ＤＪＫ List of Products and Services

Our company possesses multiple small twin-screw extruders and ancillary equipment for testing and prototyping. We undertake various tests and prototypes, including polymer alloys, polymer blends, the formulation of additives and fillers, reactive extrusion, and the removal of volatiles, solvents, and unreacted components. We also offer evaluations of extrusion kneadability, optimization of kneading conditions, and the prototyping and evaluation of compounds. Please feel free to consult us if you have any requests. 【Features】 ■ One-stop service from extrusion kneading tests to sample production and physical property measurement ■ Support for compound processing considerations *For more details, please download the PDF or feel free to contact us.

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We measure the resin flow length when injection molding is performed under certain conditions. The mold is designed with a resin injection port at the center, and a spiral groove with a constant spacing based on an Archimedean spiral is used. A flow velocity meter is incorporated within the cavity to measure the flow velocity immediately after injection. Additionally, a flow velocity sensor installed in the mold allows for the determination of the initial flow velocity into the cavity, as well as the shear rate and shear viscosity at the time of passing through the sensor. [Features] ■ Capable of calculating shear rate and shear viscosity during cavity passage ■ Allows comparison of flow length and shear viscosity *For more details, please download the PDF or feel free to contact us.

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We measure thermal conductivity using methods such as the disk heat flow meter method, the hot wire (probe) method, and the alternating current steady-state method. The measurement targets include disk-shaped test pieces (solids), powders, solids, and molten resins. Please feel free to consult us if you have any requests. 【Measurement Methods】 ■ Disk Heat Flow Meter Method ASTM E1530 (compliant) - This method, also known as the steady-state comparison method, is referred to as the guarded heat flow meter method in ASTM E1530. - Measurement target: Disk-shaped test pieces (solids) ■ Hot Wire (Probe) Method JIS R 2616 (compliant), ASTM D5930 (compliant) - Thermal conductivity is directly measured from the heat generated by the hot wire (heater wire) and the temperature rise. - Measurement targets: Powders, solids, molten resins ■ Alternating Current Steady-State Method ISO 22007-6 (reference) - Measurement of the thermal conductivity of insulation materials using temperature waves. - Measurement targets: Foams, insulation materials *For more details, please download the PDF or feel free to contact us.

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Supercritical fluid (SCF) is a fluid that possesses both gas and liquid properties above its critical temperature and pressure. It has low viscosity and high diffusivity, making it advantageous for mass transfer compared to liquid solvents, and it can achieve significant differences in solubility with only changes in pressure. The technology of supercritical foaming molding, utilizing the characteristics of SCF, was established in the 1980s by MIT in the United States, and is currently licensed under the name "MuCell(R)" by Trexel Inc. Our company conducts evaluation tests for supercritical foaming injection molding. Please feel free to consult us if you have any requests. [Test] ■ Molding tests using the client's product mold (on-site observation available) ■ Molding tests using molds owned by DJK (on-site observation available) - Foaming molding using a short shot method with a test piece mold - Full shot molding (shrinkage, warpage, dimensional accuracy, appearance of molded products) - Core-back molding (foaming ratio of approximately 1.5 to 2 times, up to a maximum of 6 times) *For more details, please download the PDF or feel free to contact us.

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"Carbon Fiber Reinforced Polymer (CFRP)" is a composite material that combines lightweight polymers with lightweight and high-strength carbon fibers. The strength is enhanced through stress transfer between fibers mediated by the interface and matrix, allowing more fibers to effectively bear the load, contributing to strength development, and resulting in a strength higher than that of the individual fiber (filament) breakage strength. 【Related Contract Services】 ■ Evaluation and modification studies of matrix resins - Epoxy resins (impregnation, curing, properties of cured resins, processing considerations) - Thermoplastic resins (flowability, impregnation, resin properties, resin modification) ■ Prototype and improvement studies of prepregs and composites - Impregnation and lamination conditions (vacuum press) - Interlayer adhesion, toughness improvement ■ Evaluation tests of composites - Mechanical properties (tensile, compression, bending, shear, impact) - Composition (CF content, matrix resin analysis, residual fiber length) - Durability (thermal aging, heat cycles, fatigue characteristics) - Adhesion with other materials (adhesive bonding, insert molding) *For more details, please download the PDF or feel free to contact us.

