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

The invention discloses a thermoshrinkable polyester film and a preparation method thereof. The preparation method comprises steps as follows: various polyester raw materials subjected to dust removal respectively enter storage bins, are respectively metered by an agravic weigher according to the proportion, simultaneously enter an inlet of a double screw extruder, are subjected to melt extrusion by a sandwich layer double screw extruder and two surface layer double screw extruders, and form a casting piece through a three-layer co-extrusion die head; the casting piece is respectively subjected to longitudinal stretching and lateral stretching, wherein the longitudinal stretching comprises a preheating zone, a stretching zone, a thermal setting zone and a cooling zone, and the thermal setting zone of the lateral stretching is more than 15m long; and the casting piece is subjected to traction rolling to obtain the thermoshrinkable polyester film. By adopting the proportioning mode of directly feeding after accurate metering by people, the instantaneous addition error range of various materials is at most 1%; and the material is biaxially stretched, so that the produced film has the advantages of greatly higher density, strength and uniformity, lower longitudinal shrinkage and lateral low-temperature shrinkage, and especially higher ductility and thermoshrinkable uniformity.

The invention discloses an overfeeding type thin film drawing process. In the thin film drawing process, the length of a thin film clamped by clamps is larger than the length of chain clamps of a drawing machine, redundant parts are formed between the length of the thin film and the length of the chain clamps in the film clamping, feeding and drawing process, and the redundant parts are accumulated in gaps between the clamps to form wrinkles. By the adoption of the overfeeding type thin film drawing process, the thin film is not accumulated in clamping sections of the clamps and only accumulated in the gaps between the front and back clamps, and when the transversely-drawn thin film shrinks longitudinally, the edges of the film do not shrink longitudinally at the clamping portions of the clamps, the portions, close to the inner side, of the thin film shrink longitudinally, and the longitudinal shrinkage ratio is reduced. The redundant parts, namely the wrinkles are reserved in clamping seams and cut off at the rear edge portion of a transversely-drawing outlet and are not components of products. By the adoption of the overfeeding type thin film drawing process, the stepless adjustment longitudinal shrinkage ratio can be acquired, so that the longitudinal shrinkage ratio of the transversely-drawn thin film is controlled within a controllable range.

The present invention relates to a heat shrinkable tube, particularly to a halogen-free double-wall heat shrinkable tube of flame-retardant properties and a preparing method thereof. The tube is prepared from an outer wall material and an inner wall material based on shares by weight. The outer wall material consists of 53 shares of first polyolefin mixed resin, 10 shares of first auxiliaries and 37 shares of flame retardant. The inner wall material consists of 53 shares of second polyolefin mixed resin, 10 shares of second auxiliaries and 37 shares of flame retardant. The preparing method comprises: preparing the inner and the outer wall materials of the double-wall heat shrinkable tube, extruding, irradiating, expanding and molding. Compared with traditional shrinkable tubes, the present invention has the technical characteristics of adoption of special halogen-free flame retardant in raw materials, good product flame-retardant effect, heat resistance, good properties, no pollution during combustion and low cost. The present invention has obvious economic benefit and environmental protection benefit, and is suitable for large-scale popularization and application.

The invention relates to a heat shrinkage tube, in particular to a high-voltage halogen-free flame-retardant heat-shrinkage tube and a preparation method thereof. The high-voltage halogen-free flame-retardant double-wall heat shrinkage tube comprises an outer-wall material and an inner-wall material; wherein the outer-wall material comprises the following ingredients in parts by weight: 80 parts of first polyolefin mixed resin, 10 parts of first auxiliary agent, 5 parts of flame retardant and 5 parts of auxiliary flame retardant; the inner-wall material comprises the following ingredients in parts by weight: 80 parts of second polyolefin mixed resin, 10 parts of second auxiliary agent, 5 parts of flame retardant and 5 parts of auxiliary flame retardant; and the preparation method comprises the following steps of: preparing the inner-wall material and the outer-wall material of the double-wall heat shrinkage tube, extruding, irradiating, expanding and molding. Compared with the traditional heat-shrinkage tube, the high-voltage halogen-free flame-retardant double-wall heat shrinkage tube has the technical characteristics that: as the flame retardant and the auxiliary flame retardant are adopted in the raw materials, the product has good flame retarding effect, high-temperature resistance, favorable performance, no pollution even in the combustion process, reduced cost, remarkable economic benefit and environment-friendly benefit and is suitable for large-scale popularization and application.

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, 10 parts 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.

The invention relates to a heat-shrinkable tube, in particular to a semiconducting halogen-free flame retardant double-wall heat-shrinkable tube and a preparation method thereof. The tube consists of an outer wall material and an inner wall material. In parts by weight, the outer wall material contains 43 parts of first polyolefin mixed resin, 10 parts of graphitized carbon black, 10 parts of first assistant and 37 parts of flame retardant, and the inner wall material contains 53 parts of second polyolefin mixed resin, 10 parts of second assistant and 37 parts of flame retardant. The preparation method comprises the following steps of: preparing the inner and the outer wall materials of the double-wall heat-shrinkable tube, extruding, irradiating and expanding molding. Compared with traditional shrinkable tubes, the double-wall heat-shrinkable tube has the technical characteristics that the special halogen-free flame retardant is employed in the raw material, and therefore, products have good flame retardant effect, high temperature resistance and good performance, and the pollution can not be generated even if the products are burnt; the cost is lowered, obvious economic benefits and environmental protection effects are obtained, thereby being suitable for large-scale popularization and application.

