List of technical points for production, R&D and quality control of plastic toys

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List of technical points for production, R&D and quality control of plastic toysWhether it is a toy designer or a toy company, in order to truly professionally…
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List of technical points for production, R&D and quality control of plastic toysWhether it is a toy designer or a toy company, in order to truly professionally engage in toy industry, in addition to timely market-related dynamics, it is also necessary to pay attention to basic design knowledge of toys, such as plastic toy production, research and development and quality control technology. Below, for main points of production of plastic toys, Gud Mould one by one for you to analyze:ď Ź First, production process Generally speaking, production process of plastic toys is roughly as follows: separate molding of injection molded parts, silicone parts, separate forming of hardware and PCB parts, other decorative parts of clothing, final assembly, inspection, and packaging. Molding of injection molded parts: Prepare toy molds, pellets, toner/color masterbatch, stabilizer, plasticizer, mold release agent, etc., and generally add degraded material that is broken by injection moulding. Proportion of degraded material added has a great influence on quality. For enterprises with good quality control level, proportion of degraded material is controlled to be no more than 30%. After preparation, it is necessary to dip in addition to PP, PS which is not easy to absorb water, especially for some water-absorbing materials such as PA, ABS, PMMA, etc. It is very important to dry moisture to 0.5% or less. After adjusting parameters such as temperature and pressure of injection moulding machine, it can be injection molded. After cooling and demoulding, remove nozzle, product can be inspected and qualified, unqualified product and degraded material are crushed, waiting for mixing with new material and next batchof injection moulding. Silicone molding: Material used is generally PVC glue, not pellets of various plastics. Toner is also adjusted into a color paste and mixed into a PVC glue. Clay mold is used to make toy molds, and finally production mold is made. Glue is injected into toy molds with a glue gun, and then placed in a heating furnace for heating. Generally, two drums are placed in one furnace, about ten. Temperature is usually around 260 ° , and time is usually about 10 minutes. Remove after molding. Hardware: Toys companies generally choose to purchase outside. PCB parts can be purchased or assembled by yourself. Clothing, accessories, etc. are processed by lathing, sewing, etc. After injecting moulding and silicone molding, injecting or pad printing is required. It is critical to formulate inks (add different diluents). Formed and printed products can be stored in warehouse. In addition, there are steps such as hair transplanting, cutting, plastic plating, vacuum flying aluminum, and screen printing. Second, industry features There are such characteristics in plastic toy industry: use of degraded material has a great impact on cost; multiple recycled materials affect product quality; quality control has relatively high detection frequency for benzene heavy metals and is extremely sensitive. Third, production, research and development process points Common plastics for injection moulding:PP: Fold-resistant, smooth, good fluidity, stable chemical properties, wear resistance, often used as moving parts, commonly known as 100% plastic. It is generally used in toy parts because it is not easy to spray oil. Disadvantage is that shrinkage is 1.6% larger and size is unstable. Injection pressure is not too large to be 80~90MPA. Because of good fluidity, there will be flashing when pressure is too high. If pressure is too low, toy molds may not be filled. Holding and cooling time are lengthened to compensate. ABS: ABS is the best electroplating of all plastics, with good finish and mechanical properties, low shrinkage, but not solvent. It is often used in housings with HIPS. It should be sufficiently dried before processing to make moisture content lower than 0.1%, and drying condition is 85 ℃ for more than 3 hours. Because of good fluidity, injection pressure is 70~100MPA, otherwise it will fly. Barrel temperature should not exceed 250 ℃ or it will decompose. Mold temperature is 40~80℃, and mold temperature is also high when gloss requirement is high. Check stress of ABS product and immerse it in kerosene for 2 minutes without cracking. MBS: Transparent ABS, excellent dimensional