{"id":1257,"date":"2026-07-20T02:17:45","date_gmt":"2026-07-20T02:17:45","guid":{"rendered":"https:\/\/lypaperchem.com\/?p=1257"},"modified":"2026-07-20T02:17:46","modified_gmt":"2026-07-20T02:17:46","slug":"neutral-sizing-agents-in-papermaking-types-mechanisms-and-modern-applications","status":"publish","type":"post","link":"https:\/\/lypaperchem.com\/pt\/neutral-sizing-agents-in-papermaking-types-mechanisms-and-modern-applications\/","title":{"rendered":"Agentes de neutraliza\u00e7\u00e3o na fabrica\u00e7\u00e3o de papel: tipos, mecanismos e aplica\u00e7\u00f5es modernas"},"content":{"rendered":"<h3 class=\"wp-block-heading\">Agentes de neutraliza\u00e7\u00e3o na fabrica\u00e7\u00e3o de papel: tipos, mecanismos e aplica\u00e7\u00f5es modernas<\/h3>\n\n\n\n<h2 class=\"wp-block-heading\">Introdu\u00e7\u00e3o<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">As fibras de papel, compostas principalmente por celulose, cont\u00eam um grande n\u00famero de grupos hidroxilo (-OH) que formam facilmente liga\u00e7\u00f5es de hidrog\u00e9nio com a \u00e1gua, conferindo ao papel uma forte tend\u00eancia hidrof\u00edlica. Quando o papel \u00e9 embebido em \u00e1gua, perde a maior parte da sua resist\u00eancia \u2014 uma propriedade desej\u00e1vel para o papel de seda e o papel de ondula\u00e7\u00e3o, mas indesej\u00e1vel para a maioria dos outros tipos de papel, tais como papel de escrit\u00f3rio, embalagens alimentares, caixas de cosm\u00e9ticos e sacos alimentares.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A colagem \u00e9 o processo atrav\u00e9s do qual os fabricantes de papel conferem resist\u00eancia \u00e0 penetra\u00e7\u00e3o de \u00e1gua e de l\u00edquidos, impedindo a difus\u00e3o e a penetra\u00e7\u00e3o de l\u00edquidos aquosos. Existem dois m\u00e9todos principais de colagem: <strong>colagem interna (ou da polpa)<\/strong>, em que o agente de colagem \u00e9 adicionado \u00e0 pasta durante a batida ou a prepara\u00e7\u00e3o da pasta, e <strong>dimensionamento da superf\u00edcie<\/strong>, onde o agente \u00e9 aplicado ap\u00f3s a forma\u00e7\u00e3o da folha de papel. Com exce\u00e7\u00e3o dos pap\u00e9is absorventes, do papel de filtro, do papel encerado, do papel de cigarro e do papel de seda, quase todos os tipos de papel requerem colagem. A colagem melhora a resist\u00eancia do papel \u00e0 \u00e1gua, ao \u00f3leo e \u00e0 tinta de impress\u00e3o, ao mesmo tempo que aumenta a suavidade, a hidrofobicidade e a capacidade de impress\u00e3o.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Entre as v\u00e1rias tecnologias de dimensionamento, <strong>agentes de dimensionamento neutros<\/strong> t\u00eam-se revelado a escolha dominante na fabrica\u00e7\u00e3o moderna de papel, permitindo a transi\u00e7\u00e3o de sistemas de fabrica\u00e7\u00e3o de papel \u00e1cidos para sistemas neutros e alcalinos. Este artigo apresenta uma vis\u00e3o geral t\u00e9cnica abrangente dos agentes de colagem neutros \u2014 a sua classifica\u00e7\u00e3o, mecanismos de a\u00e7\u00e3o, vantagens, limita\u00e7\u00f5es e tend\u00eancias de mercado.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">1. O que s\u00e3o agentes de neutraliza\u00e7\u00e3o?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Os agentes de colagem neutros constituem uma subcategoria dos agentes de colagem internos utilizados na fabrica\u00e7\u00e3o de papel. Foram concebidos para funcionar em condi\u00e7\u00f5es neutras ou alcalinas de fabrico de papel (pH 6,0\u20138,5 e superior), ao contr\u00e1rio dos sistemas tradicionais de colagem \u00e1cidos, que operam a um pH de 4,0\u20135,5.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">O princ\u00edpio de funcionamento dos agentes de colagem neutros baseia-se no efeito sin\u00e9rgico dos grupos hidrof\u00edlicos e hidrof\u00f3bicos. Quando utilizados em conjunto com cargas de carbonato de c\u00e1lcio, os agentes de colagem neutros melhoram a brancura e o volume do papel, reduzindo simultaneamente o risco de corros\u00e3o do equipamento.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">1.1 Porqu\u00ea a mudan\u00e7a para o sistema de tamanhos neutros?