Introduction of adhesive coating for fusible interlining
Fusible interlining is combined by 2 parts: base fabric and glue dots (adhesive coating). Besides base fabric is important. choosing correct type of adhesive coating also matters. In most cases, the adhesive coating of fusible interlining is made from different chemical plastic. By certain time, pressure and temperature, the coating will melt and fuse 2 layers of fabric together.
In next part INTERLINIO will introduce the glue dots from 5 parts. Below, they can be used in most fusing situations.
- PA
- PES.
- PE (HDPE and LDPE)
- EVA
- TPU
PA-Polyamide
Coating PA-polyamide is made from NYLON.
PA coating is the most welcomed adhesive coating nowadays. It looks shiny from side view. PA coating has an excellent performance in dry washing, good softness and high bond strength. In the past, PA has a relatively normal performance in water washing, but by the improving of technology nowadays, PA also can be used in normal washing from 40 degrees to 90℃, even enzyme washing. In addition, if your cloth is made from natural fiber fabric such as cotton, flax, cashmere, low temperature PA also can meet your needs.
****PA, usually are transparent and shiny compared with PES below.
PES
Coating PES is made from POLYESTER.
PES coating is also widely used because of its high cost-effectiveness. It also has advantages such as high bond strength, good hand feeling after fusing, low hygroscopicity, and excellent washability. However, PES has a general performance in dry washing. Due to cheap price, when comes to large, massive fusing works, such as full width fusing, PES is more welcomed compared with PA.
PA and PES usually produced from one factory together. They play different roles in different fusing situations. They are widely used in double dots coating machine and powder dot coating machine.
PE (LDPE and HDPE)
PE(LDPE and HDPE) is a kind of traditional coating, earlier than PA/PES, made from POLYETHYLENE.
LDPE means low density polyethylene.
HDPE means high density polyethylene.
LDPE and HDPE usually produced from one factory together. They play different roles in different fusing situations. They are widely used in powder dot coating machine.
LDPE’s performance is not good in normal washing and dry washing. The bonding strength is also not good as others. Because of its low density, the hand feeling after fusing is better than others. With these special characteristics, we need LDPE under these situations: partial support fusing, and temporary fusing (easy to tear the fusible interlining off for some special sewing process).
HDPE has a high density. Therefore, the temperature and pressure are much higher than LDPE. HDPE has a good performance in normal washing, but bad in dry washing. The hand feeling after fusing could harder compared with LDPE/PES. Because of this characteristic, the HDPE is mainly used in the hard parts and thick parts of cloth, such as collar, shoulder, cuff, fly, waist and placket.
EVA
EVA is made from ETHYLENE VINYL ACETATE.
Due to EVA’s special raw material and manufacturing process, the outlooking of EVA is more transparent than others. What most important is the fusing temperature is much lower than other adhesive coating, only 90~110℃. EVA interlining is mainly applied for heat-sensitive materials such as leather, fur. It can also be used for local temporary fusing in related garment sewing processes. However, its bonding strength after washing or dry washing is not so good as others.
TPU
TPU is made from THERMOPLASTIC URETHANES. TPU or TPU foam is a new type of adhesive coating material with wide fusing temperature range and good bonding performance.
TPU is always made into a thin foam. The fusing temperature and thickness can be customized by different requirements. It has a good bonding performance in normal washing and dry washing. In addition, the TPU foam is elastic. It performs well in fusing with elastic fabrics. When comes to small parts fusing, like embroidery fusing, repetitive fusing is acceptable. It is also applied in bonding of various outdoor clothing materials, such as ski suits, raincoats, windbreakers, cold jackets and field suits.
3 significant elements for adhesive coating
Temperature
Because of its chemical characteristics inside, the fusing temperatures of different glues are different. There are 2 steps during fusible interlining fusing with shell fabric. The first is melting and then the second is fusing (bonding). Tailors or employees should focus more on fusing temperatures more. Giving the fusible interlining enough time will be easier to bond with the shell fabric.
| Adhesive Coating Type | Melting Temperature °C | Fusing (Bonding) Temperature °C |
| PA | 90～140 | 110～165 |
| PES | 100～140 | 120～165 |
| LDPE | 95～110 | 115～135 |
| HDPE | 120～135 | 150～175 |
| EVA | 80～90 | 100～110 |
| TPU | 95～135 | 115～155 |
Some advice on temperature settings:
- Learn the parameter requirements of fusing temperature and melt index of different hot melt adhesives in advance.