stability, light transmittance, acid and alkali resistance. SBS: Commonly known as K material. Transparent and flexible. PS: Divided into GPPS (general PS is hard material, transparent, hard, fragile), HIPS (add 5~20% butadiene in GPPS, opaque milky white or light yellow, high impact) . GPPS does not require drying, and HIPS requires a feed of 80℃ for 2 h. Fluidity is excellent, barrel temperature can be low, and injection pressure should not be too large 70~130mpa to reduce internal stress. Injection speed can be higher to reduce water trap (welding marks). PVC: large shrinkage (1.0~2.5%), poor thermal stability, poor fluidity, blending with ABS can improve mechanical properties and hardness, and more for silicone. It needs to be dried at 85~95℃ for 2h. Residual PVC at dead corner of barrel will decompose HCL corrosion equipment after repeated heating, so cavity and dead angle inside machine head should be cleaned frequently. Due to easy thermal decomposition, processing temperature should be strictly controlled, front barrel 160~170, and injection time is shortened to reduce retention time of pellets. Injection speed should not be too fast, otherwise melt temperature will rise to produce shrinkage marks; mold design should not make product wall too thin, and gate should be thicker to allow melt with poor fluidity to smoothly fill mold. Mold temperature is as low as 30 ℃ as possible to make product form as quickly as possible to reduce shrinkage. POM: Good stability, no water absorption, good self-lubricating, high hardness, solvent resistance, poor heat resistance, and 2.5% shrinkage. Therefore, it is possible to improve melt fluidity by means of high pressure and low temperature without using dip. Injection pressure is 100mpa, back pressure is 0.5mpa, front barrel is about 200 ℃ , and mold temperature is about 80 ℃ . Extend pressure holding time to fill. PE: Mechanical strength is not high, stability is good, and it is often used for blow molding, molding shrinkage is 2.5%. No need to dip, generally 60mpa, front barrel can be 200℃, because warpage is relatively large, it is best to use multiple gates. Adjust mold temperature to adjust hardness of product. PC: Commonly known as bulletproof glass glue. Transparent, expensive, good dimensional stability, poor fluidity, and poor fatigue resistance are sensitive to gap. Very sensitive to trace moisture, it must be fully dip so that moisture content is less than 0.015% and dried at 120℃ for 12 hours. Due to poor fluidity, pressure needs to be increased, but pressure is too high, andinternal stress may be easily cracked. Front barrel is about 240 ℃ , all temperatures should not exceed 310 ℃ , and mold temperature is about 80. Injection speed should not be too fast to prevent exhaust gas from being burnt, melt of product, etc. Annealing: 125 ℃ for 2 hours, naturally cooled to room temperature to reduce internal stress. Nylon: self-lubricating, acid and alkali resistant, good mechanical strength, good fluidity, but easy to absorb water. Need to dip, 90℃, 24 hours. Pressure of 60~90MPA should not be too high to avoid flashing. Barrel temperature is generally around 220~250, and should not exceed 300. Mold temperature control range is 20~90℃. If mold temperature is high, crystallinity is high and hardness is strong. Mold temperature is low, flexibility is good. Higher melting point is easier to coagulate and must be injected at a high speed. In particular, nylon can be annealed to increase crystallinity by 10℃ higher than use temperature and annealed for 10 to 60 minutes. In order to improve dimensional stability, internal stress is also adjusted by temperature adjustment, and immersed in boiling water or potassium acetate solution for 2 to 16 hours. PMMA: Acrylic. Good transparency, good dimensional stability, but poor fluidity, high shrinkage, and solvent resistance. Since transparency is too good, impurities, silver filaments, bubbles, etc. may seriously affect appearance and yield is low. Must be fully dried or silver filaments or bubbles will be produced. Dry conditions should be 100 ℃ for 6 hours, and thickness of layer should not exceed 30 mm. Injection pressure is 80~100mpa, and pressure retention time is extended. Injection speed should not be too large, otherwise burnt, bubbles, poor transparency, etc. will occur. Temperature of barrel should not be too high, otherwise color change is 200~230, and mold temperature should be higher 70~90 to reduce internal stress and make transparency high. Heat treatment: 70~80℃, hot air treatment for 4 hours. Try not to use a release agent to reduce black spots.
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