The invention relates to a heat-shrinkable tube, in particular to a semiconductor high-pressure single-wall heat-shrinkable tube and a preparation method thereof. The Semiconductor high-pressure single-wall heat-shrinkable tube is prepared from a wall material which comprises the following components in parts by weight: 90 parts of mixed polyolefin resin, 10 parts of conductive carbon black and 10 parts of auxiliary agent. The preparation method comprises the following steps of: the preparation of the wall material of the semiconductor high-pressure single-wall heat-shrinkable tube; extrusion; irradiation; and extending and molding. Compared with conventional shrinkable tubes, the semiconductor high-pressure single-wall heat-shrinkable tube keeps the characteristics of good electrical property, chemical property, and the like of ordinary heat-shrinkable tubes, and has all use properties of the ordinary heat-shrinkable tubes and the properties of water proofing, sealing, damp proofing, and the like.

The invention relates to a heat-shrinkable tube, in particular to a semiconductor low-pressure halogen free flame retardant single-wall heat-shrinkable tube and a preparation method thereof. The heat-shrinkable tube consists of a wall which is prepared from the following components in parts by weight: 60 parts of mixed polyolefin resin, 10 parts of conductive carbon black, 10 parts of auxiliary agent, 20 parts of flame retardant and 10 parts of auxiliary flame retardant. The preparation method comprises the following steps of: preparation of an inner wall material of the single-wall heat-shrinkable tube; extrusion; irradiation; and extending and molding. Compared with conventional shrinkable tubes, due to the adoption of the halogen free flame retardant in the raw materials, the heat-shrinkable tube has the characteristics of good flame retardant effect, high temperature resistance, good performance, no pollution even when burnt, cost reduction, obvious economic benefit and environment protection benefit and is suitable for being popularized and applied in a large scale.

The invention relates to a heat-shrinkable tube, in particular to a semiconducting flame retardant single-wall heat-shrinkable tube and a preparation method thereof. The semiconducting flame retardant single-wall heat-shrinkable tube consists of a wall material. In parts by weight, the wall material contains 50 parts of polyolefin mixed resin, 10 parts of graphitized carbon black, 20 parts of assistant and 30 parts of flame retardant. The preparation method comprises the following steps of: preparing the inner and the outer wall materials of the flame retardant single-wall heat-shrinkable tube, extruding, irradiating and expanding molding. Compared with traditional shrinkable tubes, the single-wall heat-shrinkable tube has the technical characteristics that the wall material has the flame retardant performance, the outer layer keeps the characteristics of good electrical properties, chemical properties and the like of common heat-shrinkable tubes; and the single-wall heat-shrinkable tube has all use characteristics of the common heat-shrinkable tubes and also has the performances of water proofing, sealing, moisture proofing, corrosion prevention and the like.

The invention relates to a heat-shrinkable tube, in particular to a semi-conducting halogen-free fire retardant single-wall heat-shrinkable tube and a preparation method thereof. The semi-conducting fire retardant single-wall heat-shrinkable tube comprises wall materials which contain the following raw materials in parts by mass: 53 parts of polyolefin mixed resin, 10 parts of conductive black, 10 parts of assistants and 37 parts of fire retardant. The preparation method of the heat-shrinkable tube comprises the following steps of wall material preparation, extrusion, irradiation and expansion-moulding. Compared with a traditional heat-shrinkable tube, the invention has the technical characteristics that since special halogen-free fire retardant is adopted in the raw materials, the semi-conducting halogen-free fire retardant single-wall heat-shrinkable tube has better fire retardant effect, high-temperature resistant character and good performances, no pollution after burnt, cost reduction, remarkable economic benefits and environmental protection benefits; therefore, the invention is suitable for mass promotion and application.

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 invention relates to a heat-shrinkable tube, in particular to a middle and low-pressure halogen-free flame-retarding single-wall heat-shrinkable tube and a manufacturing method thereof. The tube is composed of a wall. The material of the comprises the following components by mass: 70 portions of polyolefine mixed resin, 10 portions of auxiliary agent, 20 portions of flame retardant and 10 portions of auxiliary flame retardant. The manufacturing method comprises the step of preparing the inner wall material of the single-wall heat-shrinkable tube, extruding, radiating, expanding and forming. Compared with the traditional technology for manufacturing heat-shrinkable tube, the invention has the characteristics that the halogen-free flame retardant is adopted, the product has good flame retardant effectiveness, high temperature resistance, no pollution even in combustion and low cost; the product is applicable to operating under the conditions of 10 kV, has significant economical benefits and environment protection benefits, and is suitable for large-scale popularization and application.