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">A transi\u00e7\u00e3o da ind\u00fastria do papel da produ\u00e7\u00e3o \u00e1cida para a produ\u00e7\u00e3o neutra\/alcalina tem sido impulsionada por v\u00e1rios fatores determinantes:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Compatibilidade dos preenchimentos<\/strong>: Os sistemas neutros permitem a utiliza\u00e7\u00e3o de carbonato de c\u00e1lcio \u2014 um enchimento que \u00e9 30\u201350% mais barato do que o talco e que melhora significativamente a brancura do papel (+5\u20138% ISO), a opacidade (+10\u201315%) e o volume<\/li>\n\n\n\n<li><strong>Prote\u00e7\u00e3o das fibras<\/strong>: As condi\u00e7\u00f5es \u00e1cidas (pH &lt; 6) provocam a hidr\u00f3lise das fibras, reduzindo a resist\u00eancia do papel. As condi\u00e7\u00f5es neutras preservam a integridade das fibras, com o \u00edndice de tra\u00e7\u00e3o a melhorar em 10\u201315% e a resist\u00eancia \u00e0 dobragem em 20%<\/li>\n\n\n\n<li><strong>Durabilidade do equipamento<\/strong>: Os sistemas neutros s\u00e3o menos corrosivos para o equipamento das m\u00e1quinas de fabrico de papel, prolongando a vida \u00fatil e reduzindo os custos de manuten\u00e7\u00e3o<\/li>\n\n\n\n<li><strong>Benef\u00edcios ambientais<\/strong>: A neutraliza\u00e7\u00e3o elimina ou reduz significativamente a utiliza\u00e7\u00e3o de sulfato de alum\u00ednio, diminuindo a descarga de DQO em 40\u201360% por tonelada de papel<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">2. Classifica\u00e7\u00e3o dos agentes de dimensionamento neutros<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Os agentes de neutraliza\u00e7\u00e3o s\u00e3o geralmente classificados em tr\u00eas categorias principais:<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>Agentes de colagem \u00e0 base de resina de colof\u00f3nia<\/strong> (resina cati\u00f4nica dispersa, resina refor\u00e7ada)<\/li>\n\n\n\n<li><strong>Agentes de colagem sint\u00e9ticos<\/strong> (AKD, ASA)<\/li>\n\n\n\n<li><strong>Agentes de colagem do tipo pol\u00edmero<\/strong> (dispers\u00f5es de pol\u00edmeros cati\u00f3nicos)<\/li>\n<\/ol>\n\n\n\n<p class=\"wp-block-paragraph\">Cada categoria apresenta propriedades qu\u00edmicas, mecanismos de dimensionamento e caracter\u00edsticas de aplica\u00e7\u00e3o distintos.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">3. Agentes de colagem neutros \u00e0 base de resina de colof\u00f3nia<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">3.1 De sistemas de resina \u00e1cidos a neutros<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">O colagem tradicional com resina de pinheiro recorre ao sulfato de alum\u00ednio (al\u00famen) como auxiliar de reten\u00e7\u00e3o e precipitante, exigindo condi\u00e7\u00f5es \u00e1cidas (pH 4,0\u20135,5) para uma colagem eficaz. Em condi\u00e7\u00f5es neutras ou alcalinas, o al\u00famen torna-se ineficaz, limitando a aplica\u00e7\u00e3o dos colantes convencionais \u00e0 base de resina de pinheiro.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">O desenvolvimento de <strong>agentes de colagem \u00e0 base de resina de pinheiro cati\u00f4nicos dispersos<\/strong> superou esta limita\u00e7\u00e3o. Estes agentes fixam-se espontaneamente nas fibras de celulose com carga negativa devido \u00e0 sua natureza cati\u00f3nica, eliminando a necessidade de utilizar al\u00famen como mordente.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">3.2 Propriedades e desempenho<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Os agentes de colagem neutros \u00e0 base de resina de pinheiro cati\u00f3nicos apresentam v\u00e1rias caracter\u00edsticas fundamentais:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Estabilidade<\/strong>: Algumas formula\u00e7\u00f5es podem ser armazenadas durante mais de seis meses<\/li>\n\n\n\n<li><strong>Potencial zeta<\/strong>: Normalmente em torno de +25 mV, o que indica um forte car\u00e1ter cati\u00f4nico<\/li>\n\n\n\n<li><strong>intervalo de pH<\/strong>: Eficaz num intervalo de pH entre 6,0 e 8,0, sendo que algumas formula\u00e7\u00f5es apresentam um bom desempenho at\u00e9 um pH de 8,5<\/li>\n\n\n\n<li><strong>Redu\u00e7\u00e3o do al\u00famen<\/strong>: Em compara\u00e7\u00e3o com os aglutinantes tradicionais \u00e0 base de resina fortificada, os agentes cati\u00f4nicos \u00e0 base de resina podem reduzir o consumo de sulfato de alum\u00ednio em aproximadamente 80%<\/li>\n\n\n\n<li><strong>Efici\u00eancia no dimensionamento<\/strong>: O dobro do tamanho das resinas