manufacturing process of the present invention, specifically carry out according to the following steps:

[0044] 1. Diaphragm production stage:

[0045] 1) Mixing of materials: at a temperature lower than 20°C, use polytetrafluoroethylene dispersion resin as raw material, mix it with extrusion aid at a weight ratio of 10:2, and keep it at 40°C for 30 hours , to ensure full penetration of the extrusion aid; D80 solvent oil is used as the extrusion aid, and other volatile solvent oils and organic solvents can also be used;

[0046] 2) Pre-pressing into billets: set the temperature of the pre-pressing machine to 25°C, press at 15 bar, hold for 5 minutes, and preform into a rod-shaped billet with a diameter of 149 mm;

[0047] 3) Push extrusion: set the nozzle temperature of the push machine to 40°C, set the pre-pressing speed to 110mm / min for pushing, and form a circular bar with a diameter of 24.8mm;

[0048] 4), calendering and w...

Embodiment 2

[0061] A kind of non-binding agent bulk block manufacturing process of the present invention, specifically carry out according to the following steps:

[0062] 2. Diaphragm production stage:

[0063] 1) Mixing of materials: at a temperature lower than 20°C, use polytetrafluoroethylene dispersion resin as raw material, mix evenly with extrusion aid at a weight ratio of 10:3, and keep it at 45°C for 25 hours , to ensure full penetration of the extrusion aid; D80 solvent oil is used as the extrusion aid, and other volatile solvent oils and organic solvents can also be used;

[0064] 2) Pre-pressing into a billet: set the temperature of the pre-pressing machine to 30°C, the pressure to 12 bar, and the holding time for 4 minutes to preform a rod-shaped billet with a diameter of 150 mm;

[0065] 3) Push extrusion: set the nozzle temperature of the push machine to 50°C, set the pre-pressing speed to 130mm / min to push, and form a circular bar with a diameter of 24.8-25.3mm;

[0066]...

Embodiment 3

[0079] A kind of non-binding agent bulk block manufacturing process of the present invention, specifically carry out according to the following steps:

[0080] 3. Diaphragm production stage:

[0081] 1) Mixing of materials: at a temperature lower than 20°C, use polytetrafluoroethylene dispersion resin as raw material, mix it with extrusion aid at a weight ratio of 10:5, and keep it at 50°C for 20 hours , to ensure full penetration of the extrusion aid; D80 solvent oil is used as the extrusion aid, and other volatile solvent oils and organic solvents can also be used;

[0082] 2) Pre-pressing into billets: set the temperature of the pre-pressing machine to 35°C, press at 10 bar, hold for 3 minutes, and preform into a rod-shaped billet with a diameter of 152 mm;

[0083] 3) Push extrusion: set the nozzle temperature of the push machine to 60°C, set the pre-pressing speed to 150mm / min to push, and form a circular bar with a diameter of 25.3mm;

[0084] 4), calendering and windi...

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Abstract

The invention discloses a preparation process of an adhesive-free expanded block. The method comprises the following steps of (1) cutting a membrane, (2) putting an expanded body into a mold, specially, the mold containing the expanded body comprises an expanded body membrane laminated body which is positioned at the most middle, two frame-type clamps which are connected to the expanded body membrane laminated body and are arranged symmetrically up and down, two pressing plates which are arranged symmetrically up and down, and two fastening blocks which are arranged on the left and the right of the upper pressing plate and the lower pressing plate and are arranged symmetrical up and down; the pressing plates are located in the frame-type clamps, and the two pressing plates are tightly attached to the upper surface and the lower surface of the expanded body membrane laminated body; and the upper frame-type clamp and the lower frame-type clamp are connected through bolts and the upper fastening block and the lower fastening block are connected through bolts, (3) heating and preheating, preheating pressing, (4) high-temperature curing and heat pressing, and (5), cooling and shrinking,and lower mold trimming. According to the method, an adhesive is not introduced in the heat pressing process, the bonding strength of the expanded block is completely dependent on three process parameters of temperature, pressure and time, and the three process parameters are easy to control, other substances are not introduced in the high-temperature curing and the heat pressing process, so thatthe safety of the product is improved.

Description

technical field [0001] The invention belongs to the technical field of medical material manufacturing, and relates to a manufacturing process of a non-adhesive bulk block. Background technique [0002] Expanded polytetrafluoroethylene (e-PTFE) is a new type of medical polymer material. Due to its unique microporous structure, general plastic molding processing methods are not suitable for processing this product. In the industry, high-temperature stretching and shaping methods are generally used to produce microporous structures, but the products obtained by such processing methods are generally membrane materials below 1mm, and the thickness requirements of the plastic implant products required are generally around 4-12mm. Based on the above characteristics, it is necessary to use a special process to laminate and bond several diaphragms into a sheet with a certain thickness. [0003] In the existing manufacturing process of expanded blocks, a number of expanded polytetraf...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B29C69/00B29C43/24B29C47/00B29C55/02B29C51/00
CPCB29C43/24B29C51/00B29C55/02B29C69/00
Inventor 陆锐进李锦蓓朱庆马陆军
Owner SHANGHAI KANGNING MEDICAL DEVICE
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