- Flat plate fusing machine temperature is 5~10°C lower than roller continuous fusing machine.
Pressure
Pressure: When the interlining is bonded to the garment fabric. On the one hand, pressure can increase the fit between them. On the other hand, it helps to improve the penetration of the hot melt adhesive to the fabric. Absolutely, pressure plays a crucial role in the process of fusing interlining. As you mentioned, here are some tips and advice regarding pressure settings when working with interlining glues:
- Consider fabric properties: Different fabrics have varying thicknesses, densities, and textures. It’s important to take these factors into account when choosing the appropriate interlining fabric. Thicker or denser fabrics may require higher pressure to ensure proper adhesion.
- Understand hot melt adhesive characteristics: Different hot melt adhesives have varying melt viscosities and colloid softness or hardness. These properties affect how the adhesive penetrates the fabric. Understanding these characteristics can help you select the right pressure setting for a particular adhesive.
- Tailor to clothing style: Each clothing style may have specific requirements for interlining. For example, some garments may require a higher peel strength to withstand frequent stress or laundering. In such cases, selecting an interlining with appropriate peel strength and adjusting the pressure accordingly is important.
- Balance fabric style and bond quality: When determining the pressure, it’s essential to find a balance that doesn’t negatively impact the fabric’s appearance or style. Excessive pressure can flatten the fabric or leave imprints, affecting its overall aesthetic. By finding the right pressure setting, you can ensure a quality bond while preserving the fabric’s original look.
Remember, it’s always a good practice to test the pressure settings on a scrap fabric before applying it to the actual project. This allows you to assess the bond strength and any potential impact on the fabric’s appearance.
Additionally, be sure to refer to the manufacturer’s guidelines and recommendations for pressure settings specific to the interlining glue you are using. They often provide instructions or suggested pressure ranges to achieve optimal results.
By considering fabric properties, adhesive characteristics, clothing style requirements, and finding the right balance, you can ensure a successful interlining fusion while maintaining the fabric’s integrity and bond quality.
Time
Time: A suitable bonding time is shown as: Under the premise of not affecting the physical and chemical properties of the clothing fabric and the interlining base fabric itself, it is beneficial to the hot melt adhesive to fully soften, melt, wet, penetrate, and achieve the best bonding state of them.
- Consider fabric and interlining characteristics: Take into account the properties of both the apparel fabric and the interlining backing. Different materials, thicknesses, and densities can influence the optimal bonding time. Thicker fabrics or denser interlining backings may require longer bonding times to ensure sufficient adhesion.
- Understand the melt index of the adhesive: The melt index refers to the rate at which the hot melt adhesive melts and flows when heated. It is an important characteristic to consider when determining the bonding time. Adhesives with higher melt indexes may require shorter bonding times, as they achieve the desired level of adhesion more rapidly.
- Preserve fabric texture and appearance: The ideal bonding time should be selected to avoid negatively affecting the texture and appearance of the fabric. Excessive bonding time can lead to over-softening, flattening, or altering the fabric’s original characteristics. Regularly check the fabric during the bonding process to ensure it retains its desired texture and appearance.
- Prioritize bond quality and durability: While considering the fabric’s aesthetics, it is essential to maintain a strong bond between the fabric and the interlining. The bonding time should be sufficient to achieve a secure and durable bond. Perform quality control tests, such as pull tests or laundering, to evaluate the bond’s strength and durability.
- Conduct tests and adjustments: It’s a good practice to conduct tests on scrap fabric before bonding the main project. This allows you to determine the optimal bonding time for a specific combination of fabrics and interlining glues. Start with the manufacturer’s recommended bonding time and adjust it incrementally if needed, based on the results of your tests.
