5 results about "Shrinkage rate" patented technology

The invention discloses a thermal shrinkage pipe expansion device which comprises an expansion die. The expansion die comprises an outer casing and a sizing tube. The sizing tube is arranged in the outer casing. The space between the outer casing and the sizing tube is separated into a vacuum chamber and a cooling chamber. The outer casing on the cooling chamber is provided with at least one water inlet and at least one water outlet. The expansion die also comprises a plurality of water inlet holes which are arranged on the sizing tube of the cooling chamber. Cooled water can enter the inside of the sizing tube through the water inlet holes. The thermal shrinkage pipe expansion device of the invention has the advantages of good cooling effect, light friction between the thermal shrinkage pipe and the sizing tube, high expansion efficiency, fast speed, long service life of the sizing tube and small axial shrinkage rate of products.

The invention belongs to the technical field of 3D printing, and discloses a polypropylene composite material and a preparation method and application thereof. The polypropylene composite material comprises, by weight, 25-70 parts of homopolymer polypropylene, 10-40 parts of copolymerized polypropylene, 5-10 parts of polylactic resin, 10-20 parts of inorganic fillers, 2-5 parts of a compatibilizerand 0.1-5 parts of an auxiliary. According to the polypropylene composite material, a prepared product has the advantages of uniform wire diameter, higher cross section roundness, good processing fluidity, excellent mechanical performance and lower shrinkage rate, the polypropylene composite material can be applied to the fields of 3D printing consumable materials, and the technical defects of easy upward tilting and deformation, nonuniform 3D printing consumable material wire diameter, the failure of being round in cross section and the like in 3D printing process in the prior art are overcome to further promote the development of the polypropylene material in the field of 3D printing materials.

The invention relates to the field of logistics articles, in particular to a PCB non-metallic material steel-plastic compound plate tray, a preparing production line and a preparing method. The tray is formed by sequentially arranging a first steel-plastic compound plate, a supporting layer and a second steel-plastic compound plate from top to bottom; the supporting layer is composed of a plurality of vertically-arranged stand columns; the first steel-plastic compound plate is fixedly connected with the top ends of the stand columns; the second steel-plastic compound plate is fixedly connected with the bottom ends of the stand columns; and the first steel-plastic compound plate and the second steel-plastic compound plate are each formed by sequentially arranging a first plastic layer, a reinforcing layer and a second plastic layer from top to bottom. The produced tray can be recycled many times, resources are saved, the requirement of the 'green and environment-friendly industry' is met, the environment is protected, the tensile strength is high, the bending resistant performance is high, deformation is not likely to be caused, the deformation amount caused by the temperature effect is small, the shrinkage rate of thermal expansion and cold shrinkage is low, the number of using and circulating times is large, waterproofness is good, fumigation is not needed, and the service life is long.

The invention discloses an additive for decreasing the shrinkage rate of synchronous grouting materials. The additive for decreasing the shrinkage rate of the synchronous grouting materials comprises industrial potash alum and industrial gypsum. The mixing amount of the additive for decreasing the shrinkage rate of the synchronous grouting materials is 5 kg/m<3>, and by adding the additive for decreasing the shrinkage rate of the synchronous grouting materials into shield synchronous grout, shrinkage of the existing synchronous grout materials in a waterless stratum can be remarkably relieved.

The invention relates to the technical field of polyamide films, in particular to a high-shrinkage biaxially oriented polyamide film as well as a preparation method and application thereof. The high-shrinkage biaxially oriented polyamide film comprises a first surface layer, a core layer and a second surface layer, the first surface layer comprises nylon, a nylon composition A and an anti-sticking nylon master batch; the core layer comprises nylon, a nylon composition B and a nylon secondary material; the second surface layer comprises nylon, a nylon composition A and an anti-sticking nylon master batch; the nylon composition A and the nylon composition B are blends of bio-based nylon and copolymerized nylon. The high-shrinkage biaxially oriented polyamide film provided by the invention has the property of high shrinkage rate under the condition of meeting high tensile strength and excellent puncture resistance, is suitable for packaging products with high shrinkage rate requirements, and has a wide application prospect.