Preparation method of friction aroma enhancement PETG heat shrinkage label film
By using microcapsule fragrances with a core-shell encapsulation structure in PETG heat-shrinkable label film, the problems of easy fragrance loss and PETG material degradation were solved, and a friction-enhanced PETG heat-shrinkable label film with slow fragrance release and stable film performance was prepared.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- JIANGSU GUANGHUI PACKAGE
- Filing Date
- 2026-03-31
- Publication Date
- 2026-05-15
AI Technical Summary
Existing PETG heat-shrink label films have strong fragrances that are easily lost during the manufacturing process, and the fragrance chemical components accelerate the degradation of PETG materials, leading to a decline in film performance.
Microcapsule fragrances with a core-shell encapsulation structure are processed with PETG to form fragrance masterbatches, and then ABA three-layer co-extruded PETG heat-shrinkable label films are prepared. The microcapsule fragrances consist of fragrance as the inner core, polyurea as the inner shell, and chitosan as the outer shell, avoiding direct contact with PETG material and releasing fragrance through hand rubbing.
It achieves long-lasting fragrance release and stable film performance, enhancing the consumer experience and the effectiveness of the label film.
Smart Images
Figure SMS_1
Abstract
Description
Technical Field
[0001] This invention belongs to the field of PETG heat shrink label film technology, specifically relating to a method for preparing a friction-enhanced fragrance PETG heat shrink label film. Background Technology
[0002] PETG heat shrink label film, as the main base film product for shrink labels on PET bottled beverages, gives PET bottled beverages a strong visual impact and excellent advertising effect by printing exquisite patterns and text, attracting consumers and enhancing their desire to buy.
[0003] Labels with fragrances, especially those matching the flavor of beverages, can significantly enhance a product's appeal and boost sales through the sense of smell. If the fragrance can be released slowly and accelerated through friction, the resulting experiential enjoyment will better align with modern consumerism's participatory nature, further increasing product attractiveness and achieving superior advertising results.
[0004] While directly adding fragrances can impart a scent characteristic to the label, the fragrance is often too strong. Furthermore, the actual amount of fragrance added is low, making it difficult to mix with PETG granules, resulting in uneven mixing and easy loss of aroma, directly impacting usability. Pre-fabricating fragrance masterbatches and then mixing them with PETG material before processing into film is a good method. However, this method has the following problems in preparing PETG heat-shrink label films: 1. The initial fragrance of the film is quite strong, but due to friction and wear during label manufacturing with multiple rollers, the fragrance is lost quickly and has a short retention time; 2. Some chemical components of the fragrance can accelerate the degradation of PETG material during film manufacturing, leading to a decline in film performance.
[0005] Therefore, there is currently no PETG heat shrink label film on the market that has a stable film structure and is fragrance-resistant, wear-resistant, and long-lasting. Summary of the Invention
[0006] To address the problems in the existing technology, this invention provides a method for preparing a friction-enhanced PETG heat-shrinkable label film, which solves the problem that fragrances accelerate the degradation of PETG materials. It utilizes microcapsule fragrances with a core-shell encapsulation structure, processes them with PETG to form fragrance masterbatches, and adds them to the label film, giving the label film a light fragrance. The fragrance intensifies when the label is rubbed by hand, enhancing the enjoyment of the beverage consumption process.
[0007] To achieve the above technical objectives, the technical solution of the present invention is as follows:
[0008] A method for preparing a friction-enhanced fragrance PETG heat-shrinkable label film includes the following steps: Step 1: Weigh the PETG resin and fragrance masterbatch according to the formula and add them to the first extruder for plasticizing and extrusion to obtain the A layer melt raw material; Step 2: Weigh the PETG resin and scrap filaments according to the ratio, and add them to the second extruder for plasticizing and extrusion to obtain the B layer melt raw material; Step 3: The A-layer melt raw material and the B-layer melt raw material are respectively fed into the film preparation mechanism through pipes for processing and shaping to obtain PETG shrink label film.
[0009] The plasticizing temperature of the first extruder in step 1 is 252-272℃; the mass ratio of PETG resin and fragrance masterbatch in the A-layer melt raw material is 100:3-5.
[0010] The plasticizing temperature of the second extruder in step 2 is 252-272℃, and the mass ratio of PETG to scrap filament in the B-layer melt raw material is 100:10. The scrap filament is the scrap filament recycled from the edge-cutting mechanism in the transverse stretching system.
