1. The definition of seals

  The seal is a product that seals something so that it cannot be easily opened, and  it plays an important role in shock absorption, waterproofing, sound insulation, heat insulation, dust proofing and fixing. It can be made of many materials, such as rubber, paper, metal, plastic and so on. Seals have been used in various industries since the 1980s, such as cars, windows, doors, refrigerators and containers. This article focuses on the common window and door seals found in the home.

2. Different types of door and window seals

  Door and window seals can be divided into three categories according to their use: door sash seals, woolen strips and glass seals.

  The door sash seal is mainly used for sealing between the door panel and the door frame,

  The woolen strip is mainly used for sealing between the door frame and the door leaf.

The glass seal is mainly used for sealing between the glass and the door leaf and frame.

3. Materials for door and window seals

  (1) TPE, a thermoplastic elastomeric material with high strength, high resilience, injection molding, excellent colorability. It is non-toxic, safe and environmentally friendly, so it is widely used in many areas.

  Characteristics of TPE:

   1) It can be processed with the general thermoplastic molding machine.

   2）It can be directly vulcanized by rubber injection molding machine, the time required is shortened from about 20min to less than 1min, which greatly improves the production efficiency.

   3) It is easy to recycle and reduce costs. The waste materials produced during the production process and the final scrap can be directly recycled and reused, reducing environmental pollution and expanding the sources of renewable resources.

   4) It can save energy. Most of the thermoplastic elastomers do not need vulcanization or the vulcanization time is very short, which can effectively save energy. Take the energy consumption of high-pressure hose production as an example: rubber is 188MJ/kg, TPE is 144MJ/kg, the use of TPE can save energy up to 25% or more.

   5) It can be applied in many areas. As TPE has the advantages of both rubber and plastic, it opens up new application areas for the rubber industry.

   6) It can be used for the reinforcement the toughness of plastics. The formulation is simplified, the influence and constraints of the compound ingredients on the polymer is small.

(2) PU, its full name is polyurethane, is a macromolecular compound containing the -NHCOO- unit, which is made by mixing and reacting of isocyanate and hydroxyl. PU is also known as recycled leather that is softer, it has less color and the main color is black or brown; softer texture.

Characteristics of PU:

  1) It has good physical property, flexural resistance, good softness, high tensile strength and breathability. To create the pattern of the PU fabric, we firstly apply the hot patterned paper to the surface of the semi-finished leather, wait for it to cool down and then proceed to separate the paper from the leather and do the surface treatment.

  2) It has high air permeability, high peel strength, high water pressure resistance, and it is the ideal material for waterproof and breathable clothing fabric top and bottom layer.

  3) It is expensive, the price of some special PU fabric is 2 to 3 times higher than that of PVC fabric. The patterned paper required for general PU fabrics can only be used 4 or 5 times, that is to say, it is easily scrapped;

  4) The use cycle of patterned rollers is long, so the cost of PU leather is higher than that of PVC leather.

(3) EPDM, a type of ethylene propylene rubber, it is a copolymer of ethylene, propylene and a small amount of non-conjugated dienes, as its main chain is composed of chemically stable saturated hydrocarbons, containing only unsaturated double bonds in the side chain.

  Characteristics of EPDM.

  1) Ozone resistance

  2) Weather resistance

  3) high and low temperature resistance

  4) Resistant to chemicals

  5) Resistant to a variety of polar solutes

  6) Low relative density

4. Characteristics of door and window seals

  There are many different kinds of seals, and the most common door and window seals are plastic door and window seals, wooden door seals.

  Plastic door and window seals are a new type of seals that have been widely used in recent years. They have better corrosion resistance, weather resistance, noise reduction and heat insulation than ordinary window and door seals. The surface of the plastic window and door seals is smooth, they not only have excellent sealing and waterproof performance, but also play a decorative role. In terms of material selection, manufacturers with high requirements generally choose EPDM or thermoplastic EPDM rubber. The main properties of EPDM products are non-toxic and environmentally friendly, They have aging resistant, high temperature resistant, stable performance, and they can keep good performance in summer and winter.