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The "Accelerated Weathering Test" is fundamentally based on outdoor exposure; however, since it takes a long time to assess performance, various accelerated tests have been implemented. Our company provides comprehensive support for product development for customers conducting accelerated weathering tests. Please feel free to consult us if you have any requests. 【Representative Testing Equipment】 ■ Sunshine Weather Meter (SWOM) - Capable of dew cycles as a high acceleration method ■ Xenon Weather Meter (XWOM) - Low degradation acceleration but high reproducibility ■ Metering Weather Meter - Utilizes strong ultraviolet light, resulting in exceptionally high acceleration ■ Ultraviolet Fluorescent Lamp Weather Meter - Conducts cycle tests combining irradiation and dark (condensation) *For more details, please download the PDF or feel free to contact us.

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The measurement can be applied to a wide range of materials such as plastics, resins, inks, paints, food, cosmetics, and pharmaceuticals, making it an important analytical method for understanding molecular structures and material properties. Measurements of resin glass transition temperature, viscosity and elasticity during melting, thermosetting behavior, steady flow viscosity, solid torsional vibrations, tensile and compressive properties, etc., are possible. 【Measurement Contents】 ■ Frequency dependence, temperature dependence, time dependence measurements ■ Stress-strain dependence measurements ■ Thermosetting behavior ■ Steady flow viscosity and shear rate dependence measurements ■ Creep and recovery measurements *For more details, please download the PDF or feel free to contact us.

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"Reactive Processing" is a technology that finely controls the dispersed structure of non-phase-separated polymer alloys through a melt kneading process accompanied by chemical reactions. The method utilizing a fully intermeshing co-rotating twin-screw extruder is mainstream, offering various advantages such as efficient stirring, mixing, and degassing capabilities for high-viscosity fluids, as well as the ability to integrate with subsequent processes (pelletizing and sheet processing). Please feel free to consult us if you have any requests. [Advantages] ■ Provision of a continuous reaction environment in a solvent-free, molten state ■ Individual supply control for a variety of materials ■ High productivity *For more details, please download the PDF or feel free to contact us.

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Polymer alloys are a technology that mixes multiple existing polymers with different properties to leverage their strengths while improving their weaknesses. This approach addresses the diversification and sophistication of performance requirements that have become difficult to meet with a single polymer. Please feel free to consult us if you have any requests. 【Related Contract Research and Testing Services】 ■ Polymer Alloy Preparation - Compatibility studies of immiscible polymer systems - Reactive extrusion - Prototype production of partially miscible and immiscible polymer alloys using a twin-screw extruder ■ Physical Property Evaluation and Composition Analysis - Mechanical properties - Thermal properties - Molding processability, etc. ■ Improvement and Compounding of Existing Alloys - Consideration of improvements to currently used existing polymer alloys based on your requests - Functional compounds with fillers blended into polymer alloys *For more details, please download the PDF or feel free to contact us.

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"UV-curable resin" is a material that forms a crosslinked structure through the reaction between oligomers and monomers with polymerization capability, such as vinyl groups, acrylate groups, and epoxy groups, using radicals or cations generated by the irradiation of light (ultraviolet rays) as initiators. Due to differences in the reaction mechanism (initiators), it is classified into radical polymerization type and cationic polymerization type. From the perspective of resin variation and cost, radical polymerization type acrylate monomers and oligomers are mainstream. 【Features】 ■ Cures at room temperature in a short time with minimal damage to the substrate ■ Energy-efficient ■ Solvent-free options available, resulting in lower environmental impact *For more details, please download the PDF or feel free to contact us.

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