[0011] The film preparation mechanism in step 3 consists of a pre-die distributor, a casting die, a casting mechanism, a transverse stretching system including a trimming mechanism, a traction system, a winding system, and a slitting system. The processing method of the film preparation mechanism includes: A-layer melt raw material enters the corresponding flow channel of the pre-die distributor through a pipe, splitting into two streams to form upper and lower surface layer streams A; B-layer melt raw material enters the middle flow channel of the pre-die distributor through a pipe to form the middle layer stream B; the A-layer melt raw material and B-layer melt raw material, after passing through the distributor, form an ABA three-layer structure stream, which is then cast into an ABA-structured PETG sheet through the casting die and casting mechanism. This sheet is then processed through the transverse stretching system, traction system, winding system, and slitting system to produce a friction-enhanced fragrance PETG heat-shrinkable label film. The friction-enhanced fragrance PETG heat-shrinkable label film prepared by this method has an ABA three-layer co-extrusion structure, and the upper and lower layers have the same thickness. Furthermore, the thickness ratio of the high-shrinkage PETG heat-shrinkable label film is 12.5:75:12.5.
[0012] The temperature of the die head pre-distributor is 267-272℃, the temperature of the casting die head is 267-272℃, the temperature of the casting roller of the casting mechanism is 28℃, the transverse stretching ratio of the transverse stretching system is 5, and the stretching temperature is 85-95℃.
[0013] In steps 1 and 2, the PETG resin used is a modified PETG resin, specifically CHDM modified PETG or NPG modified PETG. The CHDM modified PETG is one of Embrace™ copolyester, Embrace™ LV copolyester, GN001, S2008 from SK Corporation of Korea, and K2012 from SK Corporation of Korea. The NPG modified PETG is one of FG718H from Yizheng Chemical Fiber, HSF from Jiangsu Suolide Company, and W501 from Jiangyin Huahong.
[0014] The fragrance masterbatch is composed of PETG resin, microencapsulated fragrance, and antioxidant, with the following mass ratio: 100 parts PETG resin, 30 parts microencapsulated fragrance, and 5 parts antioxidant. The PETG resin used is HSF from Jiangsu Solide Company, and the antioxidant is Antioxidant 1010, namely pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]. This antioxidant can reduce or even prevent degradation of the PETG material caused by high temperature and shear during the preparation of the fragrance masterbatch. The microencapsulated fragrance is a chitosan / polyurea / fragrance microencapsulated fragrance, and the preparation method of the fragrance masterbatch includes... The next steps are: a1, weigh PETG resin, microcapsule fragrance, and antioxidant according to the mass ratio, then grind PETG in a cryogenic mill and pass it through a 40-mesh sieve to obtain fine PETG powder; a2, add the weighed fine PETG powder, microcapsule fragrance, and antioxidant to a mixer and mix at high speed for 5 minutes to obtain a uniformly mixed mixture; a3, feed the mixture into a twin-screw extruder for extrusion granulation to obtain fragrance masterbatch. The parameters of the twin-screw extruder are φ55, length-to-diameter ratio L / D=30:1, body temperature 200-255℃, die head temperature 250-255℃, and rotation speed 45rpm.
