Polyurethane potting compound
Polyurethane potting compound
Excellent high- and low-temperature stability,
Designed for flexible, low-stress insulation and waterproof potting protection.
The fundamental mechanism of polyurethane potting compounds involves the crosslinking and curing of polyol resins with MDI curing agents, facilitated by catalysts, to form a high‑molecular‑weight polymer. To achieve superior adhesive sealing, heat resistance, thermal conductivity, toughness, elasticity, and low‑stress performance, further modifications are required to ensure robust thermal stability, mechanical properties, and electrical insulation.
Shanghai Hinnel offers an extensive range of innovative polyurethane potting compounds. This product line maintains excellent thermal stability even at continuous operating temperatures as high as 165°C, enabling it to meet demanding application requirements and broadening its scope of use. The resin’s fillability significantly enhances thermal conductivity, allowing designers to achieve superior heat dissipation performance.
Hinnel’s polyurethane potting compounds in Shanghai exhibit a wide range of mechanical properties, including gel-like characteristics, elastomeric properties, impact resistance, and dimensional stability. They can also provide transparent UV-resistant solutions for clear‑coat applications.
Product用途:
Encapsulation and protection for automotive electronic components, sensors, and electrical/electronic systems; effective protection and insulation for electrical and electronic devices such as transformers, chokes, and capacitors, ensuring uniform heat dissipation across all parts; thermally conductive, waterproof encapsulation for industrial power supplies and controllers; and waterproof encapsulation and protection for charging guns used in new‑energy vehicles, among other applications.
Hinnel product features
A broad hardness range, from gel-like properties to glass-like hardness.
The operation time is adjustable, ranging from 1 minute to 90 minutes.
The temperature range spans from -60 °C to +150 °C.
Adjustable liquidity
Good electrical performance
It exhibits excellent adhesion to plastics, metals, glass, and other materials.
Excellent heat resistance and thermal conductivity
High mechanical strength
Low water absorption and excellent resistance to high temperature and high humidity (tested under damp‑heat conditions of 85% relative humidity and 85°C for 1,000 hours).
Resistance to thermal shock and thermal cycling
| Product model | Quality ratio | Mixed viscosity | Operation Time | Curing time | Curing hardness | Flame-retardant grade | Color | Key Features |
| A:B | cps 25℃ | min 25℃ | hr 25℃ | Shore | UL-94 | - | ||
| PU500 | 100:100 | 300 ±100 | 30~40 | 24~72 | 35~45A | V-0 | Yellow and transparent | Flame-retardant, low-hardness, with excellent toughness and outstanding air‑release properties; can be manually dispensed without bubbles and is insensitive to moisture. Used for waterproof sealing of printed circuit boards, offering low stress and reworkability. |
| PU500H | 100:50 | 650±200 | 20~30 | 24~72 | 65~75A | - | Colorless and transparent | Colorless and perfectly transparent, it resists yellowing, cures rapidly with low heat release, exhibits high gel strength and excellent toughness, and provides strong adhesion to metals and plastics. |
| PU500G | 100:26 | 1000±200 | 20~30 | 12~24 | 200~300 (1/10 mm) | - | Colorless and transparent | Polyurethane gel potting compound, soft and similar to silicone gel, colorless and completely transparent, with high gel strength and strong adhesion; its hardness can be adjusted by varying the amount of curing agent. |
| PU510 | 100:60 | 400±200 | 20~30 | 24~72 | 50~60D | - | Yellow and transparent | It is resistant to acids and alkalis, hydrolysis‑stable, exhibits low mixed viscosity, and generates minimal heat. It also demonstrates strong adhesion to plastics, metals, and other materials, making it suitable for encapsulating water‑treatment membranes. |
| PU550 | 100:20 | 600±200 | 40±10 | 12~24 | 75~85A | V-0 | Black | Extremely low viscosity, excellent self‑degassing performance; can be dispensed manually or by machine with no bubbles; resistant to the 85°C/85% RH test; surface is bright and smooth. |
| PU512 | 100:16 | 900±200 | 30±10 | 24~72 | 75~85A | V-0 | Black | It meets the Double 85 reliability test, exhibits excellent resistance to thermal shock, and features high gel strength and superior toughness, making it suitable for potting thin-film capacitors, controllers, and automotive-grade sensors. |
| PU552 | 100:20 | 800±200 | 30±10 | 24~72 | 80~90A | V-0 | Black | It exhibits excellent resistance to the Double 85 test and thermal shock, with strong adhesion to metals, plastics, wire harnesses, and other substrates. The adhesive boasts high hardness, superior strength, and excellent toughness. |
| PU525 | 100:25 | 750±200 | 30~50 | 24~72 | 80D | V-0 | Black | Low viscosity, excellent flowability; the cured product exhibits high gloss, high hardness, high strength, and high toughness, with outstanding adhesion to metals and engineering plastics. |
Instructions for Use
Mixed – Before mixing, check whether the filler in Component A has settled; if so, stir it thoroughly to ensure uniformity (this step is not required for transparent systems). Then, using manual or automated equipment, mix Components A and B uniformly according to the specified weight ratio, taking care to achieve complete homogeneity. In applications sensitive to air entrainment, vacuum‑degas the mixed adhesive at a pressure of at least –0.09 MPa for 3–5 minutes; extend the degassing time as needed when handling larger volumes. The purpose is to remove air bubbles introduced during mixing; otherwise, bubbles may form inside and on the surface of the cured adhesive. For high‑volume production, consider using automated metering, mixing, and dispensing equipment.