de sab\u00e3o convencionais<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">3.3 Aplica\u00e7\u00f5es<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Os agentes de colagem neutros \u00e0 base de resina de pinheiro cati\u00f3nicos s\u00e3o particularmente adequados para:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Tipos de papel de qualidade m\u00e9dia a elevada, em que a utiliza\u00e7\u00e3o de AKD ou ASA pode revelar-se economicamente invi\u00e1vel<\/li>\n\n\n\n<li>F\u00e1bricas que est\u00e3o a fazer a transi\u00e7\u00e3o de sistemas \u00e1cidos para sistemas neutros e que pretendem manter a qu\u00edmica \u00e0 base de resina<\/li>\n\n\n\n<li>Aplica\u00e7\u00f5es em que \u00e9 necess\u00e1ria uma cura r\u00e1pida (os colantes \u00e0 base de resina curam mais rapidamente do que os AKD)<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Estudos demonstraram que o desenvolvimento de agentes de colagem \u00e0 base de resina dispersa neutra est\u00e1 em conson\u00e2ncia tanto com as condi\u00e7\u00f5es nacionais da China como com a tend\u00eancia global no desenvolvimento da ind\u00fastria papeleira.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">4. Agentes de colagem neutros sint\u00e9ticos: AKD e ASA<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">O AKD (d\u00edmero de alquilceteno) e o ASA (anidrido succ\u00ednico de alquenilo) s\u00e3o os dois agentes de colagem sint\u00e9ticos mais utilizados na produ\u00e7\u00e3o moderna de papel neutro e alcalino. Ambos s\u00e3o agentes de colagem reativos que formam liga\u00e7\u00f5es covalentes com as fibras de celulose, mas diferem significativamente em termos de reatividade, requisitos de cura e condi\u00e7\u00f5es de aplica\u00e7\u00e3o.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">4.1 AKD (d\u00edmero de alquilceteno)<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Mecanismo qu\u00edmico<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">O AKD \u00e9 um agente de colagem reativo caracterizado por uma estrutura de anel de \u03b2-propiolactona tensionado. O principal mecanismo pelo qual o AKD torna a celulose hidrof\u00f3bica \u00e9 atrav\u00e9s de uma rea\u00e7\u00e3o de esterifica\u00e7\u00e3o covalente. O anel de \u03b2-propiolactona distendido da mol\u00e9cula de AKD reage com os grupos hidroxilo na estrutura principal da celulose para formar um \u03b2-ceto\u00e9ster. Esta liga\u00e7\u00e3o covalente fixa as longas cadeias alqu\u00edlicas hidrof\u00f3bicas do AKD \u00e0 superf\u00edcie da celulose, criando uma barreira permanente \u00e0 penetra\u00e7\u00e3o da \u00e1gua.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A partir de uma s\u00e9rie de t\u00e9cnicas indiretas, os investigadores conclu\u00edram que o estabelecimento de uma liga\u00e7\u00e3o covalente entre a celulose e o AKD \u00e9 essencial para conferir hidrofobicidade permanente \u00e0s superf\u00edcies celul\u00f3sicas. O AKD pode reagir com a celulose para formar liga\u00e7\u00f5es diretas de \u03b2-ceto\u00e9ster que s\u00e3o suficientemente fortes para resistir ao ataque de \u00e1cidos ou bases e s\u00e3o praticamente inertes a estas subst\u00e2ncias qu\u00edmicas.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>O Mecanismo de Tr\u00eas Fases<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">O processo de dimensionamento da AKD decorre em tr\u00eas fases essenciais:<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>Reten\u00e7\u00e3o<\/strong>: As part\u00edculas da emuls\u00e3o de AKD ficam retidas nas fibras de celulose na parte h\u00famida<\/li>\n\n\n\n<li><strong>Propaga\u00e7\u00e3o<\/strong>: \u00c0 medida que o papel seca e \u00e9 aquecido, o AKD derrete (ponto de fus\u00e3o 44,5\u201352 \u00b0C) e espalha-se pela superf\u00edcie das fibras<\/li>\n\n\n\n<li><strong>Rea\u00e7\u00e3o<\/strong>: A temperaturas elevadas, o anel de lactona do AKD reage com os grupos hidroxilo da celulose<\/li>\n<\/ol>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Vantagens<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A AKD oferece v\u00e1rias vantagens atraentes:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Excelente estabilidade a longo prazo<\/strong>: Proporciona um acabamento resistente e permanente que envelhece bem<\/li>\n\n\n\n<li><strong>Ampla compatibilidade