[0015] The microcapsule fragrance uses chitosan / polyurea / fragrance microcapsules, with fragrance as the core, polyurea as the inner shell, and chitosan as the outer shell. This microcapsule fragrance has a core-shell structure, effectively preventing direct contact between the fragrance and PETG material and degradation during PETG material processing. It also acts as a film opening agent. The preparation method of the chitosan / polyurea / fragrance microcapsule fragrance includes the following steps: b1, mixing the fragrance, isohexyl glycol, and isophorone diisocyanate evenly to obtain a homogeneous oil phase; the fragrance is an oil-soluble fragrance, and the corresponding fragrance variety is selected according to the beverage flavor, such as sweet orange flavor, strawberry flavor, mango flavor, pineapple flavor, compound fruit flavor, jasmine tea flavor, and lemon black tea flavor, taking sweet orange flavor as an example; b2, adding sodium methacrylate sulfonate and polyvinyl alcohol to deionized water, heating to 45°C, and stirring until completely dissolved. Then cool to room temperature to obtain an aqueous phase. The polyvinyl alcohol used is a product with a degree of alcoholysis of 78-88%, such as PVA-1788 or PVA-2488 from Anhui Wanwei High-Tech Materials Co., Ltd.; b3, slowly add the oil phase dropwise to the aqueous phase and stir at high speed for 3-5 minutes at room temperature to form a stable water-in-oil emulsion; the high-speed stirring speed is 650-900 rpm, preferably 750 rpm; b4, under room temperature and stirring conditions, slowly add the crosslinking agent and 3% catalyst aqueous solution to the emulsion. The addition was completed dropwise within 0 min, and the mixture was kept at room temperature for 10 min, then heated to 60℃ and reacted at a constant temperature for 2 h, then heated to 70℃ and reacted at a constant temperature for 2 h. After cooling to room temperature, a polyurea / fragrance microcapsule suspension was obtained. The crosslinking agent was ethylenediamine, and the catalyst was MTBD, namely N-methyl-1,5,7-triazabicyclo[4,4,0]dec-5-ene; b5, chitosan was added to 1% dilute hydrochloric acid to prepare a 0.5 g / mL chitosan solution; glutaraldehyde was added to water to prepare a 25% (w / w) glutaraldehyde aqueous solution. b6. Add 0.5 g / mL chitosan solution to the polyurea / fragrance microcapsule suspension and mix well. Then slowly add 25% glutaraldehyde aqueous solution, completing the addition within 30 min. Heat to 35℃ and react for 4 h. After cooling to room temperature, obtain chitosan / polyurea / fragrance microcapsule suspension. The mass ratio of chitosan to glutaraldehyde is 1:1.15. b7. Adjust the pH of the above suspension to 6.5-7.5 with 5% ammonia water. Then filter repeatedly with deionized water and dry to obtain chitosan / polyurea / fragrance microcapsule fragrance.
[0016] Using fragrance as the core, polyurea as the inner capsule wall, and chitosan as the outer capsule wall, chitosan / polyurea / fragrance microcapsules are prepared. Encapsulating the fragrance within tiny "capsules" formed by chitosan / polyurea materials effectively solves the problems of fragrance volatility and easy oxidation, and enables intelligent, long-lasting fragrance release. Simultaneously, it avoids direct contact between PETG and fragrance, solving the problem of fragrance accelerating PETG material degradation. Polyurea, an elastomer, possesses good wear resistance and toughness as a microcapsule wall material, capable of withstanding certain physical forces during processing and use. The polyurea microcapsules have a high encapsulation rate, reaching over 80%, and the dense and robust polyurea capsule walls effectively isolate light, oxygen, high temperatures, and moisture, protecting the internal fragrance from volatilization and decomposition, significantly extending the fragrance retention time. Chitosan, a natural antibacterial agent, has issues with mechanical strength as a wall material; however, chitosan wall materials prepared through glutaraldehyde cross-linking exhibit improved mechanical strength and heat resistance. Chitosan's outer wall can effectively supplement polyurea wall materials, better controlling the release rate of fragrance. Chitosan's antibacterial properties can enhance the antibacterial ability of the label film surface, improving health protection during friction. The polysaccharide / polyurea / fragrance microcapsules have a relatively large particle structure; when used in the surface layer of PETG heat-shrink label film, they are plasticized into tiny raised structures, acting as film opening agents. Therefore, the fragrance of a fragrance is an olfactory effect produced by the combination of various volatile gases. Without microcapsule encapsulation, it will evaporate and be consumed within a short time, losing its fragrance. With polysaccharide / polyurea / fragrance microcapsules, the fragrance can slowly permeate through the capsule wall without external force, achieving a long-lasting, light fragrance for hours or even months. When the microcapsules are rubbed by external force (such as by hand), they rupture, instantly releasing a richer fragrance, achieving a friction-enhanced fragrance effect.
[0017] As can be seen from the above description, the present invention has the following advantages: 1. This invention solves the problem that flavorings accelerate the degradation of PETG materials. It utilizes microcapsule flavorings with a core-shell encapsulation structure to process PETG into flavoring masterbatch, which is then added to the label film to give the label film a light fragrance. The fragrance intensifies when the label is rubbed by hand, enhancing the enjoyment of the beverage consumption process.
