Foaming system determination

Foaming system to determine: 141B’s or cyclopentane’s. The range of water volume/physical foaming agent volume is scheduled to 2, first make clear the process details of the target production line: the type of foaming machine, infusion flow, temperature control value before infusion, kang dao insulation temperature control value and insulation time, where is the box infusion port and the flow of foaming material through the route itinerary, the operation process of closing the mold and sealing the hole after infusion. 3, the current (working) environment temperature, humidity changes. 4, ask the site operator, quality inspector for advice What are the defects of the current process and raw materials and what other specific requirements they should make

Specific tests

1、Phase solubility: ① 100ml small beaker with a short glass rod, zeroed, in turn, pour in the main polyether (polyester) stir well to see if transparent. ② Add silicone oil, catalyst, water, stir well and see if it is transparent. ③Add physical foaming agent and stir well to see if it is transparent (note that the physical foaming agent evaporated after stirring should be replenished). ④The pre-mixed combination material sample should be stored for at least 3 days to be transparent without delamination. ⑤ combination of material samples were put in 35, 15 ℃ storage 24hr to see whether transparent ⑥ conditions, the need to measure the design of the combination of material viscosity (25 ℃ and the normal production state temperature) to see if the viscosity changes with the temperature has substantial fluctuations.

 

2, shrinkage resistance: free foam sample 1hr after cutting into a regular square body, measuring the size of the fixed edge in the -20 ℃ freezer 24hr to see the size change, within 2% of the linear shrinkage can be accepted

3, free foam: according to the design of the ratio of black and white material, temperature control implementation of free foam, pay attention to the material speed, core density and drawing traces.

4, fluidity: free foam density, speed to determine, must be liquidity test. The simple method is: quantitative foam material (generally 200g) stirring immediately after the mouth of the foam cup set on a slightly larger long plastic bag, straighten the vertical up to let the foam material grow upward until the shape (to two people to operate). Cup mouth to the top height L and the ratio of material weight G will be used as an important parameter to assess the fluidity of the combination of materials, the greater the L / G, the better the fluidity, after which the core density should be measured in sections as an auxiliary reference (from low to high density difference can not be too large, otherwise the fluidity can not be regarded as good, especially the highest point of that section) in fact, if the test is done more, in the normal free bubble foam, you can look at the residual bubble in the cup The shape of the residual bubble to roughly determine the advantages and disadvantages of mobility: the more like mushrooms after the bubble cup, the better, the more like a straight stick is the worse.

 

5, process conditions tolerance: ① implementation of preset temperature control +3, -3 ℃ foaming, to see whether to maintain good fluidity and bubble hole structure (“fast material” and “slow material” bubble hole can not fall too far) ② constant amount of white material, black material amount +10%, -10% free foaming test, room temperature 10% of the free foam test, at room temperature for 30 minutes when the bubble body does not shrink significantly even if it passes.

[Trial production] of “refrigerator, freezer” category

This is simple, the whole barrel of material on the machine trial production, according to the predetermined (or the reality of the implementation of) the process conditions of production, finished products installed in the machine to play cold, to see the box shrinkage and insulation situation. General procedures: trial production box in the finished bubble body to take samples to test the thermal conductivity and other comprehensive data. The site needs to be fine-tuned generally: foam temperature control, black and white material ratio, add catalyst, maturation temperature adjustment

 

Wood-like products of the combination of material / process control (internal discussion version) [white material system requirements and product requirements]

1、White material viscosity: it is related to the initial fluidity (machine foaming type), mixing effect (including manual foaming type), as well as the size of the gun flow and the ratio of black and white materials, in principle, should not be higher than 2000mPa.S (25℃, the same below), with the exception of high density (free foam density of 130kg/m3 or more).

2、Compatibility: unless the present match is used or white material on the whole barrel of the machine while stirring, white material should be transparent and not layered (if the choice of low cloud point of silicone oil white material may also be opaque in the low temperature state, but not layered), hand-made material is more so.