com diferentes valores de pH<\/strong>: Apresenta um desempenho consistente numa ampla gama de n\u00edveis de pH, desde neutros at\u00e9 alcalinos<\/li>\n\n\n\n<li><strong>Compatibilidade com o carbonato de c\u00e1lcio<\/strong>: Permite a utiliza\u00e7\u00e3o de enchimentos econ\u00f3micos<\/li>\n\n\n\n<li><strong>Baixa corrosividade<\/strong>: Menos prejudicial para o equipamento da f\u00e1brica do que os sistemas \u00e1cidos<\/li>\n\n\n\n<li><strong>Respeito pelo ambiente<\/strong>: N\u00e3o cont\u00e9m solventes org\u00e2nicos e n\u00e3o \u00e9 t\u00f3xico<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Limita\u00e7\u00f5es<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Cura lenta<\/strong>: Requer 24 a 48 horas a 25 \u00b0C e 50% de humidade para curar completamente, ocupando espa\u00e7o no armaz\u00e9m<\/li>\n\n\n\n<li><strong>Sensibilidade \u00e0 hidr\u00f3lise<\/strong>: O AKD hidrolisa na presen\u00e7a de \u00e1gua, especialmente a temperaturas elevadas<\/li>\n\n\n\n<li><strong>Limita\u00e7\u00f5es de armazenamento<\/strong>: Temperatura de armazenamento \u2264 35 \u00b0C; a 40 \u00b0C, o tempo de meia-vida \u00e9 de apenas 7 dias<\/li>\n\n\n\n<li><strong>Depend\u00eancia de ajudas \u00e0 reten\u00e7\u00e3o<\/strong>: Requer amido cati\u00f3nico ou poliacrilamida para uma reten\u00e7\u00e3o eficaz<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Em condi\u00e7\u00f5es de fabrico de papel que utilizam carbonato de c\u00e1lcio como carga, a utiliza\u00e7\u00e3o de amido cati\u00f3nico \u00e9 <strong>necess\u00e1rio<\/strong> para obter um encolagem AKD eficaz. O amido cati\u00f3nico ajuda a estabilizar o agente de encolagem e favorece a sua reten\u00e7\u00e3o na celulose.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">4.2 ASA (anidrido alcenilsucc\u00ednico)<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Mecanismo qu\u00edmico<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">O ASA \u00e9 um agente de apresto neutro reativo com elevada efici\u00eancia e atividade. Apresenta uma estrutura molecular \u00fanica com grupos de anidrido dicarbox\u00edlico c\u00edclico. Tal como o AKD, o ASA forma liga\u00e7\u00f5es de \u00e9ster com os grupos hidroxilo das fibras de celulose.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Caracter\u00edsticas principais<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Reatividade r\u00e1pida<\/strong>: O ASA reage muito mais rapidamente com as fibras de celulose do que o AKD, muitas vezes durante as fases da parte h\u00famida do processo de fabrico de papel<\/li>\n\n\n\n<li><strong>Determina\u00e7\u00e3o imediata do tamanho<\/strong>: Realiza o dimensionamento 80%+ antes de a banda chegar \u00e0 prensa de dimensionamento<\/li>\n\n\n\n<li><strong>N\u00e3o \u00e9 necess\u00e1rio deixar secar<\/strong>: Ao contr\u00e1rio do AKD, o ASA n\u00e3o requer tratamento t\u00e9rmico nem tempo de matura\u00e7\u00e3o<\/li>\n\n\n\n<li><strong>intervalo de pH<\/strong>: Effective at pH 6.5\u20138.0<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Vantagens<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">ASA offers distinct benefits for specific applications:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Desenvolvimento r\u00e1pido de tamanhos<\/strong>: Ideal for high-speed paper machines (>1500 m\/min)<\/li>\n\n\n\n<li><strong>No curing delay<\/strong>: Finished paper can be processed immediately<\/li>\n\n\n\n<li><strong>Low friction coefficient<\/strong>: No paper slipping issues<\/li>\n\n\n\n<li><strong>Suitable for recycled fiber<\/strong>: Particularly effective for heavy sizing paper based on waste paper<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Limita\u00e7\u00f5es<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Emulsion instability<\/strong>: ASA emulsions are less stable than AKD emulsions and require careful handling<\/li>\n\n\n\n<li><strong>Rapid hydrolysis<\/strong>: ASA hydrolyzes quickly to alkenyl succinic acids<\/li>\n\n\n\n<li><strong>Fresh preparation required<\/strong>: Emulsion must be freshly prepared and used within 2 hours<\/li>\n\n\n\n<li><strong>Equipment maintenance<\/strong>: Requires daily cleaning of pipelines with 50\u00b0C water and 0.1% NaOH to prevent gel blockage<\/li>\n\n\n\n<li><strong>Sensitivity<\/strong>: Performance is more