[0018] 2. This invention uses fragrance as the inner core, polyurea as the inner shell, and chitosan as the outer shell to form a chitosan / polyurea / fragrance microcapsule fragrance, which forms layers of coating on the fragrance surface, avoiding direct contact between the fragrance and PETG material, and eliminating the accelerating effect of fragrance on PETG degradation. Detailed Implementation
[0019] The present invention will be described in detail with reference to the embodiments, but the claims of the present invention are not intended to limit the scope of the invention.
[0020] The preparation method of the chitosan / polyurea / fragrance microcapsule flavor includes the following steps: b1, mixing 50g sweet orange flavor, 20g isohexyl glycol and 10g isophorone diisocyanate evenly to obtain a homogeneous oil phase; b2, adding 2g sodium methacrylate sulfonate and 0.8g polyvinyl alcohol to 197.2g deionized water, heating to 45℃, stirring until completely dissolved, and then cooling to room temperature to obtain an aqueous phase. The polyvinyl alcohol used is a polyvinyl alcohol product with a degree of alcoholysis of 78-88%, specifically PVA-2488 from Anhui Wanwei High-Tech Materials Co., Ltd.; b3, slowly adding the above oil phase dropwise to the aqueous phase, and stirring at high speed for 5 minutes at room temperature to form a stable water-in-oil emulsion; the high-speed stirring speed is 750 rpm; b4, under room temperature and stirring conditions, adding 2g ethylenediamine and 10mL of 3%... MTBD aqueous solution was slowly added to the emulsion, with the addition completed dropwise over 30 minutes. The mixture was kept at room temperature for 10 minutes, then heated to 60°C and reacted for 2 hours, followed by a further increase to 70°C and another 2 hours. After cooling to room temperature, a polyurea / fragrance microcapsule suspension was obtained. b5, Chitosan was added to 1% dilute hydrochloric acid to prepare a 0.5 g / mL chitosan solution; Glutaraldehyde was added to water to prepare a 25% (w / w) glutaraldehyde aqueous solution; b6, 100 mL of the 0.5 g / mL chitosan solution... Add the mixture to the polyurea / fragrance microcapsule suspension and mix well. Then, slowly add 230 mL of 25% glutaraldehyde aqueous solution over 30 minutes. The mixture is then heated to 35°C and reacted for 4 hours. After cooling to room temperature, a chitosan / polyurea / fragrance microcapsule suspension is obtained. The mass ratio of chitosan to glutaraldehyde is 1:1.15. b7. The pH of the suspension is adjusted to 7.2 using 5% ammonia water. The suspension is then repeatedly filtered with deionized water and dried to obtain the chitosan / polyurea / fragrance microcapsule fragrance.
[0021] The flavor masterbatch has the following mass ratio: 100 parts PETG resin, 30 parts chitosan / polyurea / flavor microcapsule flavor, and 5 parts antioxidant. The PETG resin used is HSF from Jiangsu Solide Company, and the antioxidant is antioxidant 1010. The preparation method of the flavor masterbatch includes the following steps: a1, weighing the PETG resin, chitosan / polyurea / flavor microcapsule flavor, and antioxidant according to the above mass ratio, and grinding the PETG resin in a cryogenic mill. After passing through a 40-mesh sieve, PETG fine powder is obtained; a2, PETG fine powder, chitosan / polyurea / fragrance microcapsule flavoring, and antioxidant are placed in a mixer and mixed at high speed for 5 minutes to obtain a uniformly mixed mixture; a3, the mixture is placed in a twin-screw extruder for extrusion granulation to obtain flavoring masterbatch. The parameters of the twin-screw extruder are φ55, length-to-diameter ratio L / D=30:1, body temperature 200-255℃, die head temperature 250-255℃, and rotation speed 45rpm.