Perfusion – Manual potting is acceptable, or an automated potting system equipped with a vacuum‑evacuation unit, a stirring mechanism, and a heated material tank may be used (a stirring device is not required for transparent systems). Place the component to be potted with its opening facing upward in a horizontal position, and within the working time, pour in the potting compound and allow it to self‑level. For components with complex structures or large volumes, apply the compound in multiple stages. Any trapped air bubbles can be removed by gently blowing them away with a hot‑air gun or similar tool, which will also help eliminate surface‑floating bubbles.
Curing – It is recommended to allow the material to cure at rest in an environment of 20°C to 30°C, which helps minimize bubble formation; alternatively, cure it by gently heating at low temperature once no visible bubbles remain within or on the surface of the adhesive. Curing time depends on the amount mixed each time and the temperature: larger quantities or higher temperatures will shorten the curing time, while smaller amounts or lower temperatures will lengthen it. A catalyst can significantly reduce the curing time.
Cleaning – The uncured resin is relatively easy to clean; for cured resin, please soak it in a dedicated cleaning agent (such as thinner, dichloromethane, or plate‑washing solvent). However, be aware that these solvents may corrode components other than the adhesive, so use them with caution. After soaking, soften and carefully peel off the resin.
Precautions
At low temperatures, Material A exhibits increased viscosity, while Material B is prone to crystallization. Preheating the materials to 25–45°C can enhance adhesive flow and help prevent excessive viscosity and excessive bubble formation. This product is sensitive to moisture; exposure to humidity may lead to curing‑induced bubbles. It is recommended to maintain the operating environment at 25±5°C, with relative humidity kept below 60%. Components such as PCBs and plastic enclosures that readily absorb moisture should be dried prior to potting; otherwise, tiny air bubbles may form along the edges of the board or plastic housing.
Storage and Shelf Life
This product is non-hazardous. Store it away from light, in a cool, dry place, at a temperature of 15–25°C, using the original unopened container. Each component has a shelf life of six months from the date of manufacture. The expiration date is indicated on the label affixed to the outer packaging of each product. Products past their expiration date may only be used after their performance has been verified to be within acceptable limits.
If Material A is stored for an extended period and the filler settles or forms clumps, the sediment must be thoroughly mixed by hand or with a mixer before use (this step is not required for transparent systems).
Note: The curing agent is highly sensitive to moisture; after adding it, any remaining curing agent should be tightly sealed and stored immediately. Once opened, use the A/B components in a single batch whenever possible, or reseal the container after purging it with nitrogen.
Warning Information
Before using this product or any Hinnel product, please refer to the Material Safety Data Sheet (MSDS) and the product label for instructions on safe use and handling. If you have any questions, please feel free to contact us at any time.
Frequently Asked Questions and Solutions
| Phenomenon (abnormality) |
Cause |
Measures |
| Component B is cloudy and crystalline. |
1. The packaging bucket has poor sealing; 2. The customer failed to use up the product promptly after opening the container; 3. In Component B, MDI reacts with moisture to form crystalline precipitates (rendering it ineffective); |
After opening, the product should be used up promptly; if not fully used, it must be immediately resealed and stored in a cool, dry place. |
| Precipitation of component A | The higher the temperature, the longer the duration, and the more severe the packing fouling. |
Store at the recommended temperature and use promptly. Before use, stir thoroughly with a dry stirring rod. |
| Surface bubbles |
1. Excessive on-site humidity (chemical bubbles); 2. Moisture ingress in adhesives or potting compounds (chemical bubbles); 3. After opening the A/B containers, the component ratio is imbalanced, with an excessive proportion of Component B (resulting in chemical bubbles). 4. The internal structure of potting‑encapsulated products is complex, resulting in excessive resistance to bubble removal during resin dispensing (physical bubbles). 5. The adhesive has not undergone vacuum degassing (resulting in physical air bubbles); |
1. Maintain on-site humidity below 55% RH. 2. Products to be pot‑encapsulated must be pre‑dried, and the adhesive should be inspected for moisture. 3. After separating the A and B components into their respective containers, use them up as soon as possible. If any remains, store it sealed. Before each dispensing, verify that the equipment is set to the correct mixing ratio. 4. Perform potting in multiple stages, and use a heat gun to blow away any air bubbles. 5. Before potting, subject the adhesive to vacuum degassing. |
|
1. The glue sticks to your hands. 2. Hardening 3. Don't do it 4. Local non-drying 5. Surface oil finish and grain pattern |
1. Imbalanced proportions, with an excess of Material A; 2. Imbalanced proportions, with an excess of material B; 3. Not mixed thoroughly, or an excess of Component A; 4. Not thoroughly mixed; 5. The A component precipitate was not mixed thoroughly, or the ambient humidity is high; |
1. Material A is present in a relatively high proportion; it is recommended to re-inspect the equipment and adjust the mix ratio. 2. Material B is present in a relatively high proportion; it is recommended to re-inspect the equipment and adjust the mix ratio. 3. Mix thoroughly and verify the mix ratio. 4. Stir thoroughly until uniform, making sure to scrape the sides and bottom of the mixing container as well. 5. Material A may settle; stir thoroughly in the original container before use, and maintain appropriate ambient humidity. |
Shanghai Hinnel provides innovative adhesive solutions for bonding, sealing, potting, thermal management, and protection. Our team works closely with customers to help enhance the value of their products. In an ever-evolving market, we continuously innovate and respond swiftly, committed to delivering professional products and technical support to customers worldwide.
The product’s TDS, MSDS, RoHS, REACH, and other relevant documents can be obtained via the following methods:
✓ Online Message on This Site
✓ Email: sales@hinnel.com
✓ Phone: 021-57896706
✓ Our company’s official WeChat account: Shanghai Hinnel New Materials Technology Co., Ltd.
✓ Please contact our relevant sales representatives directly to obtain it.
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