The following are suggestions for temperature, pressure and time when bonding some interlinings.
| Scope of application | Type | Flat ironing conditions | ||
| Temperature °C | Pressure（M ） | Time(s) | ||
| Outer Lining | PA | 140～170 | 0.03～0.05 | 12～20 |
| Fur Lining | EVA | 80～120 | 0.02～0.03 | 10～15 |
| Shirt Lining | HDPE | 160～170 | 0.2～0.3 | 13～15 |
| Small Clothing | LDPE | 120～140 | 0.06～0.12 | 10～15 |
| Fur Clothing | PA | 100～160 | 0.01～0.04 | 6～20 |
| Shirt | PES | 140～160 | 0.03～0.05 | 10～16 |
Cloth Factor
- Bonding temperature: The fabric type determines the bonding temperature. Natural fiber fabrics with good heat resistance can tolerate higher temperatures, typically around 160°C, while synthetic fiber fabrics generally require lower temperatures, around 140°C. Adjusting the temperature based on the fabric type helps ensure effective bonding without causing damage.
- Pressure: The pressure applied during bonding can vary based on the fabric type. Woven fabrics typically require a pressure of around 0.03MPa, while knitted fabrics may need a slightly lower pressure, around 0.02MPa, to prevent damage due to their bulkiness. Finding the right pressure balance is important to achieve a secure bond without compromising the fabric’s integrity.
- Bonding time: The bonding time is influenced by the fabric fibers. Natural fiber clothing fabrics usually benefit from slightly longer bonding times, while chemical synthetic fiber fabrics can have shorter bonding times. Blended fabrics, which consist of different fiber proportions, can have adjusted bonding times based on the specific fiber blend.
- Yarn count and fabric density: The bonding time can also be affected by the yarn count and density of the garment fabric. Fabrics with thicker yarn counts and higher densities generally require longer bonding times, while fabrics with finer yarn counts and lower densities may have shorter bonding times.
The relationship between washing conditions and rubber powder
In order to analyze the influence of different washing environments on the peel strength of hot melt adhesives, the following two tables are used for comparison.
The physical properties of the above hot melt adhesives are summarized in Table 1.
Table 1
| Type | Melting Temperature °C | Fusing Temperature °C | Adhesion | Wash ability | Dry Cleaning | Touch | Anti-aging | Discoloration |
| PA | 90～140 | 110～165 | ★ | ■ | ★ | ● | ● | ● |
| PES | 100～140 | 120～165 | ● | ★ | ■ | ● | ● | ● |
| LDPE | 95～110 | 115～135 | ■ | ▼ | x | ▼ | ▼ | ▼ |
| HDPE | 120～135 | 150～175 | ● | ★ | x | ▼ | ▼ | ▼ |
| EVA | 80～90 | 100～110 | ■ | ▼ | x | ▼ | ● | ● |
| TPU | 95～135 | 115～155 | ● | ● | ● | ★ | ● | ● |
Symbol Description:★excellent、●good、■still good、▼generally、x bad;
(Generally speaking, the melting temperature higher, the wash resistance higher)
The peel strength requirements of different washing environments are shown in Table 2.
Table 2
| Peel Strength（N/m） | Type | PA | PES | LDPE | HDPE | EVA | TPU | |
| Before Washing | 480 | 420 | 200 | 340 | 180 | 300 | ||
| After Washing | 40°C,1 time | 360 | 320 | 160 | — | — | 260 | |
| 40°C,3 times | 320 | 300 | 120 | — | — | 240 | ||
| 40°C,5times | 280 | 280 | 100 | — | — | 220 | ||
| 60°C,1 time | 300 | 280 | — | — | — | 240 | ||
| 60°C,3 times | 260 | 240 | — | — | — | 220 | ||
| 60°C,5 times | 220 | 220 | — | — | — | 200 | ||
| 92°C,1 time | 200 | 220 | — | 300 | — | — | ||
| 92°C,3 times | 140 | 160 | — | 280 | — | — | ||
| 92°C,5 times | 100 | 140 | — | 280 | — | — | ||
| Before dry cleaning | 180 | 160 | — | — | — | 220 | ||
| Before dry cleaning | 1 time | 140 | 120 | — | — | — | 200 | |
| 3 times | 120 | 100 | — | — | — | 180 | ||
Due to some special process requirements of enzyme washing. EVA hot melt adhesive with lower melting point will lose its tack completely in the enzyme washing, not suitable for enzyme wash. Some copolyamide hot melt adhesives with high melting point and high temperature washing resistance are more suitable for enzymatic washing.
Hot melt adhesive suitable for enzyme washing should have high temperature washing resistance, acid and alkali resistance and suitable melting point, all thre are indispensable.