[0022] Example 1 A method for preparing a friction-enhanced fragrance PETG heat-shrinkable label film includes the following steps: Step 1: Weigh the PETG resin and fragrance masterbatch according to the ratio, and add them to the first extruder for plasticizing and extrusion to obtain layer A melt raw material; the plasticizing temperature of the first extruder is 252-272℃; the mass ratio of PETG resin and fragrance masterbatch in the layer A melt raw material is 100:3, and the PETG used is HSF from Jiangsu Solide Company; Step 2: Weigh the PETG resin and scrap filaments according to the specified ratio, and add them to the second extruder for plasticizing and extrusion to obtain the B-layer melt raw material; the plasticizing temperature of the second extruder is 252-272℃, and the mass ratio of PETG to scrap filaments in the B-layer melt raw material is 100:10. The scrap filaments are recycled from the edge-cutting mechanism in the transverse stretching system, and the PETG used is HSF from Jiangsu Suolide Company. Step 3: The A-layer melt material and the B-layer melt material are respectively fed into the film preparation mechanism through pipes for processing and forming to obtain PETG shrink label film. The film preparation mechanism consists of a pre-die distributor, a casting die, a casting mechanism, a transverse stretching system with an edge trimming mechanism, a traction system, a winding system, and a slitting system. The processing method of the film preparation mechanism includes: the A-layer melt material is fed into the corresponding flow channel of the pre-die distributor through pipes and divided into two streams to form upper and lower surface streams A; the B-layer melt material is fed into the middle flow channel of the pre-die distributor through pipes to form the middle layer stream B; the A-layer melt material and the B-layer melt material form an ABA three-layer structure stream after passing through the distributor, which is then cast into an ABA structure PETG sheet through the casting die and casting mechanism, and then processed through the transverse stretching system, traction system, winding system, and slitting system to produce a friction-enhanced fragrance PETG heat shrink label film product. The temperature of the die head pre-distributor is 267-272℃, the temperature of the casting die head is 267-272℃, the temperature of the casting roller of the casting mechanism is 28℃, the transverse stretching ratio of the transverse stretching system is 5, and the stretching temperature is 85-95℃.
[0023] The thickness ratio of the three-layer structure in the friction-enhanced fragrance PETG heat-shrinkable label film obtained by the above method is 12.5:75:12.5.
[0024] Example 2 A method for preparing a friction-enhanced fragrance PETG heat-shrinkable label film includes the following steps: Step 1: Weigh the PETG resin and fragrance masterbatch according to the ratio, and add them to the first extruder for plasticizing and extrusion to obtain layer A melt raw material; the plasticizing temperature of the first extruder is 252-272℃; the mass ratio of PETG resin and fragrance masterbatch in the layer A melt raw material is 100:4, and the PETG used is HSF from Jiangsu Solide Company; Step 2: Weigh the PETG resin and scrap filaments according to the specified ratio, and add them to the second extruder for plasticizing and extrusion to obtain the B-layer melt raw material; the plasticizing temperature of the second extruder is 252-272℃, and the mass ratio of PETG to scrap filaments in the B-layer melt raw material is 100:10. The scrap filaments are recycled from the edge-cutting mechanism in the transverse stretching system, and the PETG used is HSF from Jiangsu Suolide Company. Step 3: The A-layer melt material and the B-layer melt material are respectively fed into the film preparation mechanism through pipes for processing and forming to obtain PETG shrink label film. The film preparation mechanism consists of a pre-die distributor, a casting die, a casting mechanism, a transverse stretching system with an edge trimming mechanism, a traction system, a winding system, and a slitting system. The processing method of the film preparation mechanism includes: the A-layer melt material is fed into the corresponding flow channel of the pre-die distributor through pipes and divided into two streams to form upper and lower surface streams A; the B-layer melt material is fed into the middle flow channel of the pre-die distributor through pipes to form the middle layer stream B; the A-layer melt material and the B-layer melt material form an ABA three-layer structure stream after passing through the distributor, which is then cast into an ABA structure PETG sheet through the casting die and casting mechanism, and then processed through the transverse stretching system, traction system, winding system, and slitting system to produce a friction-enhanced fragrance PETG heat shrink label film product. The temperature of the die head pre-distributor is 267-272℃, the temperature of the casting die head is 267-272℃, the temperature of the casting roller of the casting mechanism is 28℃, the transverse stretching ratio of the transverse stretching system is 5, and the stretching temperature is 85-95℃.
[0025] The thickness ratio of the three-layer structure in the friction-enhanced fragrance PETG heat-shrinkable label film obtained by the above method is 12.5:75:12.5.