  Wooden door seals are made of EPDM rubber with imported double-sided adhesive tape on the back and grid-like glass fiber. It has excellent weather and ageing resistance, ozone resistance, chemical corrosion resistance, excellent cold and heat resistance and super elasticity. This kind of product is suitable for a wide range of doors and windows and easy to install.

5. Functions of door and window seals

  When we choose windows and doors, the most important thing we should pay attention to is the rubber strip used in addition to the structure and process of the windows and doors. Seals play a vital role in windows and doors and we can justify whether the sealing performance is excellent from it.

  (1) Insect prevention: Installing sealing strip can make aluminum doors and windows be more close to the frame and fan leaf, effectively blocking outside insects from breaking into the room.

  (2) Dustproof: It is same as insect prevention, there is no gap between the window frame and the wall, so dust cannot enter.

  (3) Waterproof: water droplets can enter the room through various gaps, the seal can reduce gaps to stop water droplets from entering.

  (4) Soundproof and shockproof: the material of the seal has a soundproof effect, and the seal can make gaps disappear, noise can  be blocked in the outdoor; installation of the seal can also reduce the noise when opening and closing the door  so that protect the indoor people will not be affected.

  (5) Sealing: sealing strips are generally made of PVC, modified PVC, EPDM, elastomeric sealing strips, silicone and other materials, so they have good sealing.

  (6) Warmth: Windows and doors fitted with seals can reduce the flow of air between the interior and exterior for insulation and energy saving.

6. Selections of door and window seals

  (1) Observation

  Firstly, you can observe the surface of the seal, some cheaper seals contain so much filler that it will not be sleek, which is not desirable. Then look at the cross-section of the seal to determine if the gloss is close to the color of the seal surface. If the color is close, it means that the seal material contains little filler and can be purchased.

(2) Smell

  Smell it to justify whether there is an odor. Normal PVC material will only have a little bit of sub alcohol taste and can be overlooked.

(3) Pull by hand

  Take a seal and tear it at its thinnest part. The more force needed, the higher the latex content, which means the seal has an excellent performance and is worth buying.

  Hold the seal in your hand, and pull it at both end to see if it breaks and if it springs back to its original length. The more flexible the seal is, the less likely it is to be deformed by prolonged pressure on the door.

(4) Scrape with nails

  Seals made of poor material do not have a high latex content and the surface of the strip is easily scratched and became white. After being fitted to windows and doors, these seals will easily be damaged by minor scratches or impacts.

(5) High temperature test

  Wrap the seal as tightly as possible around the section steel under high temperature for a period of time (on the roof or in a sunny place) to observe whether the surface of the section steel and seal are stained and discolored, whether the dust on the surface of the seal is yellowed (it is easy to absorb soil if there is oil on the surface of the seal), whether it oozes oil and whether it stains the hands. The seal with good material is clean, dustproof, oil resistant and high temperature resistant. It will not yellow and ooze oil or get dirty under high temperature.

(6) Weigh

  The weight of the seal with good material is relatively light, and those seals adding talcum powder, heavy calcium carbonate seals not only are made of poor materials, but also heavier than seals that contain light calcium carbonate. And the seal is priced by its weight, so it is important to weight the seals of the same material and type when choosing a seal.

  Tongxiang Zhouquan Zhenqiang Plastic Ware Co., Ltd. is a production enterprises boasts its combination of production, research and development, sales. We specialize in the production of different seals and advocate low carbon and environmental protection. Our main products are EPDM foam rubber, magnetic door seals, plastic door seals for shower room, coating type seals, TPE door and window seals, PU coated type foam seals, shower room rollers and other plastic profiles.

  If you need above products, please email us at luan.zhou@gmail.com and we will reply to you as soon as possible.