42results about How to "Longitudinal shrinkage is low" patented technology

The invention relates to a heat-shrinkable tube, in particular to a flame-retarding single-wall heat-shrinkable tube and a preparation method thereof. The flame-retarding single-wall heat-shrinkable tube consists of a wall material; the wall material consists of the following components in part by mass: 50 parts of polyolefin mixed resin, 20 parts of auxiliary agent and 30 parts of flame retardant; and the preparation method comprises the steps of preparation, extrusion, radiation and expansion molding of an inner wall material of the flame-retarding single-wall heat-shrinkable tube.. Compared with the conventional shrinkable tubes, the flame-retarding single-wall heat-shrinkable tube has the technical characteristics that: the wall material is flame-retarding; the external layer has goodelectrical performance, chemical performance and the like of a common heat-shrinkable tube; and the flame-retarding single-wall heat-shrinkable tube has all using properties of the common heat-shrinkable tube and has waterproof, sealing, moisture-preventing and anti-corrosion performance and other performance.

The invention relates to a thermal shrinkage pipe, in particular to a medium and low pressure flame retardant single wall thermal shrinkage pipe and a preparation method thereof. The medium and low pressure flame retardant single wall thermal shrinkage pipe is made from a wall material which comprises 70 parts of polyolefin mixed resin, 10 parts of auxiliary agent and 30 parts of flame retardant by weight. The preparation method comprises the following steps: preparing the inner wall material of the flame retardant single wall thermal shrinkage pipe, extruding, irradiating and expanding for molding. Compared with the traditional shrinkage pipe, the invention has the technical characteristics that the wall material has flame resistance and can be applied under 10kV high voltage, and the medium and low pressure flame retardant single wall thermal shrinkage pipe not only has all operational properties of the common thermal shrinkage pipe, but also has the properties of water prevention, sealing, moisture prevention, corrosion prevention and the like; and the shrinkage pipe fully meets the environmental requirements of the ROHS instructions of European Union and other countries, and has the advantages of low temperature shrinkage, 3-4 times stable expansion, low longitudinal shrinkage rate, and the like.

The process of producing thick polyester film with low thermal shrinkage rate includes the following steps: 1. melting material, extruding thick sheet and cooling; 2. stripping thick sheet, heating, longitudinally stretching in the line speed of 0.2-1.1 m / s and stretching power of 2.0-3.5 to 1, longitudinally relaxing and fixing; 3. preheating, transversely stretching at 110-160 deg.c and in stretching power of 3.0-5.0 to 1, longitudinally and transversely relaxing, and fixing; 4. cooling in the line speed lower than line speed in transverse stretching, heating, longitudinally post-relaxing, cooling and fixing; 5. high voltage corona treatment; and 6. winding the film in the line speed lower than the longitudinally relaxing line speed and in the tension controlled in 100-250 N. The process can reduce the longitudinal thermal shrinkage rate to near to or equal to the transverse thermal shrinkage rate.

The invention provides a method and device for inflating and continuously expanding a heat-shrinkable tube. A heat-shrinkable tube guide roller is arranged on the expansion machine platform, and a traction mechanism, a water bath box, an oil bath box, an expansion mold box, and a cooling and setting room are sequentially arranged between them. , the control mechanism is connected with the water bath box, the oil bath box and the control end of the traction mechanism through the corresponding lines. The expansion mold box is equipped with a heat shrinkable tube expansion mold, and the two ends are connected with the oil bath box and the cooling and shaping through the sizing outlet connector. chamber sealed connection. Using the principle of high-pressure gas-assisted forming, adopting the positive pressure inflation expansion method, the heat-shrinkable tube is heated and softened, and the high-pressure gas is introduced into the expansion mold to be inflated and formed by high-pressure gas, and then cooled and shaped, through heating, expansion and cooling. , traction, and complete the expansion production process of the heat shrinkable tube. The invention reduces the friction between the pipe material and the expanded sizing, and the longitudinal shrinkage rate of the product is less than 10%. The production efficiency is improved, and the expansion speed can reach more than 2-10 m / min.

The invention relates to a heat-shrinkable tube, in particular to a semi-conducting low-medium voltage fire retardant single-wall heat-shrinkable tube and a preparation method thereof. The semi-conducting low-medium voltage fire retardant single-wall heat-shrinkable tube comprises wall materials which contain the following raw materials in parts by mass: 70 parts of polyolefin mixed resin, 10 parts of conductive black, 10 parts of assistants and 30 parts of fire retardant. The preparation method of the heat-shrinkable tube comprises the following steps of preparation of internal wall materials, extrusion, irradiation, and expansion-moulding. Compared with a traditional heat-shrinkable tube, the invention has the technical characteristics that the wall materials are fire retardant, and theheat-shrinkable tube is applied to a 10 kV high voltage, has all the service performances of the traditional heat-shrinkable tube and also has watertightness, leakproofness, corrosion-resistance and dampproof performance; in addition, the heat-shrinkable tube completely meets the environmental protection requirement of ROHS of countries of European Union and has the advantages of low-temperature shrinkage, three-time to four-time stable expansion, low longitudinal shrinking rate and the like.

The invention relates to a heat-shrinkage tube, in particular to a low-voltage halogen-free retarding two-wall heat-shrinkage tube and a preparation method thereof. The low-voltage halogen-free retarding two-wall heat-shrinkage tube comprises an outer wall material and an inner wall material, wherein the outer wall material comprises 60 parts by mass of first polyolefin mixed resin, 10 parts by mass of first assistant, 20 parts by mass of fire retardant and 10 parts by mass of auxiliary fire retardant; and the inner wall material comprises 60 parts by mass of second polyolefin mixed resin, 10parts by mass of second assistant, 20 parts by mass of fire retardant and 10 parts by mass of auxiliary fire retardant. The preparation method comprises the following steps of preparing, extruding, radiating and expanding to form the inner wall material and the outer wall material of the two-wall heat-shrinkage tube. Compared with the traditional heat-shrinkage tube, the invention has the technical characteristics that because the fire retardant and the auxiliary fire retardant are adopted in the raw materials, the low-voltage halogen-free retarding two-wall heat-shrinkage tube has good retarding property, high temperature resistance, better property, no pollution in combustion, cost reduction and remarkable economic and environmental-friendly benefits, and is suitable for massive popularization and application.