sensitive to variations in pH and process conditions<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">4.3 AKD vs. ASA: A Comparative Summary<\/h3>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>Caracter\u00edstica<\/th><th>AKD<\/th><th>ASA<\/th><\/tr><\/thead><tbody><tr><td>Reactivity<\/td><td>Moderate (slower)<\/td><td>High (very fast)<\/td><\/tr><tr><td>Cura<\/td><td>Requires 24\u201348 hours<\/td><td>No curing needed<\/td><\/tr><tr><td>Sizing development<\/td><td>Off-machine<\/td><td>On-machine<\/td><\/tr><tr><td>Emulsion stability<\/td><td>Bom<\/td><td>Poor (requires fresh preparation)<\/td><\/tr><tr><td>intervalo de pH<\/td><td>Broad (neutral to alkaline)<\/td><td>Narrower (6.5\u20138.0)<\/td><\/tr><tr><td>Hydrolysis<\/td><td>Slow<\/td><td>Fast<\/td><\/tr><tr><td>Storage<\/td><td>\u226435\u00b0C; limited shelf life<\/td><td>Must be used within hours<\/td><\/tr><tr><td>Best suited for<\/td><td>Medium-to-low speed machines (&lt;800 m\/min)<\/td><td>High-speed machines (&gt;1500 m\/min)<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">5. Polymer-Type Neutral Sizing Agents<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">5.1 Cationic Polymer Dispersions<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Cationic polymer dispersions represent a third category of neutral sizing agents. These agents function through a combination of mechanisms:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Electrostatic attraction<\/strong>: The cationic nature of the polymer ensures strong retention on anionic cellulose fibers<\/li>\n\n\n\n<li><strong>Film formation<\/strong>: The polymer forms a hydrophobic film on the fiber surface<\/li>\n\n\n\n<li><strong>Synergistic effects<\/strong>: Often used in combination with polymeric retention aids for enhanced performance<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">5.2 Applications<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Cationic polymer dispersions are used for:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Internal sizing of raw paper pulps at neutral pH<\/li>\n\n\n\n<li>Combination with rosin sizes in neutral-alkaline systems<\/li>\n\n\n\n<li>Specialty paper applications requiring specific surface properties<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">5.3 Emerging Polymer Technologies<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Recent developments include the use of water-soluble chitosan as a sizing agent incorporated in paper composites. Chitosan and its derivatives offer:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Excellent film-forming properties and film strength<\/li>\n\n\n\n<li>Strong hydrogen bonding with cellulose carboxyl groups<\/li>\n\n\n\n<li>Schiff base formation with aldehyde groups<\/li>\n\n\n\n<li>Environmentally friendly characteristics (natural origin, biodegradability)<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">6. The Role of Retention Aids<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">A critical factor in the effectiveness of neutral sizing agents\u2014particularly AKD\u2014is the use of retention aids. <strong>Cationic starch<\/strong> is the most widely used retention aid for AKD systems. Under papermaking conditions using calcium carbonate as a filler, the use of cationic starch is necessary to achieve effective AKD sizing.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Some cationic polymers work not only to improve AKD sizing performance but also to prevent press and smoothing roll deposits. Surface-active substances such as defoamers and deaerators have no significant effect on size retention, but agglomeration and hydrolysis can be reduced by increased starch addition or by the introduction of long-chain polymers such as polyacrylamides.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For ASA sizing, cationic additives\u2014especially starch and aluminum products\u2014have a very positive effect on sizing performance.