[0026] Example 3 A method for preparing a friction-enhanced fragrance PETG heat-shrinkable label film includes the following steps: Step 1: Weigh the PETG resin and fragrance masterbatch according to the ratio, and add them to the first extruder for plasticizing and extrusion to obtain layer A melt raw material; the plasticizing temperature of the first extruder is 252-272℃; the mass ratio of PETG resin and fragrance masterbatch in the layer A melt raw material is 100:5, and the PETG used is HSF from Jiangsu Solide Company; Step 2: Weigh the PETG resin and scrap filaments according to the specified ratio, and add them to the second extruder for plasticizing and extrusion to obtain the B-layer melt raw material; the plasticizing temperature of the second extruder is 252-272℃, and the mass ratio of PETG to scrap filaments in the B-layer melt raw material is 100:10. The scrap filaments are recycled from the edge-cutting mechanism in the transverse stretching system, and the PETG used is HSF from Jiangsu Suolide Company. Step 3: The A-layer melt material and the B-layer melt material are respectively fed into the film preparation mechanism through pipes for processing and forming to obtain PETG shrink label film. The film preparation mechanism consists of a pre-die distributor, a casting die, a casting mechanism, a transverse stretching system with an edge trimming mechanism, a traction system, a winding system, and a slitting system. The processing method of the film preparation mechanism includes: the A-layer melt material is fed into the corresponding flow channel of the pre-die distributor through pipes and divided into two streams to form upper and lower surface streams A; the B-layer melt material is fed into the middle flow channel of the pre-die distributor through pipes to form the middle layer stream B; the A-layer melt material and the B-layer melt material form an ABA three-layer structure stream after passing through the distributor, which is then cast into an ABA structure PETG sheet through the casting die and casting mechanism, and then processed through the transverse stretching system, traction system, winding system, and slitting system to produce a friction-enhanced fragrance PETG heat shrink label film product. The temperature of the die head pre-distributor is 267-272℃, the temperature of the casting die head is 267-272℃, the temperature of the casting roller of the casting mechanism is 28℃, the transverse stretching ratio of the transverse stretching system is 5, and the stretching temperature is 85-95℃.
[0027] The thickness ratio of the three-layer structure in the friction-enhanced fragrance PETG heat-shrinkable label film obtained by the above method is 12.5:75:12.5.
[0028] Comparative Example 1 A method for preparing a flavor-enhanced PETG heat-shrinkable label film includes the following steps: Step 1: Weigh the PETG resin and fragrance masterbatch according to the ratio, and add them to the first extruder for plasticizing and extrusion to obtain layer A melt raw material; the plasticizing temperature of the first extruder is 252-272℃; the mass ratio of PETG resin and fragrance masterbatch in the layer A melt raw material is 100:4, and the PETG used is HSF from Jiangsu Solide Company; Step 2: Weigh the PETG resin and scrap filaments according to the specified ratio, and add them to the second extruder for plasticizing and extrusion to obtain the B-layer melt raw material; the plasticizing temperature of the second extruder is 252-272℃, and the mass ratio of PETG to scrap filaments in the B-layer melt raw material is 100:10. The scrap filaments are recycled from the edge-cutting mechanism in the transverse stretching system, and the PETG used is HSF from Jiangsu Suolide Company. Step 3: The A-layer melt material and the B-layer melt material are respectively fed into the film preparation mechanism through pipes for processing and forming to obtain PETG shrink label film. The film preparation mechanism consists of a pre-die distributor, a casting die, a casting mechanism, a transverse stretching system with an edge trimming mechanism, a traction system, a winding system, and a slitting system. The processing method of the film preparation mechanism includes: the A-layer melt material is fed into the corresponding flow channel of the pre-die distributor through pipes and divided into two streams to form upper and lower surface streams A; the B-layer melt material is fed into the middle flow channel of the pre-die distributor through pipes to form the middle layer stream B; the A-layer melt material and the B-layer melt material form an ABA three-layer structure stream after passing through the distributor, which is then cast into an ABA structure PETG sheet through the casting die and casting mechanism, and then processed through the transverse stretching system, traction system, winding system, and slitting system to produce a flavored PETG heat shrink label film product. The temperature of the die head pre-distributor is 267-272℃, the temperature of the casting die head is 267-272℃, the temperature of the casting roller of the casting mechanism is 28℃, the transverse stretching ratio of the transverse stretching system is 5, and the stretching temperature is 85-95℃.