3, fluidity: general imitation wood material fluidity requirements are not too high, which depends on its own production process of reasonable arrangements. For special size closed mold casting products or require material foaming process to have good fluidity, at least it will affect the product density distribution.

 

4, adapt to the black material varieties and black and white material ratio changes: white material system is best to be able to switch the black material varieties (M20S, 44V20, 5005, etc.) under a slight adjustment of process parameters (material temperature, tube pressure, etc.) or within a reasonable fluctuation of black and white material ratio to ensure that the products meet the requirements.

5、Product appearance crust thickness and hardness: imitation wood products at least to ensure that the surface “hard enough”, generally require a certain thickness of the skin to ensure that the surface hardness. Specific indicators are difficult to quantify because of the product density requirements and operating environment temperature, humidity changes and other factors. Some special products are required to be rigid inside and outside, and can even play self-tapping screws without slipping.

6, product surface finish and bubbles: the surface of the product should be smooth, no bubbles, pinhole, dark bubble (some products can be reduced requirements on the back, such as picture frames, wall hanging)

7, white line: this is the most likely to appear defects (the surface of the product appears irregular white block spot, long line spot, the place is obviously soft), to try to avoid, at least the white spot should be hard enough.

8、Bubble hole density: the internal bubble hole of the product is dense and proportional, and the fewer the large bubble eyes (diameter 0.2mm or more), the better.

9、Lacquer and gold foil: products do not flake and bulge after spraying or pasting gold foil.

10, deformation resistance: stable products, long size embryo products after opening the mold not only can not “see cold shrinkage”, the final product across the ocean through the cold and heat can not be deformed.

11, impact resistance: sufficient toughness (usually can withstand 1 meter high flat fall, throwing fall).

12, the surface of the product corrosion resistance: before painting the foil, products often need to use solvent to wash away the release agent, roughening treatment, can not pass this level certainly not

[Brief description of raw material selection]

A. Main polyether (polyester):

①Most cases are “4110” is the main (most share is more than 60%). As one of the most widely used hard foam polyether species, it has a more ideal rigid skeleton and flexible long chain (sucrose and diol for the starting agent graft propylene oxide), the price is also suitable. There are not many on the market suitable for imitation wood, at least the quality of stable, those adulterated, hydroxyl value / viscosity with the PO price fluctuations, the bubble pore is not fine enough best not to use. In terms of 4110 production formula, the most suitable for imitation wood is [sucrose + glycerin] starting type (unfortunately, as of now I have only used twice, now seems to be no sale), followed by [sucrose + propylene glycol] starting type, the rest is [sucrose + ethylene glycol or diethylene glycol] starting type. The other hook-up type is really not good. 4110 specifications are also concerned about the viscosity: generally 2500-3500mPa.S, used as a full water foaming system is also lower. Hydroxyl value: higher than 430mgKOH/g products made only hard not tough, need to add other low hydroxyl value of polyether with, preferably 380-420mgKOH/g this range. Chromaticity appearance: the color is too dark itself means that the polyether production process is not well controlled, and then the appearance of the products made from it will be dark and make the white line contrast more harsh, most customers will not be satisfied with this.

②403. It is recommended to add more or less (3-12%). With it, the bubble hole will be fine, the product surface bubbles, pinhole, dark bubble will be much less, and the overall hardness of the product will be improved. The fault is too sticky is not conducive to white material viscosity control. 403 on the market is also mixed, the real 403 should be ethylenediamine start, raw materials are indeed more expensive (seems to be more than 20 yuan / kg), there are people playing crooked ideas, starting agent with urea, glycerin, or increase the amount of PO to reduce costs. Add urea ammonia smell is very heavy, the bubble pore is coarse, add glycerin hardness is affected, more connected to the PO of 403 viscosity is lower is also hard enough.

③ sorbitol type. To 635 series as a representative (10-20%). Cost considerations can not be added, but after using can also significantly improve the overall hardness of the product and surface effects (glossy, pinhole, etc. or something). Trouble: the viscosity of this kind of polyether is not small and the price is high.

