Crystallizing Dishes Singapore
A crystallizing dish is the quiet workhorse of the bench: shallow enough to evaporate, deep enough to hold a small flask in a bath, and transparent enough that you can watch a crop of crystals form without lifting a lid. Get the diameter and the material right and it does three jobs well; get them wrong and it cracks in an ice bath or sheds fine particles into a hot sample.
At JW RESEARCH SUPPLY, we supply borosilicate glass, porcelain, quartz and PTFE crystallizing dishes in a wide range of diameters to laboratories across Singapore. This guide explains how to match the dish to the crystallisation, bath or drying task in front of you.
Crystallizing Dish Types Compared
| Type | Material | Diameter Range | Best For |
|---|---|---|---|
| Standard dish | Borosilicate glass | 40 – 190 mm | Crystallisation, evaporation, general work |
| Wide bath dish | Borosilicate glass | 100 – 190 mm | Water and oil baths for small vessels |
| Narrow dish | Borosilicate glass | 40 – 70 mm | Small-volume recrystallisation |
| Oven and furnace dish | Porcelain | 50 – 180 mm | Drying and ignition steps above glass limits |
| Trace-analysis dish | Quartz | 60 – 120 mm | Low extractables for sensitive analysis |
| Aggressive-chemistry dish | PTFE | 50 – 150 mm | HF, strong alkalis, unbreakable bath work |
Selection Data and Material Properties
| Parameter | Typical Range | Why It Matters |
|---|---|---|
| Capacity | 25 – 1000 mL | Sets how much solution or bath volume it holds |
| Wall form | Straight cylindrical | Lets crystals form undisturbed and views clearly |
| Working temperature | Glass ~500 °C, porcelain ~1000 °C | Glass is unsuitable for ignition work |
| Thermal shock | Quartz > porcelain > glass | Ice baths and cold pours crack thin glass |
| Chemical resistance | PTFE > quartz > porcelain > glass | Alkalis and HF attack glass and porcelain |
| Surface finish | Polished interior | Fewer scratches mean fewer stray nucleation sites |
Choosing the Right Dish
- Growing crystals? Go borosilicate glass — Transparency and a polished wall give the best habit.
- Then ashing the product? Go porcelain — Glass will not survive the furnace.
- Packing an ice bath? Go PTFE or thick glass — Thin walls crack under direct thermal shock.
- HF or hot alkali? Go PTFE — It is the only material on this list that is unharmed.
- Size above the inner vessel — A bath dish must be wider than whatever stands in it.
Bench Practice That Protects the Result
Set the dish on a level, stable surface before you fill it, because a dish that rocks on a hotplate concentrates heat at one point of the base and that is where a crack begins. For crystallisation, dissolve the solid in the minimum volume of hot solvent, decant or filter the hot solution into the dish rather than pouring it over an undissolved crust, and cover the dish loosely so that dust cannot fall in and seed a crop of tiny crystals. Control the cooling rate rather than the final temperature: slow cooling gives larger, cleaner crystals, and the dish has enough thermal mass to hold its warmth for a while if you leave it undisturbed. When the dish is used as a bath, check the inner vessel cannot float or tip, add a support if it can, and keep the bath level above the part of the vessel that must be controlled. Wash dishes promptly with warm detergent and a soft brush, rinse with distilled water, and store them inverted or lidded so the interior stays dust-free; never use a scratched dish for trace work, and never pour cold liquid into a dish that has just come off a hotplate.
Why Choose JWRESEARCH for Crystallizing Dishes in Singapore?
- Full material range — Borosilicate glass, porcelain, quartz and PTFE dishes.
- Wide size choice — From 40 mm small-format dishes to 190 mm bath sizes.
- Consistent form — Straight walls and flat bases for stable bath and crystallisation work.
- Fast local delivery — Quick dispatch across Singapore so work never waits.
JWRESEARCH supplies crystallizing dishes in borosilicate glass, porcelain, quartz and PTFE to laboratories across Singapore. Contact us for diameters, capacities and volume pricing.
📞 +65 8039 3660 | ✉️ SINGAPORE@JWSHY.COM
🌐 www.jwresearch.cn
Frequently Asked Questions
Q: What is a crystallizing dish and how is it different from an evaporating dish?
A crystallizing dish is a wide, shallow cylindrical vessel with straight vertical walls and a flat base, used for crystallisation, recrystallisation, evaporating to a small volume and for heating or cooling baths. An evaporating dish is shallower and usually has sloping or rounded walls with a pouring lip, and it is designed to expose the maximum liquid surface so a solvent leaves quickly. A crystallizing dish keeps a more upright wall and a defined diameter, so crystals can be grown undisturbed at the bottom, a seed crystal can be observed through the transparent side, and the dish can double as a water bath or ice bath to control the temperature of a small flask or beaker standing inside it. The two overlap in routine use, but the straight-walled dish is the better vessel for anything where crystal habit, slow cooling or a shallow bath matters.
Q: Which material of crystallizing dish should I choose for my laboratory?
Borosilicate glass covers the great majority of crystallisation, bath and general heating work: it is transparent, so crystal formation can be watched, it tolerates repeated warm and cool cycles without clouding, and it is resistant to most aqueous reagents and organic solvents. Porcelain is chosen when the dish must go to a higher temperature than glass allows, such as drying a residue in an oven or taking crystals through an ignition step, and it is also preferred for its weight on a hotplate. PTFE is the choice for hydrofluoric acid, strong alkalis and other aggressive chemistry that dissolves glass, and it is also popular as a bath vessel because it is unbreakable and does not scratch. Quartz is reserved for trace analysis where the glass itself would give up ions into the sample. Match the material to the temperature and the chemistry first, then to the transparency and durability you prefer.
Q: How do I grow better crystals in a crystallizing dish?
Start with a solution that is not more supersaturated than it needs to be, because a heavily supersaturated solution nucleates a shower of tiny crystals instead of a few good ones. Use a clean, scratch-free dish: a polished interior gives fewer nucleation sites and a smooth wall lets crystals slide down without seeding the upper liquid, while a scratched dish seeds crystals all over its surface. Cover the dish loosely with a watch glass or filter paper to slow evaporation and to keep dust from falling in, since a single dust particle can start a crop of fine crystals. Cool the solution slowly, ideally by wrapping the dish or by letting it stand at room temperature after a warm bath rather than putting it straight into a cold place. Do not disturb the dish while crystals are forming, and pour off the mother liquor gently before drying the crystals in air rather than with heat, which can dissolve or decrepitate them.
Q: Can crystallizing dishes be used as water baths or ice baths?
Yes, and this is one of their most useful roles. A wide crystallizing dish filled with water, oil, sand or an ice and salt mixture makes a simple temperature bath for a small flask, beaker or vial, and its large flat base transfers heat steadily from a hotplate. Choose a diameter comfortably wider than the vessel you will stand in it, and leave enough depth that the liquid covers the level of the inner vessel that needs control. For oil baths kept above one hundred degrees, use a borosilicate dish and fit it with a thermometer and a support so the inner vessel cannot tip, and never heat a bath of flammable oil on an open flame. For ice baths, a plastic or PTFE dish avoids the risk of thermal shock breaking a glass dish when the ice is packed directly against the wall, and for cryogenic slush baths follow the method exactly because some mixtures are far colder than ice alone.