[0029] The flavor masterbatch is formulated with the following mass ratio: 100 parts PETG resin, 8.8 parts sweet orange flavoring, and 5 parts antioxidant. The PETG resin used is HSF from Jiangsu Solide Company, which is finely ground. The antioxidant used is antioxidant 1010. The preparation method of the flavor masterbatch includes: weighing PETG resin, sweet orange flavoring, and antioxidant according to the ratio, adding them to a mixer and mixing at high speed for 5 minutes to obtain a uniform mixture, and then feeding the mixture into a twin-screw extruder for extrusion granulation to obtain the flavor masterbatch. The parameters of the twin-screw extruder are: φ55, length-to-diameter ratio L / D=30:1, body temperature 200-255℃, die head temperature 250-255℃, and rotation speed 45rpm.
[0030] The thickness ratio of the three layers in the flavor-enhanced PETG heat-shrinkable label film obtained by the above method is 12.5:75:12.5.
[0031] Comparative Example 2 A method for preparing a PETG heat-shrinkable label film includes the following steps: Step 1: Weigh the PETG resin and open-end slip masterbatch according to the specified ratio, and add them to the first extruder for plasticizing and extrusion to obtain layer A melt raw material; the plasticizing temperature of the first extruder is 252-272℃; the mass ratio of PETG resin to open-end slip masterbatch in the layer A melt raw material is 100:3, the PETG used is HSF from Jiangsu Suolide Company; the open-end slip masterbatch used is Sukano® TA10-08MB13 from Sukano Company, Switzerland; Step 2: Weigh the PETG resin and scrap filaments according to the specified ratio, and add them to the second extruder for plasticizing and extrusion to obtain the B-layer melt raw material; the plasticizing temperature of the second extruder is 252-272℃, and the mass ratio of PETG to scrap filaments in the B-layer melt raw material is 100:10. The scrap filaments are recycled from the edge-cutting mechanism in the transverse stretching system, and the PETG used is HSF from Jiangsu Suolide Company. Step 3: The A-layer melt material and the B-layer melt material are respectively fed into the film preparation mechanism through pipes for processing and forming to obtain PETG shrink label film. The film preparation mechanism consists of a pre-die distributor, a casting die, a casting mechanism, a transverse stretching system including a trimming mechanism, a traction system, a winding system, and a slitting system. The processing method of the film preparation mechanism includes: the A-layer melt material is fed into the corresponding flow channel of the pre-die distributor through pipes and divided into two streams to form upper and lower surface layer streams A; the B-layer melt material is fed into the middle flow channel of the pre-die distributor through pipes to form the middle layer stream B; the A-layer melt material and the B-layer melt material form an ABA three-layer structure stream after passing through the distributor, which is then cast into an ABA structure PETG sheet through the casting die and casting mechanism, and then processed through the transverse stretching system, traction system, winding system, and slitting system to produce PETG heat shrink label film products. The temperature of the die head pre-distributor is 267-272℃, the temperature of the casting die head is 267-272℃, the temperature of the casting roller of the casting mechanism is 28℃, the transverse stretching ratio of the transverse stretching system is 5, and the stretching temperature is 85-95℃.
[0032] The thickness ratio of the three layers in the PETG heat-shrinkable label film obtained by the above method is 12.5:75:12.5.
[0033] Performance testing The performance of PETG heat-shrinkable label films prepared in Examples 1-3 and Comparative Examples 1-2 was tested, and the results are shown below: Table 1. Main properties of PETG heat-shrink label films from Examples 1-3 and Comparative Examples 1-2.
[0034] The fragrance is assessed using a direct sensory smelling method. First, the label film is placed near the nose, and hydrogen gas is inhaled through the nose to allow the aroma to enter the nasal cavity. The fragrance is then perceived through the sense of smell. Next, the label film is rubbed with the hand, and the change in fragrance is smelled again after 1 second. The sensory fragrance levels are indicated by numbers 0-10, with 1-10 representing a range from faint to strong, and 0 representing no fragrance.
[0035] The data comparison above shows that this technical solution uses fragrance as the core, polyurea as the inner shell, and chitosan as the outer shell to form a microcapsule structure for the fragrance. This protects the fragrance and enables long-lasting release of the aroma, while also preventing the performance degradation of the PETG heat-shrink label film caused by direct addition of fragrance. When the fragrance in this microcapsule structure is subjected to external force, surface cracks are formed, increasing the amount of aroma released and the aroma concentration, thereby achieving the effect of friction-enhanced fragrance.