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">7. Market Landscape and Growth Trends<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">7.1 Global Market Size<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">The global sizing agents market is substantial and growing steadily:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>The global Sizing Agents market was valued at <strong>USD 4.43 billion in 2025<\/strong> and is expected to register a revenue CAGR of 4.5% during the forecast period<\/li>\n\n\n\n<li>The global Pulp and Paper Sizing Agents market was valued at <strong>USD 1,789 million in 2025<\/strong> and is forecast to reach <strong>USD 2,460 million by 2032<\/strong> at a CAGR of 4.6%<\/li>\n\n\n\n<li>The Neutral Sizing Agent market was valued at <strong>USD 1.2 billion in 2024<\/strong> e prev\u00ea-se que atinja <strong>USD 2.5 billion by 2034<\/strong>, registering a CAGR of 7.5%<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">7.2 AKD and ASA Market Share<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Among synthetic sizing agents:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>AKD holds the largest market share<\/strong>, contributing nearly 38% of global revenue in the paper sizing chemical market in 2024<\/li>\n\n\n\n<li>The global ASA Sizing Agent market is projected to grow from <strong>USD 877 million in 2024<\/strong> to <strong>USD 1,159 million by 2031<\/strong> at a CAGR of 4.4%<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">7.3 Key Market Drivers<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Sustainable Paper Packaging<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The shift from plastic packaging toward recyclable fiber-based formats is increasing demand for high-performance sizing chemistry across food packaging, e-commerce shipping, and industrial wrapping applications. Containerboard shipments continue to expand as online retail and packaged food demand increases, directly increasing consumption of AKD and polymer sizing agents because recycled fibers absorb moisture more easily than virgin pulp.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Neutral Sizing as the Mainstream Choice<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Neutral sizing agents have become the mainstream choice for mid-to-high-grade paper grades due to their wide pH adaptability, environmental friendliness, and aging resistance. A key trend is the shift toward neutral sizing agents, with AKD leading the charge.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Innovation in Bio-Based Solutions<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">In September 2024, Kemira (Finland) expanded production capacity for water-based barrier and sizing chemistries at its European paper chemicals network to support food packaging converters shifting away from fluorochemical coatings. In April 2024, Solenis (U.S.) introduced upgraded barrier and sizing solutions for molded fiber packaging applications.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">8. Application Guidelines for Neutral Sizing Agents<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">8.1 Recommended Dosage<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">The dosage of neutral sizing agents varies by product type and paper grade:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Cationic rosin sizes<\/strong>: 0.3\u20131.2% based on dry pulp<\/li>\n\n\n\n<li><strong>AKD<\/strong>: Typically 0.6\u20133.5% based on dry pulp<\/li>\n\n\n\n<li><strong>ASA<\/strong>: Dosage adjusted based on target sizing degree and furnish composition<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">8.2 Addition Sequence<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">The typical addition sequence for neutral sizing is:<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li>Neutral sizing agent<\/li>\n\n\n\n<li>Precipitant\/retention aid (if required)<\/li>\n\n\n\n<li>Filler<\/li>\n<\/ol>\n\n\n\n<h3 class=\"wp-block-heading\">8.3 Critical Process Parameters<\/h3>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>Par\u00e2metro<\/th><th>AKD<\/th><th>ASA<\/th><th>Cationic Rosin<\/th><\/tr><\/thead><tbody><tr><td>Optimal pH<\/td><td>7.5\u20138.5<\/td><td>6.5\u20138.0<\/td><td>6.0\u20138.0<\/td><\/tr><tr><td>Cura<\/td><td>24\u201348 hours<\/td><td>Imediato<\/td><td>Imediato<\/td><\/tr><tr><td>Retention aid<\/td><td>Essential (cationic starch)<\/td><td>Recommended<\/td><td>Self-retaining<\/td><\/tr><tr><td>Storage<\/td><td>\u226435\u00b0C<\/td><td>Use within 2 hours of emulsification<\/td><td>\u22656 months<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<h3 class=\"wp-block-heading\">8.4 