④ Soft foam polyether. 220, 210, 330N, even graft polyether (36/28 and so on). Ordinary hard wood imitation material can not be added. Do high-grade products, flower pots must be added. This kind of polyether hydroxyl value is low, the product flexibility is good, the product surface crust thickness will improve. Disadvantage: except 210, other than the main polyether and poor inter-solubility, love to delamination ha independent.

⑤ Polyester class. Aromatic polyester class (depending on the quality of raw materials, character, 5-20%). In principle, the use of discouraged. Add the biggest purpose is the cost of “cost-effective”, but if the small material with improper trouble is also much. High acid value will cause coarse bubble holes, pinholes and even the surface of the product will appear “white mist”

(6) Other polyol. (8% or less). There are a variety of natural vegetable oils or their modified derivatives can be used, can improve the flexibility of the product, but also can slightly reduce costs. The risk is the same as ⑤, and the consequences are at your own risk.

 

Other ideas: If the product is a high value-added products, you can consider using imported similar polyether, especially the full water foaming system, domestic polyether raw materials are difficult to reach the level of Dow.

Second, auxiliary small molecules: (0.5-3%) have glycerol and its starting small molecules of polyether, N ethanolamine (N: one, two, three), small molecules of diols, and even MOCA, the function is the first reaction, the overall hardening, or add skin thickness hardness, shorten the production cycle. It is also necessary to choose the right type, the amount of reasonable.

Third, silicone oil: (1.5-2.5%)

This is followed by other raw materials (raw materials with), the general hard foam silicone oil can be used, but to improve the product some character (bubble hole fine, white line, fluidity) or should be fee. Price of 24 yuan / kg below the best not to use. Especially pay attention to polyether (ester) main body changes after the silicone oil model may have to be changed.

 

Fourth, the catalyst: ① pre-type: ROAOCAT-A1, ROAOCAT-5 catalyst, the function is to control the starting time, drive other catalysts to play an effective, improve the fine density of pores, improve the flow of the foaming process. The dosage is 0.5% or less, depending on the amount of “water”, and it is better to be a “constant” when the weather condition is stable ②Smooth type: ROAOCAT-8 Catalysts, dosage 0.3-0.6%, the most cost-effective hard foam catalyst at present Catalysts, the catalytic ability of each phase is very average. ③Main catalyst: A-33 essential catalyst in imitation wood, directly affects the crust effect and product hardness, dosage at least 0.4%. Here A-33 refers to solid amine (triethylene diamine) plus small molecule diol dissolved, not the commercially available sponge on supplies (there are many counterfeit products). ④ Organic tin: ROAOCAT-D22 is the best, the dosage is very small (one ten thousandth) can significantly improve the crust effect and shorten the opening time. Note: Be careful with the storage cycle of white materials, because ordinary organic tin is not resistant to hydrolysis of tin catalysts, will slowly fail, like D22, used in the combination of materials after a week of signs of failure is very obvious, it is recommended to move to the use of hydrolysis-resistant type. ⑤ Trimer: best to use ROAOCAT-41 (0.3-0.5%) to add hardness without affecting the bubble structure. There is a period of time used DMP-30 up to 0.5% effect is not very satisfactory. Can also be used in small amounts with dimethylethanolamine,. (6) other types: dimethyl benzylamine (0.5%) to improve the quality of the product is not good, except for lower density, long size, closed mold infusion of decorative line corner board, can improve the flow of the material. roaocat-112 catalyst can thicken the crust and increase the hardness of the foam.

V. Foaming agent with Now most of the 141B/water foaming system. The amount of water 0.2-0.7%, ordinary imitation wood 141B generally do not exceed 10 copies. 141B use will directly affect the crust thickness and hardness, with more will also cause the surface of the dark bubble

Sixth, other additives to reduce viscosity, color, anti-yellowing, etc. Can add some non-reactive things to reduce the viscosity of white material, such as DBP and so on to a 3%. Color, antioxidants, etc. directly added to the line, no need to consider.

Seven, filler here only for manual foam. Inert fine powder can be added to strengthen the stiffness of things. Note: you can not add too much water content of things.