[0036] It is understood that the above detailed description of the present invention is for illustrative purposes only and is not intended to limit the technical solutions described in the embodiments of the present invention. Those skilled in the art should understand that modifications or equivalent substitutions can still be made to the present invention to achieve the same technical effects; as long as the usage requirements are met, they are all within the protection scope of the present invention.
Claims
1. A method for preparing a friction-enhanced fragrance PETG heat-shrinkable label film, characterized in that: Includes the following steps: Step 1: Weigh the PETG resin and fragrance masterbatch according to the formula and add them to the first extruder for plasticizing and extrusion to obtain the A layer melt raw material; Step 2: Weigh the PETG resin and scrap filaments according to the ratio, and add them to the second extruder for plasticizing and extrusion to obtain the B layer melt raw material; Step 3: The A-layer melt raw material and the B-layer melt raw material are respectively fed into the film preparation mechanism through pipes for processing and shaping to obtain PETG shrink label film; The flavor masterbatch is composed of PETG resin, microcapsule flavoring, and antioxidants, and the microcapsule flavoring uses chitosan / polyurea / flavor microcapsule flavoring.
2. The method for preparing the friction-enhanced fragrance PETG heat-shrinkable label film according to claim 1, characterized in that: The plasticizing temperature of the first extruder in step 1 is 252-272℃.
3. The method for preparing the friction-enhanced fragrance PETG heat-shrinkable label film according to claim 1, characterized in that: The mass ratio of PETG resin and fragrance masterbatch in the A-layer melt raw material is 100:3-5.
4. The method for preparing the friction-enhanced fragrance PETG heat-shrinkable label film according to claim 1, characterized in that: The plasticizing temperature of the second extruder in step 2 is 252-272℃.
5. The method for preparing the friction-enhanced fragrance PETG heat-shrinkable label film according to claim 1, characterized in that: The mass ratio of PETG to scrap wire in the B-layer melt raw material is 100:
10. The scrap wire is the scrap wire recycled from the edge-cutting mechanism in the transverse stretching system.
6. The method for preparing the friction-enhanced fragrance PETG heat-shrinkable label film according to claim 1, characterized in that: The film preparation mechanism in step 3 consists of a pre-distributor die, a casting die, a casting mechanism, a transverse stretching system including a trimming mechanism, a traction system, a winding system, and a slitting system. The processing method of the film preparation mechanism includes: the A-layer melt raw material enters the corresponding flow channel of the pre-distributor die through a pipe, and is divided into two streams to form upper and lower surface streams A; the B-layer melt raw material enters the middle flow channel of the pre-distributor die through a pipe to form the middle layer stream B; the A-layer melt raw material and the B-layer melt raw material form an ABA three-layer structure stream after passing through the distributor, and are cast into an ABA structure PETG sheet through the casting die and casting mechanism, and then processed by the transverse stretching system, traction system, winding system, and slitting system to produce a friction-enhanced fragrance PETG heat shrink label film product.
7. The method for preparing the friction-enhanced fragrance PETG heat-shrinkable label film according to claim 6, characterized in that: The friction-enhanced fragrance PETG heat-shrinkable label film has an ABA three-layer co-extruded structure, and the upper and lower layers have the same thickness.
8. The method for preparing the friction-enhanced fragrance PETG heat-shrinkable label film according to claim 6, characterized in that: The temperature of the die head pre-distributor is 267-272℃, the temperature of the casting die head is 267-272℃, the temperature of the casting roller of the casting mechanism is 28℃, the transverse stretching ratio of the transverse stretching system is 5, and the stretching temperature is 85-95℃.
9. The method for preparing the friction-enhanced fragrance PETG heat-shrinkable label film according to claim 1, characterized in that: The PETG resin used in steps 1 and 2 is a modified PETG resin, specifically CHDM modified PETG or NPG modified PETG; wherein, the CHDM modified PETG is one of Embrace™ copolyester, Embrace™ LV copolyester, GN001, S2008 from SK Corporation of Korea, and K2012 from SK Corporation of Korea; the NPG modified PETG is one of FG718H from Yizheng Chemical Fiber, HSF from Jiangsu Suolide Company, and W501 from Jiangyin Huahong.
10. The method for preparing the friction-enhanced fragrance PETG heat-shrinkable label film according to claim 8, characterized in that: The microcapsule fragrance has a fragrance core, a polyurea inner shell, and a chitosan outer shell.