Troubleshooting Common Issues<\/h3>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>Issue<\/th><th>Possible Cause<\/th><th>Recommended Action<\/th><\/tr><\/thead><tbody><tr><td>Poor sizing (AKD)<\/td><td>Low retention; pH too high or low<\/td><td>Improve retention aid system; optimize pH<\/td><\/tr><tr><td>Hydrolysis (AKD)<\/td><td>High temperature; prolonged retention<\/td><td>Reduce temperature; improve single-pass retention<\/td><\/tr><tr><td>Emulsion instability (ASA)<\/td><td>Delayed application; contamination<\/td><td>Prepare fresh emulsion; use immediately<\/td><\/tr><tr><td>Inconsistent sizing<\/td><td>pH fluctuations; retention variations<\/td><td>Stabilize wet-end chemistry; monitor retention<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">9. Conclusion<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Neutral sizing agents represent a cornerstone technology in modern papermaking, enabling the transition from acidic to neutral and alkaline systems that deliver superior paper quality, reduced environmental impact, and enhanced operational efficiency.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The three main categories\u2014rosin-based, synthetic (AKD\/ASA), and polymer-type\u2014offer papermakers a range of options to suit different paper grades, production conditions, and economic considerations. AKD, with its durable covalent bonding and broad pH compatibility, has emerged as the dominant choice, holding nearly 38% of the global market. ASA offers rapid sizing development for high-speed machines, while cationic rosin sizes provide a cost-effective bridge for mills transitioning from acidic systems.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">As the paper industry continues to embrace sustainability, with growing demand for recyclable packaging and reduced chemical footprints, neutral sizing technologies\u2014particularly AKD and emerging bio-based alternatives\u2014are well-positioned to meet the challenges of the future. Understanding the chemistry, advantages, and limitations of each neutral sizing agent type is essential for papermakers seeking to optimize product quality, production efficiency, and environmental performance in an increasingly competitive global market.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><\/p>","protected":false},"excerpt":{"rendered":"<p>Neutral Sizing Agents in Papermaking: Types, Mechanisms, and Modern Applications Introduction Paper fibers, composed primarily &#8230; <a title=\"Agentes de neutraliza\u00e7\u00e3o na fabrica\u00e7\u00e3o de papel: tipos, mecanismos e aplica\u00e7\u00f5es modernas\" class=\"read-more\" href=\"https:\/\/lypaperchem.com\/pt\/neutral-sizing-agents-in-papermaking-types-mechanisms-and-modern-applications\/\" aria-label=\"Leia mais sobre Neutral Sizing Agents in Papermaking: Types, Mechanisms, and Modern Applications\">Leia mais<\/a><\/p>","protected":false},"author":1,"featured_media":1139,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[20],"tags":[],"class_list":["post-1257","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-product-deep-dives","generate-columns","tablet-grid-50","mobile-grid-100","grid-parent","grid-33"],"_links":{"self":[{"href":"https:\/\/lypaperchem.com\/pt\/wp-json\/wp\/v2\/posts\/1257","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/lypaperchem.com\/pt\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/lypaperchem.com\/pt\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/lypaperchem.com\/pt\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/lypaperchem.com\/pt\/wp-json\/wp\/v2\/comments?post=1257"}],"version-history":[{"count":1,"href":"https:\/\/lypaperchem.com\/pt\/wp-json\/wp\/v2\/posts\/1257\/revisions"}],"predecessor-version":[{"id":1258,"href":"https:\/\/lypaperchem.com\/pt\/wp-json\/wp\/v2\/posts\/1257\/revisions\/1258"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/lypaperchem.com\/pt\/wp-json\/wp\/v2\/media\/1139"}],"wp:attachment":[{"href":"https:\/\/lypaperchem.com\/pt\/wp-json\/wp\/v2\/media?parent=1257"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/lypaperchem.com\/pt\/wp-json\/wp\/v2\/categories?post=1257"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/lypaperchem.com\/pt\/wp-json\/wp\/v2\/tags?post=1257"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}